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tsunami

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Photo Gallery: Tsunamis - National Geographic

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See photos of the destructive power of a tsunami-a giant wave caused by undersea earthquakes that can wipe out anything that didn't make it to higher ground.

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2004 Indian Ocean

earthquake and tsunami

UTC time

2004-12-26 00:58:53

ISC event

7453151

USGS-ANSS

ComCat

Local date

26 December 2004

Local time

Magnitude

9.1-9.3 Mw

Depth

30 km (19 mi)

Epicentre

3°18′58″N 95°51′14″E ﻿ / ﻿ 3.316°N 95.854°E

Type
Megathrust

Areas affected

Indian Ocean coastline areas

Max. intensity
IX (Violent)

Tsunami

Casualties

227,898 dead

The 2004 Indian Ocean earthquake and tsunami, also called the Sumatra-Andaman earthquake, was a great underwater earthquake. It happened at 00:58:53 UTC (07:58:53 local time) December 26, 2004.

The epicenter of the earthquake was off the west coast of Sumatra, Indonesia. At first, the earthquake was measured as a 9.0 on the Richter scale. Later, scientists said it was as high as a 9.3. In modern times, only the Great Chilean Earthquake of 1960 has been more powerful. The Indian Ocean earthquake was the longest ever recorded. It lasted between 500 (8.3 minutes) and 600 (10 minutes) seconds. It was so powerful that it caused the entire Earth to vibrate. It started other earthquakes as far away as Alaska.

The Asian tsunami

The large movement of earth under the water caused a very large and powerful tsunami. The tsunami was called the Asian tsunami, or the Boxing Day tsunami in Australia, Canada, England, and South Africa because it happened on Boxing Day. It spread all over the Indian Ocean. The tsunami caused heavy damage to countries such as Malaysia, Thailand, Indonesia and Sri Lanka. It also devastated the eastern coast of India, such as the states of Tamil Nadu, Orissa and Andhra Pradesh.

Waves as high as 30 m (100 ft) killed many people and damaged or destroyed a lot of buildings and other property.

Over 227,898 people died or were not found after the tsunami. The wave did damage in East Africa as far away as South Africa (8000 km/ 5000 mi) where as many as 8 people died because of high water caused by the wave. Because of how much damage was caused and the number of people the earthquake affected, over $7 billion ( USD) was donated to help rebuild the areas damaged.

Environmental impact

Beyond the heavy toll on human lives, the Indian Ocean earthquake has caused an enormous environmental impact that will affect the region for many years to come. It has been reported that severe damage has been inflicted on ecosystems such as mangroves, coral reefs, forests, coastal wetlands, vegetation, sand dunes and rock formations, animal and plant biodiversity and groundwater. Also, the spread of solid and liquid waste and industrial chemicals, water pollution and the destruction of sewage collectors and treatment plants threaten the environment even further, in untold ways. The environmental impact will take a long time and significant resources to assess.

According to specialists, the main effect is being caused by poisoning of the freshwater supplies and of the soil by saltwater infiltration and a deposit of a salt layer over arable land. Salted-over soil becomes sterile, and it is difficult and costly to restore for agriculture. It also causes the death of plants and important soil micro-organisms. Thousands of rice, mango, and banana plantations in Sri Lanka were destroyed almost entirely and will take years to recover.

Economic impact

The level of damage to the economy resulting from the tsunami depends on the scale examined. While the overall impact on the national economies was minor, local economies were devastated. The two main occupations affected by the tsunami were fishing and tourism.

Images for kids

Initial earthquake and aftershocks measuring greater than 4.0 M w from 26 December 2004 to 10 January 2005

The tsunami's propagation took 5 hours to reach Western Australia, 7 hours to reach the Arabian Peninsula, and did not reach the South African coast until nearly 11 hours after the earthquake

Apung 1, a 2,600-ton vessel, was flung some 2 km (1.2 mi) to 3 km (1.9 mi) inland. In the years following the disaster, it became a local tourist attraction and has remained where it came to rest.

Baiturrahim Mosque survived the tsunami in Ulee Lheue, banda Aceh

In Spanish: Terremoto del océano Índico de 2004 para niños

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2004 Indian Ocean earthquake and tsunami Facts for Kids

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Learn 2004 Indian Ocean earthquake and tsunami facts for kids

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Thistle is a ghost town in Utah County, Utah, United States, about 65 miles (105 km) southeast of Salt Lake City. During the era of steam locomotives, the town's primary industry was servicing trains for the Denver and Rio Grande Western Railroad (often shortened to D&RG, D&RGW, or Rio Grande). The fortunes of the town were closely linked with those of the railroad until the changeover to diesel locomotives, when the town started to decline.

In April 1983, a massive landslide (specifically a complex earthflow The residents were evacuated as nearly 65,000 acre feet (80,000,000 m ³) of water backed up, flooding the town. Thistle was destroyed; only a few structures were left partially standing. Federal and state government agencies have said this was the most costly landslide in United States history, the economic consequences of which affected the entire region. The landslide resulted in the first presidentially declared disaster area in Utah.

U.S. Route 6 (US-6), US-89 and the railroad (now part of Union Pacific Railroad's Central Corridor) were closed for several months, until they were rebuilt on a higher alignment overlooking the area. The remains of Thistle are visible from a rest area along US-6 or from the California Zephyr passenger train.

Thistle is about 65 miles (105 km) southeast of Salt Lake City, at the confluence of the two primary tributaries to the Spanish Fork River, Thistle Creek and Soldier Creek. This confluence, at an elevation of 5,043 feet (1,537 m), is also the junction of two naturally formed routes across the mountains of central Utah. The primary route crosses the Wasatch Mountains, via the Wasatch Plateau and Soldier Summit. This route was carved by the tributaries of the Price River on the eastern side of the mountains and the Spanish Fork River on the west. In addition, Thistle Creek provides a route south from Thistle towards the communities of the Sanpete and Sevier Valleys. The Spanish Fork River flows northwest from Thistle, towards the city of Spanish Fork, before reaching Utah Lake.

These natural paths have provided the route of several transcontinental trails, highways and railroads since their discovery. The named transportation arteries passing through Thistle include: US-6 (originally numbered US-50), US-89, the Denver and Rio Grande Western Railroad's Utah Division (now part of Union Pacific Railroad's Central Corridor) and D&RGW's Marysvale branch line (abandoned because of the landslide).

The trade route on which Thistle lies was used by Native American tribes before the arrival of European settlers; two Ute chiefs, Taby and Peteetneet, led seasonal migrations through the canyon each spring and fall. The first recorded journey by Europeans to modern Thistle was the Dominguez-Escalante Expedition, which was escorted through the territory by Indian guides. A small group of Utes inhabiting the canyon frequently clashed with newcomers, and as a result were forcibly relocated in the 1870s.

Most of Thistle's residents were railroad employees sent to live in the town, but there were some who had settled before the railroads arrived. The first Europeans were part of the Mormon migration to Utah, and the first of these was the Pace family, who migrated from Nauvoo, Illinois, reaching Thistle in 1848. Fifth-generation descendants of the Pace settlers continued to operate a family-owned cattle ranch until the town was evacuated. Other settlers included Mormons who originally settled elsewhere in Utah but subsequently arrived to homestead fertile ground on Billies Mountain, on the north wall of the canyon. Among them was the mountain's presumed namesake, William Johnson. Homesteading was practiced in Thistle until the early 1900s. Until the arrival of the railroads, the town's economy was based mainly on farming and ranching, although there was also some mining activity in the region, including a vein of asphaltum that was mined between 1892 and 1914.

The first railroad track laid through Thistle was a narrow-gauge spur line servicing coal mines near today's Scofield Reservoir, built in 1878 by the Utah and Pleasant Valley Railway. By 1890, the Denver and Rio Grande Western, which acquired the line in a foreclosure sale in 1882, had rebuilt the line to standard gauge. The D&RGW connected this line with one they had built west from Colorado, completing a link from Salt Lake City to Denver.

The railroad built several facilities in Thistle to service and prepare trains for the change in grade and curvature of the line. The railroad placed helper engines on eastbound trains at Thistle for the ascent to Soldier Summit. The town provided a meal service for the trains until the use of on-board dining cars eliminated the need for meal stops.

Thistle saw more rail traffic with the construction of the Marysvale branch line. This line branched from the main at Thistle, following modern US-89 towards mines near Marysvale. Another line through Thistle, paralleling the D&RGW main, was built by the Utah Railway. The two lines were later combined into a dual-track main line, as part of a trackage rights agreement between the two companies.

Rail traffic through Thistle continued to increase as the Rio Grande cooperated with connecting railroads, making the rail line through Thistle a bridge line for transcontinental rail traffic. The growth of Thistle was closely tied to the success of the Denver and Rio Grande Railroad throughout the era of steam locomotives.

At its peak, around 1917, Thistle had about 600 residents. The town's railroad infrastructure included a five-stall roundhouse, depot, machine shop, and structures to restock passing trains with sand, coal and water. Non-railroad infrastructure included general stores, a post office, barber shop, saloon, pool hall, bakeries and restaurants. The largest building was a two-story schoolhouse, built in 1911.

In the 1950s, the Denver & Rio Grande Western began to phase out steam locomotives in favor of diesel locomotives, which require less maintenance. With the change in technology, Thistle faded in importance. Gradually the town shrank in population; the passenger depot was torn down in 1972 and the post office closed in 1974. By 1983, only a few families remained in Thistle.

Rio Grande maintenance personnel began noticing unstable ground downstream from Thistle years before the landslide occurred. Maintenance crews repaired the track on several occasions, but they did not fully investigate the problem. Beginning with the remnants of Hurricane Olivia, the autumn and winter of 1982-83 featured record-breaking snow and rainfall. As the spring thaw melted the winter snow, the mountains in the area became saturated with water.

By April 1983, track deformation was a serious issue. On April 13, the division track master flew to Denver to explain the situation at a specially-called staff meeting. On the same day, a Utah Highway Patrol officer struck a newly created buckle in the highway that threw him against the roof of his vehicle. By the end of the day, a full maintenance crew was struggling to keep US-6 open. All trains were limited to speeds less than 10 miles per hour (16 km/h), and were accompanied by maintenance personnel who had to continually work to keep the tracks in line. The last train to pass through downtown Thistle was the westbound Rio Grande Zephyr, on April 14, 1983 at about 8:30 p.m. That night, both US-6 and the rail line were closed. One westbound freight train that had already left Denver was turned back. All through trains between Denver and Salt Lake City were rerouted to Union Pacific Railroad's Overland Route through Wyoming. By April 16, the tracks were completely buried and a voluntary evacuation order was issued for the town.

On April 17, a final attempt to keep the landslide from blocking the flow of the river failed. That day, the Utah Department of Transportation and the Rio Grande announced plans to abandon the existing transportation arteries and build new corridors. Both the highway and railroad would be re-routed by blasting a path scaling the north wall of Spanish Fork Canyon. The new arteries would pass the slide by dynamiting through Billies Mountain, also along the north canyon wall. Engineers estimated the dam created by the toe of the landslide would eventually reach between 200 feet (60 m) and 300 feet (90 m) tall. The evacuation order was changed from voluntary to mandatory. Volunteers transported as many people and belongings as possible to the small town of Birdseye, about 5 miles (8.0 km) south. Most residents were able to recover only a fraction of their belongings; some had less than two hours' notice before the water reached their house. Thistle's oldest resident celebrated her 90th birthday at the evacuation center in Birdseye. By the 18th, the waterline had reached the rooftops of the 22 previously occupied houses. By the 19th, an entire mountain was moving at about 2 feet (0.6 m) per hour and US-6 was buried by 50 feet (15 m) of soil.

Governor Scott Matheson requested federal aid to deal with the situation. After a visit to the area by the director of the Federal Emergency Management Agency, U.S. president Ronald Reagan issued the first presidential disaster area declaration for the state of Utah. The landslide eventually formed a dam that created a lake 3 miles (5 km) long and over 200 feet (60 m) deep. Concerned the dam could fail, the state of Utah decided to build a tunnel to re-route the flow of the Spanish Fork River. The residents of downstream Spanish Fork were told to be prepared to evacuate. Engineers estimated that if the dam failed, they would have 30 to 45 minutes notice before the water reached the city.

Thistle was almost completely destroyed. Most wooden buildings were carried away in the floodwaters. The state installed a temporary pumping station to prevent the lake from overflowing the dam; patrol boats skimmed up the floating remains of the town to prevent the debris from blocking the pumps. Most remains were either naturally deposited or placed on the eastern shore of the lake.

By autumn, the tunnels to restore the flow of the river and drain the lake were operational. Shortly after, debates between former residents, neighboring residents, and government agencies began on what to do with the dam created by the landslide; some wanted to make the lake permanent. The state engineer commissioned a study to determine if the landslide dam could be used to retain water; it recommended building a new dam upstream from the landslide, rather than attempting engineering work on the landslide dam.

In the years following, the former residents of Thistle filed various lawsuits to recover their losses. In one, they claimed that their property was taken to rebuild the road and railroad without just compensation. Another lawsuit claimed negligence on the part of the D&RGW. The residents argued that the railroad's maintenance workers knew the ground was unstable; however, they only repaired the track. The residents contended the slide could have been prevented by using a water drainage system to relieve pressure at the head of the unstable area. They further contended that such a system could have been put in place had the railroad thoroughly investigated the problem upon first noticing it. The engineering firm employed by the Rio Grande said that their studies indicated the crown of the landslide was about 300 feet (90 m) above the level of the tracks, and that the Rio Grande did not know the true size of the unstable area until the slide was in motion. A jury absolved the D&RGW of responsibility. The plaintiffs appealed the decision, and a second trial in 1993 resulted in a $1.1 million award for the landowners (equivalent to $2 million in 2021). The D&RGW filed suit against the Utah Railway over sharing the costs from the landslide. The Utah Railway had an ownership interest in the line, based on a track-sharing agreement.

Economic effects

The landslide closed the main railroad for three months, and U.S. Route 6 and U.S. Route 89 for eight months, during which time the communities of eastern and southeastern Utah were cut off from the rest of the state. Security for the isolated part of Utah County was temporarily assigned to the Utah Highway Patrol.

The economic effects of the closure of these transportation arteries were felt throughout the western United States; the closure devastated rural Utah. The operations of coal mines, uranium mines, turkey farms, animal feed companies, gypsum mines, and cement and clay factories were severely impacted. At least two trucking firms and one oil-producing firm suspended or ceased operations. Southeastern Utah's tourism industry suffered without access for visitors from the north and west. Some people who lived and worked on opposite sides of the landslide area suddenly had commutes exceeding 100 miles (160 km). The highway patrol temporarily closed a weigh station at Peerless (a location along the US-6 corridor near Helper) and built a temporary weigh station near Salina (along I-70 about 90 miles (140 km) south of Thistle), which saw a sudden increase in truck traffic. The highway patrol estimated the temporary facilities inspected 57,000 trucks and made 80 arrests.

The direct cost of the landslide was estimated at $200 million (equivalent to $428 million in 2021). However, some estimates of the total cost reached as high as $400 million (equivalent to $855 million in 2021). The D&RGW estimated the slide cost them $80 million in lost revenue (equivalent to $171 million in 2021), averaging $1 million for each day that the tracks were out-of-service. This figure included $19 million in payments to the Union Pacific for the use of their lines. The United States Geological Survey and the state of Utah have called the Thistle landslide the most costly ever in the United States.

To expedite construction, the railroad had crews in Utah focused on grading the new path and boring a 3,000-foot (910 m) tunnel, while crews in Colorado built track segments that were transported to site. On July 4, 1983, at 3:05 p.m., safety inspectors declared the line ready for operation. At 3:12 p.m., the centralized traffic control signals gave a green light to the first train to pass through the Thistle area since the slide began, an eastbound freight train coming from the Southern Pacific Railroad at Ogden, destined for Herington, Kansas. Although the line's re-opening on Independence Day was coincidental, the first train became part of the local holiday celebrations. The first passenger train to use the new alignment was the California Zephyr, on July 16.

Debates ensued over the fate of the Marysvale branch line. The mines at the end of the line had long closed; the last train to traverse the entire length of the line passed through in 1970. Still, farmers and industry in the Sevier and Sanpete Valleys generated enough traffic that the line broke even most years. However, this line was severely damaged, with several washed-out bridges and railroad tracks draping over the sides of newly created cliffs. The railroad determined that at best it would take years to recover the cost of rebuilding the line.

The residents of Richfield pressured the Rio Grande to use the portion of the line that was still intact and build a connection to an existing Union Pacific line near Nephi, roughly parallel to State Route 28. However, the railroad determined that including land acquisition, the cost would be comparable to rebuilding the old route. In addition, the Rio Grande would have to pay trackage rights to the Union Pacific for the connection from Nephi, which would further erode profits on a line that was barely profitable. In the end, the Rio Grande sold the line to a scrap dealer who dismantled it. A 2002 study placed the cost of rebuilding the modified routing of the Marysvale branch line at $80 million (equivalent to $95 million in 2021).

The new alignment of US-6 was opened on December 30, 1983. The dedication was planned for the next day, but lines of cars formed at the barricades as soon as news broke that the highway was complete. Some were residents anxious to see the area or visit relatives they had not seen since the slide; others were truck drivers frustrated by long detours. The Highway Patrol requested the ceremony be canceled and the highway opened early, as they were unable to disperse the crowds.

When the first traffic flowed, crews had not finished some final tasks, such as painting stripes. Motorists saw a relocation with several mountain cuts built high up the canyon wall, with a view of the slide and former lake. The roadbed was not expected to last, as weather conditions had been unfavorable when the asphalt was laid. Two mountain cuts were unstable, requiring several months of work before they could be left unattended. During this time, the state stationed two full-time watches at the cuts, who would close the road while falling rocks were cleared. The cut through Billies Mountain was described by the construction crews as a new, man-made mountain pass.

The pending completion of the again-rebuilt US-6, with properly laid asphalt and stable rock cuts, was announced in November 1984, 18 months after the closure of the original alignment. Starting in 1993, the Utah Department of Transportation began discussions with former Thistle residents to build a memorial to the town. The department maintains a view area overlooking the townsite along US-6.

Geology and climate

The landslide area near Thistle is a paleovalley formed in a depression in an area of bedrock known as the Charleston-Nebo thrust plate. The rock in this plate dates from the Permian and Pennsylvanian to the Jurassic periods, but the plate appears to have formed elsewhere and moved to the modern Thistle area during the Late Cretaceous epoch. The layers of sedimentary rock above the thrust plate are younger, dating to the Cretaceous and Tertiary periods. The rock debris in the landslide itself comes from the North Horn and Ankareh formations.

The area around Thistle has always been prone to landslides. Pre-historic landslides created the more gentle slopes that made the area usable as a transportation corridor across the Wasatch Mountains. Minor landslides have been frequently observed, and continue to occur. The largest recorded landslides are the 1983 slide which destroyed the town, and a smaller one in 1998.

The climate at downstream Spanish Fork is classified as arid with four distinct seasons. Temperatures range from an average high of 92 °F (33 °C) in July and an average low of 20 °F (−7 °C) in January. Except for the spring months, precipitation averages less than 2 inches (5.1 cm) per month.

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Thistle is a ghost town in Utah County, Utah, United States, about 65 miles (105 km) southeast of Salt Lake City. During the era of steam locomotives, the town's primary industry was servicing trains for the Denver and Rio Grande Western Railroad (often shortened to D&RG, D&RGW, or Rio Grande).

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On May 18, 1980, a major volcanic eruption occurred from Mount St. Helens, a volcano in Washington, in the United States. The eruption was recorded as a 5 on the Volcanic Explosivity Index. Throughout the two months before the eruption, there was a series of earthquakes and steam was vented from the mouth of the volcano. A total of 57 people died in the eruption. Including Harry R. Truman, who ran Spirit Lake, and volcano expert David A. Johnston.

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In Spanish: Erupción del monte Santa Helena de 1980 para niños

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1980 eruption of Mount St. Helens Facts for Kids

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Learn 1980 eruption of Mount St. Helens facts for kids

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The Great Chilean Earthquake or Valdivian Earthquake was the most powerful earthquake ever recorded. The quake occurred in the early afternoon (19:11 UTC) of May 22, 1960, and had a 9.5 rating on the Moment magnitude scale. The earthquake affected southern Chile, Hawaii, Japan, the Philippines, and the Aleutian Islands in Alaska.

Its epicenter was Valdivia, Chile. The earthquake caused tsunamis that pounded the Chilean coastline with waves of up to 25 meters. The main tsunami traveled across the Pacific Ocean and caused great damage to Hilo, Hawaii. Waves as high as 10.7 meters (about 35 feet) were recorded 10,000 kilometers from where the earthquake started. These waves travelled as far as Japan and the Philippines.

The total number of deaths from the earthquake and subsequent tsunami in Chile has been estimated at 490 to 5700. The Chilean government estimated 2 million people were left homeless and the damage was $550 million USD.

Images for kids

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The Great Chilean Earthquake or Valdivian Earthquake was the most powerful earthquake ever recorded. The quake occurred in the early afternoon (19:11 UTC) of May 22, 1960, and had a 9.5 rating on the Moment magnitude scale. The earthquake affected southern Chile, Hawaii, Japan, the Philippines, and the Aleutian Islands in Alaska.

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What is a landslide?
A landslide is defined as the movement of a mass of rock, debris, or earth down a slope due to gravity. The materials may move by falling, toppling, sliding, spreading, or flowing.

What causes a landslide?
Almost every landslide has multiple causes. Slope movement occurs when forces acting down-slope (mainly due to gravity) exceed the strength of the earth materials that compose the slope. Landslides can be triggered by rainfall, snowmelt, changes in water level, stream erosion, changes in ground water, earthquakes, volcanic activity, disturbance by human activities, or any combination of these factors.

What are submarine landslides?
Earthquake shaking and other factors can also induce landslides underwater. These landslides are called submarine landslides. Submarine landslides sometimes cause tsunamis that damage coastal areas.

Where do landslides occur?
Landslides in the United States occur in all 50 States. The primary regions of landslide occurrence and potential are the coastal and mountainous areas of California, Oregon, and Washington, the States comprising the intermountain west, and the mountainous and hilly regions of the Eastern United States. Alaska and Hawaii also experience all types of landslides.

How fast do landslide travel?
Landslides can move slowly, (millimeters per year) or can move quickly and disastrously, as is the case with debris flows. Debris flows can travel down a hillside at speeds up to 200 miles per hour (more commonly, 30 - 50 miles per hour), depending on the slope angle, water content, volume of debris, and type of earth and debris in the flow. These flows are initiated by heavy periods of rainfall, but sometimes can happen as a result of short bursts of concentrated rainfall or other factors in susceptible areas. Burned areas charred by wildfires are particularly susceptible to debris flows, given certain soil characteristics and slope conditions.

Why study landslides?
Landslides are a serious geologic hazard. It is estimated that in the United States they cause in excess of $1 billion in damages and from about 25 to 50 deaths each year. Globally, landslides cause billions of dollars in damages and thousands of deaths and injuries each year.

Who is most at risk for landslides?
As people move into new areas of hilly or mountainous terrain, it is important to understand the nature of their potential exposure to landslide hazards, and how cities, towns, and counties can plan for land-use, engineering of new construction and infrastructure, and other measures which will reduce the costs of living with landslides. Although the physical causes of many landslides cannot be removed, geologic investigations, good engineering practices, and effective enforcement of land-use management regulations can reduce landslide hazards.

Do human activities cause landslides?
Yes, in some cases human activities can be a contributing factor in causing landslides. Many human-caused landslides can be avoided or mitigated. They are commonly a result of building roads and structures without adequate grading of slopes, of poorly planned alteration of drainage patterns, and of disturbing old landslides.

Where can I find landslide information for my area?
The USGS National Landslide Information Center (NLIC) is a part of the U.S. Geological Survey Landslide Hazards Program that collects and distributes all forms of information related to landslides. The NLIC is designed to serve landslide researchers, geotechnical practitioners engaged in landslide stabilization, and anyone else concerned in any way with landslide education, hazard, safety, and mitigation. Every state in the US has a geoscience agency and most have some landslide information. The Association of American State Geologists provides links to the State Geologist for every state.

What was the most expensive landslide to fix in the United States?
The Thistle, Utah, landslide cost in excess of $200 million dollars to fix. The landslide occurred during the spring of 1983, when unseasonably warm weather caused rapid snowmelt to saturate the slope. The landslide destroyed the railroad tracks of the Denver and Rio Grande Western Railway Company, and the adjacent Highway 89. It also flowed across the Spanish Fork River, forming a dam. The impounded river water inundated the small town of Thistle. The inhabitants of the town of Thistle, directly upstream from the landslide, were evacuated as the lake began to flood the town, and within a day the town was completely covered with water. Populations downstream from the dam were at risk because of the possible overtopping of the landslide by the lake. This could cause a catastrophic outburst of the dam with a massive flood downstream. Eventually, a drain system was engineered to drain the lake and avert the potential disaster.

How many deaths result from landslides?
An average of between 25 and 50 people are killed by landslides each year in the United States. The worldwide death toll per year due to landslides is in the thousands. Most landslide fatalities are from rock fall, debris-flows, or volcanic debris flows.

What should I know about wildfires and debris flows?
Wild land fires are inevitable in the western United States. Expansion of human development into forested areas has created a situation where wildfires can adversely affect lives and property, as can the flooding and landslides that occur in the aftermath of the fires. There is a need to develop tools and methods to identify and quantify the potential hazards posed by landslides produced from burned watersheds. Post-fire landslide hazards include fast-moving, highly destructive debris flows that can occur in the years immediately after wildfires in response to high intensity rainfall events, and those flows that are generated over longer time periods accompanied by root decay and loss of soil strength. Post-fire debris flows are particularly hazardous because they can occur with little warning, can exert great impulsive loads on objects in their paths, and can strip vegetation, block drainage ways, damage structures, and endanger human life. Wildfires could potentially result in the destabilization of pre-existing deep-seated landslides over long time periods.

How do landslides cause tsunamis?
Tsunamis are large, potentially deadly and destructive sea waves, most of which are formed as a result of submarine earthquakes. They may also result from the eruption or collapse of island or coastal volcanoes and the formation of giant landslides on marine margins. These landslides, in turn, are often triggered by earthquakes. Tsunamis can be generated on impact as a rapidly moving landslide mass enters the water or as water displaces behind and ahead of a rapidly moving underwater landslide.

What are some examples of landslides that have caused tsunamis?
The 1964 Alaska earthquake caused 115 deaths in Alaska alone, with 106 of those due to tsunamis generated by tectonic uplift of the sea floor, and by localized subareal and submarine landslides. The earthquake shaking caused at least 5 local slide-generated tsunamis within minutes after the shaking began. An eyewitness account of the tsunami caused by the movement and landslides of the 1964 Alaska earthquake.

Research in the Canary Islands concludes that there have been at least five massive volcano landslides that occurred in the past, and that similar large events may occur in the future. Giant landslides have the potential of generating large tsunami waves at close and also very great distances and would have the potential to devastate large areas of coastal land as far away as the eastern seaboard of North America.

Rock falls and rock avalanches in coastal inlets, such as those that have occurred in the past at Tidal Inlet, Glacier Bay National Park, Alaska, have the potential to cause regional tsunamis that pose a hazard to coastal ecosystems and human settlements. On July 9, 1958, a magnitude M 7.9 earthquake on the Fairweather Fault triggered a rock avalanche at the head of Lituya Bay, Alaska. The landslide generated a wave that ran up 524 m on the opposite shore and sent a 30-m high wave through Lituya Bay, sinking two of three fishing boats and killing two persons.

How soon does the danger of landslides end after the rain stops?
It's not possible to exactly predict the number of days or weeks that landslides remain a danger after heavy rain. Residents near mountain slopes, canyons, and landslide prone areas should stay alert even after heavy rain subsides.

Why is southern California vulnerable to landslides?
Areas that have been burned by recent wildfires are highly susceptible to debris-flow activity that can be triggered by significantly less rainfall than that which triggers debris flows from unburned hill slopes.

What was the biggest landslide in the world?
The world's biggest historic landslide occurred during the 1980 eruption of Mount St. Helens, a volcano in the Cascade Mountain Range in the State of Washington, USA. The volume of material was 2.8 cubic kilometers (km).

What was the biggest prehistoric landslide?
The world's biggest prehistoric landslide, discovered so far on land, is in southwestern Iran, and is named the Saidmarreh landslide. The landslide is located on the Kabir Kuh anticline in Southwest Iran at 33 degrees north latitude, 47.65 degrees east longitude. The landslide has a volume of about 20 cubic kilometers, a depth of 300 m, a travel distance of 14 km and a width of 5 km. This means that about 50 billion tons of rock moved in this single event!

Rotational slide: This is a slide in which the surface of rupture is curved concavely upward and the slide movement is roughly rotational about an axis that is parallel to the ground surface and transverse across the slide.

Translational slide: In this type of slide, the landslide mass moves along a roughly planar surface with little rotation or backward tilting.

Block slide: is a translational slide in which the moving mass consists of a single unit or a few closely related units that move downslope as a relatively coherent mass.

Fall: Falls are abrupt movements of masses of geologic materials, such as rocks and boulders, that become detached from steep slopes or cliffs. Separation occurs along discontinuities such as fractures, joints, and bedding planes, and movement occurs by free-fall, bouncing, and rolling. Falls are strongly influenced by gravity, mechanical weathering, and the presence of interstitial water.

Topple: Toppling failures are distinguished by the forward rotation of a unit or units about some pivotal point, below or low in the unit, under the actions of gravity and forces exerted by adjacent units or by fluids in cracks.

Debris flow: A debris flow is a form of rapid mass movement in which a combination of loose soil, rock, organic matter, air, and water mobilize as a slurry that flows downslope. Debris flows include less than 50% fines. Debris flows are commonly caused by intense surface-water flow, due to heavy precipitation or rapid snowmelt, that erodes and mobilizes loose soil or rock on steep slopes. Debris flows also commonly mobilize from other types of landslides that occur on steep slopes, are nearly saturated, and consist of a large proportion of silt- and sand-sized material. Debris-flow source areas are often associated with steep gullies, and debris-flow deposits are usually indicated by the presence of debris fans at the mouths of gullies. Fires that denude slopes of vegetation intensify the susceptibility of slopes to debris flows.

Debris avalanche: This is a variety of very rapid to extremely rapid debris flow.

Earthflow: Earthflows have a characteristic "hourglass" shape. The slope material liquefies and runs out, forming a bowl or depression at the head. The flow itself is elongate and usually occurs in fine-grained materials or clay-bearing rocks on moderate slopes and under saturated conditions. However, dry flows of granular material are also possible.
Mudflow: A mudflow is an earthflow consisting of material that is wet enough to flow rapidly and that contains at least 50 percent sand-, silt-, and clay-sized particles. In some instances, for example in many newspaper reports, mudflows and debris flows are commonly referred to as "mudslides."

Creep: Creep is the imperceptibly slow, steady, downward movement of slope-forming soil or rock. Movement is caused by shear stress sufficient to produce permanent deformation, but too small to produce shear failure. There are generally three types of creep: (1) seasonal, where movement is within the depth of soil affected by seasonal changes in soil moisture and soil temperature; (2) continuous, where shear stress continuously exceeds the strength of the material; and (3) progressive, where slopes are reaching the point of failure as other types of mass movements. Creep is indicated by curved tree trunks, bent fences or retaining walls, tilted poles or fences, and small soil ripples or ridges.

Lateral Spreads: Lateral spreads are distinctive because they usually occur on very gentle slopes or flat terrain. The dominant mode of movement is lateral extension accompanied by shear or tensile fractures. The failure is caused by liquefaction, the process whereby saturated, loose, cohesionless sediments (usually sands and silts) are transformed from a solid into a liquefied state. Failure is usually triggered by rapid ground motion, such as that experienced during an earthquake, but can also be artificially induced. When coherent material, either bedrock or soil, rests on materials that liquefy, the upper units may undergo fracturing and extension and may then subside, translate, rotate, disintegrate, or liquefy and flow. Lateral spreading in fine-grained materials on shallow slopes is usually progressive. The failure starts suddenly in a small area and spreads rapidly. Often the initial failure is a slump, but in some materials movement occurs for no apparent reason. Combination of two or more of the above types is known as a complex landslide.

SLIDES: Although many types of mass movements are included in the general term "landslide," the more restrictive use of the term refers only to mass movements, where there is a distinct zone of weakness that separates the slide material from more stable underlying material. The two major types of slides are rotational slides and translational slides.

FLOWS: There are five basic categories of flows that differ from one another in fundamental ways. Although there are multiple types of causes of landslides, the three that cause most of the damaging landslides around the world are these:

Landslides and Water: Slope saturation by water is a primary cause of landslides. This effect can occur in the form of intense rainfall, snowmelt, changes in ground-water levels, and waterlevel changes along coastlines, earth dams, and the banks of lakes, reservoirs, canals, and rivers. Landsliding and flooding are closely allied because both are related to precipitation, runoff, and the saturation of ground by water. In addition, debris flows and mudflows usually occur in small, steep stream channels and often are mistaken for floods; in fact, these two events often occur simultaneously in the same area. Landslides can cause flooding by forming landslide dams that block valleys and stream channels, allowing large amounts of water to back up. This causes backwater flooding and, if the dam fails, subsequent downstream flooding. Also, solid landslide debris can "bulk" or add volume and density to otherwise normal streamflow or cause channel blockages and diversions creating flood conditions or localized erosion. Landslides can also cause overtopping of reservoirs and/or reduced capacity of reservoirs to store water.

Landslides and Seismic Activity: Many mountainous areas that are vulnerable to landslides have also experienced at least moderate rates of earthquake occurrence in recorded times. The occurrence of earthquakes in steep landslide-prone areas greatly increases the likelihood that landslides will occur, due to ground shaking alone or shaking- caused dilation of soil materials, which allows rapid infiltration of water. The 1964 Great Alaska Earthquake caused widespread landsliding and other ground failure, which caused most of the monetary loss due to the earthquake. Other areas of the United States, such as California and the Puget Sound region in Washington, have experienced slides, lateral spreading, and other types of ground failure due to moderate to large earthquakes. Widespread rockfalls also are caused by loosening of rocks as a result of ground shaking. Worldwide, landslides caused by earthquakes kill people and damage structures at higher rates than in the United States.

Landslides and Volcanic Activity: Landslides due to volcanic activity are some of the most devastating types. Volcanic lava may melt snow at a rapid rate, causing a deluge of rock, soil, ash, and water that accelerates rapidly on the steep slopes of volcanoes, devastating anything in its path. These volcanic debris flows (also known as lahars) reach great distances, once they leave the flanks of the volcano, and can damage structures in flat areas surrounding the volcanoes. The 1980 eruption of Mount St. Helens, in Washington triggered a massive landslide on the north flank of the volcano, the largest landslide in recorded times.

Landslide Mitigation - How to Reduce the Effects of Landslides: Vulnerability to landslide hazards is a function of location, type of human activity, use, and frequency of landslide events. The effects of landslides on people and structures can be lessened by total avoidance of landslide hazard areas or by restricting, prohibiting, or imposing conditions on hazard-zone activity. Local governments can reduce landslide effects through land-use policies and regulations. Individuals can reduce their exposure to hazards by educating themselves on the past hazard history of a site and by making inquiries to planning and engineering departments of local governments. They can also obtain the professional services of an engineering geologist, a geotechnical engineer, or a civil engineer, who can properly evaluate the hazard potential of a site, built or unbuilt.

The hazard from landslides can be reduced by avoiding construction on steep slopes and existing landslides, or by stabilizing the slopes. Stability increases when groundwater is prevented from rising in the landslide mass by (1) covering the landslide with an impermeable membrane, (2) directing surface water away from the landslide, (3) draining groundwater away from the landslide, and (4) minimizing surface irrigation. Slope stability is also increased when a retaining structure and/ or the weight of a soil/rock berm are placed at the toe of the landslide or when mass is removed from the top of the slope.

LANDSLIDE ADVISORY - a general statement about the potential of landslide activity in a given region relative to developing rainfall predictions. An advisory may include general statements about rainfall conditions that can lead to debris-flow activity, and list precautions to be taken in the event of heavy rainfall.

LANDSLIDE WATCH - means that landslide-activity will be possible, but is not imminent. People in, or planning to travel through, a watch area should check preparedness and stay informed about developing weather patterns.

LANDSLIDE WARNING - indicates that landslide activity is presently occurring and extreme caution should be taken.

FLOOD WATCH - means that an overflow of water from a river is possible for your area.

FLASH FLOOD WATCH - means that flash flooding is possible in or close to the watch area. Flash Flood Watches can be put into effect for as long as 12 hours, while heavy rains move into and across the area.

FLOOD WARNING - means flooding conditions are actually occurring in the warning area.

FLASH FLOOD WARNING - means that flash flooding is actually occurring in the warning area. A warning can also be issued as a result of torrential rains, a dam failure or snow thaw.

URBAN and SMALL STREAM ADVISORY - means flooding of small streams, streets and low-lying areas, such as railroad underpasses and urban storm drains is occurring.

DEBRIS - The scattered remains of something broken or destroyed; rubble or wreckage.

DEBRIS FLOW - A churning, water-saturated mass of rock, soil and organic matter that rushes down mountain slopes, typically originating as a landslide.

GRAVITY - The natural force of attraction exerted by a celestial body, such as Earth, upon objects at or near its surface, tending to draw them toward the center of the body.

FRICTION - Force that resists the relative motion or tendency to such motion of two bodies in contact.

TRIGGER - An event that initiates a landslide.

Click Here to see if there are any active warnings in your area.

BEFORE A LANDSLIDE: Avoid building near steep slopes, close to mountain edges, near drainage ways, or natural erosion valleys. Get a ground assessment of your property. Landslides occur where they have before, and in identifiable hazard locations. Ask for information on landslides in your area, specific information on areas vulnerable to landslides, and request a professional referral for a very detailed site analysis of your property, and corrective measures you can take, if necessary. Watch the patterns of storm-water drainage near your home, and note the places where runoff water converges, increasing flow in channels. These are areas to avoid during a storm. Make evacuation plans. Plan at least two evacuation routes since roads may become blocked or closed. Develop your own emergency plan for your family or business.

MINIMIZE HOME HAZARDS: Have flexible pipe fittings installed to avoid gas or water leaks, as flexible fittings are more resistant to breakage. Plant ground cover on slopes and build retaining walls. In mudflow areas, build channels or deflection walls to direct the flow around buildings. Remember: If you build walls to divert debris flow and the flow lands on a neighbor's property, you may be liable for damages. Design and construction of walls and channels strong enough to resist or divert landslides is highly specialized work, best done by qualified professionals.

DURING A STORM/LANDSLIDE: Stay alert and awake. Many debris-flow fatalities occur when people are sleeping. Listen to a NOAA Weather Radio or portable, battery-powered radio or television for warnings of intense rainfall. Be aware that intense, short bursts of rain may be particularly dangerous, especially after longer periods of heavy rainfall and damp weather. If you are in areas susceptible to landslides and debris flows, consider leaving if it is safe to do so. Remember that driving during an intense storm can be hazardous. If you remain at home, move to a second story if possible. Staying out of the path of a landslide or debris flow saves lives. Listen for any unusual sounds that might indicate moving debris, such as trees cracking or boulders knocking together. A trickle of flowing or falling mud or debris may precede larger landslides. Moving debris can flow quickly and sometimes without warning. If you are near a stream or channel, be alert for any sudden increase or decrease in water flow and for a change from clear to muddy water. Such changes may indicate landslide activity upstream, so be prepared to move quickly. Don't delay! Save yourself, not your belongings. Be especially alert when driving. Bridges may be washed out, and culverts overtopped. Do not cross flooding streams...Turn Around, Don't Drown! Embankments along roadsides are particularly susceptible to landslides. Watch the road for collapsed pavement, mud, fallen rocks, and other indications of possible debris flows. Be aware that strong shaking from earthquakes can induce or intensify the effects of landslides.

AFTER A LANDSLIDE: Stay away from the slide area. There may be danger of additional slides. Check for injured and trapped persons near the slide area. Give first aid if trained. Remember to help your neighbors who may require special assistance-infants, elderly people, and people with disabilities. Listen to a battery-operated radio or television for the latest emergency information. Remember that flooding may occur after a mudflow or a landslide. Check for damaged utility lines. Report any damage to the utility company. Check the building foundation, chimney, and surrounding land for damage. Replant damaged ground as soon as possible since erosion caused by loss of ground cover can lead to flash flooding. Seek the advice of geotechnical expert for evaluating landslide hazards or designing corrective techniques to reduce landslide risk.

Lesson Plan: Here is a great lesson plan on erosion and landslides.

Lesson Plan: Here is a great lesson plan on landslides for grades 6-8.

Lesson Plan: This lesson consists of landslides, liquefaction, and structural failure caused by earthquakes.

Science Fair Project Ideas: Here is a complete list of science fair project ideas. Discover the science behind the weather that impacts us every day.

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What is a landslide? A landslide is defined as the movement of a mass of rock, debris, or earth down a slope due to gravity. The materials may move by falling, toppling, sliding, spreading, or flowing. What causes a landslide? Almost every landslide has multiple causes.

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Date

April 18, 1906

Magnitude

7.8 Mw

Depth

8 kilometers (5.0 mi)

Epicenter

37°45′N 122°33′W ﻿ / ﻿ 37.75°N 122.55°W

Areas affected

United States
( San Francisco Bay Area)

Max. intensity
X - Intense

Casualties

3,000+ (Estimated 3425)

The 1906 San Francisco earthquake was a big earthquake that hit San Francisco on April 18, 1906. It was felt from Los Angeles to Oregon and Nevada. The earthquake was about a 7.8 on the Richter scale. Around 3,000 people were killed and between 227,000 and 300,000 people were left homeless.

There were also fires because gas pipes were destroyed, and the gas caught on fire. The mayor had an idea that if some buildings were dynamite destroyed, than they wouldn't spread fire. He was wrong. The firestorm raged through the city at an alarming pace.

Over 80% of the city was destroyed by the earthquake and fires that came later. The city is on the San Andreas Fault, which slid, causing the earthquake. Many people looted so then the Army had to come in to keep the peace, but there were reports of the army looting as well.

At the time, 375 deaths were reported. Partly because hundreds of fatalities in Chinatown went ignored and unrecorded, the total number of deaths is still uncertain today, and is estimated to be roughly 3,000 at minimum. Most of the deaths occurred in San Francisco itself, but 189 were reported elsewhere in the Bay Area; nearby cities, such as Santa Rosa and San Jose, also suffered severe damage. In Monterey County, the earthquake permanently shifted the course of the Salinas River near its mouth. Where previously the river emptied into Monterey Bay between Moss Landing and Watsonville, it was diverted 6 miles south to a new outlet just north of Marina.

Between 227,000 and 300,000 people were left homeless out of a population of about 410,000; half of the people who evacuated fled across the bay to Oakland and Berkeley. Newspapers at the time described Golden Gate Park, the Presidio, the Panhandle and the beaches between Ingleside and North Beach as being covered with makeshift tents. More than two years later, many of these refugee camps were still in full operation.

The earthquake and fire left long-standing and significant pressures on the development of California. At the time of the disaster, San Francisco had been the ninth-largest city in the United States and the largest on the West Coast, with a population of about 410,000. Over a period of 60 years, the city had become the financial, trade and cultural center of the West; operated the busiest port on the West Coast; and was the "gateway to the Pacific", through which growing U.S. economic and military power was projected into the Pacific and Asia. Over 80% of the city was destroyed by the earthquake and fire. Though San Francisco rebuilt quickly, the disaster diverted trade, industry and population growth south to Los Angeles, which during the 20th century became the largest and most important urban area in the West. Many of the city's leading poets and writers retreated to Carmel-by-the-Sea where, as "The Barness", they established the arts colony reputation that continues today.

The 1908 Lawson Report, a study of the 1906 quake led and edited by Professor Andrew Lawson of the University of California, showed that the same San Andreas Fault which had caused the disaster in San Francisco ran close to Los Angeles as well. The earthquake was the first natural disaster of its magnitude to be documented by photography and motion picture footage and occurred at a time when the science of seismology was blossoming. The overall cost of the damage from the earthquake was estimated at the time to be around US$400 million ($8.2 billion in 2009 dollars).

Although the impact of the earthquake on San Francisco was the most famous, the earthquake also inflicted considerable damage on several other cities. These include San Jose and Santa Rosa, the entire downtown of which was essentially destroyed.

Magnitude and geology

The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude (M w) of 7.8; however, other values have been proposed, from 7.7 to as high as 8.25. The main shock epicenter occurred offshore about 2 miles (3.2 km) from the city, near Mussel Rock. Shaking was felt from Oregon to Los Angeles, and inland as far as central Nevada.

The earthquake was caused by a rupture on the San Andreas Fault, a continental transform fault that forms part of the tectonic boundary between the Pacific Plate and the North American Plate. The fault is characterized by mainly lateral motion in a dextral sense, where the western (Pacific) plate moves northward relative to the eastern (North American) plate. The 1906 rupture propagated both northward and southward for a total of 296 miles (476 km). This fault runs the length of California from the Salton Sea in the south to Cape Mendocino to the north, a distance of about 810 miles (1,300 km). The earthquake ruptured the northern third of the fault for a distance of 296 miles (476 km). The maximum observed surface displacement was about 20 feet (6 m); however, geodetic measurements show displacements of up to 28 feet (8.5 m).

A strong foreshock preceded the mainshock by about 20 to 25 seconds. The strong shaking of the main shock lasted about 42 seconds. The shaking intensity as described on the Modified Mercalli intensity scale reached VIII in San Francisco and up to IX in areas to the north like Santa Rosa where destruction was devastating. There were decades of minor earthquakes - more than at any other time in the historical record for northern California - before the 1906 quake. Widely interpreted previously as precursory activity to the 1906 earthquake, they have been found to have a strong seasonal pattern and have been postulated to be due to large seasonal sediment loads in coastal bays that overlie faults as a result of the erosion caused by hydraulic mining in the later years of the California Gold Rush.

this killed over 2 people

The city's fire chief, Dennis T. Sullivan, was seriously injured when the earthquake first struck and later died from his injuries. The interim fire chief sent an urgent request to the Presidio, an army post on the edge of the stricken city, for dynamite. General Funston had already decided the situation required the use of troops. Collaring a policeman, he sent word to Mayor Eugene Schmitz of his decision to assist, and then ordered army troops from nearby Angel Island to mobilize and come into the city. Explosives were ferried across the bay from the California Powder Works in what is now Hercules.

During the first few days, soldiers provided valuable services like patrolling streets to discourage looting and guarding buildings such as the U.S. Mint, post office, and county jail. They aided the fire department in dynamiting to demolish buildings in the path of the fires. The army also became responsible for feeding, sheltering, and clothing the tens of thousands of displaced residents of the city. Under the command of Funston's superior, Major General Adolphus Greely, Commanding Officer, Pacific Division, over 4,000 troops saw service during the emergency. On July 1, 1906, civil authorities assumed responsibility for relief efforts, and the army withdrew from the city.

On April 18, in response to riots among evacuees and looting, Mayor Schmitz issued and ordered posted a proclamation that "The Federal Troops, the members of the Regular Police Force and all Special Police Officers have been authorized by me to kill any and all persons found engaged in Looting or in the Commission of Any Other Crime".

Early on April 18, 1906, recently retired Captain Edward Ord of the 22nd Infantry Regiment was appointed a Special Police Officer by Mayor Eugene Schmitz and liasioned with Major General Adolphus Greely for relief work with the 22nd Infantry and other military units involved in the emergency. Ord later wrote a long letter to his mother on the April 20 regarding Schmitz' "Shoot-to-Kill" Order and some "despicable" behavior of certain soldiers of the 22nd Infantry who were looting. He also made it clear that the majority of soldiers served the community well.

Relocation and housing

The army built 5,610 redwood and fir "relief houses" to accommodate 20,000 displaced people. The houses were designed by John McLaren, and were grouped in eleven camps, packed close to each other and rented to people for two dollars per month until rebuilding was completed. They were painted olive drab, partly to blend in with the site, and partly because the military had large quantities of olive drab paint on hand. The camps had a peak population of 16,448 people, but by 1907 most people had moved out. The camps were then re-used as garages, storage spaces or shops. The cottages cost on average $100 to put up. The $2 monthly rents went towards the full purchase price of $50. Most of the shacks have been destroyed, but a small number survived. One of the modest 720 sq ft (67 m ²) homes was recently purchased for more than $600,000. The last official refugee camp was closed on June 30, 1908.

Aftermath and reconstruction

Property losses from the disaster have been estimated to be more than $400 million. An insurance industry source tallies insured losses at $235 million, the equivalent to $7.09 billion in 2022 dollars.

Political and business leaders strongly downplayed the effects of the earthquake, fearing loss of outside investment in the city which was badly needed to rebuild. In his first public statement, California governor George C. Pardee emphasized the need to rebuild quickly: "This is not the first time that San Francisco has been destroyed by fire, I have not the slightest doubt that the City by the Golden Gate will be speedily rebuilt, and will, almost before we know it, resume her former great activity". The earthquake itself is not even mentioned in the statement. Fatality and monetary damage estimates were manipulated.

Almost immediately after the quake (and even during the disaster), planning and reconstruction plans were hatched to quickly rebuild the city. Rebuilding funds were immediately tied up by the fact that virtually all the major banks had been sites of the conflagration, requiring a lengthy wait of seven-to-ten days before their fire-proof vaults could cool sufficiently to be safely opened. The Bank of Italy, however, had evacuated its funds and was able to provide liquidity in the immediate aftermath. Its president also immediately chartered and financed the sending of two ships to return with shiploads of lumber from Washington and Oregon mills which provided the initial reconstruction materials and surge. In 1929, Bank of Italy was renamed and is now known as Bank of America.

William James, the pioneering American psychologist, was teaching at Stanford at the time of the earthquake and traveled into San Francisco to observe first-hand its aftermath. He was most impressed by the positive attitude of the survivors and the speed with which they improvised services and created order out of chaos. This formed the basis of the chapter "On some Mental Effects of the Earthquake" in his book Memories and Studies.

H. G. Wells had just arrived in New York on his first visit to America when he learned, at lunch, of the San Francisco earthquake. What struck him about the reaction of those around him was that "it does not seem to have affected any one with a sense of final destruction, with any foreboding of irreparable disaster. Every one is talking of it this afternoon, and no one is in the least degree dismayed. I have talked and listened in two clubs, watched people in cars and in the street, and one man is glad that Chinatown will be cleared out for good; another's chief solicitude is for Millet's 'Man with the Hoe.' 'They'll cut it out of the frame,' he says, a little anxiously. 'Sure.' But there is no doubt anywhere that San Francisco can be rebuilt, larger, better, and soon. Just as there would be none at all if all this New York that has so obsessed me with its limitless bigness was itself a blazing ruin. I believe these people would more than half like the situation."

The grander of citywide reconstruction schemes required investment from Eastern monetary sources, hence the spin and de-emphasis of the earthquake, the promulgation of the tough new building codes, and subsequent reputation sensitive actions such as the official low death toll. One of the more famous and ambitious plans came from famed urban planner Daniel Burnham. His bold plan called for, among other proposals, Haussmann-style avenues, boulevards, arterial thoroughfares that radiated across the city, a massive civic center complex with classical structures, and what would have been the largest urban park in the world, stretching from Twin Peaks to Lake Merced with a large atheneum at its peak. But this plan was dismissed at the time as impractical and unrealistic.

For example, real estate investors and other land owners were against the idea due to the large amount of land the city would have to purchase to realize such proposals. City fathers likewise attempted at the time to eliminate the Chinese population and export Chinatown (and other poor populations) to the edge of the county where the Chinese could still contribute to the local taxbase. The Chinese occupants had other ideas and prevailed instead. Chinatown was rebuilt in the newer, modern, Western form that exists today. The destruction of City Hall and the Hall of Records enabled thousands of Chinese immigrants to claim residency and citizenship, creating a backdoor to the Chinese Exclusion Act, and bring in their relatives from China.

While the original street grid was restored, many of Burnham's proposals inadvertently saw the light of day, such as a neoclassical civic center complex, wider streets, a preference of arterial thoroughfares, a subway under Market Street, a more people-friendly Fisherman's Wharf, and a monument to the city on Telegraph Hill, Coit Tower.

The earthquake was also responsible for the development of the Pacific Heights neighborhood. The immense power of the earthquake had destroyed almost all of the mansions on Nob Hill except for the Flood Mansion. Others that hadn't been destroyed were dynamited by the Army forces aiding the firefighting efforts in attempts to create firebreaks. As one indirect result, the wealthy looked westward where the land was cheap and relatively undeveloped, and where there were better views and a consistently warmer climate. Constructing new mansions without reclaiming and clearing old rubble simply sped attaining new homes in the tent city during the reconstruction. In the years after the first world war, the "money" on Nob Hill migrated to Pacific Heights, where it has remained to this day.

Reconstruction was swift, and largely completed by 1915, in time for the Panama-Pacific Exposition which celebrated the reconstruction of the city and its "rise from the ashes".

Since 1915, the city has officially commemorated the disaster each year by gathering the remaining survivors at Lotta's Fountain, a fountain in the city's financial district that served as a meeting point during the disaster for people to look for loved ones and exchange information.

Images for kids

USGS ShakeMap showing the earthquake's intensity

Arnold Genthe's photograph, looking toward the fire on Sacramento Street

Evacuees leaving the city

One of the eleven housing camps

In Spanish: Terremoto de San Francisco de 1906 para niños

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1906 San Francisco earthquake Facts for Kids

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Learn 1906 San Francisco earthquake facts for kids

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What is an earthquake?
Earthquakes are the shaking, rolling or sudden shock of the earth's surface. They are the Earth's natural means of releasing stress. More than a million earthquakes rattle the world each year. The West Coast is most at risk of having an earthquake, but earthquakes can happen in the Midwest and along the East Coast. Earthquakes can be felt over large areas although they usually last less than one minute. Earthquakes cannot be predicted - although scientists are working on it!

Click Here to learn more about earthquakes from USGS.

What causes an earthquake?
There are about 20 plates along the surface of the earth that move continuously and slowly past each other. When the plates squeeze or stretch, huge rocks form at their edges and the rocks shift with great force, causing an earthquake. Think of it this way: Imagine holding a pencil horizontally. If you were to apply a force to both ends of the pencil by pushing down on them, you would see the pencil bend. After enough force was applied, the pencil would break in the middle, releasing the stress you have put on it. The Earth's crust acts in the same way. As the plates move they put forces on themselves and each other. When the force is large enough, the crust is forced to break. When the break occurs, the stress is released as energy which moves through the Earth in the form of waves, which we feel and call an earthquake. (Graphic Credit: Wheeling Jesuit University/NASA Classroom of the Future)

Click Here to see an animation of an earthquake. It's great for kids, because they get to see how it actually happens!

What is a fault?
A fault is an area of stress in the earth where broken rocks slide past each other, causing a crack in the Earth's surface. There are the major types of faults: dip-slip normal, dip-slip reverse, strike-slip, and oblique-slip.

What are plate tectonics?
The theory of plate tectonics is a interesting story of continents drifting from place to place breaking apart, colliding, and grinding against each other. The plate tectonic theory is supported by a wide range of evidence that considers the earth's crust and upper mantle to be composed of several large, thin, relatively rigid plates that move relative to one another. (See plate tectonic graphic above.) The plates are all moving in different directions and at different speeds. Sometimes the plates crash together, pull apart or sideswipe each other. When this happens, it commonly results in earthquakes.

Continental Drift: To see this animation again, just refresh this page! This animation shows you what our planet looked like millions of years ago and what it looks like now! (Graphic Credit: Geology Department at University of California, Berkeley)

What is a seismograph?
A seismograph is an instrument used for recording the intensity and duration of an earthquake.

Click Here to calculate the strength of earthquakes!

What is a tsunami? A tsunami is a large ocean wave usually caused by an underwater earthquake or a volcanic explosion. Tsunamis are NOT tidal waves. Tidal waves are caused by the forces of the moon, sun, and planets upon the tides, as well as the wind as it moves over the water. With typical waves, water flows in circles, but with a tsunami, water flows straight. This is why tsunamis cause so much damage!

Know the Lingo

EPICENTER - The point on the earth's surface directly above the source of the earthquake.

SEISMIC WAVES - The energy created by the quake travels in waves from the epicenter, where they are the strongest. The waves shake buildings, structures and the earth vertically, causing them to move horizontally!

RICHTER SCALE - A measurement of an earthquake's intensity. Each one-point increase on the scale indicates ten times the amount of shaking and 33 times the amount of energy. The energy released by a large earthquake may be equal to 10,000 times the energy of the first atomic bomb.

4

Minor Earthquake

5

Moderate Earthquake

6

Strong Earthquake

7

Major Earthquake

8

Great Earthquake

Richter Scale

Earthquake Safety Tips
BEFORE AN EARTHQUAKE: Have a disaster plan. Emergency preparedness can save lives. Choose a safe place in every room. It's best to get under a sturdy piece of furniture like a table or a desk where nothing can fall on you. Practice DROP, COVER AND HOLD ON! Drop under something sturdy, hold on, and protect your eyes by pressing your face against your arm. If you live in an earthquake prone area, bolt tall furniture to the wall and install strong latches to cupboards. Prepare a first aid kit for your home. By taking special precautions and checking for hazards before a disaster strikes, you will be much more likely to stay safe. DURING AN EARTHQUAKE: DROP, COVER AND HOLD ON! Stay indoors until the shaking stops. Stay away from windows. If you're in bed, hold on and stay there, protecting your head with a pillow. If you're outdoors, find a clear spot away from buildings, trees and power lines. Then, drop to the ground. If you're in a car, slow down and drive to a safe place. Stay in the car until the shaking stops.

AFTER THE SHAKING STOPS: Check for injuries. Inspect your home for damage. Eliminate fire hazards, so turn off the gas if you think its leaking. Expect aftershocks. Each time you feel one, DROP, COVER AND HOLD ON.
Earthquake Activities
Lesson Plan: Here is a great lesson plan on learning about how thrust faults are responsible for the uplift of many mountain ranges across the world, including the Los Angeles Basin. This is a great lesson plan for middle and high school students.

Lesson Plan: Here is a great lesson plan keeping track of earthquakes around the world. In this activity, kids keep a record of the location of earthquakes for a week and learn about plate tectonics.

Earthquake Experiment: Here is a great experiment that explains how to prepare for an earthquake.Science Fair Ideas: Here is a list of science fair project ideas that deal with earthquakes.

Science Fair Project Ideas: Here is a complete list of science fair project ideas. Discover the science behind the weather that impacts us every day.

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Weather Wiz Kids weather information for kids

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Weather Wiz Kids is a fun and safe website for kids about all the weather info they need to know. It contains tools for weather education, including weather games, activities, experiments, photos, a glossary and educational teaching materials for the classroom.

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Landslides occur when ground on slopes becomes unstable. The unstable ground collapses and flows down the side of a hill or mountain, and can consist of earth, rocks, mud and any debris which may be caught in its wake.

If a landslide occurs near inhabited areas, it can cause a great deal of damage. They can strike quickly and bury entire villages. Buildings are damaged or flattened and roads, bridges and infrastructure can be damaged or destroyed by the debris.

Given the nature of such disasters, fast relief and rescue operations are required to get to trapped survivors but this can be delayed due to landslides cutting off easy access to the affected area. Satellites provide key observations of the area, assessing the damage and identifying areas where survivors may potentially be.

The destabilisation of ground can be caused by heavy rain and floods, seismic activity, erosion from oceans and rivers, or changes to vegetation affecting soil composition.

The first activation of the Charter was for a landslide in Slovenia in 2000.

Product Examples

Landslide inventory mapping from the British Geological Survey, Durham University and other agencies

WorldView © DigitalGlobe Inc.
UK-DMC2 © DMCii 2015
SPOT © CNES 2015
Pleiades © CNES 2015
RADARSAT-2 Data and Products © MacDonald, Dettwiler and Associates Ltd. (2015) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency.
Map produced by British Geological Survey

Landslide, Karangkobar subdistrict, Central Java Province, Indonesia

Pleiades © CNES 2014 - Distribution: Airbus Defence and Space, all rights reserved
Map produced by LAPAN

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Landslides occur when ground on slopes becomes unstable. The unstable ground collapses and flows down the side of a hill or mountain, and can consist of earth, rocks, mud and any debris which may be caught in its wake. If a landslide occurs near inhabited areas, it can cause a great deal of damage.

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What was the magnitude of the earthquake that caused the tsunami that devastated coastal areas of Japan in 2011?

Where was the epicenter of the Great Sendai Earthquake?

What was the death toll of the earthquake and tsunami that struck Japan in 2011?

What effects did the Japan earthquake and tsunami of 2011 have?

By what names is the Japan earthquake and tsunami of 2011 known?

Japan earthquake and tsunami of 2011, severe natural disaster that occurred in northeastern Japan on March 11, 2011. The event began with a powerful earthquake off the northeastern coast of Honshu, Japan's main island, which caused widespread damage on land and initiated a series of large tsunami waves that devastated many coastal areas of the country, most notably in the Tōhoku region (northeastern Honshu). The tsunami also instigated a major nuclear accident at a power station along the coast.

The earthquake and tsunami

The magnitude-9.0 earthquake struck at 2:46 pm. (The early estimate of magnitude 8.9 was later revised upward.) The epicentre was located some 80 miles (130 km) east of the city of Sendai, Miyagi prefecture, and the focus occurred at a depth of 18.6 miles (about 30 km) below the floor of the western Pacific Ocean. The earthquake was caused by the rupture of a stretch of the subduction zone associated with the Japan Trench, which separates the Eurasian Plate from the subducting Pacific Plate. (Some geologists argue that this portion of the Eurasian Plate is actually a fragment of the North American Plate called the Okhotsk microplate.) A part of the subduction zone measuring approximately 190 miles (300 km) long by 95 miles (150 km) wide lurched as much as 164 feet (50 metres) to the east-southeast and thrust upward about 33 feet (10 metres). The March 11 temblor was felt as far away as Petropavlovsk-Kamchatsky, Russia; Kao-hsiung, Taiwan; and Beijing, China. It was preceded by several foreshocks, including a magnitude-7.2 event centred approximately 25 miles (40 km) away from the epicentre of the main quake. Hundreds of aftershocks, dozens of magnitude 6.0 or greater and two of magnitude 7.0 or greater, followed in the days and weeks after the main quake. (Nearly two years later, on December 7, 2012, a magnitude-7.3 tremor originated from the same plate boundary region. The quake caused no injuries and little damage.) The March 11, 2011, earthquake was the strongest to strike the region since the beginning of record keeping in the late 19th century, and it is considered one of the most powerful earthquakes ever recorded. It was later reported that a satellite orbiting at the outer edge of Earth's atmosphere that day had detected infrasonics (very low-frequency sound waves) from the quake.

The sudden horizontal and vertical thrusting of the Pacific Plate, which has been slowly advancing under the Eurasian Plate near Japan, displaced the water above and spawned a series of highly destructive tsunami waves. A wave measuring some 33 feet high inundated the coast and flooded parts of the city of Sendai, including its airport and the surrounding countryside. According to some reports, one wave penetrated some 6 miles (10 km) inland after causing the Natori River, which separates Sendai from the city of Natori to the south, to overflow. Damaging tsunami waves struck the coasts of Iwate prefecture, just north of Miyagi prefecture, and Fukushima, Ibaraki, and Chiba, the prefectures extending along the Pacific coast south of Miyagi. In addition to Sendai, other communities hard-hit by the tsunami included Kamaishi and Miyako in Iwate; Ishinomaki, Kesennuma, and Shiogama in Miyagi; and Kitaibaraki and Hitachinaka in Ibaraki. As the floodwaters retreated back to the sea, they carried with them enormous quantities of debris, as well as thousands of victims caught in the deluge. Large stretches of land were left submerged under seawater, particularly in lower-lying areas.

The earthquake triggered tsunami warnings throughout the Pacific basin. The tsunami raced outward from the epicentre at speeds that approached about 500 miles (800 km) per hour. It generated waves 11 to 12 feet (3.3 to 3.6 metres) high along the coasts of Kauai and Hawaii in the Hawaiian Islands chain and 5-foot (1.5-metre) waves along the island of Shemya in the Aleutian Islands chain. Several hours later 9-foot (2.7-metre) tsunami waves struck the coasts of California and Oregon in North America. Finally, some 18 hours after the quake, waves roughly 1 foot (0.3 metre) high reached the coast of Antarctica and caused a portion of the Sulzberger Ice Shelf to break off its outer edge.

Disasters of Historic Proportion

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Japan earthquake and tsunami of 2011 | Facts & Death Toll

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Japan earthquake and tsunami, severe natural disaster that occurred in northeastern Japan on March 11, 2011, and killed at least 20,000 people. The event began with a powerful earthquake off the coast of Honshu, Japan's main island, which initiated a series of large tsunami waves that devastated many coastal areas.

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Pompeii, a flourishing resort city south of ancient Rome, was nestled along the coast of Italy in the shadow of Mount Vesuvius, an active volcano. Its most famous eruption took place in the year 79 A.D., when it buried the city of Pompeii under a thick carpet of volcanic ash. The dust "poured across the land" like a flood, one witness wrote, and shrouded the city in "a darkness...like the black of closed and unlighted rooms." Two thousand people died, and the city was abandoned for almost as many years. When a group of explorers rediscovered the site in 1748, they were surprised to find that beneath a thick layer of dust and debris, Pompeii was mostly intact. The buildings, artifacts and skeletons left behind in the entombed city have taught us a great deal about everyday life in the ancient world.
WATCH: Rome: Rise and Fall of an Empire on HISTORY Vault
Where Is Pompeii?

Located on the west coast of Italy along the shores of the Bay of Naples-south of the modern-day city of Naples- ancient Greek settlers made Pompeii part of the Hellenistic sphere in the 8th century B.C. An independent-minded town, Pompeii fell under the influence of Rome in the 2nd century B.C., and eventually the Bay of Naples became an attraction for wealthy vacationers from Rome who relished the Campania coastline.

By the turn of the first century A.D., the town of Pompeii, located about five miles from Mount Vesuvius, was a flourishing resort for the most distinguished citizens of the Roman Empire. Elegant houses and elaborate villas-many filled with exquisite artworks and sparkling fountains-lined the paved streets.

Much of the city's wealth derived from its rich volcanic soil-the region was a center for olives, grapes and other crops, and wine from Pompeii was enjoyed in some of Rome's most fashionable houses.

Tourists, townspeople and enslaved people bustled in and out of small factories and artisans' shops, taverns, cafes, brothels and bathhouses. People gathered in the 20,000-seat arena and lounged in the open-air squares and marketplaces.

On the eve of the fateful eruption in 79 A.D., scholars estimate that there were about 12,000 people living in Pompeii and almost as many in the surrounding region.

Did you know? Mount Vesuvius has not erupted since 1944, but it is still one of the most dangerous volcanoes in the world. Experts believe that another catastrophic eruption is due any day-an almost unfathomable catastrophe, since almost 3 million people live within 20 miles of the volcano's crater.

Mount Vesuvius

Mount Vesuvius did not form overnight, of course. Vesuvius is part of the Campanian volcanic arc that stretches along the convergence of the African and Eurasian tectonic plates on the Italian peninsula-it been erupting for thousands of years.

Sometime around 1995 B.C., for example, an unusually violent eruption (known today as the " Avellino eruption") shot millions of tons of superheated lava, ash and rocks about 22 miles into the sky. That Bronze Age catastrophe destroyed almost every village, house and farm within 15 miles of the mountain.

Villagers around the volcano had long learned to live with their volatile neighbor. Even after a massive earthquake struck the Campania region in 63 A.D.-a quake that, scientists now understand, offered a warning rumble of the disaster to come-people still flocked to the shores of the Bay of Naples, and Pompeii grew more crowded every year.

Pompeii Eruption

Sixteen years after that telltale earthquake, in either August or October of 79 A.D., a number of small earthquakes rocked the Pompeii region. The people there shrugged off the temblors since they "were not particularly alarming because they are frequent in Campania," according to the writer and eyewitness Pliny the Younger.

Then, shortly after noon on that fateful day, Mount Vesuvius erupted again. The blast sent a plume of ash, rock and scorching-hot volcanic gases so high into the sky that people could see it for hundreds of miles around.

Pliny the Younger, who watched the eruption from across the Bay of Naples, compared this "cloud of unusual size and appearance" to a pine tree that "rose to a great height on a sort of trunk and then split off into branches." (Today, geologists refer to this type of volcanic blast as a "Plinean eruption.")

As it cooled, this tower of debris drifted to earth: first the fine-grained ash, then the lightweight chunks of pumice and other rocks. It was terrifying-"I believed I was perishing with the world," Pliny wrote, "and the world with me"-but it was not yet lethal: Most Pompeiians had plenty of time to flee, and many did.

Herculaneum and Pompeii

For those who stayed behind in Pompeii, Herculaneum and other towns, conditions soon grew much worse. As more and more ash fell, it clogged the air, making it difficult to breathe. Buildings collapsed under overloaded roofs, but still some people remained in the city, now covered under several feet of ash.

Then, on the morning of the following day, a "pyroclastic flow"-a 100-miles-per-hour blast of superheated gas and pulverized rock-poured down the side of the mountain and vaporized everything and everyone in its path.

By the time the Vesuvius eruption sputtered to an end on the second day of the eruption, Pompeii was buried under millions of tons of volcanic ash.

Some people drifted back to town in search of lost relatives or belongings, but there was virtually nothing left to find. Pompeii, along with the neighboring town of Herculaneum and a number of villas in the area, was abandoned for centuries.

Pompeii Bodies

About 2,000 Pompeiians died in the city, but the eruption in total killed up to 16,000 people in Pompeii, Herculaneum and other towns and villages in the region.

Bodies of men, women, children and animals were frozen right where they'd fallen-many of the bodies uncovered later were still clutching valuable household objects they'd hoped to carry safely out of the city. Some bodies were found with their arms poignantly wrapped around children or other loved ones.

Later archaeologists even uncovered jars of preserved fruit and loaves of bread. Most of the city's buildings were intact, and everyday objects and household goods still littered the streets. The powdery volcanic ash that buried Pompeii had proved to be an excellent preservative.

Pompeii Exhibit

Pompeii remained mostly untouched until 1748, when a group of explorers looking for ancient artifacts arrived in Campania and began to dig. They found that the ashes had acted as a marvelous preservative: Underneath all that dust, Pompeii was almost exactly as it had been almost 2,000 years before.

Many scholars cite the excavation of Pompeii as an influence in the neo-Classical revival of the 18th century. Europe's wealthiest and most fashionable families displayed art and reproductions of objects from the ruins, and drawings of Pompeii's buildings helped shape the architectural trends of the era.

For example, wealthy British families often built "Etruscan rooms" that mimicked those in Pompeiian villas. Today, many of the preserved artworks, frescoes and other artifacts are on exhibit at the Pompeii Antiquarium, located among the city's ruins.

The excavation of Pompeii that has been going on for almost three centuries continues today, and the entire site has been declared a UNESCO World Heritage Site. Scholars and tourists remain just as fascinated by the city's eerie ruins-and the artifacts and bodies buried on that fateful day over 2,000 years ago-as they were in the 18th century.

"Many disasters have befallen the world," wrote the German philosopher-poet Goethe, after touring Pompeii's ruins in the 1780s, "but few have brought posterity so much joy."
READ MORE: The Deadliest Volcanic Eruption in History
Sources

History of Pompeii. Pompeii Online.
Antiquarium. Pompeiisites.org.
Resurrecting Pompeii. Smithsonian Magazine.
Archaeological Areas of Pompei, Herculaneum and Torre Annunziata. UNESCO World Heritage Convention.

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Pompeii, a flourishing resort city south of ancient Rome, was nestled along the coast of Italy in the shadow of Mount Vesuvius, an active volcano. Its most famous eruption took place in the year 79 A.D., when it buried the city of Pompeii under a thick carpet of volcanic ash.