# data[].attributes.body
LANDSLIDES -This is a rapid movement of earth materials down a slope, the materials ranging from huge boulders to soil. Landslides can involve the movement of just a small amount of material or enough to bury whole towns in their path. They can have a number of causes, of which earthquakes are just one. The shock of an earthquake may be sufficient to start the slide.

ROCKFALLS - Rock exists above a slope steep enough to allow rapid downslope movement of dislodged rocks by falling, rolling, bouncing, and sliding.

AVALANCHES - a mass of snow, ice, and rocks falling rapidly down a mountainside

# data[].attributes.body
Surface rupture with folding due to reversing faulting along the chelugnepsuebtu fault, Taiwan

# data[].attributes.body
Surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where there is no displacement at ground level. This is a major risk to any structure that is built across a fault zone that may be active, in addition to any risk from ground shaking. Surface ruptures commonly occur on pre-existing faults. There is shallow hypocenter and large fracture energy on the asperities, the asperity shallower than 5 kilometres. An asperity is an area on an active fault where there is increased friction, such that the fault may become locked, rather than continuously slipping as in aseismic creep.

# data[].attributes.attachment_link.title
Raw Video: Japanese Ship Rides Tsunami Waves

# data[].attributes.body
Tsunamis are large ocean waves caused by underwater earthquakes, volcanic eruptions, or landslides. The term "tsunami" is Japanese, meaning "harbour wave." Despite their relatively low frequency, tsunamis can have devastating impacts on coastal regions and communities.

# data[].attributes.body
Formation:

1. Underwater Earthquakes: The majority of tsunamis are triggered by undersea earthquakes, especially those along tectonic plate boundaries. Subduction zones, where one tectonic plate is forced beneath another, displace large volumes of water.

2. Volcanic Eruptions: Volcanic eruptions, particularly those involving the sudden collapse of volcanic islands or the explosive release of gas and ash, can also generate tsunamis through displacement of water.

# data[].attributes.body
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes. For example, the 1964 Niigata earthquake caused widespread liquefaction in Niigata, Japan which destroyed many buildings. Also, during the 1989 Loma Prieta, California earthquake, liquefaction of the soils and debris used to fill in a lagoon caused major subsidence, fracturing, and horizontal sliding of the ground surface in the Marina district in San Francisco.

# data[].attributes.body
The image of the right shows how soil has become water logged therefore meaning that the ground becomes weaker and therefore cannot stabily hold infrastructure like the housing block on the digram when it stats to fall into the ground

# data[].attributes.attachment_link.title
Christchurch Earthquake 6.3, 2011 liquefaction

# data[].attributes.body
Once generated, tsunami waves can travel across entire ocean basins at high speeds, often exceeding 500 miles per hour (800 kilometers per hour) in deep ocean waters. While the amplitude of the waves is relatively low in deep water, they can extend across vast distances.

Propagation

# data[].attributes.body
1. Wave Amplification: As tsunamis approach shallower coastal waters, their velocity decreases, causing the wave height to increase significantly through a process called wave shoaling. This can result in massive waves crashing onto shorelines.

2. Inundation: Tsunamis can inundate coastal areas, causing widespread flooding and destruction. The force of the waves can erode coastlines, damage infrastructure, and sweep away buildings and vegetation.

# data[].attributes.body
31 May 1970- large earthquake beneath the Pacific Ocean about 25 km from the coast of Peru. The ground shaking produced by the earthquake loosened rocks and ice on Mount Huascaran, one of South America's highest mountains, 130 km away from the earthquake. This initiated a gigantic landslide, which increased in speed and size as it moved down the mountain, reaching a speed of over 200 km h⁻¹. It swept along the valley at the foot of the mountain, filling it with rock, mud and ice, and partially destroying the town of Ranrahirca, 12 km from the mountain. Part of the landslide branched off to one side, swept over a ridge and went through and destroyed the village of Yungay.

67 000 dead and 800 000 homeless.

# data[].attributes.body
1. 2004 Indian Ocean Tsunami: Triggered by a massive undersea earthquake off the coast of Sumatra, Indonesia, this tsunami affected numerous countries around the Indian Ocean, causing extensive loss of life and property.

2. 2011 Tohoku Earthquake and Tsunami: The earthquake off the coast of Japan generated a powerful tsunami that led to the Fukushima nuclear disaster and caused widespread devastation along the Japanese coastline.

# data[].attributes.headline
the vibration of the ground during an earthquake

# data[].attributes.subject
the vibration of the ground during an earthquake

# data[].attributes.body
Description:

primary earthquake hazard, result of rapid ground acceleration

ground shaking can vary over an area as a result of factors such as topography, bedrock type and the location and orientation of the fault rupture

the severity of ground shaking increases as magnitude increases and decreases as distance from the fault increases

Impacts:

buildings can be damaged by the shaking itself or by the ground beneath them settling to a different level than it was before the earthquake

it may also cause landslides, mudslides, and avalanches on steeper hills or mountains, (destabilised ground) all of which can damage buildings and hurt people

Mitigation:

seismic design; buildings more resistant to ground movement

good construction practices

building codes

avoidance of hazardous sites

# data[].attributes.body
The risk of liquefaction can be reduced by various improvement methods such as densification (rearranging the soil particles into a tighter configuration, resulting in increased density), solidification (such as using cementation), and gravel drains (this uses gravel to allow the water to flow freely and seep down through into the land drain where the water is carried to a discharge point) or stone columns. This will therefore make the ground less likely to saturate and become weaker therefore reducing the risk of liquefaction taking place.

# data[].attributes.body
1. Early Warning Systems:

Japan Meteorological Agency (JMA): The JMA operates an advanced earthquake early warning system that detects the initial seismic waves from an earthquake and estimates the location, magnitude, and expected intensity of shaking. This information is used to issue warnings within seconds to minutes after the earthquake occurs.

Tsunami Warning Systems: Japan has a sophisticated tsunami warning system that utilizes data from seismographs and oceanographic sensors. This system provides early warnings to coastal communities about the potential arrival of a tsunami.

2. Public Education and Evacuation Plans:

Education Programs: The Japanese government conducts regular public education programs to raise awareness about earthquake and tsunami risks. This includes teaching people how to respond to warnings and educating them about evacuation routes and procedures.

Evacuation Drills: Coastal communities regularly conduct evacuation drills to practice and prepare for a quick and organized response to tsunami warnings. These drills involve schools, businesses, and local residents.

3. Engineering and Infrastructure Measures:

Tsunami Walls and Embankments: Japan has constructed tsunami walls and embankments along vulnerable coastal areas to reduce the impact of tsunami waves. These structures are designed to either absorb or redirect the energy of incoming waves.

Land-use Planning: Zoning regulations and land-use planning aim to limit the development of critical infrastructure and residential areas in high-risk coastal zones.

4. Building Codes and Construction Standards:

Seismic Design Regulations: Japan has stringent building codes that require structures to be designed and constructed to withstand earthquakes. This includes measures such as base isolation and damping systems to reduce the transmission of seismic forces.

Vertical Evacuation Buildings: In some coastal areas, buildings have been constructed with reinforced structures and elevated platforms to serve as vertical evacuation sites during tsunamis.

# data[].attributes.body
Liquefaction caused major damage to port facilities in Kobe, Japan in the 1995 Hyogo-ken Nanbu earthquake.

# data[].attributes.body
1. site Selection:

Avoid building in areas with loose, water-saturated soils prone to liquefaction.

Choose sites with firmer soil types, such as dense sands or gravels, if possible.

Ground Improvement Techniques:

Compaction: Increase the density of loose soils through compaction to reduce their susceptibility to liquefaction.

Drainage Systems:

Implement effective drainage systems to control groundwater levels and reduce water content in the soil.

Well-designed drainage can help prevent the buildup of excess pore water pressure

Liquefaction-resistant Foundations:

Design foundations that can accommodate the lateral and vertical movements associated with liquefaction without failure. Examples include pile foundations with proper reinforcement.

Ground Improvement Using Chemicals:

Injecting chemicals into the soil can alter its properties, making it less susceptible to liquefaction.

Ensure that structures are designed to withstand the forces associated with liquefaction.

# data[].attributes.body
Vegetation placement and management

improving drainage

reducing the angle of the slope

excavating to unload the top of the slope

building a protective wall to buttress the bottom of the slope

artificial channels or chutes to redirect debris flow

nets and artificial walls to prevent falling rock or earth from hitting roads or structures

# data[].attributes.body
A Seiche is a standing wave in an enclosed or partially enclosed body of water. Seiches and seiche-related examples have been observed on lakes, reservoirs, swimming pools, bays, harbours, caves and seas.

# data[].attributes.body
Lake Biwa - waves were observed after the 2011 earthquake in Japan.

# data[].attributes.headline
A seiche is not the same as a tsunami! 

# data[].attributes.subject
A seiche is not the same as a tsunami! 

# data[].attributes.body
They produce an impulse that travels the length of the basin at a velocity that depends on the depth of the water.

A standing wave (black) depicted as a sum of two propagating waves travelling in opposite directions (blue and red). (image to follow)