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This is a cool engineering design challenge, but I think it would have to be done in person or with a lot of adult support for younger students.

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Why Do Buildings Fall Down During Earthquakes?

How would a one or two-story building behave in an earthquake? How do the building's materials used affect the stability of the structure? How does the way those materials are joined or connected influence the behavior of a falling structure?

From the perspective of an engineer, failures are important. Houses are built to stand up; it's when they fall down that a problem presents itself. Each failure provides new information about how a house can fall down, about what works, and what doesn't. In this activity, you will investigate how a house collapses and then build a structure to test various ways to use materials to withstand an earthquake.

Can You Design a Structure to Withstand an Earthquake?

The first step is to understand how and why a structure collapses during an earthquake. How might a house frame behave in an earthquake, and what is the best way to make it earthquake resistant?

Earthquakes are usually measured using a seismograph, but this activity is more concerned with how structures are affected by the shaking caused by an earthquake. You will use meters per second squared (m/s2) to determine the acceleration of the structure. Fortunately, Google's Science Journal app makes this easy by utilizing the accelerometer built into many modern cell phone and tablet devices.

Set Up Your Own Earthquake Simulator

Gather the following materials:

2 equally sized pieces of cardboard (These must be larger than the size of the structure you will build so that the structure can rest on it.)

4 marbles

2 large rubber bands

Device with the Science Journal app

Tape

Evenly place the rubber bands around the two pieces of cardboard. Squeeze the marbles in between the two pieces of cardboard as evenly distributed as possible. If you tug on one of the cardboard pieces, it should shake.

You now have your earthquake simulator! The structure you build will go directly on top to test its earthquake readiness.

Next, tape your device with the Science Journal app onto the top surface of your earthquake simulator. Make sure to leave plenty of room for the structure you will create. Your setup should look similar to the image below:

Make sure the Science Journal app is measuring acceleration in the appropriate direction and give it a test. You should be able to get at least 6 m/s2 (meters per second squared) worth of vibration from your simulator.

Time To Build Your Structure

There are many things you can use and many ways to complete this activity. The following lists include potential materials to get you started. Feel free to experiment with other materials.
Edible Materials

Graham crackers

Frosting or fluff

Plastic knives

Popsicle sticks

Tape

Sugar cubes

Cardboard or construction paper (to serve as a base for your structure)

Simple Materials

Cardboard (ideally uniform pieces)

Tape

Scissors or crafting blade

Popsicle sticks

Rubber bands

Cardstock/Construction paper

Some questions you need to answer before you begin construction are:

How many stories will your structure be? Why?

How will you connect and join the pieces?

What will the overall shape of the structure be?

Once you've answered these questions and made your design choices, it's time to make your structure. This is your opportunity to let your creativity flow. Explore a variety of ways to use the materials you have chosen and see which proves most efficient.

Here are some ideas for joining two pieces of cardboard (or other materials) together:

Try using slots.

Slotted joints can be very effective depending on where your structure bears weight. Tip: When cutting slots, make sure they're not bigger than the thickness of the material, otherwise your joint will be very loose and unstable.

Don't be afraid to try different shapes.

You can also try using popsicle sticks as cross-cutting beams.

Of course, you can use tape or other materials you would like to experiment with to attach pieces.

In addition to the above ideas, there are plenty of resources online for different types of joints. Often, the type of joint you use will depend on the type of material you are using, but inspiration can come from imagining what is possible. Have a look at the following websites for possible ideas:
http://www.craftsmanspace.com/knowledge/woodworking-joints.html
http://cardboardchair.weebly.com/
https://www.theartofed.com/2016/06/24/6-amazing-things-tab/

Building Tip:
Be sure to secure your structure onto the top of the earthquake simulator so that it does not slide off when it is being shaken!

Your finished structure should be fastened to its cardboard base. The cardboard base, the structure and the device with the Science Journal app should be fastened to the earthquake simulator like so:

Make Predictions

Take a minute to predict what will happen to your building/structure. Do you think it will stay upright? How long do you think it will be able to withstand the earthquake? Can you predict what the weakest part of your structure is? To achieve a successful design, engineers imagine how a design might fail; their job is to identify (and prevent) each way the design could fail.

Shake the House!

Now imagine there is an earthquake and the ground beneath the house shakes. The average earthquake lasts between 10 - 30 seconds. Keep shaking your simulator for 30 seconds. Try to get the Science Journal app to a peak acceleration of 6 m/s2. What happens to the house?

Results-What Happened?

Evaluate the test results to determine why it may have failed. Now that you have seen how your design handled a simulated earthquake, there will be a whole new series of questions to answer. Was your guess about the weakest part of the structure correct? Did anything unexpected happen? How do you think the way you shook your structure comes into play - how would frequency, amplitude, and duration affect the results?

Redesign

Making your observations and forming new questions will give you ideas to make improvements and prevent the same weaknesses from causing another failure. You can use the same materials. However, if you think one of the materials used was part of the problem, consider trying other materials.

Real Earthquakes

For this activity, we are just simulating earthquakes. The truth is, real earthquakes can be much more complex. An earthquake is the shaking of the Earth caused by pieces of the Earth's upper crust, or tectonic plates, suddenly shifting. This shifting of tectonic plates causes the ground to shake in many directions. When the shaking occurs, structures can potentially get thrown from side to side and/or up and down, but the structures have entropy; this means that a structure that is resting with no acceleration tries to remain at rest. The problem is, the tectonic plate that it's resting on is moving. This is illustrated below:

Another factor that affects structures during an earthquake is what that structure is built on. The surface over the tectonic plate can be hard rock of soft soil. Before actual construction workers begin the process of making a building there are many things to consider. Will the materials be strong, rigid and well reinforced, or flexible, thereby able to absorb movement without deforming? Also, is the planned construction site near a fault or in a place that has a higher chance of earthquakes? Often, hazard maps like this one will be used:

The green, outer portions of the map are farthest away from the fault line located in the center of the map. Areas closing in on the center gradually change colors from yellow to red indicating an increasingly greater risk of experiencing earthquakes. (Hazard Map courtesy of Dr. Robert Herrmann, Saint Louis University)
As you try this activity, we encourage you to learn more about earthquakes. Have a look at the research being run by the Multidisciplinary Center for Earthquake Engineering Research (MCEER). But most of all, we encourage you to try out your own ideas. There is nothing like learning first hand what works and what doesn't work.

Shake, Rattle and Roll - An Earthquake Simulation activity is made possible with support from Making & Science, an initiative of Google.

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Shake, Rattle and Roll - An Earthquake Simulation - NYSCI

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How would a one or two-story building behave in an earthquake? How do the building's materials used affect the stability of the structure? How does the way those materials are joined or connected influence the behavior of a falling structure?

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Introduction
What causes earthquakes? Earthquakes are vibrations inside the Earth that follow the release of energy that has built up inside rocks. Rocks fracturing, volcanoes erupting, and man made explosions can all release the energy stored in the rocks.

Loma Prieta earthquake damage to
homes in Marina District, USGS

P waves and Love waves
All earthquakes produce earthquake waves. There are four types of earthquake waves. P waves are also know as primary waves that travel through all parts of the Earth. Love waves are only produced by the most powerful earthquakes. They travel around the surface of the Earth.

Earthquake zones and megathrust earthquakes
Earthquakes occur in earthquake zones. These zones form around crustal plates. As the plates smash into other plates, move apart and subduct they create earthquake faults. Megathrust earthquakes are associated with subduction zones where powerful earthquakes cause tsunamis.

Great earthquakes
The moment magnitude scale was developed after the 1960 Chile earthquake and the 1964 Alaska earthquake. These were the two most powerful earthquakes of the 20th Century.

New Madrid and Haiti earthquakes
The New Madrid earthquakes occurred in 1811 and 1812 were very powerful quakes that rang bells in Boston. The Haiti earthquake occurred in an area that has large numbers of very powerful earthquakes.

What causes earthquakes
Earthquakes waves radiate outward in all directions from the earthquake focus. The focus is where the rocks first break apart during an earthquake. Earthquake faults are places where two crustal plates are moving together, apart or slipping past each other. Normal faults occur when plates are moving apart and one section of land moves downward.

More Earthquake Links

1960 Chile Earthquake The 1960 Chile earthquake was a magnitude 9.5 the largest earthquake ever recorded!

Earthquake Faults Find out more about fault that go up, down and sideways!

Earthquake Focus Learn where the focus and epicenter of an earthquake are located and exactly what they are?

Haiti Earthquake The devastating Haiti earthquake occurred in a region prone to large earthquakes. Find out why these large earthquakes occur.

P waves Find out more about P Waves that are produced by large and small earthquakes.

Love Waves Find out more about Love waves that can topple tall buildings during large earthquakes!

The Mercalli Scale Did you know there can be twelve different intensities of an earthquake but only one magnitude? Find out why!

Normal Fault Find out why miners often find valuable ore in sites where normal faults have occurred.

Megathrust Earthquake Find out why megathrust earthquakes will occur off the coasts of Alaska, Washington, Oregon and California in the future.

Earthquake Zones Find out where and why earthquakes occur and why there are earthquake zones.

Moment Magnitude Scale Find out why the moment magnitude scale is used to measure great earthquakes.

1964 Alaska Earthquake The Great Alaskan Earthquake find out why Good Friday saved many people's lives!

New Madrid Earthquakes The New Madrid earthquakes were a series of three very large earthquakes felt by people over almost 2 million square miles.

Earthquake Waves Earthquake waves are produced by the more than three million earthquakes each year.

What Causes Earthquakes. Find out what causes earthquakes and other fascinating facts about when our planet shakes, rattles, and rolls.

Kids Fun Science The links on our home page include information about volcanoes, science activities, plate tectonics, the rock cycle and much more.

Ring of Fire Science Bookstore

Check out Myrna Martin's award winning textbooks, e-books, videos and rock sets. The Ring of Fire Science Bookstore covers a wide range of earth science topics. Click here to browse.

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Introduction What causes earthquakes? Earthquakes are vibrations inside the Earth that follow the release of energy that has built up inside rocks. Rocks fracturing, volcanoes erupting, and man made explosions can all release the energy stored in the rocks. Loma Prieta earthquake damage to homes in Marina District, USGS P waves and Love waves All earthquakes produce earthquake waves.

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San Francisco Earthquake of 1906

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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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Great books about the San Francisco Earthquake of 1906

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Great books about the San Francisco Earthquake of 1906

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Disaster! The Great San Francisco Earthquake and Fire of 1906

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Disaster! The Great San Francisco Earthquake and Fire of 1906 has 101 ratings and 18 reviews. Geevee said: This had the promise to be a very good book, e...