Q: Your site is very interesting and I have a suggestion: have more things for kids like easy to read maps and interesting but true stories about earthquakes and a way for kids to submit earthquake stories. I also have a question: What kind of destruction occurs during earthquakes that take place along the ocean floor? Also, is it true that animals can detect earthquakes before they occur?
Kelly
A: Many earthquakes that occur under the ocean are close enough to land that the shaking from the earthquake will cause some damage. Large earthquakes in the oceans can also cause movement in the ocean floor that creates tsunamis (sometimes incorrectly called tidal waves). There are some anecdotes that have claimed that animals can detect something prior to earthquakes, but there are no cases where scientists have been able to confirm this.

Q: Hi! Just in case my last e-mail was terminated I will repeat my message. Please, send me some information on what seismologists do because I am thinking of majoring in it.
A: A seismologist studies earthquakes. They also study the structure of the earth using seismic waves much like dolphins use sonar to see objects underwater. Other scientists use the Global Positioning System to study earth movements and they are called geodesists. Earthquake geologists study the structure of modern faults and paleo-earthquakes, otherwise known as prehistoric earthquakes. All of us work together to understand earthquakes, when they occur and where they occur. Together with civil engineers, we help build better earthquake-resistant buildings.

Q: Hi, I go to Indian Trail Junior High School and I am doing research on earthquakes, and I want to know where are the places that earthquakes mostly happen?
A: About 70% of the earthquakes in the world happen around the Pacific rim, going from New Zealand to New Guinea, past the Philippines, Taiwan, Japan, Kamchatka, Alaska, the western United States, Mexico, Central America, and western South America. This is also called the "ring of fire." Many of the rest happen in an east-west band across southern Europe, the Middle East, and northern India/southern China.

Earthquakes mostly happen along the boundaries between tectonic plates. The places mentioned above are all along plate boundaries. (Look at a World Seismicity Map from the U.S. Geological Survey.) The San Andreas fault is the most studied fault which is a major part of the plate boundary between the North American and Pacific plates. Hundreds of small earthquakes occur within California along this plate boundary every week. (Look at a Western U.S. Seismicity Map.)

Q: Hello! I'm Carrie! We're studying earthquakes in English! I just wanted to know if you could send me some info on earthquakes and pictures on earthquakes. What has been the largest earthquake ever recorded in the United States?
A: The largest earthquake ever recorded in the United States would probably be the 1964 Alaska earthquake, which measured in with a moment magnitude of 9.2

Q: I was just wondering what a foreshock does and what it can do to you if it can do anything to you? I was also wondering what an aftershock does and what it can do to you if it can do anything? If you would please write me back I would appreciate it very much!! Thanks for your cooperation!!
Thank you, Nicole
A: The important thing to note about foreshocks and aftershocks is that they are all earthquakes. So, if they are large enough, they can cause damage, just like a "main shock." After a sequence of earthquakes is over, we call the largest one that happened the "main shock," and the ones that happened before it, if any, foreshocks, and the ones that happened afterwards aftershocks. Foreshocks are usually small, but before the 1960 Chile earthquake there was a "foreshock" with magnitude Ms=7.3. The largest aftershock is typically about one magnitude unit smaller than the main shock.

A foreshock can be thought of as the fault preparing for a larger earthquake. It can also be thought of as a set of dominos, with one domino knocking down another, one after another until a larger earthquake occurs. Scientists are still studying foreshocks carefully to see if they can alert us to a possible bigger earthquake. Aftershocks occur after bigger earthquakes and are usually the result of the earth readjusting to stress changes. Aftershocks are important to seismologist and we study them carefully to understand earthquakes.

Q: Hello.
I would like to know as much information as possible about earthquakes.
Can you help me?
A: Try: http://www.seismo.unr.edu/htdocs/abouteq.html

Q: How do earthquakes happen? How often do they happen? What is the lab's biggest earthquake ever reported? Your site is the coolest site I've ever been to. It encourages me to be my best in school. Science is my favorite subject of all time. I go to your site every day. I hope you update it soon.
from,
Tim
A: The movement of tectonic plates causes most earthquake. Strain accumulates in the earth along faults from the movement of tectonic plates. When the rocks break the strain accumulated is suddenly released. The energy goes into heat and making seismic waves. Hundreds of small earthquakes happen every day, most of which go unfelt. A magnitude 8 earthquake usually occurs somewhere on the earth once every year. The largest earthquake ever recorded was in Chile on May 22, 1960, with a magnitude (Mw) of 9.5. The largest earthquake in Nevada was the 1915 Pleasant Valley earthquake, which had a magnitude of 7.3.

Q: I was wondering how how big earthquakes can get? I was also wondering how big of a chance that an earthquake (can) form a volcano? Thank you for reading this. Please email back if you have a chance.
A: The largest earthquake recorded this century is the 1960 magnitude (Mw) 9.5 earthquake in Chile, South America. Volcanos can trigger earthquakes by the movement of magma in the volcano. Single earthquakes do not result in the creation of a volcano, but it is common that when volcanos erupt, there are earthquakes at the same time.

Q: Hi! My name is Jessica from Olathe, KS. I was wondering when and where the biggest earthquake ever recorded was and when it happened. I was also wondering if there was an earthquake in Kansas, because I know I've never felt one here. I used to live in CA where I once slept through an earthquake! Pretty weird, huh!
Stay NSYNC!
Jessica Y.
P.S. (write back if you ever get the time.)
A: The largest earthquake recorded this century is the 1960 magnitude 9.5 in Chile, South America (see a map from the U.S. Geological Survey). You can search to get a list of all the earthquakes known in Kansas by going to http://wwwneic.cr.usgs.gov/neis/epic/epic.html. The largest earthquake in that catalog is April 24, 1867, with an estimated magnitude of 5.1. It happened at 39.2 degrees North, 96.3 degrees West, in an area northwest of Topeka. The U.S. Geological Survey also lists major earthquakes for each state.

Large earthquakes have happened near Saint Louis, Missouri and Charleston, South Carolina, so it is a misconception that quakes only happen in California.

Q: What was the longest Earthquake ever to ocur and where? And what did the people in that area if any, have to do for that period of time? How long does it take to rebuild everything that had been destroyed?
A: Some of the people in central Alaska who felt the ground shaking in the 1964 magnitude 9.2 Alaska earthquake said that it lasted for five minutes. Their reports are believable, considering the size of that earthquake. Not everything is destroyed by an earthquake. Modern structures mostly survive but old buildings and sometimes new ones also do not survive. Rebuilding can take years, but often the main phase of rebuilding is over in one to two years.

Q: How many more years will it take for California to break away from the rest of the United States? Please write back when possible.
A: Parts of California and Baja California ride along on the Pacific plate as it slides past the North America plate. Over the last 20 million years, the Pacific plate has slid 200 miles towards the north. Some would say that in 12 million years Los Angeles would be next to San Francisco.

Q: Are there any earthquakes in Australia? I like your page; it encourages me to do my best. You should make maps of earthquakes in Australia. I like Australia, it's very warm there right now. I wouldn't know, though, because I don't live there. Your site is very cool and stuff.
A: The largest earthquake recorded in Australia happened on January 22, 1988. It had a magnitude (Ms) of 6.9. It was located at 19.8 degrees south latitude, 133.9 degrees east longitude. There are not any tectonic plate boundaries there. But like in eastern North America, large earthquakes occasionally happen far from plate boundaries. The U.S. Geological Survey has posted a map of earthquakes in Austrailia.

Q: How long does an earthquake last?
Lacy Meyers
A: A small magnitude 5 earthquake can last several seconds but a magnitude 8 earthquake can shake the ground for up to a minute. If you are farther away from the earthquake then the shaking lasts longer but is weaker.