Biggest Earthquakes in America - History of the Great Quakes in the United States, and Information About Yellowstone's Supervolcano

Earthquakes - Famous Quakes and Biggest Shakes in the United States and Other Facts

The history of big earthquakes in the United States helps to predict future quakes. It also includes some in place you probably wouldn't expect. There is a list of the most famous quakes and a map of the historical earthquakes below, followed by details of the quakes.


Famous Big Earthquakes

  1. Northridge, California (20 miles from Los Angeles)
    January 17, 1994
    4:31 a.m.
    Magnitude: 6.7
    Deaths: 57
    Injuries: 9,000
    Property Damage: $15 billion
  2. Loma Prieta Earthquake (south of San Francisco)
    October 17, 1989
    5:04 p.m.
    Length of time: 15 seconds
    Deaths: 62
    Injuries: 3,757
    Property Damage: More than $6 billion
  3. Coalinga, CA
    May 2, 1983
    Magnitude: 6.4
    Deaths: 0
    Injuries: 47
    Property damage: $31 million
  4. San Francisco, CA
    April 18, 1906
    5:12 a.m.
    Magnitude: 8.25
    Length of time: 40 seconds
    Deaths: 700 to 2,500 people
    Note: The "Great San Francisco Earthquake" is one of the strongest ever recorded in North America. Much of the city was destroyed by the strong shaking, which toppled buildings, and by the fires that followed

The Yellowstone Supervolcano

Seventy thousand years ago was the last time Yellowstone’s volcano erupted. In the last few days swarms of tremors have been detected there – up to 250 small earthquakes. No one’s predicting Yellowstone is about to blow its top but scientists are interested, since a eruption is always possible.

The term "supervolcano" implies an eruption of magnitude 8 on the Volcano Explosivity Index, meaning that more than 1,000 cubic kilometers (240 cubic miles) of magma (partially molten rock) are erupted. The most recent such event on Earth occurred 74,000 years ago at the Toba Caldera in Sumatra, Indonesia.

Volcanoes that produced exceedingly voluminous pyroclastic eruptions and formed large calderas in the past 2 million years would include Yellowstone, Long Valley in eastern California, Toba in Indonesia, and Taupo in New Zealand. Other "supervolcanoes" would likely include the large caldera volcanoes of Japan, Indonesia, and South America.

Will Yellowstone Erupt?

Although it is possible, scientists are not convinced that there will ever be another catastrophic eruption at Yellowstone. Given Yellowstone's past history, the yearly probability of another caldera—forming eruption could be calculated as 1 in 730,000 or 0.00014%. However, this number is based simply on averaging the two intervals between the three major past eruptions at Yellowstone — this is hardly enough to make a critical judgement. This probability is roughly similar to that of a large (1 kilometer) asteroid hitting the Earth. Moreover, catastrophic geologic events are neither regular nor predictable.

What would happen if a "supervolcano" eruption occurred again at Yellowstone?

Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate. The surrounding states of Montana, Idaho, and Wyoming would be affected, as well as other places in the United States and the world. Such eruptions usually form calderas, broad volcanic depressions created as the ground surface collapses as a result of withdrawal of partially molten rock (magma) below. Fortunately, the chances of this sort of eruption at Yellowstone are exceedingly small in the next few thousands of years.

Yellowstone monitored for volcanic activity. The Yellowstone Volcano Observatory (YVO), a partnership between the United States Geological Survey (USGS), Yellowstone National Park, and the University of Utah, closely monitors volcanic activity at Yellowstone. The YVO website (http://volcanoes.usgs.gov/yvo) features real-time data for earthquakes, ground deformation, streamflow, and selected stream temperatures. In addition, YVO scientists collaborate with scientists from around the world to study the Yellowstone volcano.

Do scientists know if a catastrophic eruption is currently imminent at Yellowstone?

There is no evidence that a catastrophic eruption at Yellowstone is imminent, and such events are unlikely to occur in the next few centuries. Scientists have also found no indication of an imminent smaller eruption of lava.

All Large Earthquakes in the continental United States (excludes Alaska and Hawaii)

map of the largest earthquakes in the United States
  Location Date Time 
(Year - month - day - time)
Magnitude
(Richter scale)
Damage
Photos
Isoseismal
Map
1. Cascadia subduction zone 1700 01 26  UTC ˜9    
2. New Madrid, Missouri 1811 12 16 08:15 UTC 8.1   Isoseismal map available
3. New Madrid, Missouri 1812 02 07 09:45 UTC ˜8    
4. Fort Tejon, California 1857 01 09 16:24 UTC 7.9   Isoseismal map available
5. San Francisco, California 1906 04 18 13:12 UTC 7.8 Damage photos available Isoseismal map available
6. Imperial Valley, California 1892 02 24 07:20 UTC 7.8    
7. New Madrid, Missouri 1812 01 23 15:00 UTC 7.8    
8. Owens Valley, California 1872 03 26 10:30 UTC 7.4   Isoseismal map available
9. Landers, California 1992 06 28 11:57 UTC 7.3    
10. Hebgen Lake, Montana 1959 08 18 06:37 UTC 7.3 Damage photos available Isoseismal map available
11. Kern County, California 1952 07 21 11:52 UTC 7.3   Isoseismal map available
12. West of Eureka, California 1922 01 31 13:17 UTC 7.3    
13. Charleston, South Carolina 1886 09 01 02:51 UTC 7.3    
14. California - Oregon Coast 1873 11 23 05:00 UTC 7.3    
15. N Cascades, Washington 1872 12 15 05:40 UTC 7.3    

Note: Widely differing magnitudes have been computed for some of these earthquakes; the values differ according to the methods and data used. For example, some sources list the magnitude of the 8.7 Rat Islands earthquake as low as 7.7. On the other hand, some sources list the magnitude of the February 7, 1812 New Madrid quake as high as 8.8. Similar variations exist for most events on this list, although generally not so large as for the examples given.

In general, the magnitudes given in the list above have been determined from the seismic moment, when available. For very large earthquakes, the moment magnitude is considered to be a more accurate determination than the traditional amplitude magnitude computation procedures. Note that all of these values can be called "magnitudes on the Richter scale," regardless of the method used to compute them.


History of Earthquakes in United States - all noteworthy quakes

All earthquake dates are UTC, not local time.

 

This page was updated on 23-Mar-2017