Earthquake

Measuring Earthquakes

On this page you will find earthquake facts and statistics.

Click here for information on earthquake preparedness.

Earthquakes like volcanos are more prone to certain geographical areas such as the Pacific Rim, they can occur anywhere; New York, North Carolina or Washington DC.

Mineral, Va. was the epicenter for the most recent east coast quake measuring 5.9. The epicenter is just 83 miles from DC and was felt as far south as Atlanta and as far north as Ontario. If you want to read more about the history of DC quakes follow this link to the USGS website.

The largest earthquake to ever hit the US was in 1811 along the New Madrid fault in Missouri.

The New Madrid quake and its aftershocks continued for 3 months from late 1811 into early 1812, which included three aftershocks of magnitudes greater than 8 on the Richter Scale.

These were felt throughout the entire eastern United States (over 2 million square miles), with Missouri, Tennessee, Kentucky, Indiana, Illinois, Ohio, Alabama, Arkansas, and Mississippi experiencing the strongest ground shaking. It was said to have even caused church bells to ring as far away as Boston.

What if it were to happened again?

New Madrid Seismic Hazard Map In a report filed in November 2008, The U.S. Federal Emergency Management Agency warned that a serious earthquake in the New Madrid Seismic Zone could result in "the highest economic losses due to a natural disaster in the United States," further predicting "widespread and catastrophic" damage across Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and particularly Tennessee.

A 7.7 magnitude quake or greater would cause damage to tens of thousands of structures, affecting water distribution, transportation systems, and other vital infrastructure.

We are approaching the 200 year anniversary of this major earthquake and with an increased in solar activity, which is thought to trigger earthquakes, it is wise to be prepared and stay alert.

Japan Moves Closer to US

3D Map of Japan According to geophysicist Ross Stein at the United States Geological Survey (USGS) the recent earthquake in Japan cause the island to move 13 feet closer to the United States and shifted the earth's axis by 6.5 inches, shortening the day by 1.6 microseconds.

The USGS has updated the magnitude of the March 11, 2011, Tohoku earthquake in northern Honshu, Japan, to 9.0 from the previous estimate of 8.9.

Independently, Japanese seismologists have also updated their estimate of the earthquake’s magnitude to 9.0. This magnitude places the earthquake as the fourth largest in the world since 1900 and the largest in Japan since modern instrumental recordings began 130 years ago.

Are you looking for someone that was either living in or visiting Japan - click here to access Googles People Finder, get Emergency Numbers and make an online donation.

Earthquake Facts

Five largest Quakes Worldwide

9.5 Chile May 22, 1960
9.2 Prince William Sound, Alaska March 28, 1964
9.1 Andreanof Islands, Aleutian Islands March 9, 1957
9.0 Kamchatka Nov. 4, 1952
9.0 Japan March 11, 2011

They strike suddenly, violently, and without warning at any time of the year and at any time of the day or night.

Smaller ones often follow the main shock.

They are caused by the breaking and shifting of rock beneath the Earth's surface. Ground shaking from earthquakes can collapse buildings and bridges; disrupt gas, electric, and phone service; and sometimes trigger landslides, avalanches, flash floods, fires, and huge, destructive ocean waves (tsunamis).

Most injuries are caused from collapsing walls, flying glass, and falling objects.

Several thousand shocks of varying sizes occur annually in the United States, and 70 to 75 damaging earthquakes occur throughout the world each year.

All 50 states and all U.S. territories are vulnerable to earthquakes.

Where they have occurred in the past, they will happen again.

California experiences the most frequent damaging earthquakes; however, Alaska experiences the greatest number of larger quakes—most located in uninhabited areas.

They occur most frequently west of the Rocky Mountains, although historically the most violent earthquakes have occurred in the central United States.

It is estimated that a major one in a highly populated area of the United States could cause as much as $200 billion in losses.

How Earthquakes are Measured

They are measured with a device called a seismograph. The Richter scale measures the magnitude (size) of an earthquake on a scale of 1 to 10 using a seismograph. Each step in the scale indicates a tenfold increase in the energy of the earthquake.

The Richter Scale, developed by Charles F. Richter in 1935, is a logarithmic measurement of the amount of energy released by a quake.

The ones with a magnitude of at least 4.5 are strong enough to be recorded by sensitive seismographs all over the world.

New Fault Line Discovered

Another fault line was recently discovered in the Rockies at the base of the Sawtooth Mountains. Click here to read more about this latest discovery.