Earthquake

Earthquake Map

Meehaa's Earthquake map displays earth movement activity picked up in the last 7 days, as well as plate shifting data when applicable.

Earthquakes

An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air and wreak destruction across entire cities. The seismicity, or seismic activity, of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The word tremor is also used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides and, occasionally, volcanic activity.

Earthquake Data

Data is pulled from the USGS Earthquake Hazards Program of the U.S. Geological Survey (USGS).

USGS is part of the National Earthquake Hazards Reduction Program (NEHRP) led by the National Institute of Standards and Technology (NIST). The USGS role in NEHRP is to provide Earth sciences information and products for earthquake loss reduction.

Plate Boundaries Data

Data is pulled from the USGS Earthquake Hazards Program of the U.S. Geological Survey (USGS).

Data shows the outermost shell of the Earth, which consists of a mosaic of rigid “plates” that have been moving relative to one another for hundreds of millions of years.

Earthquake Map

Preparing for Earthquakes

An earthquake is a sudden, rapid shaking of the ground caused by the shifting of rocks deep underneath the earth’s surface. Earthquakes can cause fires, tsunamis, landslides or avalanches. While they can happen anywhere without warning, areas at higher risk for earthquakes include Alaska, California, Hawaii, Oregon, Puerto Rico, Washington and the entire Mississippi River Valley.

During An Earthquake

If an earthquake happens, protect yourself right away:

  • If you are in a car, pull over and stop. Set your parking brake.

  • If you are in bed, turn face down and cover your head and neck with a pillow.

  • If you are outdoors, stay outdoors away from buildings.

  • If you are inside, stay and do not run outside and avoid doorways.

Ready.Gov

Ready.Gov is a National public service campaign designed to educate and empower the American people to prepare for, respond to and mitigate emergencies, including natural and man-made disasters. It is maintained by The Federal Emergency Management Agency (FEMA), a part of the U.S. Department of Homeland Security.

It is an excellent resource for information on emergency preparation and preparedness.

Earthquake Dashboard

Richter Scale

The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are included for the variation in the distance between the various seismographs and the epicenter of the earthquakes. On the Richter Scale, magnitude is expressed in whole numbers and decimal fractions. For example, a magnitude 5.3 might be computed for a moderate earthquake, and a strong earthquake might be rated as magnitude 6.3. Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value.

Description:

Micro

Mercalli

Intensity: I

Microearthquakes, not felt, or felt rarely. Recorded by seismographs.

Description:

Minor

Mercalli

Intensity: I to II

Felt slightly by some people. No damage to buildings.

Description:

Minor

Mercalli

Intensity: III to IV

Often felt by people, but very rarely causes damage. Shaking of indoor objects can be noticeable.

Description:

Light

Mercalli

Intensity: IV to VI

Noticeable shaking of indoor objects and rattling noises. Felt by most people in the affected area. Slightly felt outside. Generally causes zero to minimal damage. Moderate to significant damage very unlikely. Some objects may fall off shelves or be knocked over.

Description:

Moderate

Mercalli

Intensity: VI to VII

Can cause damage of varying severity to poorly constructed buildings. Zero to slight damage to all other buildings. Felt by everyone.

Description:

Strong

Mercalli

Intensity: VIII to X

Damage to a moderate number of well-built structures in populated areas. Poorly designed structures receive moderate to severe damage. Felt in wider areas; up to hundreds of kilometers from the epicenter. Strong to violent shaking in epicentral area.

Description:

Major

Mercalli

Intensity: X +

Causes damage to most buildings, some to partially or completely collapse or receive severe damage. Well-designed structures are likely to receive damage. Felt across great distances with major damage mostly limited to 250 km from epicenter.

Description:

Great

Mercalli

Intensity: X +

Major damage to buildings, structures likely to be destroyed. Will cause moderate to heavy damage to sturdy or earthquake-resistant buildings. Damaging in large areas. Felt in extremely large regions.

Description:

Great

Mercalli

Intensity: X +

At or near total destruction – severe damage or collapse to all buildings. Heavy damage and shaking extends to distant locations. Permanent changes in ground topography.