Geology / Earthquakes

Earthquakes are the most widely spread evidence that the Earth is still active. It has been active since it was first formed billions of years ago. Just one billion years ago the Earth had somewhat settled down, there were areas of land (continental crust) surrounded by oceans with their thinner, denser oceanic crust deep beneath the waves. The earth's surface became divided into stable areas of crust with mobile unstable margins. As the oceanic crust cooled it became denser and fell back into the semi-liquid (on a geological time scale) vast volume of the Earth's mantle. This thick mantle is itself driven by convection currents that are continually transporting heat energy from the still hot Core to the cold crust.

One of the main causes of earthquakes are the jerky but remoreseful movements of the plates as they slide, crush or descend past each other. These events cause the really big earthquakes. Alternatively the ascent of the hot magma from the mantle can cause earthquakes, but these tend to be not as strong and not as deep. An eruption of a large volcano can cause local earthquakes as the magma rises and stresses the shallow rocks. Human activity can create small earthquakes too, this often happens when a rivers are dammed and the huge weight of the water building up in the lake causes stresses in the underlying rocks.

This site has an archive of earthquakes in recent times both as a list of events and as an animation. Looking at the pattern of earthquakes over the last few months quickly demonstrates the location of the active plate margins around the world.

If you'd like to look at recent earthquakes, we have generated some pages using data supplied by : U.S. Geological Survey

Date and Time Strength, Location Latitude Longtitude

May 08, 2008 23:44:14 GMT M 3.1, Greater Los Angeles area, California 34.0241 -117.1463

May 08, 2008 23:21:07 GMT M 5.5, near the east coast of Honshu, Japan 36.1273 141.6902

May 08, 2008 22:43:08 GMT M 4.6, near the south coast of Honshu, Japan 35.6149 139.9915

May 08, 2008 21:18:55 GMT M 4.9, near the east coast of Honshu, Japan 36.0191 141.0223

May 08, 2008 20:56:00 GMT M 3.6, Andreanof Islands, Aleutian Islands, Alaska 51.9895 -177.8552

May 08, 2008 17:04:32 GMT M 4.5, Fiji region -20.0605 -177.9726

May 08, 2008 16:49:49 GMT M 4.5, off the coast of Central America 3.4405 -88.3455

May 08, 2008 16:41:00 GMT M 4.4, Simeulue, Indonesia 2.8876 96.2805

May 08, 2008 16:21:34 GMT M 2.8, Andreanof Islands, Aleutian Islands, Alaska 52.0675 -177.6627

May 08, 2008 14:51:52 GMT M 2.5, Andreanof Islands, Aleutian Islands, Alaska 51.8898 -177.6294

May 08, 2008 14:12:55 GMT M 5.0, Andreanof Islands, Aleutian Islands, Alaska 52.1044 -177.5497

May 08, 2008 13:21:50 GMT M 4.9, Mariana Islands region 12.1545 141.1657

May 08, 2008 12:26:22 GMT M 4.7, southern Greece 36.1167 22.0251

May 08, 2008 12:17:27 GMT M 2.6, Southern Alaska 61.5943 -141.2470

May 08, 2008 11:31:29 GMT M 5.0, northern Sumatra, Indonesia 5.4004 94.6346

May 08, 2008 10:04:53 GMT M 3.1, Puerto Rico region 18.9840 -67.4913

May 08, 2008 09:48:40 GMT M 4.7, off the east coast of Honshu, Japan 35.9413 142.0991

May 08, 2008 09:40:35 GMT M 4.8, near the east coast of Honshu, Japan 36.1971 141.9229

May 08, 2008 09:19:24 GMT M 3.3, Andreanof Islands, Aleutian Islands, Alaska 53.8343 -177.4231

May 08, 2008 08:45:21 GMT M 3.6, Andreanof Islands, Aleutian Islands, Alaska 51.8376 -177.5543

May 08, 2008 06:12:40 GMT M 2.6, Virgin Islands region 18.6323 -64.9358

May 08, 2008 05:55:01 GMT M 3.8, Nevada 39.5420 -119.9210

May 08, 2008 05:26:31 GMT M 4.7, near the east coast of Honshu, Japan 36.0228 141.8758

May 08, 2008 04:54:44 GMT M 3.3, Andreanof Islands, Aleutian Islands, Alaska 51.9315 -177.2971

May 08, 2008 04:24:43 GMT M 3.1, Puerto Rico region 19.1280 -67.6667

May 08, 2008 02:57:29 GMT M 2.5, Nevada 39.5420 -119.9210

May 08, 2008 02:49:58 GMT M 3.6, Saint Martin region, Leeward Islands 17.5602 -63.6063

May 08, 2008 02:47:39 GMT M 2.6, Nevada 39.5470 -119.9210

May 08, 2008 01:37:30 GMT M 2.9, Kenai Peninsula, Alaska 60.6055 -150.0022