EARTHQUAKES

BY: ANDREA

What are EARTHQUAKES caused by ??

Earthquakes are caused by a sudden shift / movement deep under ground in the Earth's plates. On the surface, we see this as the shaking of the ground, causing damage to poorly built structures.Earthquakes can also cause other disasters including tsunami and volcanic eruptions.Earthquakes occur unpredictably along fault lines, capable of killing thousands of people.

What does an earthquake do??

1. they shake the ground ... up and down or sidewise 2. the relieve the internal pressure that builds up as the tectonic plates move. Here effects of an earthquakes: Tsunami A tsunami is a series of huge waves caused by an earthquake under the sea. These waves travel at about 800 km per hour. Before a tsunami reaches the shore, it slows down. The water along the shore recedes as if there were a very low tide. When the water comes back, the height of its waves may reach up to 30 m. It can destroy houses, crops and people as it goes inland and then back to the sea. Seiche An underwater earthquake can also generate a big wave in an enclosed body of water like a lake or a pond.This big wave which can be about 3 m high is called a seiche. A seiche can cause immediate flooding of areas near the lake. Faulting Strong earthquakes can also change the earth's surface. Cracks may form on the crust.

Here is some more picures of eartquakes!!!!

The Great Alaska Earthquake of 1964

It all happened on March 27, 1964 at 5:36 p.m


As a result of the 1964 quake, the Latouche Island area moved about 18 meters to the southeast. Also, the patterns of uplift and subsidence which had been slowly developing prior to the earthquake were suddenly reversed, with areas around Montague Island being uplifted 4-9 meters and areas around Portage down-dropped as much as 3 meters. The hinge line (line of no vertical change separating the uplift and subsidence zones) extended from near the epicenter in Prince William Sound to the SE coast of Kodiak Island. This vertical deformation affected and area of approximately 250,000 km2 (100,000 miles2). The end results was the movement of the Pacific plate under the North American plate by about 9 meters on average.

The number of deaths from the earthquake totalled 131,115 in Alaska, and 16 in Oregon and California