Sarah's+Earthquake+Page

Back EARTHQUAKES 22/2/11

Where do earthquakes come from? Earthquakes come from when a plate is pushed under another plate or breaks in half. When this happens it causes the ground to shake. How do plates move?

The plates move by the inner core’s intense heat moving the molton rock in the mantle.the the plates just float on top of the mantle witch is moving. How deep does the ground crack?

How deep are the cracks in the ground? Earthquake cracks can be as deep as 10 k/m that is called depth of focus.

How long do earthquakes go for? Small earthquakes last for a few seconds and very large earthquakes last for some minutes.

16/3/11 Week 7/22/3/11 Week8 Earthquakes

1. What is the epicentre of an earthquake? The epiccentre of a earthquake is directly above the surface. 2. How do aftershocks occur? After the major earthquake the plates need to reposition there selves into a now position even though they are cracked. 3. Explain how a seismograph works? A seismograph has a base that sets firmly in the ground and a heavy weight that is hanging free. When the earthquake causes ground shake the base of a seismograph shakes too, but not the hanging weight.