Volcanoes and Earthquakes (all possible short questions that can be asked in an exam)

Volcanoes and Earthquakes (all possible short questions that can be asked in an exam) Explain a fault line pressure from plate movement causes the rock to fracture (break/tear) What's the focus? the point on the fault line where an earthquake starts - the depth of the focus has a direct impact to the damage it can cause Why are shallow focus earthquakes extremely dangerous? they're closely to the earth's surface - the energy released during an earthquake only needs a short distance to reach the earth's surface - What's the intermediate focus and where are they usually located at? earthquakes that can happen between 11 - 300 km below the surface - they're located within the earth's solid upper mantle Where can you find deep focus earthquakes? deep focus earthquakes are located between 300-700 km below the surface and mainly occur at subduction zones Explain Epicentre the point on the earth's surface directly above the focus and it is where seismic waves are the strongest - the further away the seismic waves are from the epicentre the weaker it is and contains less energy causing a lower impact What are aftershocks? smaller earthquakes that follow a major earthquake - this is mainly due to rock vibrations What are seismic waves? they're known as shockwaves or tremors - they're vibrations caused by an earthquake that are sent out from the focus Name the instrument used to measure the force of an earthquake seismometer Endogenic forces are forces that happen inside the earth. True or False? True