The layer or shell of the earth below the lithosphere, which is
weak and in which isostatic adjustments take place, magmas may
be generated and seismic waves are strongly attenuated. The
asthenosphere begins about 100 km below the surface and extends
to a depth of about 350 km.
An area of the surface of the earth directly above the
A measure of the effects of an earthquake at a particular place.
The solid outer shell of the earth, including the crust and
uppermost rigid mantle.
A segment of the lithosphere that moves over the plastic
A measure of the strength of an earthquake.
An arbitrary scale of earthquake intensity graduated from I to
A numerical scale of earthquake magnitude, devised in 1935 by
C.F. Richter. It runs from 1 to 10.
The likelihood of an area being subjected to earthquakes.
Seismic zone: A zone of the Earth where earthquakes occur.