EARTHQUAKE

(a)   is a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.

(a)   is the study of earthquakes and seismic waves that move through and around the earth.

The point within the earth where rock is under stress is called _________________________.

• Focus

• Epicenter

The point directly above the focus on the surface is called ___________________.

• Epicenter

• Hypocenter

(a)   is a thin zone of crushed rock separating blocks of the earth's crust.

An instrument used to detect and record earthquakes is called (a)   .

_______________is a measure of the “size,” or amplitude, of the seismic waves generated by an earthquake source and recorded by seismographs.

• magnitude

• intensity

_________________is a number (written as a Roman numeral) describing the severity of an earthquake in terms of its effects on the earth's surface and on humans and their structures.

• magnitude

• intensity

(a)   is a measure of the strength of earthquakes, developed by Charles F. Richter and presented in his landmark 1935 paper, where he called it the "magnitude scale".

These earthquakes are of weak magnitude earthquakes happen in the caverns and mines.

(a)