Exam 16: Earthquakes

A _____ is the first wave to arrive at a recording station following an earthquake.

The most important concentration of earthquakes by far is ______.

_____ is a measure of an earthquake's effect on people and buildings.

Most earthquakes occur at great depths.

The elastic rebound theory involves the sudden release of progressively stored energy in rocks.

___ stations are the minimum needed to determine the location of an earthquake epicenter.

The Modified Mercalli Scale determines earthquake intensity, a measure of an earthquake's effect on people and buildings.

Both P-waves and S-waves can pass through ____.

Surface seismic waves originate at the epicenter of an earthquake.

Perhaps 90 percent of the destruction in the 1906 San Francisco earthquake was caused by ____.

____ are earthquake waves that cause the most property damage.

The __, the distance between the epicenter and focus, for earthquakes is about 670 km.

Small earthquakes following the main surface wave arrival are called foreshocks.

The most important concentration of earthquakes in the world is the Mediterranean-Himalayan Belt.

Deep focus earthquakes occur at a maximum depth of ______.

The time interval between the first arrival of a P-wave and the first arrival of an S-wave increases with distance from the focus of an earthquake.

The time interval between the first arrival of P-waves and the first arrival of S-waves ____ with distance from the focus of an earthquake.

First motion studies of mid-ocean ridges show that the faults there are ____, and parallel to the rift valley.

A series of earthquakes that occurred near _____ in 1811-1812 were the most widely felt earthquakes to occur in recorded history.

Tsunami waves may move faster than ____.