An intermittent lake on the floor of a desert valley is called a(n) ________.

________ is(are) 20 times more effective than carbon dioxide at absorbing infrared radiation emitted by Earth.

The general term ________ denotes a buried, erosional surface where rock layers are missing.

Currents within the surf zone that flow parallel to the shore are known as ________ currents.

________ refers to the tendency for a foundation material to lose its internal cohesion and fail mechanically during earthquake shaking.

At high pressures and elevated temperatures of regional metamorphism, silicate rocks are more resistant to flowage and deformation than at low temperatures and pressures.

What fundamental concept states that in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it?

________ is the name of the earthquake-magnitude scale based on the amount of total energy released during a large earthquake.

By applying the law of superposition, ________ dates can be determined.

Assume that man’s recorded history can be stretched back to 4600 years before the present. This is approximately what fraction of geologic time?