What percent of Earth’s land surface is currently covered by glaciers?

The distance between a seismological recording station and the earthquake source is determined from the ________.

Vents that emit only heated, volcanic gases and water are called fumaroles.

The movement of water within the surf zone that parallels the shore is termed ________.

________ is a major dissolved volatile constituent in both magmas and volcanic gases.

The Columbia Plateau in Washington and Oregon is ________.

Amphibolite is a foliated metamorphic rock composed principally of hornblende and plagioclase. It forms ________.

The first stage in the formation of coal involves a substance composed of partially altered plant material called ________.

The eruptions of the Hawaiian volcanoes may be described as explosive in comparison to the 1980 Mount St. Helens eruption.

Which characteristic is absolutely necessary for a sedimentary rock to have potential as a possible reservoir rock for oil or gas?