Geological History and Climate Change Concepts

These flashcards cover key vocabulary and concepts related to geological history and climate change, specifically the processes associated with glaciation and Earth's climatic variations.

Glacial Maximum

The point in a glaciation when ice reaches its maximum extent.

Quaternary Glaciation

A period beginning 2.6 million years ago characterized by repeated glacial cycles.

Snowball Earth Theory

The hypothesis that Earth was entirely or nearly entirely frozen at certain times in its history.

Isostatic Rebound

The rise of land masses that were depressed by the weight of ice sheets.

Cryogenity

Refers to the scientific understanding of ice ages and glaciation periods.

Pleistocene Epoch

The geological epoch during which the most recent ice ages occurred.

Holocene Epoch

The current geological epoch, beginning about 12,000 years ago after the last glaciation.

Subglacial Lakes

Lakes located beneath ice sheets, which can influence ice dynamics as they can affect pressure and melt rates.

Proglacial Lake

A lake that forms at the forefront of a glacier, as a result of meltwater from the glacier.

Champlain Sea

A temporary body of saline water that flooded parts of North America after the retreat of ice sheets during the last glaciation.

Milankovitch Cycles

Orbital cycles including eccentricity, obliquity, and precession that affect Earth's climate over tens of thousands of years.

Moraine

A mass of dirt and rocks that has been pushed along and deposited by a glacier.

Eccentricity

The shape of Earth's orbit around the sun, which varies from circular to elliptical every 100,000 years.

Obliquity

The tilt of Earth's rotational axis, which changes from about 22 to 24 degrees over a cycle of about 41,000 years.

Precession

The gradual wobble of Earth's axis of rotation, completing a cycle approximately every 26,000 years.

Striations

Grooves and scratches in rocks caused by the movement of glaciers.