Geomorphology and Quaternary Geology Flashcards

Isostatic rebound (glacial isostasy) refers to:

Answer: The upward movement of the crust after glacier removal

Isostatic rebound is the upward rise of Earth's crust after the removal of glacial ice load, a process still ongoing in Scandinavia and Canada.

Which feature is characteristic of karst topography?

Answer: Sinkholes, caves, and disappearing streams

Karst topography develops on soluble rocks like limestone and is characterized by sinkholes, caverns, springs, and disrupted surface drainage.

A kettle hole is formed when:

Answer: A buried block of glacial ice melts, causing the overlying sediment to collapse

Kettle holes form as depressions in glacial outwash plains when stagnant ice blocks buried by sediment melt out.

What does a negative or falling stream gradient indicate in longitudinal profile analysis?

Answer: A knickpoint may be present due to differential resistance or base level change

A steepened reach or knickpoint in a stream's longitudinal profile indicates differential erosion, resistant rock, or upstream migration of a base-level change.

The Milankovitch cycles that drive glacial-interglacial cycles include all of the following EXCEPT:

Answer: Solar luminosity changes (~11-year sunspot cycle)

Milankovitch cycles involve eccentricity, obliquity, and precession of Earth's orbit and axial tilt, not short-term solar luminosity cycles.

Alluvial fans typically develop where:

Answer: Streams emerge from confined canyons onto open piedmont slopes

Alluvial fans form at the base of mountain fronts where confined streams spread out, lose velocity, and deposit coarse sediment in a fan shape.

The Younger Dryas event (~12,900–11,700 years ago) represents:

Answer: A sudden return to near-glacial conditions during the last deglaciation

The Younger Dryas was a rapid return to cold, near-glacial conditions that interrupted the warming trend of the last deglaciation.