Earth Surface Dynamics: 17 flashcards

Endogenic processes originate from within the Earth (e.g., plate tectonics, volcanism), building up landforms. Exogenic processes originate from external forces (e.g., weathering, erosion), wearing down landforms.

Slow movements (diastrophism) and sudden movements (e.g., earthquakes, volcanic eruptions).

Diastrophism is the slow deformation of the Earth's crust. Its two main types are orogenic (mountain-building) and epeirogenic (continental uplift/subsidence).

Internal heat of the Earth, including radioactive decay and residual heat from planetary formation.

Solar energy, which drives atmospheric and oceanic circulation, and gravitational energy.

Weathering is the in-situ breakdown of rocks by physical, chemical, or biological agents. Erosion is the removal and transport of weathered material by moving agents like water, wind, or ice.

Physical (e.g., frost wedging), Chemical (e.g., oxidation of iron), Biological (e.g., root growth in cracks).

Mass wasting is the downslope movement of rock, soil, and regolith under the influence of gravity. Examples: landslides, rockfalls, mudflows, soil creep.

Weathering breaks down rocks into sediments, erosion transports them, and deposition accumulates them in layers. Over time, lithification (compaction and cementation) turns these sediments into sedimentary rocks.

A delta — a depositional landform formed when a river enters a standing body of water and deposits its sediment load.

A U-shaped valley is a glacial landform carved by the erosive action of a glacier, which widens and deepens a pre-existing V-shaped river valley.

A stalactite is an icicle-like deposit of calcium carbonate hanging from the ceiling of a cave. It forms when mineral-rich groundwater drips and evaporates, leaving behind calcite.

A barchan is a crescent-shaped dune with its horns pointing downwind, formed where sand supply is limited. A seif is a long, linear dune oriented parallel to the prevailing wind direction.

Isostasy is the gravitational equilibrium between the Earth's crust and mantle. Epeirogenic movements (continental uplift or subsidence) are adjustments to maintain isostatic balance, e.g., when a mountain range erodes, the crust may rebound upward.

A yardang (streamlined ridge) or a ventifact (wind-polished rock). Mushroom rocks are also formed by wind abrasion.

Gradation is the leveling of the land surface by erosion and deposition. It includes degradation (wearing down highlands) and aggradation (building up lowlands), ultimately aiming to create a base level profile.

Endogenic processes build up relief (e.g., mountain building), while exogenic processes wear it down (e.g., erosion). They act simultaneously; for example, as the Himalayas rise (endogenic), rivers erode them (exogenic), creating deep gorges and transporting sediment.