Geomorphic Processes

A cirque is a bowl-shaped or amphitheater-like depression carved by a glacier at the head of a valley, typically high on a mountainside. It forms through plucking and abrasion by glacial ice at the snow accumulation zone. Glacial troughs are U-shaped valleys, hanging valleys are tributary valleys left above the main valley, and 'hum' is not a standard glacial landform term.

Exfoliation is a weathering process where outer layers of rock peel off in sheets due to repeated expansion and contraction from temperature changes. This onion-skin weathering creates rounded domes and is common in granite and homogeneous rocks. It differs from shattering (A), block separation (B), or granular disintegration (C).

Trellis drainage pattern develops on folded sedimentary rocks where streams flow along parallel valleys (synclines) and then cut across ridges (anticlines) at right angles, creating a trellis-like pattern similar to a grapevine support system. This is characteristic of alternately resistant and soft rock layers in folded terrain, unlike dendritic (tree-like), radial (spokes), or rectangular (fault-controlled) patterns.

Inselberg (German for 'island mountain') is a residual hill that stands isolated in a desert landscape, resistant to erosion while surrounding material weathers away. These are typically hard rock outcrops (often granite) that remain after softer material erodes. Inlier (A) is younger rock surrounded by older; playa (C) is a desert lake bed; pediment (D) is a sloping plain at mountain base.

Valley-in-valley profiles develop through stream rejuvenation creating multiple terrace levels (A-4). Collapse sinks form from limestone dissolution creating karst topography (B-1). The term shadow zone in seismology refers to areas where seismic waves don't transmit during earthquakes (C-2). Exhumed erosion surfaces represent planation processes exposing ancient landscapes (D-3).

Consequent valleys follow the initial land slope as streams establish their courses (A-4). Subsequent valleys shift from original consequent paths to exploit more readily erosible rock units (B-3). Insequent valleys show random drainage patterns with no apparent adjustment to geological structure (C-2). Obsequent valleys drain in directions opposite to the original consequent streams (D-1).

A cliff is a steep rock face, often coastal, formed by erosion or tectonic activity where land elevation drops sharply. The key characteristic is the vertical or near-vertical drop. Ablation is a process, sleet is precipitation, pampero is a wind, and moraines are glacial deposits.

The Dead Sea depression is a classic example of a graben, which is a depressed block of land bordered by parallel faults. A graben forms when tectonic forces cause the crust to drop between two normal faults, creating a rift valley. The Dead Sea lies within the Jordan Rift Valley, which is part of the larger Dead Sea Transform fault system.

A bajada is a depositional landform in arid regions formed by the coalescence of several alluvial fans. Alluvial cones are individual fan-shaped deposits at the base of mountains where streams deposit sediment. When multiple alluvial fans merge together along a mountain front, they form a continuous sloping surface called a bajada. This creates an extensive depositional plain with a gentle gradient away from the mountains. A pediment is a different feature - a bedrock surface at the mountain base.

Glaciation areas are marked by significant glacial erosion and deposition, leaving behind landforms and features associated with deranged drainage patterns where normal river networks have been disrupted.

A braided channel is characterized by a network of interconnected channels that repeatedly divide (diverge) and rejoin (converge) around sediment bars or islands. This occurs when the sediment load is too high for the channel to transport, causing deposition that forces the flow to split. The description matches perfectly: extensive floodplain, gentle slopes (2-5 degrees), very low channel gradient, sluggish flow, and a tangled network of shallow diverging and converging channels.

In geomorphology, deflation (removal of fine particles by wind) and abrasion (rock grinding by friction) are the two primary mechanical actions of wind erosion in topography. Attrition involves reduction in particle size through collisions but is more associated with fluvial (river) processes. Corrosion refers to chemical weathering, which is not classified as a topographic action in the same mechanical sense.

Glacial depositional landforms are features formed by sediment deposited by ice or meltwater. Eskers are sinuous ridges of sand and gravel deposited by streams flowing under or within glaciers. Outwash plains are broad, flat areas of sorted sediment deposited by meltwater streams emerging from glaciers. In contrast, U-shaped valleys and roches moutonnées are erosional features carved by moving ice, not depositional.

Playas (spelled 'Players' in this question, likely a typo) are shallow, flat-floored desert basins that periodically fill with water. They are formed by the deflating action of winds, which remove fine particles and leave behind a depressed, flat surface. This is distinct from glacial, river, or marine erosion processes. Playa formation is characteristic of arid and semi-arid regions where wind is the dominant erosional agent.

In the fluvial cycle of erosion, a river first forms a gorge in the mountains. As it erodes downward and laterally, it creates a piedmont plain at the mountain foot. With continued deposition, a floodplain forms. Finally, at the mouth, a delta develops where sediment is deposited.