Earth's Dynamic Landforms: A Compendium of Geological Features

Understanding Earth's Landforms

Fluvial Landforms: Shaped by Water

• Furrows and Ravines

  These are trails formed by wild waters, causing grooves that group together and deepen. Increased concentration of water flow and erosion widens and deepens these grooves, forming gullies or ravines.

• V-shaped Valleys

  In mountainous regions, the river deepens its channel, increasing both width and depth, creating a characteristic 'V' shape.

• Trough Valleys

  The river erodes the channel walls above its bed, moving materials through gravitational processes, leading to a wider, U-shaped valley.

• Alluvial Fan

  An accumulation of material eroded and transported by a stream, deposited upon reaching flatter areas.

• Flood Plains

  Deposits formed by rivers during flood events. They create very flat surfaces along river margins, often called river meadows due to their fertile, arable land.

• Meanders

  These are the curves rivers describe. On the outer bend, water velocity is high, leading to increased erosion. Sedimentation occurs on the inner bend.

• River Terraces

  Elevated, ancient floodplains where the river has incised its channel, flowing significantly below them. Consequently, they are not inundated during typical flood events.

Glacial Landforms: Sculpted by Ice

• Hanging Valleys

  These are former glacial valleys that flow into a primary glacial valley. Their floor is significantly higher than the main valley's floor.

• Cirques (Glacial Gaps)

  The glacier over-excavates its bed, making the bottom of the cirque deeper.

• Frontal or Terminal Moraine

  Located at the front of the glacier, marking its furthest extent.

• Lateral Moraine

  Located on both sides of the glacial tongue.

• Central Moraine

  Formed when two glacial tongues merge, and their lateral moraines combine.

Aeolian Landforms: Shaped by Wind

• Alveoli

  Small cavities in rocks caused by wind abrasion.

• Mushroom Rocks

  Wind abrasion can sculpt isolated rock masses into mushroom shapes, as sand grains are primarily moved close to the ground.

• Desert Pavement

  The result of deflation, where fine and medium-sized materials have been removed, leaving behind coarser particles that could not be transported.

• Dunes

  Sand deposits transported by wind. Common forms include barchans, or crescentic dunes.

• Loess

  Deposits of very fine-grained materials transported by wind over long distances.

Coastal Landforms: Formed by the Sea

• Cliff

  Characterized by a steep drop that separates the sea from the landmasses.

• Abrasion Platform

  The horizontal platform at the foot of a cliff, created by wave erosion.

• Promontories and Inlets

  The presence of coastal rocks resistant to marine erosion, alongside less resistant ones, promotes the formation of an irregular coastline.

• Coastal Islets

  Remnants of ancient headlands or landmasses, isolated by erosion.

• Natural Arches

  Natural voids that traverse headlands or are located in front of a cliff, formed by wave action.