Coastal Geomorphology Overview

Wave Refraction

• Waves curve over the peak to form a circle
• Wave parts move in different directions
• Longshore currents run parallel to shorelines
• Beach drift is sediment carried by currents
• Groins show how this sediment moves

Tsunami

• Initial height is small, but length is long
• Water level moves offshore

Coast Types

• Sandy coasts
• Rocky coasts (boulder beaches, cliffs)
• Muddy coasts (silt, clay, tidal flats)

Primary vs. Secondary Coasts

• Primary coasts' features are from terrestrial processes
• Secondary coasts have been changed by marine processes
• Riyas, deltas, and fjords are examples of primary land formation.

Erosional Landforms

• Wave-cut platforms are formed by waves wearing down rock
• Arches are formed by waves carving through headlands
• Stacks are remnants of arches that collapsed

Depositional Landforms

• Beaches are areas where sediment is deposited
• Spits are long ridges of sediment created by longshore transport
• Tombolos connect islands and the mainland by sand
• Barrier islands are parallel to coastlines, separated by water
• Barrier islands' formation is from marine processes
• Salt marshes have peat soil under the surface

Biological Landforms (Coral Reefs)

• Coral reefs are slow-growing organisms that build up
• They are found in warm waters
• They grow throughout many generations
• Flowing water is generally warmer in the northern hemisphere and cooler in the southern hemisphere

Coral Reef Development Stages

• Fringing reefs form near volcanic islands
• Barrier reefs form as islands sink
• Atolls are barrier reefs that continue to grow around a sinking island

Human Impacts on Coasts

• Sea level rise impacts shorelines
• Hard protection structures, like walls, can change sediment movement.

Cryosphere

• Glaciers cover about 10% of the Earth's surface, mostly in Antarctica.
• Snow accumulation forms glaciers
• The cryosphere is made up of ice caps and sea ice.

Glacial Processes

•  Glaciers move through internal deformation and basal slip
•  Glacial erosion creates U-shaped valleys and other features.
• Glacial drift are sediments from glaciers.

Glacial Landforms

•  Moraines are ridges of gravel and rock
•  Erratics are large rocks that are transported by glaciers
•  Cirques are bowl-shaped depressions at the head of a glacier
•  Aretes are sharp ridges between glacial valleys
•  Horns are sharp-pointed mountain peaks

Periglacial Environments

• Active layers melt in spring and refreeze in winter
• Frost action creates ice wedges in the ground
• Ice wedges help control soil movement.

Explore the dynamic processes shaping our coastlines in this quiz on coastal geomorphology. Learn about wave refraction, tsunami characteristics, different coast types, and the distinction between primary and secondary coasts. Dive into the fascinating erosional and depositional landforms that define our beaches and shores.