Large Scale Depositional Features

Sand Spits Bay mouth bars Barrier Islands Sea Islands Tombolos Lagoons Inlets Deltas

Barrier Island MigrationBarrier Island: Formed from sedimentAccumulating on submerged rises parallelTo shoreline.

Also formed from drowned former coastlinesAnd are remnants of old dunes.

Migration: When sea level rises, sand is erodedOn ocean-side and deposited on lagoon side.This causes barrier islands to move landward.

When sea level falls, sand can be deposited Seaward and migration stalls or the island canMove seaward.

Right now, sea level is rising.

Coral Reefs (Atolls, fringing reefs, barrier reefs)

Mangroves

Coasts formed by Biological Activity

Atolls and Reefs

Mangroves

Trees that grow in Salt water.

Mostly in tropical areas likeFlorida, Central America,And parts of Australia.

A body of water partially surrounded by land where fresh water from rivers mixes with salt water.

Brackish water: mixture of salt and fresh water (8-25 PPT on average).

Chesapeake Bay is an estuary. We will learn more about Estuaries when we

look at marine communities.

Estuaries

Breakwaters: Wall build parallel to shoreline to build up beach behind it.

Groins/Jetties: Rock walls or other material placed at right angles to the shoreline to build up beach by stopping longshore transport.

Seawalls: Built parallel to shoreline to protect property from wave erosion.

Importing Sand: Dredged from the seabed, the sand is then deposited on the eroding beach.

Human Interference