Chapter 16The Oceans, Coastal

Processes, and Landforms

Geosystems 6eAn Introduction to Physical Geography

Robert W. ChristophersonCharles E. Thomsen

The Oceans, Coastal Processes, and Landforms

Global Oceans and Seas  Coastal System Components  Coastal System Actions  Coastal System Outputs  Wetlands, Salt Marshes, and Mangrove Swamps   Human Impact on Coastal Environments

Global Oceans and Seas Chemical Composition of Seawater

Salinity – the concentration of dissolved solids in seawaterBrine – water that exceeds the average 35 parts per thousand salinityBrackish – water that is less than the aver 35 parts per thousand salinity  

Salinity by Latitude

Figure 16.3

Ocean’s Physical Structure

Figure 16.4

Coastal System Components  Inputs to the Coastal System  

Solar energyAtmospheric windsClimatic regimesCoastal geomorphologyHuman activities

The Coastal Environment and Sea Level  Littoral zone – the coastal or shore zone; includes land and waterShoreline – contact line between the sea and the land

Littoral Zone

Figure 16.5

Coast – area of high tide to the first major landform change

Sea level – the average surface elevation of the world’s oceans

Coastal System Components  

Coastal System Actions  Tides – complex daily oscillations in sea level

Produced by the gravitational pull of the Sun and Moon

Waves – undulations of water caused by the friction between moving air and the ocean surfaceTsunami – seismic sea waves

Coastal System Outputs  Erosional Coastal Processes and Landforms  

Erosional coastlines – rugged, high relief, techtonically activeWave-cut terrace

Depositional Coastal Processes and Landforms Beach – place along the coast where sediment is in motion, deposited by waves and currentsBarrier islands – long, narrow depositional features that form offshore parallel to the coast 

Erosional Features

Figure 16.13

Figure 16.19

Florida Barrier Islands

Littoral Drift

Figure 16.15

Biological Processes: Coral FormationsCoral – marine animal with small cylindrical, sack-shaped body

Secrete calcium carbonate from their bodies creating an external skeleton  

Require clear, sediment-free water

Coral reef – biologically derived sedimentary rock

bleaching

Coastal System Outputs  

Coral Reef Distribution

Figure 16.20

Wetlands, Salt Marshes, and Mangrove Swamps 

Wetlands – land covered by water for a significant period of time supporting hydrophytic vegetation

BogsCypress swampsBottomlandsPotholesTundra

Coastal WetlandsSalt marshes – midlatitudes

estuaries

Mangrove swamps - tropics

Coastal Salt Marsh

Figure 16.22

Mangroves

Figure 16.23

Coastal Planning

Figure FS 16.1.1

End of Chapter 16

Geosystems 6eAn Introduction to Physical Geography

Robert W. ChristophersonCharles E. Thomsen