coastal environments

what is a coastal environment?

where land settings meet marine settings

what shapes coastlines?

waves, tides, currents, storms, and the interactions between sedimentary processes

true or false: do humans directly shape the morphology of the coastlines?

true

nearly now much of the US population lives along the coast?

40%

what kind of terrain do shorelines have?

rugged or gentle, sandy or rocky beaches

true or false: changes in the coastline morphology can impact how humans interact with it?

true

true or false: often how rugged or gentle the shoreline is in a region is dictated by the local tectonic activity or lack thereof?

true

the leading-edge shoreline is also called the__

active margin

what is an active margin?

an area along the coast where tectonic forces are actively deforming and uplifting the area (ex. US west coast)

the trailing-edge shoreline is also called__

passive margin

what is a passive margin?

an area along the coast where there is little ot no tectonic activity (ex. US east coast)

what dictates the position of the shoreline and whether it migrates seaward?

1. tectonics

2. global sea level

what natural processes are important when shaping coastlines?

1. tides

2. currents

3. waves

as waves get closer to shore, what do they begin to feel?

the drag of the seafloor

what is wave refraction?

when the top of a wave moves faster than the base. this causes the wave to bend as it interacts with the sea floor

what is a result of wave refraction?

a longshore current

what is a longshore current?

the water builds up in the surf zone and a current runs parallel to the shoreline

define shoreline retreat:

movement of the shoreline landward

define shoreline progradation:

movement of the shoreline seaward

define barrier islands:

elongated sediment deposits that run parallel to the shore and are separated from the mainland by open water, lagoons, tidal flats, or saltwater marshes