ess -- water movement

wave of translation

wave breaks and advances up the shore; forms surf

wave of oscillation

in open sea; shape moves in a circular pattern

parts of a wave

3 factors that influence wave height

wind speed, length of time wind blows, fetch (the distance the wind travels)

surface currents

 individual currents part of a huge, slowly moving, circular whorl (a gyre); generated by and related to wind; deflected by Coriolis effect (right in N, left in S)

upwelling

the vertical movement of water; cold water rises to replace warm surface water blown away from shore; found along eastern shores of oceans; caused by Coriolis Effect and surface water moving from the shore (wind)

deep ocean circulation

governed by gravity and driven by density differences; cold water is dense, density increases with increasing salinity; AKA thermohaline circulation (affected by temp and salinity)

tidal causes

gravitational forces of the MOON and the sun, shape of the coastline, and the ocean floor

diurnal tides

one high, one low each day, occur along the northern shore of the Gulf of Mexico

semi-diurnal tides

two high, two low each day with little differences in height; occur along the Atlantic Coast of US

mixed tides

two high, two low each day with low inequality in heights; prevalent along the Pacific coast of the US

neap tides

first and third quarters of the moon; gravitational forces are offset; daily tidal range is least

spring tides

 new and full moon; gravitational forces from moon and sun add together; especially high and low tides; largest daily tidal range

spit

 ridge of sand extending from the land into a bay with an end that often hooks inward

baymouth bar

sandbar that completely crosses a bay

tombolo

connects an island to the mainland

barrier island

mainly along Atlantic and Gulf Coasts “South Padre”; parallels the coast; 3 to 30km offshore

wave cut cliff

wave cut platform

sea arch

erosion happens from both directions, cutting an arch

sea stack

form from collapsed sea arches

emergent coast

caused by uplift or drop in sea level; features include wave-cut cliffs and platforms

submergent coast

caused by land subsidence or a rise in sea level; features include highly irregular shorelines and estuaries (drowned river mouths)

3 man-made structures to prevent erosion

groin, breakwater, and seawall

groin

barrier built at a right angle to the beach to trap sand

breakwater

barrier built offshore and parallel to the coast to protect boats from large breaking waves

seawall

barrier built parallel to the shore that stops waves from reaching beach areas

what are two major regions where dense water masses are created?

polar waters and deep ocean water

what are two mechanisms responsible for transporting sediment along a coast

longshore currents and beach drift

an increase in ____ could lead to higher air temps which would then cause sea levels to rise

CO2