Coasts

CoastsCoastal classification based on tectonic activityActive coast- close to tectonic plate boundaryPassive coast- far from tectonic plate boundary

Shepard Coastal classification systemPrimary coast- formed by processes not directly related to the oceanRiver erosion or depositionErosion from glaciersTectonic activityVolcanic activity

Shepard Coastal Classification systemSecondary coasts- formed directly by marine actionWave erosionMarine depositionMarine organisms (reefs and mangrove forests)

Combination coasts= combo of both primary and secondaryCoastal dynamicsLongshore Drift- tendency for material to move along the coastline due to longshore current

Coastal dynamicsSections of a BeachDune- hill of sand toward back of beachBackshore- region rarely touched by sea waterForeshore- part that water sometimes coversOffshore- extends below low tide mark

Coastal dynamicsCoastal cell- coastal region that changes in shape but there is no net loss or gain in sandErosion- loss of sandAccretion- gain in sand

Coastal dynamicsLarge scale sand featuresSpit- length of accumulated sand attached to land at one end, pointing in the direction of the longshore drift

Coastal dynamicsLarge scale sand featuresTombolo- spit that extends between two islands

Coastal dynamicsLarge-scale sand featuresBarrier island- large sediment deposits that form between the ocean and the shoreline