Shorelines and Shoreline Processes

rising tide

rising tide

Also known as flood tide

falling tide

Also known as ebb tide

impact of tides on shorelines

control how much of the shore is effected by wave action

difference between tidal wave and tsunami

tidal waves are caused by ocean tides, tsunamis are caused by seismic waves

impact of waves on shoreline

erodes and transports sediment

highest part of a wave

Also known as crest

lowest part of a wave

Also known as trough

wave height

Difference between crest and trough

factors affecting wave height

wind velocity, wind duration, and the fetch

depth at which orbital water motion dissipates

the wave base

calculation of depth at which orbital water motion dissipates

wave base = L/2

classification of ocean waves

deep water, intermediate, and shallow water waves

wave base

When reached by nearshore waves, wave velocity and wave energy decrease, while wave height increases

wave refraction

waves that approach parallel to the shoreline and get bent by friction

longshore drift

Movement of sediment parallel to shore when waves approach the shoreline at an angle

fingerlike ridge of sediment that cuts bay from ocean

baymouth bar/spit

profile of coastal environment

beach face, berm, dunes and lagoon

depositional and erosional features

wave erosion produces sea coasts

Marine platform/terrace

A gently sloping surface

Two types of marine terraces

wave cut and wave built

barrier islands

Ridges of sand that parallel mainland & exist seperate from mainland thanks to lagoon.

factor responsible for changes in beach profile

Changing wave conditions

seasonal changes in width of depositional environment

The berm changes in width seasonally

groin

short walls built perpendicular to shore to restrict sediment transport.

breakwaters

Structures built off shore & built parallel to shore. Gets less deposition then groins.

jetties

rock walls designed to protect the inlands

characteristics of an erosional coast

Consists of steep rocks or soluble rock. (wave cut cliffs, sea stacks, arches, headlands)

How an irregular coastline become straight over time

Coastal straightening

erosional features of retreating headlands

seastacks and arches

current cause of global sea level rise

the melting of glaciers

bad coastal management practices

building structures too close to water, ocean dumping, overfishing

coastal classifications based on sea level

Emergent Coast & Submergent Coast (VA Beach)

What classification is an emergent coast

Marine terrace

What classification is a submergent coast

Estuary