The Oceans - Chapter 2: Shoreline Erosion Problems Flashcards
True or false: the shoreline can change rapidly in response to a natural force
True
Name the factors associated with change along coasts
Proximity of a coast to sediment-laden rivers
Degree of tectonic activity
Topography and composition of the land
Prevailing winds and weather patterns
Configuration of coastline and nearshore areas
Typically barrier islands consist of a wide ___ backed by ___ and separated from the mainland by marshy ____
beach
dunes
lagoons
Why do barrier islands receive the full force of major storms that strike the coast?
They face the open ocean
Describe a few attempts at controlling the dynamic beach environment
jetties, breakwaters, groins, and seawalls
These are usually built in pairs and extend into the ocean at the entrances to rivers and harbors… with flow of water confined to narrow zone, ebb and flow caused by rise and fall of tides keeps the sand in motion and prevents deposition in the channel
Jetties
The jetty MAY at as a ___ against which the longshore current and beach drift deposit sand
dam
What are sometimes constructed to maintain or widen beaches losing sand?
groins
What is the purpose of a groin?
To stand at a right angle to the beach in order to trap sand that is moving parallel to the shore
In some coastal areas a ____ may be constructed parallel to the shore to protect boats from the force of large breaking waves by creating a quiet water zone near the shore
breakwater
Massive barriers intended to prevent waves from reaching areas behind the wall
seawall
Waves expand much of their energy as ______
they move across an open beach
Seawalls cut the process of waves losing energy by ___ the force of unspent waves seaward
reflecting
What is beach nourishment?
The addition of large quantities of sand to the beach system
What four qualities do beaches need to be a good candidate for beach nourishment?
Dense development
Large supplies of sand
~low wave energy
Reconcilable environmental issues
