Coasts, Beaches, & Estuaries

Front 1

Berms

Back 1

-Are sand deposited by waves (can be winter or summer)

Front 2

Beach Scarp

Back 2

-Vertical wall that is carved by high tide wave action.

Front 3

Longshore Trough

Back 3

-Low tide wave excavation.

Front 4

Longshore Bar

Back 4

-accumulation of sediment from inshore.

Front 5

Drift Sector

Back 5

=coastal circulation cells
-is the path traveled by beach sediments a the longhshore current transports them from their source to their area of deposition.

Front 6

Circulation Cell

Back 6

-A series of drift sectors that are linked together along a stretch of coast.

Front 7

Submarine Canyon

Back 7

-Underwater Canyons that may be originally formed by glaciation and is then submerged due to sea level rise.

Front 8

Primary Coasts

Back 8

-Are coasts created by the erosion of the land by running surface water, wind, or land ice, followed by the sinkig of the land or a rise in sea level.
-Deposits of sediments carried by rivers, glaciers, or wind.
-Volcanic activity.
-Uplift and land subsidence of the land by earthquakes.

Front 9

Secondary Coasts

Back 9

-Are coasts created by erosion due to waves, currents or the dissolving action of seawater.
-Deposition of sediments by waves, tides, and currents.
-Alteration by marine plants and/or animals.

Front 10

Describe why sand moves longshore along beaches.

Back 10

-Sand moves longshore along beaches because ocean waves create longshore currents that strike the shore at a slight angle. They carry alot of sedimentation within them that will get deposited along the shore.

Front 11

What is the seasonal change in beach structure and why?

Back 11

-Seasonal change in beach structure describes how the seasonal changes in ocean waves physically affect beach structure.
-During the summer, ocean waves and tides are shallow so burms are further down the coast.
-During the winter, ocean waves and tides are deeper and stronger, so burms are further up the coast and the winter storm causes beach scarping to occur.

Front 12

Describe how barrier islands from.

Back 12

-Barrier islands are formed by the deposition of sediment by longshore currents that have slowed down.
-When deposited sand accumulates, barrier islands are formed.

Front 13

Name three ways to slow down beach erosion.

Back 13

-Beach erosion is slowed down by Groins, Seawalls, and Importing sand.

Front 14

What are four ways to characterize beaches?

Back 14

-Beaches are characterized by their Shape and Structure.
-Composition of beach material.
-Size of beach material.
-Color of beach material.

Front 15

Groins

Back 15

-Structures that extend from the beach at 90 degrees, into the water. The help counter erosion by trapping sand from currents.

Front 16

Seawalls

Back 16

-Walls placed parallel to the beach which can temporarily protect property. Unfortunately, it increases beach erosion by deflecting wave energy to the front of the wall and beside them.

Front 17

Importing sand

Back 17

-Taking sand from an offshore location (via dredging) and importing it onto the beach. Its the best response to beach erosion but they erode quickly. Millions of dollars are spent.

Front 18

Estuaries

Back 18

-Are partially enclosed coastal waters in which ocean water is diluted by freshwater runoff.
-The head of the estuary is found at the source of the freshwater.
-the mouth of the estuary is found at the source of the saltwater.

Front 19

Salt wedge Estuaries

Back 19

-Occur in the mouth of a river flowing directly into saltwater, which wedges upwards (because its less dense) and saltwater is mixed upward in a process called entrainment.

Front 20

Well-mixed Estuaries

Back 20

-Occur where there is strong tidal mixing and freshwater flow is slow.
-Salinity is uniform over depth

Front 21

Partially-mixed Estuaries

Back 21

-Occurs where there is a strong outward flow from freshwater and a strong inward bottom flow of seawater (often somewhat deeper).

Front 22

Fjord Estuary

Back 22

-Occurs where there is a high freshwater input, weak tide, weak mixing, and an anoxic layer.
-deep water can become stagnant.

Front 23

How can the Coriolis force affect flows in estuaries?

Back 23

-Because the coriolis force affects the direction of flow, instead of mixing occurring head-on in an estuary, both fresh and salt water are forced to "hug" the right side of the coast (in the northern hemisphere).