Human Impact on Beaches. Erosion and the Outer Banks Read the article on Outer Banks beach erosion As you read, highlight words or things that you do.

Human Impact on Beaches

Erosion and the Outer Banks

• Read the article on Outer Banks beach erosion• As you read, highlight words or things that you

do not know.• Once you finish reading, write a summary of

the article.

Longshore Drift

• When swimming in the ocean, have you ever wondered why you tend to be carried down the beach, away from your towel in an undertow?

• The transportation of sediments along a coast at an angle to the shoreline

Preventing Beach Erosion

• Sea Wall – a structure to protect a coast from erosion– Built parallel to the

shore– Designed to shield the

coast and defend property from the force of breaking waves

• Causes the sediments in front of the wall to be swept in the ocean.

• Further loss of beach prompts people to build a bigger, “better” wall to stop the erosion caused by the original seawall.

Preventing Beach Erosion

• Breakwater - sediment movement is blocked from continuing along the coastline, disrupting the longshore transport. – Built parallel to the shore

line– Protects boats from the

force of large breaking waves by creating a quiet water zone near the shore

Preventing Beach Erosion

Groin - designed to trap sediments in an area of the beach.–disrupt the longshore transport –Perpendicular to the shore–the beach on the other side of the groin will continue to loose sediments

Preventing Beach Erosion

Preventing Beach Erosion

• Beach Nourishment – sediment lost through long shore drift or erosion is replaced

• Beach nourishment video– http://outerbanksvoice.com/2011/07/14/see-24-h

ours-of-beach-nourishment-in-2-minutes/

Preventing Beach Erosion

• Vegetation – helps hold sand in place