Presentation on theme: "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."— Presentation transcript:
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
Beach Nourishment – sediment lost through long shore drift or erosion is replaced Beach nourishment video – http://outerbanksvoice.com/2011/07/14/see-24- hours-of-beach-nourishment-in-2-minutes/ http://outerbanksvoice.com/2011/07/14/see-24- hours-of-beach-nourishment-in-2-minutes/
Preventing Beach Erosion Vegetation – helps hold sand in place