SHORELINES

In this lesson we will learn: Topics to cover In this lesson we will learn: how human and natural causes have changed the shapes of shorelines and barrier islands.

Introduction Human activities have a significant impact on shorelines The 3 major impacts are: Shoreline Development Artificial Stabilization (structures built to prevent erosion and protect barrier islands) Sea-level rise from climate change (melting glaciers & thermal expansion) There are also natural changes in shorelines. These include Natural sea level rise and fall over short term and long term periods What term is used to describe structures that are built in coastal areas to prevent erosion? What are 2 factors that impact climate change

Human Related - Sea Level Rise The world’s oceans are definitely rising as the planet gets warmer. Two factors contribute to this: Melting glaciers Thermal expansion in the ocean Oceans are expected to rise up to 6.6 feet by 2100 due to thermal expansion and glacier melt. What is thermal expansion? To what level might oceans rise by 2100?

Shoreline Development The coastline of the United States is highly populated. Of the 25 most densely populated U.S. counties, 23 are along a coast.   Coastal and ocean activities include: marine transportation of goods, offshore energy drilling, resource extraction, fish cultivation, Recreation tourism Development leads to the destruction of many marine species and habitats that provide benefits to society and natural ecosystems. What are three activities that take place in coastal communities? What are the consequences of coastal development?

Coastal Crisis The coastal crisis is developing because of heavily populated areas with significant coastal development (construction) – These areas that lack sufficient sand volumes, wide beaches, and protective dunes – risk great damage from hurricanes and coastal storms. Describe the coastal crisis

Shoreline Development Facts In 2010, 123.3 million people — 39 percent of the U.S. population — lived in shoreline counties Since 1970, the shoreline population grew by 40 percent. Along the U.S. Atlantic Coast alone, almost 60 percent of the land that is within 3 feet of sea level is planned for further development What percent of people on the Atlantic coast live within 3 feet of sea level?

Coastal Erosion The most immediate threat to islands and coastal areas isn’t sea level rise, but erosion. Shoreline erosion is the temporary or permanent loss of sand from the beach or dune systems- Erosion is driven by wave action, and big storms. What is the most immediate threat to islands and coastal areas? What is shoreline erosion?

Sea-level rise leads to coastal erosion and damage. As the planet warms, cities, towns and villages face a double threat of rising sea levels and more severe storms that will wash away the shorelines How are severe storms connected to shoreline erosion?

Coastal Erosion Example 1 Long Branch, NJ May 2009- May 2012 Describe what happened to the shoreline between May 2009 and November 2012 in New Jersey

Coastal Erosion Example 2 Rodanthe, NC August 2012- November 2012

Artificial Stabilization Efforts Man-made structures have been created to prevent shoreline erosion. Examples include: Groins Jetties Sea walls Why are artificial stabilization structures created?

Artificial Stabilization Efforts Groins and jetties are walls built perpendicular to the shoreline, to prevent sand from washing away The problem with these structures is that they trap sand that is probably flowing to a neighboring beach. So, if a groin on one beach is functioning well, it must be causing erosion elsewhere by “starving” another beach

Artificial Stabilization Efforts There are groins present today on many North Carolina beaches, including Cape Hatteras, Cape Lookout, Bogue Banks, Kure Beach, Fort Fisher, and Yaupon Beach. Where can you find groins in North Carolina?

Artificial Stabilization with Beach Nourishment Includes dredging sand and sediment from outside locations. Beach nourishment is the only shore protection method that adds sand to the coastal system and it is the preferred method for shore protection today What is beach nourishment? Why is beach nourishment the preferred method for artificial stabilization? Nags Head, NC November 2010 – August 2011