Beaches on the Move

Beaches on the Move. Shifting Sand, Sinking Land, and Rising Seas. , Beaches are dynamic places where wind, waves, and currents constantly move sand and where ocean water is creeping inland due to sinking land and rising sea level., Why is the beach sand always in motion? , Breaking waves create a long-shore current that moves sand along the beach., Sand is pulled away from the beach during storms, forming offshore sandbars., When calm conditions return, gentler waves push sand back to the beach., Why is the land sinking in Coastal Virginia? ,

. As glaciers melt, the compressed land underneath rises up, causing land in other areas, like Virginia, to sink. , . 35 million years ago, a meteor strike created a crater in this area that is now covered by more than 800 ft of sediment. As debris in the crater continues to settle, the land above sinks. , . People also have contributed by pumping out millions of gallons of groundwater for drinking and industrial uses.

, How do we know sea level is rising? , Tide data illustrates the increase in sea level around the US since 1880. Current data indicates that sea level is continuing to rise., Climate Change and Sea Level Rise. , Local Sea Level Rise: 1970-2020 , Sea levels are rising along the East Coast and Gulf of Mexico. The local rate varies depending on both global and local factors, including currents, ocean floor topography, variations in ocean density, and land uplift or subsidence due to geologic processes or human activities., The upward creep in water level results in more nuisance flooding , flooding that occurs when not expected, even on sunny days., In 1950, nuisance flooding was infrequent., Since 2010, it no longer takes a strong storm or hurricane to cause flooding. Today, nuisance flooding is frequent, and it can be caused merely by high tide., Nuisance flood thresholds vary by location, but are generally 1-2 feet above the high tide level.