30 December 2014

A Sinking Jewel of Sand and Sea

Posted by Dan Satterfield

The image above is from a piece i the Washington Post today about rising sea level around Assateague NS.

The image above is from the USGS and an excellent piece in the Washington Post today about rising sea level around Assateague NS.

One of the great thing about living on the Eastern Shore of Maryland is being nearby to a jewel of sea and sand, Assateague National Seashore is a place my family and I visit frequently, but most folks don’t know that it is also one of the spots where sea level is rising the fastest.. The National Seashore’s Facebook Page had an interesting post today about it, and they also linked to a good piece in the Washington Post. It’s well worth a read. The Assateague N.S. Facebook post is below:

Assateague Nat. Seashore. Photo by WBOC Chief Metr. Dan Satterfield

Assateague Nat. Seashore. Photo by  Dan Satterfield

There is no question about it – Assateague is the seam where the continent meets the ocean. At the edge of it all, we are on the front line of constant change; rather than trying to fight it we are trying to better understand it so that we can adapt to it. We’ve known for years now that the sea level is rising – the historical tide gauge data spells it out for us as plain as day. But at the same time the sea level has been rising, something a little more complicated has been happening – glacial isostatic adjustment.

In a nutshell, glacial isostatic adjustment causes the land to sink or subside. Most land subsidence in the United States is caused by human activity. For example, in the Galveston, TX area land sank by as much as nine feet over 50 years because of intensive groundwater and petroleum extraction. Along the east coast of the US, however, land subsidence is occurring because of melting glaciers.

So how does glacial isostatic adjustment work? The article in the link below does a really good job of explaining it. If you are still craving more knowledge after you read the article, click on the highlighted link embedded within the text of the article to read a report about subsidence in our area that was prepared by the Virginia Institute of Marine Science.