10 December 2015

Historic Chesapeake Bay Island Is Running Out of Time

Posted by Dan Satterfield


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Most people have probably never heard of Tangier Island, but those who live around the Chesapeake bay have, and it has a long history. The island’s people speak in  distinct dialect that may very well be a close approximation of how colonial period Americans spoke. This island is part of the viewing area that I forecast for daily, but new research shows that Tangier is in serious jeopardy. The research was published this week in the Nature journal Scientific Reports, and it indicates that the combination of sinking land in the Chesapeake Region, along with rising sea levels will put an end to the long history of Tangier over the coming  decades. Sea level globally is rising at a rate of 3.3 mm/year while tide gauges around the Chesapeake Bay show rise rates of over 4.6 mm per year.


flooding-norfolk-streetsThe land around the Bay is sinking because of the ice that covered the New England area during the last ice age, which ended around 10,000 years ago. The weight of the ice pushed the land downward, but as this happened the Chesapeake region bulged upward. Now that the ice is gone, the land over New England is rising back up, and the Bay region is slowly sinking. This is causing the sea level to rise rapidly around the Delmarva region and it’s likely that sea level rise will exceed one meter by the end of this century. It may exceed 2 meters in the worst case scenarios (assuming a very slow switch to a clean energy economy).

The global oceans are rising because of two main factors. Rising greenhouse gases have warmed the planet and caused most of the world’s ice sheets to begin melting. The oceans are also warming, and as they do so, the water expands. These two factors have about an equal effect on the water level. There is very high confidence that the ocean will rise around 2 feet by the end of the century since this is what we will see if the rate changes little. It will almost certainly increase though and there is moderately high confidence among researchers, that it will approach at least 3 feet (or around 1 meter).