United kingdom Daily news: Reclaimed from the ocean, the island that is being re-born in the Atlantic Ocean as a nature reserve by the U.S. military

Selasa, 03 Juli 2012

Reclaimed from the ocean, the island that is being re-born in the Atlantic Ocean as a nature reserve by the U.S. military

Reclaimed from the ocean, the island that is being re-born in the Atlantic Ocean as a nature reserve by the U.S. military

By Eddie Wrenn

PUBLISHED: 11:00 EST, 3 July 2012 | UPDATED: 11:29 EST, 3 July 2012

Not so long ago, many islands rose above the brackish waters of the Chesapeake Bay near Virginia in the United States.

But these small islands, part of an estuary on the edge of the Atlantic Ocean, began to vanish, thanks to the combined forces of geology and climate change, according to NASA.

The very crust under Chesapeake Bay is sinking, while sea levels are rising. Made of clay and silt, the islands erode quickly, and many have disappeared altogether.

But, thanks to the U.S. military, Poplar Island, is being reclaimed from the depths in a restoration project which has seen the island grow from just ten acres at its lowest, to more than 1,100 acres today.

Poplar island: The little dot in the centre of the map is the island as it was in June 1997

By June 2006, the island has begun to rise out of the silt, forming a land-mass once again

By July 2011, much of the 1,140 acres of land had been re-vegetated

Poplar Island offered a predator-free haven for nesting water birds and turtles, as well as other larger islands, which supported fishing communities along with wildlife.

In the 1800s, the island had an area just over 1,000 acres and held a small town of about 100 people.

By the 1990s, the island was nearly gone, containing a mere 10 acres of land.

In the top image, taken by the Landsat 5 satellite on June 28, 1997, Poplar Island had been reduced to a tiny green dot surrounded by clouds of silt-laden water.

In 1998, the U.S. Army Corp of Engineers began to restore Poplar Island. The project serves two purposes: it restores lost habitat to birds and turtles, and it provides a use for material dredged from Baltimore Harbor and Chesapeake Bay shipping lanes.

Climbing out of the ocean: Poplar Island as it looked in 2001, during the reclamation process

Struggling against the Atlantic: Chesapeake Bay, near Virginia, is losing islands due to the Atlantic and shifting sands

The method of restoration is visible in the center image, taken on June 21, 2006.

Engineers built dikes around sections of the island and have been gradually filling in the center with dredged silt. By 2006, the island had regained the shape it held in the 1800s.

As each cell is filled with new soil, the Army Corp of Engineers plants vegetation.

The bottom image, taken on July 5, 2011, shows that much of the island has been re-vegetated.

Poplar Island now has an area of 1,140 acres and may continue to expand by another 500 acres before the restoration is completed in 2027.

Upon completion, Poplar Island will be half wetlands and half uplands covered by forest. The restoration project is expected to cost $667 million, says the U.S. Army Corp of Engineers.

Islands and shorelines in the Mid-Atlantic may become increasingly vulnerable to erosion. Sea levels are rising as the ocean warms and expands - and as glaciers and ice sheets mel t - but the rise isn't uniform around the planet.

Currents, salinity, and topography create areas where sea levels are increasing more quickly, and recent research found that the U.S. Mid-Atlantic coast is one of the areas of accelerated sea-level rise.

The rate of increase in the densely populated Mid-Atlantic is three to four times greater than average global sea-level rise. The increased sea level will make coastal regions and islands more prone to flooding and erosion.