Block Island from space
By Adam Voiland, NASA Earth Observatory August 3, 2024
 |
| Block Island and the southern mainland of Rhode Island captured on July 3, 2024, by the Operational Land Imager on Landsat 8. |
Formation and Geography of Southern New England Islands
Roughly 20,000 years ago, the Laurentide
Ice Sheet smothered what is now southern New England beneath a
thick layer of ice. The leading edge of this hulking mass plowed into the
landscape as it advanced, depositing piles of debris called terminal
moraines at its southernmost extent. These piles of glacial
till became the foundation for the archipelago of islands that now
flank southern New England: Long Island, Nantucket, Martha’s Vineyard, and
Block Island.
 |
| Block Island captured on July 3, 2024, by the Operational Land Imager on Landsat 8. |
Observing Block Island
Block Island is visible in these images, acquired on July 3, 2024, by the OLI (Operational Land Imager) on Landsat 8. The pear-shaped island, located about 9 miles (14 kilometers) south of mainland Rhode Island, is about 6 miles long and 3.5 miles wide. Roughly 1,400 people live on Block Island, mostly in the town of New Shoreham. A combination of sunglint and a phytoplankton bloom made the wakes trailing behind the many boats near the island especially visible at the time of this image.
Evolution of Great Salt Pond
Great Salt Pond, once a freshwater pond, became tidal in 1905 when the U.S. Army Corps of Engineers dug a 0.6-mile-long channel to the ocean. The channel helped turn Great Salt Pond (also called New Harbor) into one of the most popular harbors in the Northeast, attracting about 1,500 boats to its three marinas on any given day in the summer.
The smaller Old Harbor on
the east side of the island is protected by a breakwater and serves as the main
entry point for ferries arriving from Rhode Island, Connecticut, Massachusetts,
and New York. The harbor also contains slips for commercial and charter fishing
boats.
 |
| Wind turbines and ship wakes off the southern mainland of Rhode Island captured on July 3, 2024, by the Operational Land Imager on Landsat 8. |
Renewable Energy and Conservation on Block Island
Five wind turbines form a line several miles southeast of
Block Island. The turbines, installed in 2016 as part of the first offshore
wind farm in the United States, replaced five diesel generators.
Now, just 10
percent of the electricity they generate powers all of Block
Island. The rest is exported to the mainland.
Conservation areas span about 40 percent of the island, including much of the land north of Great Salt Pond. The Block Island National Wildlife Refuge is one such area and hosts more than 70 species of migratory songbirds, as well as the largest colony of gulls in Rhode Island.
The refuge also provides habitat for the American
burying beetle, a large black-and-orange beetle that feeds on carrion.
When the beetle was listed as endangered in 1989, the community on Block Island
was just one of two populations known to remain in the United States. The
beetles were recategorized as threatened in 2020.
NASA Earth Observatory images by Lauren Dauphin,
using Landsat data from the U.S. Geological Survey.
