Today’s Image of the Day from NASA Earth Observatory features Bahrain, an archipelago on the southwestern coast of the Persian Gulf. The small island country, which is officially called the Kingdom of Bahrain, has grown rapidly in recent years.
“As developers reclaimed land from the sea, the shape of the island nation’s coastline has changed. So, too, has the underwater habitat around it,” says NASA.
Norman Kuring is a retired researcher from NASA’s ocean biology group, who processed the image using color-filtering techniques to draw out details in the water. “I wasn’t looking for Persian Gulf imagery specifically in this case,” said Kuring. “The region just looked clear that day, and the shallow bottom offered interesting possibilities.”
Near the shores of Bahrain, the Gulf is just a few meters deep in some places, and sunlight reflects off of surfaces beneath the water.
Eman Ghoneim, a physical geographer at UNC Wilmington, thinks the dark shapes along the seafloor toward the bottom-left of the image are old sand dunes. “Thousands of years ago, when sea levels were lower, the dunes were sculpted by wind into crescent shapes. Then rising seas submerged them,” explains NASA.
“Perhaps most obvious submerged features in the images are the large reefs surrounding Bahrain, visible as the light-green areas offshore.” “Historically, these structures known as ‘fasht’ were coral or pearl oyster reefs. Today, most of them are dead coral skeletons, although some rocky surfaces still have living corals attached to them, according to Ghoneim, who has studied this underwater habitat with satellites and field surveys.”
The image was captured on July 24, 2022 by the Operational Land Imager-2 (OLI-2) on Landsat 9.
Image Credit: NASA Earth Observatory