From 438 miles (705 kilometers) up, the ground of the north Caspian Sea seems like a person's simply scoured it with a Brillo Pad. What could these weird marks be? Trawling scars? Propeller marks in sea algae or seagrass? An extraterrestrial message?
don't get out the tinfoil hat yet: NASA scientists say these secret strains are the work of sea ice.
NASA Goddard space Flight core ocean scientists seen the photo this month, shortly after it become got through the Operational Land Imager on the Landsat eight satellite tv for pc, based on NASA's Earth Observatory. The house company put out the puzzler on Twitter, asking readers what the strains may be.
Now, the reply seems clear. Stanislav Ogorodov, an earth scientist at Lomonosov Moscow State college in Russi, advised the Earth Observatory that the phenomenon was well-nigh certainly all natural: "surely, most of these tracks are the result of ice gouging," he talked about. [14 of the Strangest Sites on Google Earth]a picture of the scoured area of the north Caspian Sea from Jan. 17, 2016, reveals ice at the ends of the marks, primarily seen in the upper appropriate of this satellite photograph.credit: NASA images by means of Norman Kuring, NASA's Ocean colour net
The water in this enviornment close Novyy Island is simply about 10 ft (3 meters) deep, Ogorodov pointed out, and the sea ice receives to be most effective about 1.6 ft (0.5 m) thick. but winds and currents sculpt this ice cowl into jagged patterns called hummocks, that could reach the seabed. When wind or water pushes the floating ice round, Ogorodov explained to the Earth Observatory, the protruding components can dig into the ocean ground and leave the scouring patterns considered from space.
humans can cause identical-looking patterns. Propellers have scarred seagrass within the Everglades in Florida, and ships that fish by backside trawling can bulldoze swaths of the seafloor with their nets. in the Caspian, although, the ice is well-nigh definitely the predominant cause of these scours, based on the Earth Observatory. a glance at a evaluation photo taken in January, when the ice was thick, indicates chunks of ice on the ends of scour marks — the geoscience equivalent of a smoking gun.
The image additionally suggests darkish green coloration, which is likely seagrass or algae. The island within the image, Novyy Island, is the easternmost island of the Tyuleniy Archipelago, a bunch of islands in the northeastern a part of the Caspian Sea that belong to Kazakhstan.
The Caspian is the largest inland sea on the earth, and is bordered by way of Iran, Turkmenistan, Kazakhstan, Russia, Azerbaijan and Iran. the ocean has no outflow to the ocean, and is, by an unusual quirk of fate, beneath sea level. The northern conclusion of the sea seen in the NASA photograph is in the Caspian depression. the ocean during this spot is ready 92 ft (28 m) under sea level.
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