Mystery lines in satellite image of Caspian

Yahoo has an article by Stephanie Pappas about some mysterious stuff:

From five hundred miles up, the floor of the north Caspian Sea looks like someone's just scoured it with a Brillo pad. What are these bizarre marks? Trawling scars? Propeller marks in sea algae or seagrass? An extraterrestrial message?
Don't get out the tinfoil hat just yet: NASA scientists say these mystery lines are the work of sea ice.
NASA Goddard Space Flight Center ocean scientists noticed the image (photo) this month, shortly after it was acquired by the Operational Land Imager on the Landsat 8 satellite, according to NASA's Earth Observatory. The space agency put out the puzzler on Twitter, asking readers what the lines might be.
Now, the answer seems clear. Stanislav Ogorodov, an earth scientist at Lomonosov Moscow State University in Russia, told Earth Observatory that the phenomenon was almost certainly all natural: "Undoubtedly, most of these tracks are the result of ice gouging," he said.
The water in this area near Novvy Island is only about ten feet deep, Ogorodov said, and the sea ice gets to be only about two feet thick. But winds and currents sculpt this ice cover into jagged patterns called hummocks, which can reach the seabed. When wind or water pushes the floating ice around, Ogorodov explained, the protruding parts can dig into the ocean floor and leave the scouring patterns seen from space.
Humans can cause similar-looking patterns. Propellers have scarred seagrass in the Everglades in Florida, and ships that fish by bottom trawling can bulldoze swaths of the seafloor with their nets. In the Caspian, though, ice is almost certainly the predominant cause of these scours, according to the Earth Observatory. A look at a comparison image taken in January, when the ice was thick, shows chunks of ice at the ends of scour marks, the geoscience equivalent of a smoking gun. The image also shows dark green coloration, which is likely seagrass or algae. The island in the image, Novyy Island, is the easternmost island of the Tyuleniy Archipelago, a group of islands in the northeastern part of the Caspian Sea that belong to Kazakhstan.
The Caspian is the largest inland sea in the world, and is bordered by Iran, Turkmenistan, Kazakhstan, Russia, Azerbaijan, and Iran. The sea has no outflow to the ocean, and is, by an odd quirk of fate, below sea level. The northern end of the sea, seen in the NASA image, is in the Caspian Depression. The sea in this spot is about a hundred feet below sea level.

Rico says the world continues to be amazing...