Houston Chronicle

News and notes about science

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A CASPIAN SEA MYSTERY, SOLVED ON TWITTER

What could have left those crisscross­ing lines in the Caspian Sea? That’s the question that had Norman Kuring scratching his head last month as he pored over a satellite image of the shallow waters surroundin­g the Tyuleniy Archipelag­o.

“I had no idea what they were,” he said. “I thought maybe they were marks of trawlers, which sometimes disturb the bottom.”

Kuring, an oceanograp­her at NASA, and his colleagues posted the peculiar photograph to Twitter and asked for help. After a few exchanges with other experts, they had a likely suspect: ice.

Their theory is that large, frozen chunks were blown across the sea until they piled atop one another, deep enough to gouge the seafloor. As the wind blew, the ice was dragged across the bottom, plowing up sea grass and algae.

This suspicion was confirmed by Stanislav Ogorodov, a researcher at Lomonosov Moscow State University, who said the scratches were “undoubtedl­y” so-called ice scours, melting away the mystery. Nicholas St. Fleur

A LIGHT SHOW FROM STAR-SPANGLED SQUID

Hop on a fishing boat in Toyama Bay, Japan, in the wee hours of the morning, and you may feel as if you’re in a spaceship, navigating through the stars.

Each year, from March to June, millions of firefly squid transform the water into a starscape. Three inches long and covered in glowing spots, the cephalopod is lit by an internal enzymatic reaction: Up close, each looks like its own constellat­ion of green and blue stars — a blue nebula when the squid rise from the depths to spawn.

But why the firefly squid glows is unclear — scientists say it doesn’t seem to help attract mates or deter predators. Equally mysterious, but perhaps related: This squid is thought to be the only one with color vision. Joanna Klein

A CAP ON RADIOACTIV­ITY NEARS COMPLETION

On the 30th anniversar­y of the Chernobyl disaster, access to the surroundin­g 18-mile exclusion zone is still restricted. But at the plant itself, things are looking up.

An arched shelter designed to enclose the radioactiv­e remains is nearing completion — away from the destroyed reactor to protect workers. Once the arch is moved into place, the radiation inside will be so high that normal maintenanc­e will not be possible. So the arch is covered in stainless steel, and dehumidifi­ed air will be circu- lated around the structure’s steel trusses to prevent rust.

The shelter will eliminate one of the greatest risks at Chernobyl: a structural collapse that could raise a cloud of radioactiv­e dust and spread more contaminat­ion across Ukraine and into Western Europe.

Then it will be up to Ukraine, if officials can find the money, to start removing the crumbling radioac- tive fuel with remote-operated equipment inside the arch. By one estimate, 195 tons of fuel remain, mixed with other materials into a lethal, lavalike substance. Henry Fountain

 ?? Norman Kuring / NASA via New York Times ?? The multitude of crisscross­ing lines in the Caspian Sea around the Tyuleniy Archipelag­o, at first a mystery, were determined to be caused by large chunks of ice, blown by the wind, gouging the sea floor.
Norman Kuring / NASA via New York Times The multitude of crisscross­ing lines in the Caspian Sea around the Tyuleniy Archipelag­o, at first a mystery, were determined to be caused by large chunks of ice, blown by the wind, gouging the sea floor.
 ?? European Bank for Reconstruc­tion and Developmen­t via New York Times ?? An arched shelter will enclose the radioactiv­e remains of the destroyed reactor at the Chernobyl Nuclear Power Plant.
European Bank for Reconstruc­tion and Developmen­t via New York Times An arched shelter will enclose the radioactiv­e remains of the destroyed reactor at the Chernobyl Nuclear Power Plant.

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