- Photo: Shining Lake Confirms Presence of Liquid on Titan
- First Ever Video of Deep-Sea Volcanic Eruption
- Mysterious Collapse of Reindeer Herd Blamed on Freak Storms
Posted: 17 Dec 2009 03:13 PM PST
SAN FRANCISCO — A glint of light from a large lake confirms the presence of surface liquid in Titan's northern hemisphere. This image, released Thursday here at the American Geophysical Union meeting, was captured on July 8, using the Cassini spacecraft's visual and infrared mapping spectrometer.
"This one image communicates so much about Titan — thick atmosphere, surface lakes and an otherworldliness," said Cassini project scientist Bob Pappalardo, of NASA's Jet Propulsion Laboratory, in a press release. "It's an unsettling combination of strangeness yet similarity to Earth."
Titan, Saturn's largest moon, has a dense nitrogenous atmosphere and is the only place, other than earth, containing stable pools of liquid on its surface. In 2008, Cassini confirmed liquid methane lakes in Titan's southern hemisphere using infrared data.
Cassini has been looking for this mystical glint since reaching Saturn in 2004, but winter had shrouded the northern half of Titan. The sun began shining on this area, which contains more lakes than the southern hemisphere, in August 2009 during the moon's spring equinox.
The glint comes from the southern shoreline of the sprawling Kraken Mare lake, which covers about 400,000 square kilometers of Titan's surface. The image proves the lake has been stable for at least three years, indicating that Titan cycles liquid methane to its surface, said Ralf Jaumann, Cassini team member at the German Aerospace Center in Berlin, Germany.
"These results remind us how unique Titan is in the solar system," Jaumann said in a press release. "But they also show us that liquid has a universal power to shape geological surfaces in the same way, no matter what the liquid is."
Image: NASA/JPL/University of Arizona/DLR
Posted: 17 Dec 2009 01:03 PM PST
In high-definition video released Thursday here at the American Geophysical Union meeting, lava bubbles explode as the eruption's deep rumble fills the bass end of the spectrum.
"We thought we could just show the video over and over and not say anything," joked oceanographer John Resing of the University of Washington, who led the expedition.
But the new video is more than just spectacular to look at, it also provides scientists with their first look at the geological process that creates the seafloor.
"On our very own home planet, we haven't seen lava flowing on the seafloor," said Resing. "We haven't seen new ocean crust being made."
And now they have. The National Oceanographic and Atmospheric Agency had been sponsoring submarine volcano research for more than two decades without ever observing lava on the seafloor. "This is historic," Resing said.
The new footage was captured in May about 4,000 feet below the surface of the Pacific Ocean near Samoa, at an underwater volcano called West Mata. Scientists on a University of Washington research vessel gathered around monitors to watch the Jason remotely operated submarine as it approached the volcano. As the sub neared the summit, warm water, which shimmers like a highway on a hot day, began to stream out of the rocks.
"We turned and saw this willowy, wispy white smoke-like fluid coming up off the side of the steep volcano. We knew we were at the right site," said Bob Embley, a marine geologist with NOAA who co-led the expedition. "Then it was up to the pilot to very skillfully maneuver down to the site then turn to look at it. When we turned around, we started to see the red flashes of light, and we knew we were seeing the primordial eruption on the sea floor that we'd never seen before."
They named the spot Hades. And now, you can see what they saw in the videos posted here. (Editor's tip: put on your headphones and turn up the bass.)
The discovery came in part because of NOAA's effort to do more ocean exploration to simply find out more about the vast, largely mysterious oceans that cover 70 percent of the Earth.
"When we go exploring, we make discoveries," said Steve Hammond, chief scientist at NOAA's Office of Ocean Exploration and Research.
In fact, West Mata is the second underwater volcano discovered by NOAA, in conjunction with the National Science Foundation. The previous one was discovered in much shallower water in the Mariana Arc.
Posted: 17 Dec 2009 11:53 AM PST
SAN FRANCISCO — On a remote island in the Bering Strait during World War II, a tiny band of Americans ran a radar station. Twenty-nine reindeer were placed on St. Matthew Island with them, to be eaten in case of emergency.
The emergency never came, and population biologist Dave Klein counted 6,000 reindeer on the island by 1963, spread out over just 50 square miles of land. Then, sailors started to report seeing bleached reindeer skeletons dotting the island. When Klein returned in 1966, there were only 42 left and no males with the ability to reproduce. The herd dwindled and eventually went extinct.
There this strange mystery sat for decades until extreme weather specialist John Walsh of the University of Alaska-Fairbanks and University of Nebraska climatologist Martha Shulski teamed up with the now 80-year-old Klein to solve it. They announced their findings this week here at the American Geophysical Union meeting.
It turns out that a series of winter cyclones comparable in intensity to a Category 2 hurricane buffeted the island in early 1964. Overpopulated and isolated as the island was, the reindeer herd proved vulnerable to the extreme storms, which brought much heavier than normal snowfall, stronger winds, and lower temperatures.
The question that remains is why these extra-strong storms occurred. For reasons that still aren't understood, a series of weather systems sweeping across the Pacific from Japan intensified just east of the dateline and then headed north.
Over that winter, the closest weather station to reindeer's home, St. Paul Island, got more than six and a half feet more snow than normal. The barometric pressure differential between the low of the strongest storm and the regional high in Siberia was the highest in the 60-year period for which measurements are available. The reindeer were no match.
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