Wednesday, June 07, 2006

Mt. Manaro is full of surprises!

A lake atop Mt. Manaro on the South Pacific island of Ambae has changed color from blue to bright red, puzzling scientists in the island nation of Vanuatu. Mt. Manaro, one of four active volcanos in the nation, has been showing signs of erupting for the second time in 122 years.
"We are still ... trying to understand this change of color in the lake from blue to red," geology and mines department director Esline Garae said this week from Vanuatu's capital, Port-Vila. She said two scientists on Ambae Island were monitoring Lake Vui as well as seismic activity on the 5,000-foot Mt. Manaro.

Mt. Manaro last erupted in November, forcing half of the island's 10,000 inhabitants to evacuate. An 1884 eruption killed scores of villagers.

New Zealand volcanologist Brad Scott said Lake Vui's color was "quite a spectacular red," but what had caused it "is the $64,000-question."

He said water samples from the lake would help determine what was happening in the crater and below it.

Vanuatu, formerly the New Hebrides Islands, is made up of 13 main islands located about 1,400 miles east of Australia.

UNDERSEA CREATURES: Odd animals growing in gulf; oil rigs headed there
Some 200 miles from shore and more than a mile below the surface of the Gulf of Mexico, researchers are exploring a cold, dark world inhabited by bizarre creatures that feed on toxic chemicals seeping out of the sea floor.

The scientists are racing to catalog strange undersea communities of tubeworms and giant mussels because the deepwater neighborhoods on the fringes of the Outer Continental Shelf are the next frontier for the oil and natural gas industry's drilling rigs.

"The oil and gas business is moving out into very deep water," said Harry Roberts, a Louisiana State University marine geologist, "People want to know what the sea floor is like and what are the oil companies damaging or are they being responsible citizens and staying away from these communities we're studying."

The U.S. Minerals Management Service plans to use the research to guide offshore drilling in the Gulf of Mexico.

Although communities of chemosynthetic animals were first seen in the Gulf of Mexico in 1984, little is known about these bottom-dwelling critters at depths below 3,280 feet.

Unlike plants that use photosynthesis to convert sunlight into life-sustaining fuel, chemosynthetic microorganisms convert hydrogen sulfide, methane or ammonium into organic compounds.
The tiny chemical factories perform their energy-conversion trick inside larger deepwater organisms like tubeworms and mussels, providing their hosts with necessary nutrition.

Both hosts and guests are found only in harsh seabed locations where methane and oil seep from underground deposits directly into the sea floor sediment.

GLOBAL ITCHING: Climate change could mean more poison ivy

If warmer temperatures, rising sea levels and the increased risk of severe weather haven't gotten you concerned about global climate change, maybe this will.

A Duke University study has shown that poison ivy may become more of a problem as the concentration of the greenhouse gas carbon dioxide increases.

The study, by Jacqueline Mohan, now at Harvard, and colleagues from Duke and other institutions, was conducted over six years at Duke's Forest-Atmosphere Carbon Transfer and Storage center, which consists of forest plots that allow carbon dioxide levels to be controlled. It is being published this week in the Proceedings of the National Academy of Sciences.

Earlier studies had shown that some vines grew faster in elevated carbon dioxide conditions.
Elevated CO2 levels increase photosynthesis, which, because vines grab hold of other plants and don't need much support tissue, can go into producing even more photosynthesizing tissue.

At Duke, the researchers studied poison ivy growth under CO2 levels matching those forecast for the middle of the century. They found that over five growing seasons, plants grown under increased CO2 weighed about 60% more than control plants. The increase was greater than it was for woody plants in similar experiments.

The Duke research also showed that CO2 levels affected the production of urushiol, the rash-inducing oil that puts the poison in poison ivy. Plants grown in elevated CO2 levels produced more of the unsaturated version of this compound than control plants. And the unsaturated form is more allergenic.

FUNGUS SPREADERS: Waterborne infection killing off amphibians

Populations of certain frogs and other amphibians are plunging around the world, and an aquatic fungus has been implicated in the die-offs.

The fungus, Batrachochytrium dendrobatidis, infects the skin and kills either by releasing toxins or by blocking the intake of water and oxygen through the skin. Some species are only mildly affected; others can be wiped out by the disease.

Scientists aren't sure how the fungus has spread, but a study by Trenton W.J. Garner of the Zoological Society of London and colleagues gives a clue. Even though it shows no symptoms of fungal infection, the North American bullfrog, Rana catesbeiana, is a carrier.

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