Earth ChangesS


Arctic Sea Ice Annual Freeze-up Underway

After reaching the second-lowest extent ever recorded last month, sea ice in the Arctic has begun to refreeze in the face of autumn temperatures, closing both the Northern Sea Route and the direct route through the Northwest Passage.
Parry Channel in the Canadian Arctic Archipelago
© ESAParry Channel in the Canadian Arctic Archipelago, as seen by Envisat's ASAR on 25 August 2008, when the direct Northwest Passage was open (right image), and on 22 September 2008 when sea ice is closing the direct Northwest Passage.

This year marked the first time since satellite measurements began in the 1970s that the Northern Sea Route, also known as the Northeast Passage, and the Northwest Passage were both open at the same time for a few weeks.

"NIC analysis of ESA's Envisat and other satellite datasets indicated that the Northern Sea Route opened when a path through the Vilkitski Strait finally cleared by 5 September," NIC Chief Scientist Dr Pablo Clemente-Colón said via email from aboard the US Coast Guard icebreaker Healy in the Arctic, where he is conducting joint mapping operations with the Canadian Coast Guard.

"This is the first time in our charting records that both historic passages opened up in the same year," Clemente-Colón said. "Both of the routes appeared as closed by 22 September."


Russia hit by 4.0-magnitude earthquake

Yuzhno-Sakhalinsk, Russia -- A mild earthquake measuring 4.0 on the Richter scale hit the Russian island of Sakhalin Saturday, the Russian Emergencies Ministry says.

The ministry's Sakhalin regional department said the earthquake on the North Pacific island controlled by Russia occurred nearly 20 miles north of the city of Yuzhno-Sakhalinsk, ITAR-TASS reported.


Earthquake rocks the Andaman Islands, India Region

There was an earthquake at the Andaman Islands, India Region with the magnitude of 5.5 on the Richter scale.

The earthquake occurred on Friday, October 03, 2008 at 21:20:26 UTC (Coordinated Universal Time ) and Saturday, October 04, 2008 at 03:20:26 AM at epicenter of the local time as reported by the U.S. Geological Survey.

Bizarro Earth

In warm Brazil, a perplexing inrush of penguins

© Washington Post
Not everyone in Rio de Janeiro has taken to the penguins quite the way Cecilia Breves has, but even for her, there is a learning curve.

Bizarro Earth

US: Debris of daily life washes onto Texas beaches

Padre Island National Seashore, TX - The world's longest undeveloped barrier island now looks as if people have been living - and dumping - on it for decades.
Padre Island National Seashore debris
© AP Photo/Eric GayPieces of debris collected by cleanup crews that are cleaning up the Padre Island National Seashore, Tuesday, Sept. 30, 2008, on South Padre Island, Texas. Debris from Hurricane Ike litters more than 60 miles of the national seashore.

Tons of debris swept up by Hurricane Ike last month were carried by Gulf of Mexico currents hundreds of miles from the upper Texas coast to this ordinarily pristine landscape just north of the Mexican border.

Sections of roofs, refrigerators, loveseats, beds, TVs, hot tubs and holiday decorations litter the more than 60 miles of gently arcing sand in the national park.

Some of the junk is good for a laugh, like the lifejacket-clad snowman someone placed next to a plastic pumpkin, a small but real palm tree and an acoustic guitar. But it's no joke to wildlife workers who are worried the trash will harm birds and other animals, including an endangered turtle that nests here in the spring.

Bizarro Earth

Marine 'dead zones' leave crabs gasping

It's not easy being a fish these days, but it could be even harder being a crab. Research into marine "dead zones" around the world suggests that crustaceans are the first to gasp for air when oxygen levels get low.

The findings, based on a review of 872 published studies of 206 ocean-floor dwelling species, also suggest that a much greater area than we thought is dangerously low on oxygen.

In marine dead zones - also known as hypoxic zones - the amount of dissolved oxygen in the water becomes too low for organisms to survive.

They are usually caused by synthetic fertilisers, which are carried from fields, down rivers, and out to sea, where algal blooms gorge on the extra nutrients. When these phytoplankton die, they fall to the bottom where they are eaten by bacteria that consume all the local oxygen in the process.

Marine biologists generally hold that any area that has less than 2 milligrams of dissolved oxygen per litre of seawater is hypoxic - "dead". The threshold was set by a study in 1983 in the Gulf of Mexico, when marine biologists found that fish and shrimp had deserted bottom waters that had 2 mg/l of oxygen or less.


Giant tuna kindergarten identified in Atlantic

Bluefin tuna born on opposite sides of the Atlantic spend their juvenile years together, before returning to natal waters in the Gulf of Mexico and the Mediterranean Sea to breed.
Bluefin Tuna
© WikimediaBluefin Tuna

The findings could have implications for the management of what were once thought to be entirely distinct populations.

David Secor of the University of Maryland and colleagues looked at chemical signatures in the fish's inner ear to determine where each of the highly endangered fish came from.

Specifically, the team looked at a bone-like structure called the otolith, a calcium-carbonate deposit that is laid down after a fish hatches. These carry different concentrations of oxygen isotopes depending on whether the fish developed in cool Mediterranean waters - eastern bluefin - or warmer Gulf waters, which spawn western bluefin.


New Fish Species May Emerge Because Of How Females See Males

Eye colour and hair colour play a role in human partner choice, but visual stimuli can also determine mating preferences in the animal kingdom. In many species, the male's fortunes in the mating stakes are decided by a conspicuous breeding dress.
Pundamilia nyererei fish
© EawagPundamilia nyererei fish. Nuptial coloration in males of the cichlid species Pundamilia nyererei and Pundamilia pundamilia is adapted to the red or blue ambient light of their respective habitats and to the corresponding visual sensitivity of the females.

A study of brightly coloured fish has now demonstrated that this has less to do with aesthetics than with the sensitivity of female eyes, which varies as a result of adaptation to the environment. Females more attuned to blue will choose a metallic blue mate, while those better able to see red will prefer a bright red male. These mating preferences can be strong enough to drive the formation of new species - provided that habitat diversity is not reduced by human activities.


Chernobyl Fallout? Plutonium Found In Swedish Soil

When a reactor in the Chernobyl nuclear power plant exploded in 1986 in what was then the Soviet republic of Ukraine, radioactive elements were released in the air and dispersed over the Soviet Union, Europe and even eastern portions of North America.
plutonium in Swedish soil
© iStockphoto/Marcus LindströmSmall red cottage by a green summer meadow in Sweden. Researchers found much more plutonium in Swedish soil at a depth that corresponded with the Chernobyl nuclear explosion than that of Poland.

More than 20 years later, researchers from Case Western Reserve University traveled to Sweden and Poland to gain insight into the downward migration of Chernobyl-derived radionuclides in the soil. Among the team's findings was the fact that much more plutonium was found in the Swedish soil at a depth that corresponded with the nuclear explosion than that of Poland.

Radionuclides occur in soil both from natural processes and as fallout from nuclear testing.

Gerald Matisoff, chair of the department of geological sciences at Case Western Reserve University, Lauren Vitko, field assistant from Case Western Reserve, and others took soil samples in various locations in the two countries, measuring the presence and location of cesium (137Cs), plutonium (239, 240Pu), and lead (210Pbxs).

Better Earth

Tiny Organisms Feast On Oil Thousands Of Feet Below Bottom Of Sea

Thousands of feet below the bottom of the sea, off the shores of Santa Barbara, single-celled organisms are busy feasting on oil.
Bubble of oil oozing from the ocean floor
© David ValentineBubble of oil oozing from the ocean floor.

Until now, nobody knew how many oily compounds were being devoured by the microscopic creatures, but new research led by David Valentine of UC Santa Barbara and Chris Reddy of Woods Hole Oceanographic Institution in Massachusetts has shed new light on just how extensive their diet can be.

In a report to be published in the Oct. 1 edition of the journal Environmental Science & Technology, Valentine, Reddy, lead author George Wardlaw of UCSB, and three other co-authors detail how the microbes are dining on thousands of compounds that make up the oil seeping from the sea floor.

"It takes a special organism to live half a mile deep in the Earth and eat oil for a living," said Valentine, an associate professor of earth science at UCSB. "There's this incredibly complex diet for organisms down there eating the oil. It's like a buffet."