Earth ChangesS


Bizarro Earth

Earth's Early Ocean Cooled More than a Billion Years Earlier than Thought

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© Michael Tice, Texas A&M UniversityGreen and orange photosynthetic microbial mats line an outflow channel from a hot spring in Yellowstone National Park.
The scalding-hot sea that supposedly covered the early Earth may in fact never have existed, according to a new study by Stanford University researchers who analyzed isotope ratios in 3.4 billion-year-old ocean floor rocks. Their findings suggest that the early ocean was much more temperate and that, as a result, life likely diversified and spread across the globe much sooner in Earth's history than has been generally theorized.

It also means that the chemical composition of the ancient ocean was significantly different from today's ocean, which in turn may change interpretations of how the early atmosphere evolved, said Page Chamberlain, professor of environmental earth system science.

When rocks form on the ocean floor, they form in chemical equilibrium with the ocean water, incorporating similar proportions of different isotopes into the rock as are in the water. Isotopes are atoms of the same element that have different numbers of neutrons in the nucleus, giving them different masses. However, because the exact proportion of different isotopes that go into the rock is partly temperature dependent, the ratios in the rock provide critical clues into how warm the ocean was when the rock formed.

Bizarro Earth

Mini Ice Age Took Hold Of Europe In Just Months

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© Tancrediphoto.com/Stone/GettyBig freezes can happen fast
Just months - that's how long it took for Europe to be engulfed by an ice age. The scenario, which comes straight out of Hollywood blockbuster The Day After Tomorrow, was revealed by the most precise record of the climate from palaeohistory ever generated.

Around 12,800 years ago the northern hemisphere was hit by the Younger Dryas mini ice age, or "Big Freeze". It was triggered by the slowdown of the Gulf Stream, led to the decline of the Clovis culture in North America, and lasted around 1300 years.

Until now, it was thought that the mini ice age took a decade or so to take hold, on the evidence provided by Greenland ice cores. Not so, say William Patterson of the University of Saskatchewan in Saskatoon, Canada, and his colleagues.

The group studied a mud core from an ancient lake, Lough Monreagh, in western Ireland. Using a scalpel they sliced off layers 0.5 to 1 millimetre thick, each representing up to three months of time. No other measurements from the period have approached this level of detail.

Carbon isotopes in each slice revealed how productive the lake was and oxygen isotopes gave a picture of temperature and rainfall. They show that at the start of the Big Freeze, temperatures plummeted and lake productivity stopped within months, or a year at most. "It would be like taking Ireland today and moving it up to Svalbard" in the Arctic, says Patterson, who presented the findings at the BOREAS conference in Rovaniemi, Finland, on 31 October.

Fish

Last chance for Tuna - Tagging the tigers of the sea

Pablo Cermeño balances at the back of the small boat, legs braced, harpoon at the ready. Beneath him in the crystal waters his target is clearly visible: a shimmer of metallic turquoise that tacks left, right, left again as it is hauled inexorably towards the surface. The fisherman grunts and sweats as he does battle with the giant fish, reeling, pulling and reeling again.


Better Earth

Are Our Oceans Made of Extraterrestrial Material?

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© Michele HoganPacific ocean.
Contrary to preconceived notions, the atmosphere and the oceans were perhaps not formed from vapors emitted during intense volcanism at the dawning of our planet. Francis Albarède of the Laboratoire des Sciences de la Terre (CNRS / ENS Lyon / Université Claude Bernard) suggests that water was not part of the Earth's initial inventory but stems from the turbulence caused in the outer Solar System by giant planets. Ice-covered asteroids thus reached the Earth around one hundred million years after the birth of the planets.

The Earth's water could therefore be extraterrestrial, have arrived late in its accretion history, and its presence could have facilitated plate tectonics even before life appeared. The conclusions of the study carried out by Albarède feature in an article published on the 29 October 2009 in the journal Nature.

Space agencies have got the message: wherever there is life there has to be water. Around 4.5 billion years ago, the Earth was bequeathed with sufficient water for oceans to form and for life to find favorable niches in the seas and on the continents resulting from plate tectonics. In comparison, the Moon and Mercury are dry, mortally cold deserts, Mars dried up very quickly and the surface of Venus is a burning inferno.

Bizarro Earth

5.6 Earthquake Hits Mindanao, Philippines

A moderate earthquake measuring 5.6 on the Richter scale occurred in Mindanao, the Philippines at 9.48pm on Wednesday night.

The Malaysian Meteorological Department said in a statement that the quake's epicentre was located 231km southeast of Cebu, the Philippines and 934km northeast of Sandakan, Sabah.

However, the earthquake did not pose any tsunami threat.

Binoculars

Elephant Seals Sleep While Diving, Study Suggests

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© Karen SeagleA pair of elephant seals takes an afternoon snooze on the beach near San Simon, California
Migrating northern elephant seals slowly drift downward to rest in the ocean depths, according to a new study of the animals' dive patterns.

Moving from their breeding colonies in California to their wintering areas in the mid-Pacific and around Alaska, the seals spend two to eight months at sea without a single pit stop.

There's no land to climb on along the roughly 2,000- to 3,000-mile (3,200- to 4,800-kilometer) voyage, and the seabed is often miles below the surface.

The marine mammals' grueling trek had many researchers wondering: When and how do elephant seals sleep?

It's long been known that, during the seals' epic migrations, the animals engage in repetitive dives down to depths of 984 feet (300 meters) or more.

Now a study of young elephant seals has revealed that during some of these dives, elephant seals roll on their backs and allow themselves to sink.

Attention

Hurricane Ida Kills 152 in El Salvador

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© RIA Novosti
The death toll from mudslides and flooding in El Salvador caused by hurricane Ida has risen to 152 with many more missing, national media quoted rescuers as saying on Wednesday.

Over 13,000 people were left homeless as mudslides destroyed about 2,000 houses in the small Central American country, amid torrential rains triggered by the hurricane.

The mayor of San Vicente, Medadro Hernandez Lara, said that around 500 people are missing.

Addressing an extraordinary Cabinet meeting on Monday, President Mauricio Funes described the damage inflicted by the hurricane as "uncountable." He also said that $150 million will be allocated for cleanup and rescue operations.

International humanitarian packages have started arriving in the country. Venezuela has sent a planeload of food, while Guatemala and Nicaragua have provided relief workers and rescue equipment. The United States has channeled $100,000 into the construction of temporary housing.

Bizarro Earth

Blizzard Hits North China, Paralyzes Major Cities

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© ShanghaiDailyA man walks on a snow-covered street in Shijiazhuang, capital of north China's Hebei Province, today.
Heavy snow blanketed Shijiazhuang, capital of north China's Hebei Province, for a second day today and paralyzed all transport, including aviation and highway services, provincial authorities said today.

Meteorological officials said city recorded 74 mm of snow in the 24 hours till 6 am today, with the accumulated snow 48 mm thick in most areas.

It was the heaviest snow fall in the city since 1955 when the city began to make meteorological records.

Xinhua reporters saw no traffic on roads in the city, and pedestrians struggled through knee-high snow. All middle and primary schools were informed they could suspend classes if necessary.

All flights from and to the city have been canceled, and all local sections of the six expressways traversing the city, including the Beijing-Shijiazhuang, Zhangjiakou-Shijiazhuang,Shijiangzhuang-Huanghua, and Qingdao-Yinchuan expressways were closed, said transport authorities.

Binoculars

Philippines: Mayon Volcano Erupts

More ash explosions seen

The Philippine Institute of Volcanology and Seismology recorded an ash explosion in Mayon Volcano early Wednesday, which caused ash fall in Albay towns located southwest and northwest of the volcano.

"The explosion, which occurred at around 1:58 a.m., is a clear sign of magma intrusion toward the summit crater of the volcano," said Alex Baloloy, Phivolcs science research analyst.

The explosion, which lasted for about three minutes, was accompanied by rumbling sounds. Residents in the towns of Camalig, Guinobatan, Polangui, Oas, and Ligao City reported experiencing the ash fall.

Baloloy said, however, that the height of the ash column was not recorded because clouds covered the view of the volcano and it was still dark when the explosion happened.

Arrow Down

Koalas Face Extinction Within 30 years

Koala
© camelotbears.com
Australia's koalas could be become extinct within 30 years unless urgent action is taken to halt a decline in the population, researchers say.

Development, climate change and bushfires have all contributed in reducing the numbers of wild koalas. The sexually transmitted disease chlamydia has also played a part in the animal's demise. In the past six years alone the population may have dropped by half according to a survey carried out by the Australian Koala Foundation.

Previous estimates put the number of koalas at more than 100,000. However recent estimates show there may be as few as 43,000. The foundation collected field data from 1,800 sites and 80,000 trees to calculate the numbers. In one area in northern Queensland estimated to have 20,000 koalas a decade ago, a team of eight people could not find a single animal in four days of searching.