Earth ChangesS


Cave Study Links Climate Change to California Droughts

California experienced centuries-long droughts in the past 20,000 years that coincided with the thawing of ice caps in the Arctic, according to a new study by UC Davis doctoral student Jessica Oster and geology professor Isabel Montañez.

The finding, which comes from analyzing stalagmites from Moaning Cavern in the central Sierra Nevada, was published online Nov. 5 in the journal Earth and Planetary Science Letters.

The sometimes spectacular mineral formations in caves such as Moaning Cavern and Black Chasm build up over centuries as water drips from the cave roof. Those drops of water pick up trace chemicals in their path through air, soil and rocks, and deposit the chemicals in the stalagmite.

"They're like tree rings made out of rock," Montañez said. "These are the only climate records of this type for California for this period when past global warming was occurring."

Bizarro Earth

NASA Sees High Thunderstorms in Newly Formed Tropical Cyclone Near India

© NASANASA's Aqua satellite captured cold thunderstorm cloud tops of Cyclone 4A with temperatures as cold as -63 degrees Fahrenheit (in purple), indicating strong convection is occurring in the storm.
Tropical Cyclone 4A formed yesterday, November 10 off the western coast of India in the Arabian Sea, and NASA's infrared imagery captured some high, powerful thunderstorms developing in the storm's center. Tropical Cyclone (TC) 4A formed yesterday around 4 p.m. ET, 380 miles south-southwest of Mumbai, India, with maximum sustained winds near 37 mph. By 10 a.m. ET today, November 10, 4A had moved north about 135 miles.

Cyclone 4A was located about 245 miles south-southwest of Mumbai, near 15.2 North and 71.1. East. It still maintained sustained winds near 37 mph, and was moving north at 13 mph.

The U.S. Navy's Joint Typhoon Warning Center, the organization that forecasts tropical cyclones in that region of the world, noted that gusty winds between 34-40 mph (55-65 kmph) and heavy rainfall (as much as 10 inches or 250 millimeters) will affect Konkan and Goa and Madhya Maharastra over the next two days as the storm moves north.

Gusty winds and heavy rainfall is also expected over coastal Karnataka, Kerala and Lakshadweep in the next day, South Gujarat will begin to feel rainfall and gusty winds from 04A on November 11.

NASA's Aqua satellite flew over Cyclone 4A on November 9 at 20:59 UTC (3:59 p.m. ET) and the Atmospheric Infrared Sounder (AIRS) instrument onboard captured an infrared image of Cyclone 4A's cold thunderstorm tops. The infrared imagery revealed that 4A's cloud tops had some strong thunderstorms around its center of circulation, where temperatures are colder than -63 Fahrenheit. That indicates strong convection and development of thunderstorms that power the cyclone. 4A is expected to continue intensifying as it moves north over the next couple of days in the Arabian Sea, paralleling the Indian coast.


Ancient Penguin DNA Raises Doubts About Accuracy of Genetic Dating Techniques

© PhysOrgAdelie penguins have survived in Antarctica for thousands of years and are invaluable for genetic research.
Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent.

In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal.

The findings raise doubts about the accuracy of many evolutionary rates based on conventional types of genetic analysis.

"Some earlier work based on small amounts of DNA indicated this same problem, but now we have more conclusive evidence based on the study of almost an entire mitochondrial genome," said Dee Denver, an evolutionary biologist with the Center for Genome Research and Biocomputing at Oregon State University.

Bizarro Earth

Landslide Triggered by Rains Kills 42 in India

A landslide triggered by torrential seasonal rains swept through a hilly region in southern India, killing at least 42 people, an official said Tuesday.

The landslide demolished nearly 300 tin-roofed mud huts Monday in the Ooty and Coonoor region of Tamil Nadu state, a state flood control official said on condition of anonymity because he was not authorized to talk to reporters. The region is nearly 1,120 miles (1,800 kilometers) south of the capital, New Delhi.

Rescuers found 14 bodies in the debris Monday and another 28 on Tuesday, the official said, adding that eight injured people were hospitalized.

The death toll was expected to rise further with the rescue operation continuing in the region, the official said.

Ooty is a popular tourist destination, but none of those killed or injured were foreigners, he said.

Cloud Lightning

Stone Age humans crossed Sahara in the rain

© Sergio Pitamitz/GettyIt used to be wetter
Wet spells in the Sahara may have opened the door for early human migration. According to new evidence, water-dependent trees and shrubs grew there between 120,000 and 45,000 years ago. This suggests that changes in the weather helped early humans cross the desert on their way out of Africa.

The Sahara would have been a formidable barrier during the Stone Age, making it hard to understand how humans made it to Europe from eastern Africa, where the earliest remains of our hominin ancestors are found.

Isla Castañeda of the Royal Netherlands Institute for Sea Research and colleagues studied land plant hydrocarbons in Saharan dust that has settled on the sea floor off west Africa over the past 192,000 years. From the ratio of carbon isotopes in the hydrocarbons they can work out which types of plants were present at different times.

Wet spells

While about 40 per cent of hydrocarbons in today's dust come from water-dependent plants, this rose to 60 per cent, first between 120,000 and 110,000 ago and again from 50,000 to 45,000 years ago. So the region seemed to be in the grip of unusually wet spells at the time.

That may have been enough to allow sub-Saharan Stone Age Homo sapiens to migrate north: the first fossils of modern humans outside Africa date from 93,000 year ago in Israel. And both genetic analysis and archaeology show that humans didn't spread extensively beyond Africa until 50,000 years ago, suggesting a second migration at the time of the second wet spell.


Andrea Marshall: Queen of manta rays

The marine ecologist discusses diving, underwater beauty parlours and the discovery of a new species.

Bizarro Earth

5.6 Quake Jolts Tibet

Beijing - An earthquake measuring 5.6 on the Richter scale hit Xigaze prefecture of southwest China's Tibet Autonomous Region early Sunday morning, a report said.

The quake struck the area bordering the Ngamring and Saga counties at 4.08 a.m. and no casualties have been reported so far, a Xinhua report quoted National Seismological Network as saying.

Bizarro Earth

Indonesia: 6.7 Richter scale earthquake

Bima Earthquake
© Unknown
Earthquake Claims Two Lives in Bima

Mataram - Two locals were reported to have died after a 6.7 Richter scale earthquake located 28 kilometers north-west of Raba, Bima city, West Nusa Tenggara (NTB), occurred Monday, approximately at 03:41:46 WITA.

Masita, a local from Raba Ngodu, East Rasanae subdistrict, Bima City, who was contacted by mobile confirmed that two locals from Kolo village, Kolo Asakota subdistrict, Bima city, died under collapsed buildings.

"That's the information we received from the relatives there. When the earthquake happened we were fast asleep and the power was still down," she stated.

Information of life casualties was also admitted by Herdin, a local from Monggonao, West Rasanae subdistrict. He said, confirmation of the two deaths due to earthquake was announced through the loud-speaker on the mosque and the Bima FM radio shortly after the disaster struck.


Scientists investigate phenomenon of the 'winter bees'

winter active bees
© UnknownWarmer winters have led to bumblebees remaining active throughout the winter months.
It is one of the sounds of summer, but now the buzz of the bumblebee is becoming increasingly familiar in deepest winter - at a time when the insects should be hibernating.

Scientists are investigating the growing phenomenon of bumblebees remaining active throughout the winter months.

They believe it is a consequence of recent warmer winters, linked to climate change, as well as the British passion for gardening and the increasing popularity of exotic, winter flowering shrubs from which bees can collect food.

Another theory being explored is that the bees may be hybridising with foreign bees, which remain active in winter, and which may have escaped into the wild after being imported into Britain to help with the pollination of crops in polytunnels.

The phenomenon has been recorded in the buff-tailed bumblebee (Bombus terrestris), one of the most common in the UK. Like other bees, it is usually only seen between March and September as it spends autumn and winter asleep underground, but there have been increasing reports of winter activity in recent years.


Why Do Animals, Especially Males, Have So Many Different Colors?

© University of California - Los AngelesThis male Hetaerina damselfly from the occisa species has red spots at the base and tip of its wings but no black pigmentation.
Why do so many animal species -- including fish, birds and insects -- display such rich diversity in coloration and other traits? In new research, Gregory Grether, UCLA professor of ecology and evolutionary biology, and Christopher Anderson, who recently earned his doctorate in Grether's laboratory, offer an answer.

At least since Charles Darwin, biologists have noticed that species differ in "secondary sexual traits," such as bright coloring or elaborate horns, Grether said. Darwin attributed this diversity to sexual selection, meaning the traits increased an animal's ability to attract mates.

But Grether and Anderson, writing in the Oct. 28 issue of the journal Proceedings of the Royal Society B: Biological Sciences, emphasize another evolutionary factor.

"The cost of attacking the wrong type of male and of being attacked by the wrong type of male favors the rich diversity of coloration and of birdsong and chemical cues, such as odors, to identify rivals," Grether said.