Earth ChangesS

Magic Wand

WFU study finds that moths mimic sounds to survive

In a night sky filled with hungry bats, good-tasting moths increase their chances of survival by mimicking the sounds of their bad-tasting cousins, according to a new Wake Forest University study.

To be published in the May 29 issue of the Proceedings of the National Academy of Sciences, the study is the first to definitively show how an animal species uses acoustic mimicry as a defensive strategy.

The research was conducted by Jesse Barber, a doctoral student in biology at Wake Forest. William E. Conner, professor of biology at Wake Forest, co-authored the study.

In response to the sonar that bats use to locate prey, the tiger moths make ultrasonic clicks of their own. They broadcast the clicks from a paired set of structures called "tymbals." Many species of tiger moth use the tymbals to make specific sounds that warn the bat of their bad taste. Other species make sounds that closely mimic those high-frequency sounds.


First captive panda released in wild is killed

The first panda to be released into the wild after being bred in captivity has been found dead in forests in southwest China.

Xiang Xiang was found in February on snow-covered ground in the forests of Sichuan province in China's southwest, the Xinhua News Agency said.

It is believed he suffered fatal injuries after he fell from a tree while being chased by other pandas. He had undergone three years of training on how to survive in the wild but he lasted less than a year.

"Xiang Xiang died of serious internal injuries in the left side of his chest and stomach by falling from a high place," Heng Yi, an official from the Wolong Giant Panda Research Centre in Sichuan, said in a telephone interview.

Bizarro Earth

Montana: State to capture, kill 300 bison

After weeks of repeated and futile hazings, the Montana Department of Livestock is preparing to slaughter about 300 bison near West Yellowstone, including scores of calves that are only a few weeks old.


Pelosi: Climate change is a reality

House Speaker Nancy Pelosi said Monday she led a congressional delegation to Greenland, where lawmakers saw "firsthand evidence that climate change is a reality," and she hoped the Bush administration would consider a new path on the issue.

Bizarro Earth

South American cold wave: Argentina rations electricity, cuts gas supplies to Chile

Argentina rationed electricity to companies and severed natural gas supplies to Chile as a cold wave prompted record demand for electricity in South America's second-largest economy.

The temperature in many parts of Argentina fell below freezing yesterday, pushing electricity demand to a record 18,300 megawatts, according to the country's energy regulator. Argentina cut shipments of gas to Chile to meet the surge in demand, forcing their neighbor to rely on residual gas in the pipeline.

Cloud Lightning

Freak snow storm hits Nepal

Dozens of people were feared killed in remote parts of north-western Nepal after the areas were hit by a freak snow storm, officials said on Tuesday.

Red Flag

Lake Okeechobee ties record low as officials struggle to keep water flowing

Florida - Lake Okeechobee water levels tied their all-time low today as dry, windy conditions caused a high evaporation rate at the drought-stricken lake.

The current drought, coupled with decisions to lower the lake last year in anticipation of hurricanes that didn't materialize, left the lake at 8.97 feet on Wednesday. That was about 4 feet below normal and equal to the record low of 8.97 feet set during the drought of 2001.


NASA: Greenland snow melting faster, higher

NASA, America's space agency, said Tuesday that Greenland had more days of melting snow and at higher altitudes last year than the average established during the previous 18 years that satellite measurements have been taken.

Areas along Greenland's western, southeastern and northeastern coast saw the largest number of melt days last year.

"The sensors detected that snowmelt occurred more than 10 days longer than the average over certain areas of Greenland in 2006," said Marco Tedesco, a scientist at the Joint Center for Earth Systems Technology, which is managed by NASA's Goddard Space Flight Center and the University of Maryland.

Comment: Readers are referred to Fire and Ice: The Day After Tomorrow and the information pertaining to Greenland 'melting'.

Here is the abstract of the recent study published in the journal Eos.

We propose a technique for monitoring snowmelt over the Greenland ice sheet between 1992 and 2005 based on the difference between ascending and descending brightness temperatures (DAV) measured either at 19.35- or 37- GHz by the Special Sensor Microwave Imager (SSM/I). Wet snow is detected when both brightness temperatures and DAV values exceed fixed thresholds. Differently from existing techniques, a multi-frequency approach allows detection of wet snow at different depths and intensities, providing a tool for improving climatological and hydrological applications. Air temperature values either recorded by ground based stations or derived from model are used for calibrating and validating the technique. Results are compared with those obtained using backscattering coefficients recorded by the NASA's Quick Scatterometer (QuikSCAT) during an extreme melting event occurring on June 2002. Long-term results show that snowmelt extent has been increasing at a rate of ∼40,000 Km2 per year for the past 14 years.

Red Flag

Guinea: Strong earthquake hits Papua New Guinea's island

A magnitude 6.1 earthquake has struck the Papua New Guinea's island of New Britain, according to the U.S. Geological Survey.

The quake hit 740 km northeast of Papua New Guinea's capital of Port Moresby at 11:03 a.m. local time Tuesday (0103GMT) and the depth is 128 km below the earth's surface.


Huge waves from one storm slam coasts some 6000 km apart

Huge waves that struck Reunion Island and coastlines across Indonesia earlier this month all originated from the same storm that occurred south of Cape Town, South Africa, and were tracked across the entire Indian Ocean for some 10 000 kilometres over a nine-day period by ESA's Envisat satellite.

Waves reaching up to 11 metres devastated France's Reunion Island in the Indian Ocean when it slammed into the southern port of Saint Pierre on 12 May. Six days later waves created from the same storm measuring as high as seven metres began crashing into Indonesia coastlines from Sumatra to Bali, killing at least one person and causing some 1200 people to flee their homes.

Dr Bertrand Chapron of IFREMER, the French Research Institute for Exploitation of the Sea, and Dr Fabrice Collard of France's BOOST Technologies in Brest located and tracked the swells using standard processed Synthetic Aperture Radar (SAR) ESA Wave Mode products, as shown in the animation below.