World's Melting Glaciers Making Large Contribution to Sea Rise

While 99 percent of Earth's land ice is locked up in the Greenland and Antarctic ice sheets, the remaining ice in the world's glaciers contributed just as much to sea rise as the two ice sheets combined from 2003 to 2009, says a new study led by Clark University and involving the University Colorado Boulder.

The new research found that all glacial regions lost mass from 2003 to 2009, with the biggest ice losses occurring in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas. The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the study period, causing the oceans to rise 0.03 inches, or about 0.7 millimeters per year.

The study compared traditional ground measurements to satellite data from NASA's Ice, Cloud and Land Elevation Satellite, or ICESat, and the Gravity Recovery and Climate Experiment, or GRACE, missions to estimate ice loss for glaciers in all regions of the planet.

"For the first time, we've been able to very precisely constrain how much these glaciers as a whole are contributing to sea rise," said geography Assistant Professor Alex Gardner of Clark University in Worcester, Mass., lead study author. "These smaller ice bodies are currently losing about as much mass as the ice sheets."

A paper on the subject is being published in the May 17 issue of the journal Science.

"Because the global glacier ice mass is relatively small in comparison with the huge ice sheets covering Greenland and Antarctica, people tend to not worry about it," said CU-Boulder Professor Tad Pfeffer, a study co-author. "But it's like a little bucket with a huge hole in the bottom: it may not last for very long, just a century or two, but while there's ice in those glaciers, it's a major contributor to sea level rise," said Pfeffer, a glaciologist at CU-Boulder's Institute of Arctic and Alpine Research

ICESat, which ceased operations in 2009, measured glacier changes using laser altimetry, which bounces laser pulses off the ice surface to determine changes in the height of ice cover. The GRACE satellite system, still operational, detects variations in Earth's gravity field resulting from changes in the planet's mass distribution, including ice displacements.

GRACE does not have a fine enough resolution and ICESat does not have sufficient sampling density to study small glaciers, but mass change estimates by the two satellite systems for large glaciated regions agree well, the scientists concluded.

"Because the two satellite techniques, ICESat and GRACE, are subject to completely different types of errors, the fact that their results are in such good agreement gives us increased confidence in those results," said CU-Boulder physics Professor John Wahr, a study co-author and fellow at the university's Cooperative Institute for Research in Environmental Sciences.

 

Ground-based estimates of glacier mass changes include measurements along a line from a glacier's summit to its edge, which are extrapolated over a glacier's entire area. Such measurements, while fairly accurate for individual glaciers, tend to cause scientists to overestimate ice loss when extrapolated over larger regions, including individual mountain ranges, according to the team.

Current estimates predict if all the glaciers in the world were to melt, they would raise sea level by about two feet. In contrast, an entire Greenland ice sheet melt would raise sea levels by about 20 feet, while if Antarctica lost its ice cover, sea levels would rise nearly 200 feet.

Source: Science Daily

R.Sawas

Robotic insect: world's smallest flying robot makes first flight

 

Scientists at Harvard University have created a flying robot that can sit on a fingertip. Inspired by the biology of a fly, the robot is able to perform the agile movements of an insect.

Researchers at the Harvard School of Engineering and Applied Sciences (SEAS) put a decade's work into developing the penny-sized robot, before it took off for the first time.

Source: science daily

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Astronomers Discover Surprising Clutch of Hydrogen Clouds Lurking Among Our Galactic Neighbors

In a dark, starless patch of intergalactic space, astronomers have discovered a never-before-seen cluster of hydrogen clouds strewn between two nearby galaxies, Andromeda (M31) and Triangulum (M33). The researchers speculate that these rarefied blobs of gas -- each about as massive as a dwarf galaxy -- condensed out of a vast and as-yet undetected reservoir of hot, ionized gas, which could have accompanied an otherwise invisible band of dark matter.

The astronomers detected these objects using the National Science Foundation's Green Bank Telescope (GBT) at the National Radio Astronomy Observatory (NRAO) in Green Bank, W.Va. The results were published in the journal Nature.

"We have known for some time that many seemingly empty stretches of the Universe contain vast but diffuse patches of hot, ionized hydrogen," said Spencer Wolfe of West Virginia University in Morgantown. "Earlier observations of the area between M31 and M33 suggested the presence of colder, neutral hydrogen, but we couldn't see any details to determine if it had a definitive structure or represented a new type of cosmic feature. Now, with high-resolution images from the GBT, we were able to detect discrete concentrations of neutral hydrogen emerging out of what was thought to be a mainly featureless field of gas."

Astronomers are able to observe neutral atomic hydrogen, which is referred to as HI (H and the Roman numeral one), because of the characteristic signal it emits at radio wavelengths, which can be detected by radio telescopes on Earth. Though this material is abundant throughout the cosmos, in the space between galaxies it can be very tenuous and the faint signal it emits can be extremely difficult to detect.

A little more than a decade ago, astronomers had the first speculative hints that a previously unrecognized reservoir of hydrogen lay between M31 and M33. The signal from this gas, however, was too faint to draw any firm conclusions about its nature, origin, or even certain existence. Last year, preliminary data taken with the GBT confirmed that there was indeed hydrogen gas, and a lot of it, smeared out between the galaxies. These preliminary observations, however, lacked the necessary sensitivity to see any fine-grain structure in the gas or deduce whence it came and what it signified. The most likely explanation at the time was that a few billion years earlier, these two galaxies had a close encounter and the resulting gravitational perturbations pulled off some wispy puffs of gas, leaving a tenuous bridge between the two.

New and more thorough studies of this region with the GBT, however, revealed that the hydrogen gas was not simply in the form of wispy streamers, as would be expected by the interactions of two galaxies in a gravitational ballet. Instead, a full 50 percent of the gas was conspicuously clumped together into very discrete and apparently self-gravitating blobs that -- apart for their lack of stars.

Source:Science Daily

R.Sawas

Google recognizes Palestine as 'independent nation'

NEW DELHI: Google seems to have recognized Palestine as an independent nation. The influential technology company last night changed the description of the area from 'Palestine Territories' to 'Palestine' on www.google.ps, a portal that serves Palestinian people. 

The notion of Palestinian state and its physical boundaries is a controversial topic. But it seems that the Google's move to term Palestine a nation is influenced by the developments in the United Nations (UN) last year. Despite the objections from "Israel" and the United States, the UN last year recognized Palestine as a "non-member observer state". India had voted in favor of the proposal in the UN General Assembly. 

Google, a multinational company, in the past has often punched above its weight on certain issues even though they have little to do with technology.

While Google complies with all the local laws across the world, the company, along with other technology firms like Twitter, is also vocal about what it perceives to be the rights of its users. It publishes data on the government requests it receives for removing content from its websites. 

In many cases, Google refuses to take down content if it feels the requests are not 'justified'. One such example was the controversial film "Innocence of Muslims" that was uploaded on the Youtube last year. Despite requests from several governments, including the US, the company refused to take it down. Though, it did censor the film in some countries.

Source: India everyday

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Scientists create bacteria that produce diesel

EXETER, United Kingdom -- A team of British scientists from Exeter University have developed a method which makes E.Coli bacteria produce a biofuel almost identical to diesel.

The discovery is considered of particular importance as the bacteria-produced diesel is a "drop-in" fuel, which requires no modification of existing engine technology in order to use it as a fuel.

Professor John Love from the University of Exeter's Biosciences department commented: "Producing a commercial biofuel that can be used without needing to modify vehicles has been the goal of this project from the outset."

Though an engine running off biodiesel will still create carbon dioxide emissions, Love said the E. Coli bacteria use carbon dioxide in the diesel-making process, leading to net-zero emissions.

Love warned against any speculation that he and his team may have discovered the magic bullet in synthetic fuel production.

"Our challenge is to increase the yield before we can go into any form of industrial production," Love said, describing that around 100 litres of bacteria would be required in order to produce just a teaspoon of diesel.

He said he hopes to implement a "pilot program" over the coming years to test the commercial viability of his new discovery.

Source: sciencedaily

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