january 2005

Astronomers have produced some amazing pictures using a remarkable new instrument on the United Kingdom Infrared Telescope in Hawaii.

The Wide Field Camera (WFCAM), built at the UK Astronomy Technology Centre in Edinburgh, is the world's most powerful infrared survey camera.

WFCAM was trained on a region of star formation in the Orion constellation about 1,500 light-years away.

The stunning images cover an area of sky that was unobtainable before.

"The ability to see such a large area at once, with state-of-the-art detectors, makes WFCAM the fastest infrared survey instrument in the world, bar none," commented Dr Andy Adamson, head of operations at the Hawaii telescope, which is sited on top of the Mauna Kea mountain.

The World's Coldest Areas suffer a Permafrost Melt


Distribution of permafrost and ground ice in the Northern Hemisphere, based on the EASE-Grid version of the IPA map. "High," "Med" and "Low" refer to ice content, and "T" and "t" refer to thick and thin overburden, respectively. Image courtesy of the International Permafrost Association, supplied by Tingjun Zhang, National Snow and Ice Data Center, University of
Colorado, Boulder.

Alaska is not the only region in a slump. The permafrost melt is accelerating throughout the world's cold regions, scientists reported at the recent Fall Meeting of the American Geophysical Union (AGU) in San Francisco.

In addition to northern Alaska, the permafrost zone includes most other Arctic land, such as northern Canada and much of Siberia, as well as the higher reaches of mountainous regions such as the Alps and Tibet. All report permafrost thaw.

"It's a very, very widespread problem," said Frederick Nelson, a geographer at the University of Delaware, US.

Scientists attribute the thaw to climate warming. As the air temperature warms, so does the frozen ground beneath it. The observations reiterate the recent findings of the Arctic Climate Impact Assessment report, which attributed the northern polar region's summer sea-ice loss and permafrost thaw to dramatic warming over the past half-century. Thawing permafrost can cause buildings and roads to droop, and pipelines to crack. Natural features are also affected. Scientists reported an increased frequency in landslides in the soil-based permafrost of Canada, and an increased instability and slope failures in mountainous regions, such as the Alps, where ice is locked in bedrock.

With the exception of Russia and its long history of permafrost monitoring, global records are insufficient - often too brief or scattered - to determine the precise extent of ice loss, said Dr Nelson.

However, monitoring programmes that are now much larger in scope, such as the Global Terrestrial Network for Permafrost (GTNP), indicate a warming trend throughout the permafrost zone. Boreholes in Svalbard, Norway, for example, indicate that ground temperatures rose 0.4C over the past decade, four times faster than they did in the previous century, according to Charles Harris, a geologist at the University of Cardiff, UK, and a coordinator of Permafrost and Climate in Europe (Pace), which is contributing data to the GTNP.

The Earthquake



"All the planet is vibrating" from the quake, said Enzo Boschi, the head of Italy's National Geophysics Institute. Speaking on SKY TG24 TV, Boschi said the quake even disturbed the Earth's rotation.

The magnitude scale is really comparing amplitudes of waves on a seismogram, not the STRENGTH (energy) of the quakes. So, a magnitude 9.7 is 794 times bigger than a 6.8 quake as measured on seismograms, but the 9.7 quake is about 23,000 times STRONGER than the 6.8! Since it is really the energy or strength that knocks down buildings, this is really the more important comparison. This means that it would take about 23,000 quakes of magnitude 6.8 to equal the energy released by one magnitude 9.7 event. Here's how we get that number:

One whole unit of magnitude represents approximately 32 times (actually 10**1.5 times) the energy, based on a long-standing empirical formula that says log(E) is proportional to 1.5M, where E is energy and M is magnitude. This means that a change of 0.1 in magnitude is about 1.4 times the energy release. Therefore, using the shortcut shown eartlier for the amplitude calculation, the energy is,

	32 * 32 * 32 / 1.4 = 23,405 or about 23,000

The actual formula would be:

	((10**1.5)**9.7)/((10**1.5)**6.8)

	= 10**(1.5*(9.7-6.8)) = 10**(1.5*2.9) = 22,387

This explains why big quakes are so much more devastating than small ones. The amplitude ("size") differences are big enough, but the energy ("strength") differences are huge. The amplitude numbers are neater and a little easier to explain, which is why those are used more often in publications. But it's the energy that does the damage.

http://neic.usgs.gov/neis/eqlists/eqstats.html

The dense mangrove forests stood like a wall to save coastal communities living behind them," said M.S. Swaminathan, Chairman, M.S. Swaminathan Research Foundation (MSSRF), Chennai.   The mangroves in Pitchavaram and Muthupet region acted like a shield and bore the brunt of the tsunami.   The impact was mitigated and lives and property of the communities inhabiting the region were saved.   "When we started the foundation 14 years ago, we initiated the anticipatory research programme - a two-pronged strategy - to meet the eventualities of sea level rise due to global warming. One is to conserve and regenerate coastal mangroves along the eastern coast of the country, and the second is transfer of salt-tolerant genes from the mangroves to selected crops grown in the coastal regions.   It is now found that wherever the mangroves have been regenerated, especially in the Orissa coast, the damage due to tsunami is minimal," he said.