Another Large Earthquake Off Coast Of Sumatra Likely

ScienceDaily (Dec. 4, 2008) — The subduction zone that brought us the 2004 Sumatra-Andaman earthquake and tsunami is ripe for yet another large event, despite a sequence of quakes that occurred in the Mentawai Islands area in 2007, according to a group of earthquake researchers led by scientists from the Tectonics Observatory at the California Institute of Technology (Caltech).

"From what we saw," says geologist Jean-Philippe Avouac, director of the Tectonics Observatory and one of the paper's lead authors, "we can say with some confidence that we're probably not done with large earthquakes in Sumatra."

The devastating magnitude 9.2 earthquake that occurred off the western coast of Sumatra on December 26, 2004—the earthquake that spawned a lethal tsunami throughout the Indian Ocean—took place in a subduction zone, an area where one tectonic plate dips under another, forming a quake-prone region.

It is that subduction zone that drew the interest of the Caltech-led team. Seismic activity has continued in the region since the 2004 event, they knew. But have the most recent earthquakes been able to relieve the previous centuries of built-up seismic stress?

Yes . . . and no. Take, for instance, an area just south of the 2004 quake, where a magnitude 8.6 earthquake hit in 2005. (That same area had also been the site of a major earthquake in 1861.) The 2005 quake, says Avouac, did a good job of "unzipping" the stuck area in that patch of the zone, effectively relieving the stresses that had built up since 1861. This means that it should be a few centuries before another large quake in that area would be likely.

The same cannot be said, however, of the area even further south along that same subduction zone, near the Mentawai Islands, a chain of about 70 islands off the western coasts of Sumatra and Indonesia. This area, too, has been hit by giant earthquakes in the past (an 8.8 in 1797 and a 9.0 in 1833). More recently, on September 12, 2007, it experienced two earthquakes just 12 hours apart: first a magnitude 8.4 quake and then a magnitude 7.9.

These earthquakes did not come as a surprise to the Caltech researchers. Caltech geologist and paper coauthor Kerry Sieh, who is now at the Nanyang Technological University in Singapore, had long been using coral growth rings to quantify the pattern of slow uplift and subsidence in the Mentawai Islands area; that pattern, he and his colleagues knew, is the result of stress build-up on the plate interface, which should eventually be released by future large earthquakes.

But was all that accumulated stress released in 2007? In the work described in the Nature letter, the researchers analyzed seismological records, remote sensing (inSAR) data, field measurements, and, most importantly, data gathered by an array of continuously recording GPS stations called SuGAr (for Sumatra Geodetic Array) to find out.

Their answer? The quakes hadn't even come close to doing their stress-reduction job. "In fact," says Ali Ozgun Konca, a Caltech scientist and the paper's first author, who did this work as a graduate student, "we saw release of only a quarter of the moment needed to make up for the accumulated deficit over the past two centuries." (Moment is a measure of earthquake size that takes into account how much the fault slips and over how much area.)

"The 2007 quakes occurred in the right place at the right time," adds Avouac. "They were not a surprise. What was a surprise was that those earthquakes were way smaller than we expected."

"The quake north of this region, in 2005, ruptured completely," says Konca. "But the 2007 sequence of quakes was more complicated. The slippage of the plates was patchy, and it didn't release all the strain that had accumulated."

"It was what we call a partial rupture," adds Avouac. "There's still enough strain to create another major earthquake in that region. We may have to wait a long time, but there's no reason to think it's over."

Their findings were published in a letter in the December 4 issue of the journal Nature.

Other authors on the paper include Anthony Sladen, Aron J. Meltzner, John Galetzka, Jeff Genrich, and Don V. Helmberger from Caltech; Danny H. Natawidjaja from the Indonesian Institute of Science (LIPI); Peng Fang and Yehuda Bock from the Scripps Institution of Oceanography in La Jolla; Zhenhong Li from the University of Glasgow in Scotland; Mohamed Chlieh from the Université de Nice Sophia-Antipolis in France; Eric J. Fielding from the Jet Propulsion Laboratory; and Chen Ji from the University of California, Santa Barbara.

The work was supported by funding from the National Science Foundation and the Gordon and Betty Moore Foundation.

Journal reference:

1. . Partial rupture of a locked patch of the Sumatra megathrust during the 2007 earthquake sequence.Nature, December 4, 2008

Adapted from materials provided by California Institute of Technology, via EurekAlert!, a service of AAAS.

Source :http://www.sciencedaily.com/releases/2008/12/081203131042.htm

Cyclones in the Indian Ocean: Facts and figures

Greg O'Hare explains the what, why, when and how of cyclones, and reviews their effects in South Asia.

'Tropical cyclone' is the general term for low-pressure atmospheric circulations in the tropics. These have anticlockwise rotating winds in the northern hemisphere and clockwise rotating winds in the southern hemisphere.

Low to moderate intensity tropical cyclones bring much needed rain for agriculture around the northern Indian Ocean. But, when tropical cyclones strengthen, they can bring great loss of life and property to the region.

Cyclonic structures

All tropical cyclones have low atmospheric pressure at ground level, and a vortex of converging winds and rising air. They all have extensive rain-bearing layered clouds (deep nimbostratus) and towering vertically extensive cumulonimbus rain-bearing clouds. Yet despite these common features, tropical cyclones in South Asia vary greatly in size, frequency and intensity, and have varying effects on the land they cross.

Table 1 shows four types of tropical cyclones. These weather systems form a continuum — if conditions are right and surface pressure continually falls, a tropical low can develop over time into a tropical depression, then into a tropical storm and eventually into an intense tropical storm. In South Asia, as in the western world, the most intense tropical storms are called hurricanes. But, confusingly, the most intense circulations in the Pacific are called cyclones.

 

Type of tropical cyclonic system	Speed (m/sec)	Height (km)	Duration (days)	Width (km)	Frequency	Rainfall (cm)
Low	<8	2–4	1–3	150–300	frequent	5–10
Depression	8–17	4–8	2–5	250–500	common	10–20
Storm	17–32	8–10	3–10	300–600	occasional	20–50
Hurricane	>32	8–12	5–7	400–1000	rare	50–150

Table 1: Types of tropical cyclones in India [1]

Lows and depressions are the most frequent systems and produce most of India's annual rainfall (about 890mm). Indeed, with their lower intensity rainfalls, they form the backbone of South Asian agriculture.

But when a long series of deep tropical depressions occur (lasting three to four weeks), the cumulative rainfall can lead to extensive flooding, dam collapses and landslides. In southern Bangladesh, more than 100 families were washed away when a dam collapsed in July 2004. In 2008, summer monsoon flooding and landslides in India (especially in Bihar State) killed 1065 people and affected approximately 7.9 million people.

How do hurricanes form?

Tropical cyclones affecting south Asia originate over surrounding oceans, especially in the Bay of Bengal. They require at least five conditions to form and develop: low pressure at the surface; abundant moist air capable of convective or upward movement in the atmosphere; ocean surface temperatures over 26–27 degrees Celsius; small wind shear — the rate at which wind strength and direction change with height in the atmosphere — (especially for the taller more intense systems); and the power of the Earth's rotation to spin the system into a rotating vortex.

Tropical cyclones in South Asia derive their main energy from intense evaporation over warm water — not, as in mid-latitude cyclones, from contrasting temperatures between cold and warmer air masses.

Water vapour, evaporated from the sea, is drawn into the developing cyclone. As the rising air within the cyclone cools, the evaporated moisture becomes cloud, forming billions of tiny water droplets. Converting the water vapour to water droplets releases a great amount of (latent) heat, providing energy that helps invigorate and maintain the cyclone's development.

Timing and monsoon regulation

The tropical cyclones that influence South Asia are part of the regional monsoon wind system. The South Asian monsoon has moist south-westerly winds blowing from the southern oceans over the South Asian continental land mass in summer, and dry north-easterly winds blowing in the opposite direction in winter.

The differential heating of land and sea drives this movement. In the summer, the land heats up more quickly than the oceans, producing low pressure over land and high pressure at sea. Winds blow from high to low pressure, bringing strong, moist winds from the oceans towards South Asia. During the winter months, the differential heating and pressure systems are reversed, and strong dry north-easterly winds end up blowing from South Asia towards the southern oceans.

Most rainfall over the region comes in the summer months (June to September) from relatively weak but frequent tropical lows and depressions. Driven by monsoon winds, these systems eventually move over land along the west coast of India, but more frequently affect the eastern coast of India and Bangladesh.

The more intense tropical storms and hurricanes, which also tend to form mainly in the Bay of Bengal, often occur as the wet summer changes to a dry winter monsoon (October to November) when wind shear is low. Powerful cyclones, which tower up into the atmosphere, do not easily form during the main monsoon season (June to September) because high wind shear easily destabilises them, knocking them over.

Hurricane damage

The areas of South Asia most vulnerable to hurricanes are the low-lying coastal regions around the Bay of Bengal (Bangladesh, Eastern India and Myanmar). These are the first areas storms hit when they reach land and are also some of the most agriculturally fertile — and densely populated — areas in South Asia, including coastal river deltas like the Godavari, Ganges and Irrawaddy.

Hurricanes' high wind speeds, intense rainfalls and storm surges (unusually high sea levels) destroy life and property, and can leave areas devastated. Winds, often travelling at more than 117 kilometres per hour, remove or seriously damage flimsy housing.

High intensity rainfall over a relatively short period (up to and above 50 centimetres over three to seven days) can cause serious flooding and major crop loss. As with the less intense cyclones, such flooding can increase loss of life and property if it causes reservoir collapses and landslides.

But the most destructive part of a cyclone is the storm surge at the front of the storm pushed up to high levels as it moves inland. Storm surges from powerful hurricanes can reach two to five metres in height along the eastern coast of Andhra Pradesh in India. At the head of the Bay of Bengal, where the coastline becomes restricted, storm surges can reach a staggering 12 or 13 metres and kill many people (see Table 2).

Region	Date	Deaths
Andhra Pradesh	10 Oct 1679	20,000
Bangladesh	07 Oct 1737	300,000
Bangladesh	13 Nov 1970	500,000
Andhra Pradesh	26 Nov 1977	>10,000
West Bengal	29 Apr 1991	140,000

Table 2: Hurricane deaths in the Bay of Bengal region [1]

Hurricanes in a warming world

There is every chance that hurricanes will do more damage in South Asia in the future as population densities increase in coastal areas. The numbers of people at risk may also rise if hurricanes become more intense as the world and oceans warm up.

Some studies have found no evidence for an increase in hurricanes' frequency or intensity in the Caribbean. [2,3] Others have found little change in the frequency and intensity of hurricanes globally during the last 20 years. [4]

By contrast, other strong evidence based on good quality data has shown that in recent years hurricanes, particularly the stronger ones (categories four and five), have become more intense in all hurricane regions, including the northern Indian Ocean (Table 3). [5,6]

Basin	1975–1989		1990–2004
	No.	Percentage of all hurricanes	No.	Percentage of all hurricanes
East Pacific	36	25	49	35
West Pacific	85	25	116	41
North Atlantic	16	20	25	25
South West Pacific	10	12	22	28
Indian Ocean	24	13	57	29

Table 3: Changes in the number and percentage of category four and five hurricanes for the periods 1975–89 and 1990–2004 for different ocean basins. [5]

Vulnerable populations

The people most vulnerable to hurricanes around the world include those with limited economic resources, low levels of technology, poor information and skills, minimal infrastructure and unstable or weak political institutions (Table 4). Such groups are not fully able to prepare for, or protect themselves from, hurricanes, nor to respond and cope with their effects.

Low cast communities

Ethnic minorities

Women, especially those who may be widowed or deserted

Old men and women

Children, particularly girls

The disabled

People dependent on low incomes

People in debt

People isolated from transport, communication and health services infrastructure

Table 4: Disaster prone groups in India [1]

When a category four hurricane hit the Godavari delta region of eastern India in November 1986, various marginalised groups responded differently to the hurricane's impact. For example, poor female agricultural labourers working in flood damaged rice fields had to sell their few possessions and become maids in nearby villages, or migrate to other paddy regions in order to cope. By contrast, poor fishing communities along the delta coast (where many people died due to storm surges) relied on close family and kinship links for money, food and fishing tackle to get over the storm's effects.

Basic precautions

There are ways to make the likely rise in hurricane impact less damaging in the region. One solution is to improve the physical structures that protect people. For example, many new hurricane shelters are being built along the coast of eastern India. Deaths from hurricanes will certainly decline if more local people can be encouraged to use the shelters.

Improvements in government-built early warning and evacuation procedures will also help save lives, although access to these may be limited because many communities suffer from isolation, language barriers, and poor transport and communication (including radio/phone) systems. Still, because of improvements, albeit slow, in the introduction and uptake of such systems, hurricanes that would have killed 10,000 people in Andhra Pradesh in the late 1970s kill around 1,000 today.

Governments and international agencies can also do a lot more to mitigate storm impacts through rehabilitation policies, such as providing basic relief (food, shelter, cooking oil and clean water). It is also crucial that affected communities get better health services, since the spread of water-borne diseases (like typhoid and dysentery) after hurricanes often kills far more people than flooding, landslides or even storm surges.

Greg O'Hare is a professor of geography at the University of Derby, United Kingdom.

REFERENCES

[1] O'Hare, G. Hurricane 07b in the Godavari Delta, Andhra Pradesh, India: vulnerability, mitigation and the spatial impact. The Geographical Journal167, 23–38 (2001)

[2] Michaels P.J., Knappenberger, P.C. & Davis, R.E. Sea surface temperatures and tropical cyclones in the Atlantic basin. Geophysical Research Letters 33, (2006)

[3] Hoyos, C.D., Agudelo, P.A., Webster, P.J. et al. Deconvolution of the factors contributing to the increase in global hurricane intensity. Science 312, 94–97 (2006)

[4] Klotzbach, P.J. Trends in global cyclone activity over the past 20 years (1986-2005) Geophysical Research Letters 33, (2006)

[5] Webster P.J., Holland, G.J., Curry, J.A. et al. Changes in tropical cyclone number, duration and intensity in a warming environment. Science 309, 1844–1846 (2005)

[6] Elsner, J.B., Kossin, J.P. & Jagger, T.H. The increasing intensity of the strongest tropical cyclones. Nature 455, 92–95 (2008)

 

 

Earth cracks in UP seismic related: Expert

Motion of a massive granitic body under the earth could be the probable reason behind alarming cracks on the earth crust that have created a panic like situation in northern Indian state of Uttar Pradesh (UP).
“If this granitic craton motion is changed due to some tectonic reason, one may see subsidence at large scale—since a fault is present along Kanpur-Lucknow—there could be danger of large surface deformation,” cautioned an US based Indian scientist Ramesh Singh.
The effect of motion of this block will be reflected in widespread cracks, he said. Singh is a Professor at George Mason University in Washington and vice chair of GeoRisk Commission of the International Union of Geodesy and Geophysics.
He further said that the Government of India should monitor seismic activities in the area to avert any major disaster due to this motion.
Singh, who had extensively studied the seismology in this part of UP during his stint at IIT Kanpur as a Professor said if the orientation of such long cracks was in the east-west direction, then the cracks could be due to stress on the surface of the earth due to motion of this massive craton (granitic body) exposed near Jhansi.
He said this massive body underlying the region is inclined towards northeast with depth reaching 300-500 metres near Kanpur and 1,200 metres in Lucknow.
About 18 months back, scientists observed a shift in the position of the Sangam—the confluence of rivers Ganges and Yamuna and mythical Saraswati near Allahabad—and thought it was due to the sediment load in the rivers or due to plate motion, Singh said.
“Now, the appearance of large widespread cracks is clear evidence of neo-tectonic activities associated with the building of stress in this region and we must monitor seismic activities along Kanpur-Lucknow and Moradabad faultlines,” the Professor said.
Singh said he initially suspected that the cracks might be due to subsidence as a result of excessive groundwater withdrawal but ruled it “since the cracks were seen on a regional scale in many parts of Kanpur, Hamirpur, and Allahabad.”
The formation of cracks on the earth continues to affect various districts of UP and two villages near Lucknow are the latest to witness long fissures on the surface.
Fields in Kakori block’s two villages, Dullu Khera and Vader Khera, about 10 km from Lucknow, have developed wide cracks up to 250 metres long, officials said.
Besides the villages in Lucknow district, six districts of Uttar Pradesh have been witnessing this phenomenon for about a week.

Source: http://www.igovernment.in/site/earth-cracks-in-up-seismic-related-expert/

Learning from failures in disaster response

The Myanmar cyclone and Chinese earthquake highlight the need for effective dissemination of information, both before and after a disaster.The effectiveness with which a country deals with a major accident or disaster is a revealing indicator of its sensitivity to the needs of its population. It depends heavily on the country's ability to respond to the population's need for information, prior to and following the event.In the mid-1980s, a key factor in the collapse of the communist regime in the Soviet Union was public resentment of the mishandling of information about the near meltdown at the Chernobyl nuclear plant. It took authorities more than 24 hours to publicly acknowledge the accident, and the lack of evacuation strategies added to losses from the disaster.The recent impact of cyclone Nargis in Myanmar (formerly Burma) and the earthquake in Sichuan province, China, has posed major challenges to both countries in dealing with the event, and handling information about prevention and mitigation.Each has raised important questions about the failure to integrate scientific knowledge into disaster planning, at the cost of thousands of lives. And each has highlighted the need for accurate communication of information, if the impact of major disasters is to be minimised and if government officials are to be held accountable for their efforts — or lack thereof.Clearest lessonIn the case of Myanmar, the failures are glaringly obvious.Firstly, there has been the failure to take on board increasingly widespread knowledge about how the destruction of mangrove forests dramatically increases the vulnerability of coastal populations.This was one of the clearest lessons of the December 2004 Indian Ocean tsunami and has been acknowledged in other countries, including Bangladesh. But Myanmar authorities seem to have paid little attention to mangrove conservation. UN Food and Agriculture Organization officials say the Irrawaddy delta — the country's largest mangrove area, where Nargis struck — has lost half its mangrove area since 1975 (see UN: Mangrove loss 'intensified' Myanmar cyclone damage).Secondly, it is clear that the country lacks the comprehensive communication infrastructure — and perhaps even the political will — to ensure that information about impending disasters reaches the areas where it is most needed.Warnings about the imminent cyclone were posted by the country's meteorological office. But there was no way of rapidly communicating these warnings to those most in danger. Furthermore, the lack of protection measures meant that even those aware could do little about it.Widespread praiseIn China, the situation has been different. The government has won widespread praise for the speed with which it has acknowledged the size of the disaster and submitted its rescue efforts to international scrutiny — in stark contrast to the Tangshan earthquakes of 1976.This new attitude has been reflected in the willingness of earthquake specialists to open themselves up to queries from local journalists. In the past, they would have insisted that all such questions be directed to government officials. Through a fortunate accident of timing, a new law on public access to information came into effect on 1 May, requiring them to act differently. But even in China, important questions have been raised.For example, there is no guarantee that the scientists who have made themselves accessible in an emergency situation will maintain this attitude in less urgent times. In addition to their willingness to deal with the media, scientific institutions must be trained to release information in a fast and comprehensible way.At the same time, media reporting on baseless rumours of new earthquake shocks has reinforced the need to train science journalists to make their own judgments about when to trust apparently scientific statements.Equally important is the need for some probing journalism into why so many schools collapsed, particularly when buildings around them often remained standing. In many cases, the problems appear to have been caused not by a lack of scientific or technical information, but by a failure to put information to use.Intense pressureIncreased openness is not without cost. The more the Soviet government unveiled information about the Chernobyl disaster, the greater became the criticism of its failure to protect its citizens.Undoubtedly, this fear lies at the heart of the situation in Myanmar. The sight on state-run television of the country's prime minister visiting a few hastily erected camps for survivors — all looking remarkably well-fed — is far less likely to generate internal criticism than film of bloated bodies and starving children almost three weeks after the cyclone.In the long-term, attempts to impose heavy-handed restrictions on the coverage of disasters, particularly in an era of global electronic communication, will inevitably be counterproductive. As they learn more about the reality of the situation, the less confidence they will have in those who tell them that the situation is different.Providing citizens with the information they need to protect themselves against future cyclones or earthquakes is a crucial role for science communicators. Identifying the political or other obstacles that prevent this information from getting through or being put into practice is potentially even more important.

Source: http://www.scidev.net/en/editorials/learning-from-failures-in-disaster-response.html

Deadly tremors that strike without warning- Facts About Earthquakes

Every day an earthquake happens somewhere in the world. Many are so light that they cannot be detected. On average just 100 quakes cause damage out of the estimated 1.4 million earthquakes that occur every year.
Scientists cannot predict when an earthquake will strike, but they have been able to map where earthquakes are most likely to happen.
Most of the largest earthquakes occur within the Pacific "Ring of Fire", a horseshoe-shaped band of volcanoes and fault lines circling the edges of the Pacific Ocean.
Tsunami are large water waves typically generated by underwater earthquakes or landslides triggered by seismic activity.
KEY FACTS:
The largest recorded earthquake in the world was magnitude 9.5 in Chile, May 22, 1960.
Most earthquakes occur at depths of less than 80 km (50 miles) from the Earth's surface.
The world's deadliest recorded earthquake occurred in 1556 in central China, where most people lived in caves carved from soft rock. An estimated 830,000 people died.
The earliest recorded evidence of an earthquake dates back to 1831 BC in China's Shandong province.
Source: The U.S. Geological Survey's Earthquake Facts page.

Study helps predict big Mediterranean quake

LONDON, March 9 (Reuters) - Scientists have found evidence that an overlooked fault in the eastern Mediterranean is likely to produce an earthquake and tsunami every 800 years as powerful as the one that destroyed Alexandria in AD 365.
Using radiocarbon dating techniques, simulations and computer models, the researchers recreated the ancient disaster in order to identify the responsible fault, they said in a study published in the journal Nature Geoscience on Sunday.
"We are saying there is probably a repeat time of 800 years for this kind of earthquake," said Beth Shaw, a seismologist at the University of Cambridge, who led the study.
Scientists study past earthquakes in order to determine the future likelihood of similar large shocks. Identifying the fault for the AD 365 earthquake and tsunami is important for the tens of millions of people in the region, Shaw said.
The fault close to the southwest coast of Crete last produced a big enough quake to generate a tsunami about 1300, which means the next powerful one could come in the next 100 years, she added in a telephone interview.
Shaw and her colleagues calculate the likely intervals by measuring the motion of either side of the fault to gauge how often such large earthquakes would have to occur to account for that level of motion, she said.
Their computer model suggested an 8 magnitude quake on the fault would produce a tsunami that inundates the coastal regions of Alexandria and North Africa, the southern coast of Greece and Sicily all the way up the Adriatic to Dubrovnik, Shaw said.
This would be similar to the ancient quake in AD 365 that caused widespread destruction in much of Greece and unleashed a tsunami that flooded Alexandria and the Nile Delta, likely killing tens of thousands of people, she said.
"This is consistent with the historical record of the tsunami," she said. (Reporting by Michael Kahn; Editing by Janet Lawrence)

Source: http://www.alertnet.org/thenews/newsdesk/L07804229.htm

Will Global Warming Increase Plant Frost Damage?

ScienceDaily (Mar. 4, 2008) — Widespread damage to plants from a sudden freeze that occurred across the Eastern United States from 5 April to 9 April 2007 was made worse because it had been preceded by two weeks of unusual warmth, according to an analysis published in the March 2008 issue of BioScience. The authors of the report, Lianhong Gu and his colleagues at the Oak Ridge National Laboratory and collaborators at NASA, the University of Missouri, and the National Oceanic and Atmospheric Administration, found that the freeze killed new leaves, shoots, flowers, and fruit of natural vegetation, caused crown dieback of trees, and led to severe damage to crops in an area encompassing Nebraska,Maryland,SouthCarolina,andTexas.

Subsequent drought limited

regrowth.Valentia orange tree damaged

by frost. Global warming may result in

increased plant frost damage.

(Credit:Stockphoto/Loretta Hostettler)

Rising levels of atmospheric carbon dioxide are believed to reduce the ability of some plants to withstand freezing, and the authors of the BioScience study suggest that global warming could lead to more freeze and thaw fluctuations in future winters. This pattern is potentially dangerous for plants because many species must acclimate to cold over a sustained period. Acclimation enables them to better withstand freezes, but unusual warmth early in the year prevents the process. A cold spring in 1996, in contrast to the 2007 event, caused little enduring damage because it was not preceded by unusual warmth.
The 2007 freeze is likely to have lasting effects on carbon balance in the region. Plants cannot resorb nutrients from dead tissue that would normally be remobilized within the plants during autumnal senescence, so many nutrients became less available for plants in 2008. Wildlife is expected to have suffered harm from lack of food, and changes to plant architecture could have long-term implications.
Gu and his colleagues propose that the 2007 spring freeze should not be viewed as an isolated event, but as a realistic climate-change scenario. Further study of its long-term consequences could help refine scenarios for ecosystem changes as carbon dioxide levels increase and the climate warms.
Reference: The 2007 Eastern US Spring Freeze: Increased Cold Damage in a Warming World. Lianhong Gu, Paul J. Hanson, W. Mac Post, Dale P. Kaiser, Bai Yang, Ramakrishna Nemani, Stephen G. Pallardy, and Tilden Meyers
Adapted from materials provided by American Institute of Biological Sciences.

Source: http://www.sciencedaily.com/releases/2008/03/080303072651.htm

Quake jolts UK, damages to property worth 10 mn pounds

Britain was on wednesday jolted by an earthquake, the biggest to hit the country in nearly 25 years that damaged property worth over 10 million pounds. The tremor, measuring 5.2 on the Richter scale, hit shortly before 1:00 am (0630 IST) with its epicentre in Lincolnshire, but people were woken as far away as Wales, Scotland and Yorkshire. One person narrowly escaped death when a chimney smashed through the roof of his terraced home and crashed into his bedroom in Wombwell in South Yorkshire. The Association of British Insurers said that the cost of damage to homes and property is likely to be in excess of 10 million pounds.

The British Geological Survey (BGS) initially gave the magnitude for the 12.56 am earthquake as 5.3 on the Richter scale but has now said it was closer to 5.2. It said the epicentre was eight km east of Market Rasen, Lincolnshire, and 22 km south west of Grimsby. The tremor is the biggest in Britain since 1984 when north Wales was hit by a quake which was registered at 5.4 on the Richter scale. "There is slight structural damage, cracks and a couple of chimneys damaged. There's nothing serious at present. "Mostly people were distressed by it so there were a large quantity of calls coming in."

The police in the Midlands received more than 5,000 calls in an hour and in Dudley, 12 people walked into the local police station in their pyjamas.

The BGS said it records around 200 earthquakes in the UK each year - an eighth of which are able to be felt by residents. Buildings are deemed to be at risk from earthquakes above 5 on the Richter Scale, according to the Environment Agency.

The United States Geological Survey claimed that while the event was "light to moderate" on a world scale, it was "very significant", given the UK's relatively uneventful seismic history. Rafael Abreu, a geophysicist at the USGS National Earthquake Information Service, said: "It was a light to moderate event in relation to what has happened in Indonesia recently. But what is interesting about this event is that it was in an area where you would not expect it. "In an seismic area like this it is very significant. The UK usually has minor activity -- it's not particularly seismic."

The largest earthquake recorded in the UK was about 120 km from north east of Great Yarmouth in the North Sea on June 7, 1931. It measured 6.1 and was felt across Britain, in eastern Ireland, Belgium, the Netherlands, and parts of Germany, France, Norway and Denmark. People in Newcastle, Yorkshire, Manchester, the Midlands and Norfolk and also parts of Wales, felt the tremor. Seismologist Dr Brian Baptie of the BGS said: "This is a significant earthquake for the UK and will have been widely felt across England and Wales." A Lincolnshire police spokeswoman said the force had received dozens of calls from residents.

Sources : PTI

12 simple things you can do... for combating Climate Change

Source: UNDP India