Experts turn to Twitter for 'real' quake reports

US seismologists have found a new way to 'follow' earthquakes around the world in real-time: Twitter the popular micro-blogging service that allows users to send messages in less than 140 characters.

Scientists at the United States Geological Survey (USGS) have recently noticed that Twitter users in seismically active areas of the world were quick to note and report any temblors and movements of the earth that they felt. The experts say tapping into their 'tweets' on the website helps them pinpoint where and how brutally earthquakes hit, the science news website 'LiveScience' reported.

"Not only were 'Twitterers' quick to note quakes, there were reports that they were beating the USGS at getting out alerts of earthquake activity," USGS scientist Paul Earle was quoted as saying.

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Discovery may lead to quake early-warning system

Scientists working at California's San Andreas Fault have detected subtle geological changes occurring hours before an earthquake that could enable them to develop an early-warning system aimed at saving lives.

Their instruments detected geological changes most likely caused by tiny fractures forming in the rock ahead of an impending earthquake due to stress in the Earth's crust, according to seismologist Paul Silver of the Carnegie Institution in Washington, one of the researchers.

"It's the opening up of cracks before an earthquake," Silver said in a telephone interview.

The research, published on Wednesday in the journal Nature, was conducted using wells dug 0.6 miles deep into the quake-prone fault at Parkfield, California.

Their equipment generated and recorded seismic waves before, during and after two small quakes, allowing them to observe these small, predictive geological changes.

In the first case, the geological signals occurred 10 hours before a magnitude 3 quake in December 2005. The same sort of signals also occurred two hours before a magnitude 1 quake that happened five days later, the researchers said.

"We are very encouraged by these observations, and we are planning for more experiments to confirm whether these changes are part of the general physical processes before an earthquake," seismologist Fenglin Niu of Rice University in Houston said in a telephone interview.

EVACUATIONS?

Scientists have made strides in understanding earthquakes, but finding changes in the Earth's crust that could allow for an advance prediction has remained difficult.

Current earthquake warning systems provide at best a few seconds notice before an earthquake strikes.

The findings were published just two months after a powerful earthquake in China. The May 12 quake in Sichuan province killed about 80,000 people, with many killed when buildings such as schools collapsed.

"To get the point where we have a practical early warning system for earthquakes, that's still a ways off -- 10 years, maybe 20," Silver said.

If more research finds this effect to be pervasive before earthquakes, these findings may make that goal attainable, the researchers said.

"No matter how much time you have, there's something you can do. Even with a few seconds, you can automatically turn off gas valves. You may even be able to get a hard hat on your head or run outside of a building," Silver said.

"But with something on the order of 10 hours, you could perhaps evacuate populations, you could certainly get people out of city centers and areas that are deemed dangerous."

Chinese man pulled to safety eight days after quake

A man was pulled alive from the rubble of a power plant on Tuesday, eight days after China's deadly earthquake and just hours after predictions of another tremor sent thousands running on to streets in terror.

Ma Yuanjiang was rescued in Wenchuan county, epicenter of the May 12 quake in mountainous Sichuan province, after 179 hours buried in the rubble, state media said.

His rescue came as authorities tried to restore calm in the provincial capital, Chengdu, after tens of thousands rushed into the streets alarmed by a television prediction of another powerful earthquake.

That, along with fresh aftershocks and forecast heavy rain, compounded the difficulties for military, government and private workers trying to ensure millions of homeless are fed and housed.

Anger was building among bereaved parents in Sichuan over the way many school buildings had collapsed, burying whole classrooms full of children. In one town, in a rare public protest, hundreds demanded punishment for anyone guilty of shoddy construction.

Chengdu residents rushed from their homes before midnight on Monday, alarmed by the prediction of another earthquake after the 7.9 magnitude tremor on May 12.

Hundreds of aftershocks have been felt over the past week, bringing down more buildings and causing landslides. A few hours after the television report, a 5-magnitude tremor was felt.

But on Tuesday, provincial television screened interviews with a series of seismological bureau officials to explain the prediction and calm a jangled populace.

"Just because you can feel aftershocks, it doesn't mean they will hurt you. Of course, that doesn't mean you should stand in harm's way," said Han Weiding, researcher with the local seismological bureau.

ANGER OVER SCHOOLS

The pandemonium showed how nerves have been stretched to breaking point by the main quake and its aftershocks, now known to have killed more than 34,000 and injured 245,000.

"I think the television coverage is overdoing it. They're scaring people," said a hotel worker surnamed Li, who spent the night in a public park.

The most lamented victims of the quake have been the thousands of children who died when school buildings collapsed.

In Juyuan town, hundreds of grieving parents demanded an annual memorial day for their children, punishment of officials or builders responsible for shoddy schools, and compensation.

"How come all the houses didn't fall down, but the school did? And how come that happened in so many places?" demanded Zhao, whose two daughters were crushed to death.

"We want a memorial day for the children, but we also want criminal prosecution of those responsible, no matter who they are."

As China's ruling Communist Party seeks to maintain a staunch front of unity and stability after the quake, the incipient protests by parents could be troublesome, for many of them blame official graft and laxity, more than nature, for the deaths.

HOPE REMAINS

The number of dead from the May 12 quake, the worst to hit China since 1976, is expected to rise dramatically. The Communist Party chief in Sichuan said on Monday nearly 30,000 were still missing and a further 5,000 were believed buried under rubble.

Ma's release raised hopes of further rescues. In 1990, a quake survivor was pulled out alive two weeks after being buried under a collapsed hotel in the northern Philippines.

Rescuers found Ma on Saturday when they were digging a hole trying to reach a colleague, Yu Jinhua, Xinhua news agency said.

"Following an amputation operation, Yu was rescued at about 6 p.m. on May 18," Xinhua said. "Rescuers then turned to Ma and sent sweetened water to him through a straw."

Rescuers had reached the most remote areas of the province by Monday, but roads to some 50 affected towns and villages were still blocked by rocks and mudslides.

Whole towns have been flattened in mountainous areas north and west of Chengdu, and about 4.8 million people are homeless. Housing and feeding during the long-term rebuilding effort will prove a major challenge.

The quake warning also prompted panic in neighboring Chongqing municipality and Guizhou province.

"The panic was much worse in Guizhou, where reports of a frog and toad migration also spread public fear," Xinhua said.

In Tongzi county in Zunyi, a city in the north of Guizhou that borders Sichuan and Chongqing, "some villagers said they saw a massive migration of frogs and toads on Monday night, which they took as quake forecast", Xinhua said, quoting Zunyi's Vice Mayor, Zeng Yongtao.

He said the city government was investigating.

Strong china quake felt as far as Thailand

An earthquake with a magnitude of 7.5 struck China's Sichuan province on Monday, less than 100 km (60 miles) from the provincial capital of Chengdu, the U.S. Geological Survey said on its website.

The quake was felt across much of China and as far west as Bangkok, Thailand's capital, some 3,300 km (2050 miles) away, where office buildings swayed for several minutes.

It was not immediately clear if there were any casualties or damage from the tremor.

"We felt continuous shaking for about two or three minutes. All the people in our office are rushing downstairs. We're still feeling slight tremblings," said an office worker in Chengdu.

In Beijing's financial district, many workers poured from their buildings but there were no visible signs of damage. The subway system was unaffected.

"People were shouting 'get out, get out', so we all ran out of our dorm," said a student surnamed Zhang at a university in nearby Chongqing.

USGS said on its website (http://earthquake.usgs.gov) that the quake struck at 2:28 a.m. EDT (0628 GMT) at a depth of 29 kms (18 miles). The agency originally put the strength of the quake at 7.8.

Japan's meteorological agency said no warnings for a tsunami has been issued.

Sources said there was no immediate impact to the Three Gorges Dam project, the weight of whose massive reservoir, hundreds of kms from Chengdu, experts have said could increase the risk of tremors.

A spokesman for the China Earthquake Administration said it was still checking the epicenter and scale of the tremor.