Monday, March 1, 2010

Chile Vs Haitian earthquakes

The Chilean earthquake was the second catastrophe to hit Latin America this year, following the disaster in Haiti - yet the death toll remains mercifully low by comparison. The 8.8 magnitude of the Chile quake made it 500 times more powerful than the one in Haiti, which had a magnitude of 7.0. As of Sunday(28-2-2010), the death toll from the earthquake in southern Chile stood at about 700. By comparison, the Jan. 12 earthquake in Haiti killed about 230,000 people,as reported by the Haitian government. Why?

Readiness: Chile was more prepared
Chile is wealthier and infinitely better prepared, with strict building codes, robust emergency response and a long history of handling seismic catastrophes. No living Haitian had experienced a quake at home when the Jan. 12 disaster crumbled their poorly constructed buildings.

Epicenter - Chile earthquake is off shore
Saturday's quake was centered offshore an estimated 21 miles (34 kilometers) underground in a relatively unpopulated area while Haiti's tectonic mayhem struck closer to the surface — about 8 miles (13 kilometers) — and right on the edge of Port-au-Prince, factors that increased its destructiveness.

"Earthquakes don't kill — they don't create damage — if there's nothing to damage," said Eric Calais, a Purdue University geophysicist studying the Haiti quake.

Building Code - Chile is strict on earthquake resistant

The U.S. Geological Survey says eight Haitian cities and towns — including this capital of 3 million — suffered "violent" to "extreme" shaking in last month's 7-magnitude quake, which Haiti's government estimates killed some 220,000 people and left about 1.2 homeless. Chile's death toll was in the hundreds.

By contrast, no Chilean urban area suffered more than "severe" shaking — the third most serious level — Saturday in its 8.8-magnitude disaster, by USGS measure. The quake was centered 200 miles (325 kms) away from Chile's capital and largest city, Santiago.

Chile has been building according to the best standards in the world for at least 20 years," García says. "As the technology and techniques have gotten better, the rules have gotten stricter. And that's what has minimized the loss of life this time around."

Chile sits on the so-called "ring of fire," a system of geological faults that circles the Pacific Ocean, and is frequently rattled by earthquakes. In 1906, a magnitude-8.6 quake near Valparaiso killed 20,000 people. A magnitude-7.8 quake near Chillan killed 28,000 people in 1939.

The quake on May 22, 1960, near Valdivia shattered the records for the strongest quake ever. With a magnitude of 9.5, it sent tsunami waves racing through the Pacific to as far away as Japan and the Aleutian Islands of Alaska. About 5,000 people were killed.

After that quake, Chile imposed strict rules about the quality of building materials, García says. It also invested heavily in research to find weak points in the soil under major cities.

"Chile has one of the most modern building codes in the world, and now we're seeing how the rules pay off," says Juan Felipe Heredia, a Mexican civil engineer who has designed buildings in South America.

"When you look at the architecture in Chile you see buildings that have damage, but not the complete pancaking that you've got in Haiti," said Cameron Sinclair, executive director of Architecture for Humanity, a 10-year-old nonprofit that has helped people in 36 countries rebuild after disasters. Sinclair said he has architect colleagues in Chile who have built thousands of low-income housing structures to be earthquake resistant.

In Haiti, by contrast, there is no building code. Patrick Midy, a leading Haitian architect, said he knew of only three earthquake-resistant buildings in the Western Hemisphere's poorest country.

Economical Strength

Chile's economic strength also gives it an advantage. It is the wealthiest country in Latin America, with a per-capita income of $14,700. Chileans, on the other hand, have homes and offices built to ride out quakes, their steel skeletons designed to sway with seismic waves rather than resist them. Haiti on other hand is the poorest nation in America.

Energy release

In terms of energy released at the epicenter, the Chilean quake was 501 times stronger. But energy dissipates rather quickly as distances grow from epicenters — and the ground beneath Port-au-Prince is less stable by comparison and "shakes like jelly," says University of Miami geologist Tim Dixon.

Survivors of Haiti's quake described abject panic — much of it well-founded as buildings imploded around them. Many Haitians grabbed cement pillars only to watch them crumble in their hands. Haitians were not schooled in how to react — by sheltering under tables and door frames, and away from glass windows.

Professionalism - No of Seismologists

Sinclair's San Francisco-based organization received 400 requests for help the day after the Haiti quake but he said it had yet to receive a single request for help for Chile.

"On a per-capita basis, Chile has more world-renowned seismologists and earthquake engineers than anywhere else," said Brian E. Tucker, president of GeoHazards International, a nonprofit organization based in Palo Alto, California.

Responsible Government

The professional advice from seismologists and earthquake engineers are heeded by the Chile government, which is Latin America's wealthiest nation, getting built not just into architects' blueprints and building codes but also into government contingency planning.

The fact that the president (Michelle Bachelet) was out giving minute-to-minute reports a few hours after the quake in the middle of the night gives you an indication of their disaster responsiveness.

Most Haitians didn't know whether their president, Rene Preval, was alive or dead for at least a day after the quake. The National Palace and his residence — like most government buildings — had collapsed. There was no direction from the President, or even the next in command of the nation. Haiti's TV, cell phone networks and radio stations were knocked off the air by the seismic jolt.

Urban Density
The construction in Haiti is absolutely appalling - it wasn't recognised by the Haitians as an area at risk from earthquakes."So they didn't have any motivation to build safe buildings."And because the country is so poor they didn't have any resources to do so anyway

Port-au-Prince, the Haitian capital, was crammed with three million human beings, and is one of the most densely populated areas in the western hemisphere.Haiti had not felt such a devastating earthquake in living memory, though it had suffered a number of smaller tremors over the years.

Earthquake Experience
Chile has experienced numerous powerful quakes over its history, including the most powerful earthquake in the world, striking with a magnitude of 9.5 in May 1960. Chile, as a result of suffering from frequent serious earthquakes throughout its history, has learned many lessons about building quake-proof structures. Chilean quake hit outside any populated centres. Economically wise, Chile is better than Haiti. Chile is South America's most stable and prosperous country.

Calais, the geologist, noted that frequent seismic activity is as common to Chile as it is to the rest of the Andean ridge. Chile experienced the strongest earthquake on record in 1960, and Saturday's quake was the nation's third of over magnitude-8.7.

"It's quite likely that every person there has felt a major earthquake in their lifetime," he said, "whereas the last one to hit Port-au-Prince was 250 years ago."

Worry of US professionals

Chile offers more lessons for U.S. planners than Haiti does, McNutt says, given similarities in building codes and earthquake awareness. Although the U.S. has made preparations more stringently than anywhere else, McNutt sees an Achilles' heel in the aging U.S. infrastructure of bridges and overpasses.

"I look at the reports of collapsing bridges and highways in Chile and worry what would happen here," she says.

In 2009, the American Society of Civil Engineers warned that 26% of the nation's bridges "are either structurally deficient or functionally obsolete." The engineers' report, based on Department of Transportation figures, showed that one in three urban bridges are either broken or obsolete, and suggested a $17 billion yearly shortfall in maintenance spending nationwide.

"Clearly infrastructure is a legitimate worry," says geotechnical earthquake engineer John Christian of Waban, Mass., a member of the National Academy of Engineering. "Engineers worry that we have plenty of buildings that fall down on their own, even without earthquakes."

California's San Andreas fault poses a much-worried threat. Californians have focused on preparing for a Big One for more than a century, since a 1906 quake in Northern California motivated people to take the hazard seriously, says Susan Hough, geologist at the U.S. Geological Survey in Pasadena. A 1933 quake centered at Long Beach led to passage a year later of tougher building requirements for schools.

"Since that time, the building codes have continued to evolve as we learn more about what buildings are dangerous and how the ground shakes under earthquakes," she says.

State and local building codes have prevented new construction of the most vulnerable building styles, unreinforced brick or concrete structures, she says. The 1994 Northridge earthquake in the San Fernando Valley of Los Angeles exposed weaknesses in steel welds and buildings.

Now the biggest worry is widespread use of apartments built atop ground-level parking, with supporting poles that can give way in a quake of sufficient size, she says.

"People may be complacent about California," Hough says. "We haven't really seen a big earthquake that really tests the infrastructure."

Such a big quake may be overdue in the heavily populated Southern California region, says Jim Goltz, earthquake and tsunami program manager for the California Emergency Management Agency.

"We have hundreds of faults in Southern California, and we could have a really large earthquake on any of them," Goltz says.

Officials in California are also focusing on non-structural hazards that can be deadly in big quakes, such as big-screen televisions, water heaters, furniture and bookshelves that can become missiles in violent quakes.

This Oct. 21, California officials will hold their third annual "Great California Shakeout" event aimed at informing people what to do in such a quake. Their advice — "Drop, cover and hold on" — suggests people take cover under furniture to protect themselves from flying objects.

The spate of recent earthquakes, starting with the magnitude-9.3 Indian Ocean event in 2004, follows a 50-year cycle of earthquake activity, said Marcia McNutt, director of the U.S. Geological Survey. The last cycle, in the 1960s, produced the two other record holders for recorded earthquakes — the magnitude-9.5 quake near Valdivia and a magnitude-9.2 quake in Alaska's Prince William Sound.

"We know earthquakes are not uniformly distributed in time; they cluster," McNutt says. "Now suddenly the earthquakes are lighting up again."

Even with the knowledge that a Big One is inevitable, retrofitting buildings and requiring better building practices is a tough sell, even in parts of the country where quakes are facts of life, says Mark Benthien of the Southern California Earthquake Center at the University of Southern California.

"Improvements to our building codes have often followed the earthquakes that we have had," Benthien says. "They are very difficult to pass in other times."

A report commissioned recently by the Earthquake Engineering Research Institute and the U.S. Geological Survey concluded that many of the deaths in Haiti's earthquake could have been prevented by using earthquake-resistant designs and construction, as well as improved quality control in concrete and masonry work of affected buildings.

"The massive human losses can be attributed to a lack of attention to earthquake-resistant design and construction practices, and the poor quality of much of the construction," according to the report. It added: "Indirect evidence suggests that the earthquake did not produce ground motions sufficient to severely damage well-engineered structures."

Chile shows that earthquake-resistant building codes don't mean that people will be able to return to buildings, "just that they won't fall on them," Christian adds. The unfolding scenario of millions of displaced Chileans would likely occur in the USA as well, after a major earthquake, he says.

"We could build things to completely survive earthquakes," Christian says. "They would all look like nuclear power plants. And cost as much."

No predictions are possible for when an earthquake will strike, but the pattern of recent events does worry U.S. planners. "It's not a matter of if, only of when an event like this strikes the people of the United States," says Marcia McNutt, director of the U.S. Geological Survey. "Shame on us if we don't prepare."

Not only US, Chile Earthquake revealed that other nations have more to learn from Chile, to be prepare for the unknown. Indonesia, Philippines, China, other earthquake prone nations, and even nations which have not experienced earthquake in their history need to learn a lesson from Chile,the earth plates are moving, the Himalaya is moving, will the earthquake belt move and affect the non-earthquake belt nations?. I am not geologist, but I know anything can happen and there is no guarantee as disaster is natural act not predictable. The earth is changing and under pressure, anything can happen, prepared.

Chile, their government stance on building code, develop a resource pool of Seismologists, and their expert views were seriously taken. The earthquake education and preparation, the government's stance and seriousness on earthquake impact risks, and a responsible government for the people which understand the geological risk of the country, were the factors that help Chile avoid great disaster. A respectable act of their government and people.

Related references/extract:

1. Compare: Chile Quake vs. Haiti Quake, Tale of two quakes - Chile quake ready, Haiti not, Text Story by Associated Press,
2.Chilean earthquake hints at dangers of 'Big One' for USA,
3. Latest updates: Disaster experts praise Chile quake response(2010),by MICHAEL WARREN (AP),dated 11-3-2010,

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