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Mother Nature Still in Charge

May 9, 2008

The Myanmar cyclone. The earthquake off the coast of Japan. The Chilean volcano. Has Earth gone bonkers?

Not at all. This level of natural activity is normal for Earth, scientists say.

“Mother Nature is just reminding us that she is in charge,” Bill Patzert, a climatologist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., told LiveScience.

That also means the recent Midwestern quake (centered in Illinois) and temblors near Reno, though unnerving and frightening to locals, were just another day for Planet Earth.

Reference point

A look back at events in 2007 serves to remind just how wild this world routinely is. EM-DAT, the OFDA/CRED International Disaster Database, tracks natural disasters in which either 10 or more people were killed, 100 or more people were affected, a State of Emergency was declared, or there was a call for international assistance.

In the United States in 2007, EM-DAT tallied four such tornado disasters, five winter storms, seven floods, two wildfires and a drought in various locations. Non-EM-DAT events included six U.S. hurricanes and 2,789 earthquakes of which 80 were 5.0-magnitude or greater, according to the U.S. Geological Survey.

Tornadoes are an American affliction primarily, it’s true, but that is a result of geography, Patzert said. About 80 percent of tornadoes in the world happen in the United States because cool Canadian air mixes with warm moist air coming from the Gulf of Mexico, he said.

The appearance of a cluster

It might look and feel like the recent disasters worldwide are a cluster of events that could be related, but scientists say they aren’t.

“It’s totally random,” said Peter Kelemen, a geologist at Columbia University’s Lamont-Doherty Earth Observatory in New York.

Kelemen this week told the story of anthropologist Bronislaw Malinowski, who detailed the thinking of Trobriand Islanders in his book, “Magic, Science, and Religion” (1948).

“He said the distinction between magic and science for those Trobriand Islanders was that for magic you only count confirming cases,” Kelemen said. “And so, say you had this idea that earthquakes occur right before or after volcanic eruptions, so when that happens you notice and you put a notch in your stick or whatever. When there is earthquake that doesn’t occur with a volcanic eruption, you don’t notice at all or say there must have been mitigating circumstances in this case.”

Scientists can fall into the same trap.

“Scientists do an awful lot of what Malinowski would’ve called magic all the time,” Kelemen said. “We filter data and come up with reasons why our [results] in one instance are not correct and that allows us to overlook that instance. Nevertheless, it’s a trap.”

Kelemen suspects people are struck by similar coincidences in nature and “probably don’t make a note of it when there is an earthquake and no volcano. It is only when these things are happening clusters that it makes an impression on you.”

He pointed out that you can use a computer to generate random numbers and plot them graphically and see patterns and clustering. Clearly though, there is no natural or scientific phenomenon behind those figures.

More disasters than usual?

The number of reported natural disasters globally has been on a fast rise since the 1960s. EM-DAT disasters are up from about 120 in 1980 to more than 400 in 2007.

But the increase has nothing to do with the planet.

Rather, the rise is the result better monitoring and reporting of natural disasters, said Charles Mandeville, a volcanologist at the American Museum of Natural History in New York.

And the actual number of people killed worldwide by natural disasters has been relatively small (under 500,000 per year) since the 1960s compared previous decades in the 20th century when death tolls sometimes exceeded 2 million or even 3 million, according to EM-DAT.

That drop is the due to better building codes and preparation, Mandeville said.

“And we’ve done a much better job of evacuating people that need to be evacuated, the evacuation of Chaiten, Chile, [this week] being a good example,” he said. “We know now that maybe 30 kilometers is a reasonable evacuation distance for a volcano that is erupting explosively from what we have learned from Krakatau [in 1883] and Monserrat [in 1997] and Mt. Pinatubo [in 1991].”

The 1982 eruption of El Chicon volcano in Chiapas, Mexico, helped planners learn about the hazards of volcanoes that have glaciers on them, he said.

“We’re starting to learn not only recognizing the precursors to certain things like volcanic eruptions,” Mandeville said. “We’re trying to get to that state of affairs with earthquakes by mapping out where strains are very high and also trying to build buildings that will withstand a moderate magnitude earthquake.”

Many past fatalities owed to people going back to partially damaged buildings, which then collapsed or experienced fires related to natural gas pipeline breaks.

The location factor

The ongoing Reno rumble and the Midwest earthquake last month spared human lives, unlike the disastrous cyclone in Myanmar, where the death toll could exceed 100,000, according to the latest reports.

“Mother Nature can be cruel especially when human nature is careless and unprepared,” Patzert said. “The Earth is very dynamic. People forget that cyclones, typhoons and hurricanes – some years are active, some years are not.”

The latest natural events are a wake-up call and reminder that Earth is dynamic, he said.

Many homes and businesses are now built in coastal and earthquake-prone regions. This shows a “disdain for the power of nature,” Patzert said. “She’s still in charge.”

For this reason, if the Indonesian tsunami of 2004 had happened half a century ago, it would’ve killed some 30,000 people, rather than nearly 300,000, Patzert said.


Source: imaginova



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