It must be the worst nightmare; the forces of nature spinning totally out of control. Is that what is about to happen? With one major ecological catastrophe after another? If so, it would be the “fattest tail” in the history of science.
“We hear about more earthquakes and it seems like they are more frequent.”
J. Ramón Arrowsmith
8,8 on The Richter Scale is quite a ride. But it’s not abnormal. Nor is the earthquake frequency out of the “normal” range, according to scientists. What’s worries me is that most scientists are using the same mathematical models when reaching their conclusions as the economists that didn’t see the financial crisis coming.
It’s part of the very active “Ring of ire,” a zone of major crustal plate clashes that surround the Pacific Ocean.
“This particular subduction zone has produced very damaging earthquakes throughout its history,” says Randy Baldwin, a geophysicist with the U.S. Geological Survey (USGS), according to Associated Press.
The world’s largest quake ever recorded, magnitude 9.5, occurred along the same fault zone in May 1960.
A Whole Lotta Shaking Going On
Magnitude-8 earthquakes occur globally, on average, just once a year.
“Since magnitudes are given on a logarithmic scale, an 8.8-magnitude is much more intense than a magnitude 8, and so this event would be even rarer,” J. Ramón Arrowsmith, a geologist at Arizona State University, says.
The Ryukyu Islands of Japan were hit with a 7.0-magnitude quake just last night. News of this, the Haiti quake and now Chile make it seem Earth is becoming ever more active. But in the grand scheme of things, geologists say this is just Mother Nature as usual.
“From our human perspective with our relatively short and incomplete memories and better and better communications around the world, we hear about more earthquakes and it seems like they are more frequent,” Arrowsmith said.
“But this is probably not any indication of a global change in earthquake rate of significance.”
“Coupled with better communication, as the human population skyrocket and we move into more hazardous regions, we’re going to hear more about the events that do occur,” Arrowsmith adds.
However, Stephen S. Gao, a geophysicist at Missouri University of Science & Technology, says: “Relative to the 20-year period from the mid 1970′s to the mid 1990′s, the Earth has been more active over the past 15 or so years.”
“We still do not know the reason for this yet. Could simply be the natural temporal variation of the stress field in the earth’s lithosphere.”
(The lithosphere; the outer solid part of the Earth.)
The latest earthquake in Chile have two common factors with the 7,0 magnitude quake in Japan recently.
For one, any seismic waves that did make their way from Japan to the Chilean coast could play a slight role in the ground-shaking.
“It is too far away for any direct triggering, and those distances also make the seismic waves as they would pass by from the Haiti or Japan events pretty small because of attenuation,” J. Ramón Arrowsmith says.
(Attenuation is the decrease in energy with distance.)
“Nevertheless, if the Chilean fault surface were close to failure, those small waves could push it even closer.”
In addition, both regions reside within the Ring of Fire, which is a zone surrounding the Pacific Ocean where the Pacific tectonic plate and other plates dive beneath other slabs of Earth.
About 90 percent of the world’s earthquakes occur along this arc.
The Fat Tail of Mother Nature
What do you think geologists, climate scientists, financial engineers and poker players have in common?
They all use – roughly – the same mathematical models, based on available historical data, to calculate probability.
Events that occur outside the statistical pattern are usually referred to as “fat tails”.
The last couple of years, the term “Black Swan” have been used about similar unexpected incidences.
(After Nassim Taleb’s famous book by the same name).
The “rocket scientists” on Wall Street obviously ran into a “fat tail” and it seems like the climate scientists, (or should I say “the climate industry”?), are about to do the same.
So, what about the geologists?
What happen if?
That’s the question probability models are used for.
The answer is only as reliable as the date you put into the formula.
And when it comes to the development of the Earth, our historical data is less than insignificant.
Even a million years is next to nothing.
Still, we’re determined to alter the composition of our delicate earthly mechanisms.
Without knowing the consequences.
What would happen if we replaced all the salt water on the Earth with fresh water?
Or, what would happen if we replaced all the oil in the Earths lithosphere with a mixture of salt water and dirt? (Or pump the empty oil wells in the North Sea full of CO2?)
Well, I’m no geologist.
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- Huge earthquake hits Chile (telegraph.co.uk)
- Haiti warned to brace for another big quake (windsorstar.com)
- 6.3 magnitude earthquake hits Tonga: USGS (nationalpost.com)
- Scientists Scramble to Analyze Haiti’s Seismic Risk (wired.com)
- Ask AP: Earthquake predictions, commander-in-chief (seattletimes.nwsource.com)
- Two South Pacific earthquakes unlikely to be connected (guardian.co.uk)
- U.S. Refines Quake Alerts (online.wsj.com)