Was the 2010 Haiti Earthquake triggered by deforestation and the 2008 hurricanes?

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Tall's picture
Tall
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Was the 2010 Haiti Earthquake triggered by deforestation and the 2008 hurricanes?

I thought that this was an interesting but technical piece.  It suggests that so-called natural phenomenon such as earthquakes may have anthropogenic triggers in addition to the increasingly recognized role of dams and large water impoundments.

At last week’s American Geophysical Union (AGU) meeting last week in San Francisco, Shimon Wdowinsky of the University of Miami proposed a different method whereby unusual strains on the crust might trigger an earthquake. In a talk titled, Triggering of the 2010 Haiti earthquake by hurricanes and possibly deforestation , Wdowinsky studied the stresses on Earth’s crust over the epicenter of the mighty January 12, 2010 Haiti earthquake that killed over 200,000 people. This quake was centered in a mountainous area of southwest Haiti that has undergone severe deforestation—over 98% of the trees have been felled on the mountain in recent decades, allowing extreme erosion to occur during Haiti’s frequent heavy rainfall events. Since 1975, the erosion rate in these mountains has been 6 mm/year, compared to the typical erosion rate of less than 1 mm/yr in forested tropical mountains.

Satellite imagery (Figure 2) reveals that the eroded material has built up significantly in the Leogane Delta to the north of the earthquake’s epicenter. In the 2008 hurricane season, four storms–Fay, Gustav, Hanna, and Ike–dumped heavy rains on the impoverished nation. The bare, rugged hillsides let flood waters rampage into large areas of the country, killing over 1,000, destroying 22,702 homes, and damaging another 84,625. About 800,000 people were affected–8% of Haiti’s total population. The flood wiped out 70% of Haiti’s crops, resulting in dozens of deaths of children due to malnutrition in the months following the storms. Damage was estimated at over $1 billion, the costliest natural disaster in Haitian history. The damage amounted to over 5% of the country’s $17 billion GDP, a staggering blow for a nation so poor. Tragically, the hurricanes of 2008 may have set up Haiti for an ever larger disaster.

Wdowinsky computed that the amount of mass eroded away from the mountains over the epicenter of the 2010 earthquake was sufficient to cause crustal strains capable of causing a vertically-oriented slippage along a previously unknown fault. This type of motion is quite unusual in this region, as most quakes in Haiti tend to be of the strike-slip variety, where the tectonic plates slide horizontally past each other. The fact that the 2010 Haiti quake occurred along a vertically moving fault lends support to the idea that the slippage was triggered due to mass stripped off the mountains by erosion over the epicenter, combined with the extra weight of the extra sediment deposited in the Leogane Delta clamping down on the northern portion of the fault. Wdowinsky gave two other examples in Taiwan where earthquakes followed several months after the passage of tropical cyclones that dumped heavy rains over mountainous regions. His theory of tropical cyclone-triggered quakes deserves consideration, and provides another excellent reason to curb excessive deforestation!

http://climateprogress.org/2010/12/21/was-the-2010-haiti-earthquake-triggered-by-deforestation-and-the-2008-hurricanes/#more-39127

Dogs_In_A_Pile's picture
Dogs_In_A_Pile
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Re: Was the 2010 Haiti Earthquake triggered by ...

Tall -

The first link goes to a site that requires a log in. The second link goes to an interesting article, but it strikes me as coming up a little short on scientific data, but long on the emotion.

It would have been nice to see some estimates and science based discussion in a few areas:

1. The weight of the eroded material

2. The size, shape and area of the tectonic plate Haiti sits on.

3. The distribution of the eroded material - was it concentrated on the edge of the plate or was it distributed over a large area?

4. What kind of moment arm the deposited material put on the plate to cause tipping and/or shifting of the plate.

5. How this tipping caused the earthquake's epicenter to be where it was.

 

It was an interesting article, but it seems to be less science and just another way to get dicussion about the adverse impact of deforestation going.  I think most readers would agree that on the "Good-Bad" spectrum, unchecked deforestation is "Bad".

One additional question.....which Weather Underground does Jeff Masters belong to?  Cool

Full Moon's picture
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Re: Was the 2010 Haiti Earthquake triggered by ...

 So  if we google  earthquake in the last 7 days .   Do we use this  theory for the rest of the world ?     Maybe it is all the oil we are sucking out of the inner earth ?    Hmmm    We could go on a whole lot of rabit trails here .

http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/quakes_all.html

 

 

EndGamePlayer's picture
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Re: Was the 2010 Haiti Earthquake triggered by ...

This is close to several years of articles I've read. In THEORY - the Earth expands & contracts for several reasons -

  • fast heating = expansion and fast cooling=contraction
  • extreme dry conditions = movement and sudden extreme wet conditions = movement (this is the first I've heard of de-forestation being a cause but I guess it makes sense when you think about how plants hold in moisture and slow run-off).
  • high gravity pulls like those that occur from solar flairs, eclipses and other ocean tidal effects.

The discussion table (and internet rumors abound) about how the Gulf Oil slowed, stopped or reversed the gulf's current and that its not flowing into the Atlantic - thus the huge fast cooling in North America, Greenland, Iceland and Europe. None of which is verfifyable nformation.

Exponetial Everything? EGP

Dogs_In_A_Pile's picture
Dogs_In_A_Pile
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Re: Was the 2010 Haiti Earthquake triggered by ...
EndGamePlayer wrote:

The discussion table (and internet rumors abound) about how the Gulf Oil slowed, stopped or reversed the gulf's current and that its not flowing into the Atlantic - thus the huge fast cooling in North America, Greenland, Iceland and Europe. None of which is verfifyable nformation.

Exponetial Everything? EGP

Sorta.

As of 0800Z this morning the Gulf Stream was measured using in situ acoustic doppler current profiler buoys off of Cape Canaveral at 3.8 knots.  Coming north through the Strait of Florida up to Hatteras, the Gulf Stream current core moves at speeds as high as 5 knots.  As it turns east and becomes broader, it slows to about 1 knot

That would verify that the Gulf Stream is still flowing and that the cold weather in Europe is due to umm, oh I don't know......December?

Tall's picture
Tall
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Posts: 564
Re: Was the 2010 Haiti Earthquake triggered by ...

Hi Dogs,

 

I think that you will need to ask the author of the study for answers to your technical questions. Professor Wdowinski may be reached through Barbra Gonzalez at barbg ‘ at’ rsmas.miami.edu or 305-984-7107.

 

I posted this article not to add to the many reasons why deforestation is ‘bad’, but to point out that human activities are increasing recognized as triggering earthquakes.  This is not widespread knowledge. My early understanding (and you see this espoused in the MSM frequently) was that in the spectrum of natural disasters, earthquakes were pretty much acts of nature.  In particular, I had never seen a link drawn between deforestation and erosion to earthquakes before, hence my post.

 

I guess you didn’t like the general audience tone of this article.  May I instead recommend:

 

A little more technical information about reservoir-triggered earthquakes from and engineering site: http://www.seis.com.au/Basics/Dams.html

 

Or, if you prefer,

 

A ‘Nature’ review (available without registration) of human activities that are associated with triggering earthquakes such as “artificial water reservoir impoundments, deep and open-pit mining, hydrocarbon production, and fluid injections/extractions”:

 

“…more than 200 damaging earthquakes, associated with industrialization and urbanization, were documented since the 20th century. This type of geohazard has impacts on human security on a regional and national level. … This article provides an overview of global statistics of human-triggered earthquakes. It describes how geomechanical pollution due to large-scale geoengineering activities can advance the clock of earthquakes or trigger new seismic events.”

 

http://precedings.nature.com/documents/4745/version/3/files/npre20104745-3.pdf

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