Was the 2010 Haiti Earthquake triggered by deforestation and the 2008 hurricanes?
Major earthquakes occur when the stress on rocks between two tectonic plates reaches a critical breaking point, allowing the earth to move along the connecting fault. While the slow creep of the tectonic plates makes earthquakes inevitable along major faults, the timing and exact location of the quake epicenter can be influenced by outside forces pushing down on Earth's crust. For example, the sloshing of water into the Eastern Pacific during El Niño events has been linked to magnitude 4, 5, and 6 earthquakes on the seafloor below, due to the extra weight of water caused by local sea level rise. Sea level rise due to rapid melting of Earth's ice sheets could also potentially trigger earthquakes, though it is unknown at what melting rate such an effect might become significant.
Figure 1. Google Earth image of Haiti taken November 8, 2010, showing the capital of Port-Au-Prince and the mountainous region to its west where the epicenter of the 2010 earthquake was. Note the brown color of the mountains, where all the vegetation has been stripped off, leaving bare slopes subject to extreme erosion. Heavy rains in recent years have washed huge amounts of sediment into the Leogane Delta to the north.
Figure 2. Zoom-in view of the Leogane Delta region of Figure 1, showing the large expansion in the Delta's area between 2002 and 2010. High amounts of sediments have been eroded from Haiti's deforested mountains and deposited in the Delta. Recent expansion of the river channel due to runoff from Hurricane Tomas' rains is apparent in the 2010 image. Image credit: Google Earth, Digital Globe, GeoEye.
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!
Figure 3. Two of 2008's four tropical cyclones that ravaged Haiti: Tropical Storm Hanna (right) and Hurricane Gustav (left). Image taken at 10:40 am EDT September 1, 2008. Image credit: NASA/GSFC.
Christmas in Haiti
Portlight.org will brighten the lives of hundreds of kids in Haiti this week, thanks to their successful Christmas in Haiti fundraiser. Portlight raised $1800 to buy toys, candies, and other assorted goodies. The shipment left Charleston last week, and will arrive in time for Christmas. Thanks to everyone who helped support this worthy effort!
Jeff Masters
Reader Comments
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Is there a better link to Shimon Wdowinsky's paper? The one provided requires an account.
:-(
It's been speculated that eruptions of certain volcanoes can be triggered by seasonal changes in wind patterns that force billions of tons of ocean water to pile up near them, in effect squeezing their underlying magma chambers like a weight on a tube of toothpaste. (Article). In light of that, it certainly seems plausible for Haitian earthquakes to be triggered by a buildup of
trillionsmillions or possibly billions of tons of sediment.Trillions or Billions?
OK, I know this is 16 days out, but the 06z run of GFS shows an Arctic blast dropping temps to below -30C (-22F) for much of Minnesota, North Dakota and Wisconsin, and below -20C (-4F) for parts of South Dakota, Montana, Iowa, Nebraska, Wyoming, Missouri, Illinois, Indiana, Ohio, Michigan and Kentucky for early January. Other models runs do not predict such cold weather, but some long-range forecasters suggest a possible warm-up of up to 45C (81F) in less than a week following that cold blast in some areas. It'll be interesting to watch the next few model runs.
Very interesting theory, Dr. Masters. Your previous blog posts connected the Arctic warming to the cold air blasts in a way similar to what I described last year, and it's exciting to finally see the full picture pieced together. We've also seen posts decribing links between weather, climate change and earthquake/volcanic activity more and more often in the past year.
Omeka was likely a cat. 2, or even a cat. 3 over the West Pacific yesterday before it was declared a TD or a TS. Hopefully we find out more about this storm that had a full-fledged eye for hours.
Pretty soon mankind is going to be blamed for the fact that the moon is moving closer and closer to the earth.
I was doing two things at once--trying to factor the weight of of water over the Alaskan volcanoes--so, yes, probably billions. The earth holds about 1,361,050,000,000,000,000 tons of water (1.36 million trillion tons), so I was working with big numbers. Edited. Mea culpa... ;-)
I'm a Christian and I believe we are in a "Climate Change", not caused by man but by the aging of the earth and planets. Is man polluting the earth? Yes, but it's not causing the weather conditions nor the ice to break down. The earth is aging and getting old, as we are. That's how I believe God created it. I am no fan of evolution or the big bang theory. Again, just my two cents, and my personal opinion, which I am subject to on here.
The amount isn't important, neither is the accuracy...it is the exaggeration that counts and is used to feed the sheeple what they need to keep them under control.
NP, Neap. I knew you would answer, though. Thanks. Would like to see Shimon's numbers.
Were those fools associated with the news media? They want to sell stories. I often feel rick-rolled by the headlines on LiveScience, Yahoo and many other outlets. They promise one thing to rope you in and the actual story is mush.
Actually (and i'm not trying to preach) if you read Matthew 24, Jesus told his disciples that many disasters and famines will take place to show people signs of His second coming. If you go by the Christian faith, it's all on the timing of what the bible says. If you go scientific theory, man is destroying the earth, causing Global Warming. Just my opinion on the theory.
Sorry if you think it was mean.
Actually, no one knows what the Druids believed. The Feast of the Unconquered Sun was a Roman thing.
The dictionary has lots of adjectives. I think you'll like it.
Anyone is absolutely allowed to have and express his or her own personal opinions, regardless of whether those opinions are based on science or not. So long as the one offering those opinions is prepared to be respond to polite and respectful challenges in a polite and respectful manner, it's all good...
Burned at the stake? Come on, how do you expected to educate people when your constantly riddiculing on the blog? You can have all the facts you want, but when you add in some mean comments, ears become closed.
The pope is not following the word of God if that is true. It was just my opinion, you didn't have to question me because honestly, you'll never change my opinion lol.
You are kidding, right??? Live a little because that is a an awesome avatar.
http://www.spc.noaa.gov/coolimg/nc_storm/index.html
And a storm complex in the upper midwest during 2009 that was so intense that the NWS gave it a new classification. A super-derecho. These storms are new phenomenon. Who knows what kind of never before seen weather patterns will emerge in the coming years?
Don't dismiss the global superstorm theory just because it was featured in a movie.
Interesting read, no matter what you believe is the cause for GW/Climate Change/End of the World/Etc.
Yes
Following up on the "If you go scientific theory, man is destroying the earth, causing Global Warming." comment previously and hydrus' reply. There is no way that global warming will destroy the earth. Don't think that is the theory. It will just change things. Repeated ice ages have come and gone. We went through a snow-ball earth a long ways back. Catastrophic meteor impacts. Don't think more CO2 will do the trick either. Of course, "super-rapid comeback" is a relative term. The time scales involved far surpass anything written into our constitution.
Tropical Cyclone Advisory #2
TROPICAL CYCLONE OMEKA (CP012010)
5:00 AM HST December 20 2010
=====================================
At 15:00 PM UTC, Tropical Storm Omeka (997 hPa) located at 21.6N 176.8W or about 400 NM south of Midway Island has sustained winds of 45 knots with gusts of 55 knots. The cyclone is reported as moving northeast at 15 knots.
Gale Force Winds
=================
45 NM from the center
Forecast and Intensity
=======================
12 HRS: 23.5N 175.4W - 40 knots (Tropical Storm)
24 HRS: 26.7N 174.1W - 35 knots (Tropical Storm)
48 HRS: 34.1N 168.1W - 25 knots (Low Pressure Area)
The Next Tropical Cyclone Advisory From Central Pacific Hurricane Center will be issued at around 21:00 PM UTC..
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