Why the Haiti earthquake may not have been a natural disaster


Steve Connor Author Biography

Saturday 10 December 2011



Deforestation and extreme weather may later cause earthquakes, scientists believe.

Their findings suggest that cutting down trees on steep slopes may increase the risk of not only landslides but earthquakes in heavily deforested places such as Haiti, which suffered a devastating magnitude 7 quake in 2010.

Geologists have previously discounted the idea that low atmospheric pressure associated with tropical cyclones can influence the timing of earthquakes. But the new study suggests a different mechanism based on changes to the weight of soil and other ground material bearing down on a geological fault under seismic stress.

"Very wet rain events are the trigger. The heavy rain induces thousands of landslides and severe erosion, which removes ground material from the Earth's surface, releasing the stress and encouraging movement along faults," said Shimon Wdowinski of the University of Miami in Florida.

"The 2010 earthquake in Haiti occurred... 18 months after the same area was hit by two tropical storms and two hurricanes," he said. "It can happen in other mountainous areas affected by cyclones, such as Japan, the Philippines, and maybe Central America," he told the American Geophysical Union in San Francisco.

The idea the weather can play a role in triggering earthquakes is controversial. But Dr Wdowinski said an analysis of the timing of earthquakes and cyclones in Taiwan over the past 60 years has demonstrated a statistical correlation, with a significant number of quakes bigger than 6 occurring within four years of major cyclones – known as typhoons in the Far East.

Taiwan was hit in 1969 by Typhoon Flossie, then a 6.2 quake hit Taiwan in 1972. In 2009, Typhoon Morakot was followed by a 6.2 quake in the same year, and a 6.4 quake in 2010. Typhoon Herb, in 1996, was followed by a 6.2 quake in 1998 and a 7.6 quake in 1999.

Dr Wdowinski said rapid soil erosion on steep slopes caused by tropical cyclones changed the stress on the geological fault over a period of months or years, which can trigger an earthquake.

"Statistical analysis showed that the timing of the earthquake is above the expected. It is way above background. If it was a random process and there was no relation between earthquakes and cyclones... there was less than 1 per cent probability of this occurring," he said.

"It is not that it happens during a cyclone but that there is a delay, and the delay of between three months and three years is due to the ground erosion. The delays can be due to the time it takes for the erosion to wash the material to the ocean," he said.

An independent analysis of ground movements caused by summer monsoons in the Himalayas also suggested a link between extreme weather and earthquakes.

A study by Thomas Ader of the California Institute of Technology in Pasadena found that earthquakes were more likely to occur in dry winter months after the monsoon period.

http://www.independent.co.uk/environment/green-living/why-the-haiti-earthquake-may-not-have-been-a-natural-disaster-6275044.html

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Phone: 703-648-6714

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RESTON, Va.—The aftershock sequence of the magnitude-7 earthquake that struck near Port-au-Prince, Haiti, on Jan. 12, 2010, will continue for months, if not years. The frequency of events will diminish with time, but damaging earthquakes will remain a threat.

U.S. Geological Survey Director Marcia McNutt asked a team of USGS earthquake scientists to provide an evaluation of the earthquakes facing Haiti now and in the future. Here is the statement in its entirety from the U.S. Geological Survey:

Earthquake Hazard and Safety in Haiti and the Caribbean Region

The magnitude-7 earthquake of January 12, 2010, near Port-au-Prince, Haiti, has generated a sharp increase in concerns about the potential for future earthquakes in Haiti and the surrounding region. These concerns extend to understanding the causes of the earthquake hazard and learning what can be done to ensure seismic safety in the future. The purpose of this statement is to convey our best judgment on these subjects.

Aftershocks: The aftershock sequence of a magnitude-7 earthquake will continue for months if not years in the affected area. The frequency of events will diminish with time, but damaging earthquakes will remain possible in the coming months. There is also a small chance of subsequent earthquakes larger than the initial shock. The sequence from the Port-au-Prince earthquake continues to be very strong and active. Based on this activity and the statistics of aftershock sequences, our estimate for aftershock activity during a 30-day period beginning January 21, 2010, is as follows:

The probability of one or more earthquakes of magnitude 7 or greater is less that 3 percent.
The probability of one or more earthquakes of magnitude 6 or greater is 25 percent.
The probability of one or more earthquakes of magnitude 5 or greater is about 90 percent.
Approximately 2 to 3 aftershocks of magnitude 5 or greater are expected within this time period.

These estimates will be updated as new information becomes available.

Precautions: Any aftershock above magnitude 5.0 will be widely felt and has the potential to cause additional damage, particularly to vulnerable, already damaged structures. Anyone living in Haiti or involved in relief work there must maintain situational awareness with regard to their personal earthquake safety. They should always be aware of what action they are going to take if the ground starts to shake. Open spaces are generally safe but running through falling debris to get to an open space may be dangerous. Only qualified engineers can determine if a damaged building is safe for reoccupation. Until engineering assistance arrives, a general rule to follow is: If it does not look safe, it probably is not safe. Entry into or reoccupation of obviously damaged structures should be avoided.

Near-term concerns: The geologic fault that caused the Port-au-Prince earthquake is part of a seismically active zone between the North American and Caribbean tectonic plates. The earthquake undoubtedly relieved some stress on the fault segment that ruptured during the event, but the extent of rupture along the fault is unclear at this time. Fault slip models, preliminary radar surface deformation measurements, and examination of satellite and airborne imagery for surface rupture suggest that the segment of the Enriquillo fault to the east of the January-12 epicenter and directly adjacent to Port-au-Prince did not slip appreciably in this event. This implies that the Enriquillo fault zone near Port-au-Prince still stores sufficient strain to be released as a large, damaging earthquake during the lifetime of structures built during the reconstruction effort. In historic times, Haiti has experienced multiple large earthquakes, apparently on adjacent faults. We shall continue to study this situation using radar, LiDAR, and photographic data taken from satellites and aircraft. Field studies and ground observations of fault offsets during this earthquake and past events are essential to evaluating the potential for future earthquakes in proximity to Port-au-Prince.

Long-term concerns: It is essential that the rebuilding effort in Haiti take into account the potential for, indeed the inevitability of, future strong earthquakes. Haiti is cut by two major plate boundary fault zones. Over the past three centuries, earthquakes comparable to or stronger than the recent one have struck Haiti at least four times, including those in 1751 and 1770 that destroyed Port-au-Prince. Engineers and construction professionals know how to design and build structures that will not collapse in strong earthquake shaking. Seismic hazard assessments provide the basis for the development of appropriate building codes and the identification of regions at greatest risk. A thorough seismic hazard assessment of Haiti, as well as of other countries in the Caribbean, will provide the basis for establishing or improving building codes and strengthening building resilience over the long-term. Such assessments involve geologic investigations of faults and soil conditions, reoccupation of geodetic measurement sites to determine strain accumulation, and studies of recent and historic earthquakes and seismicity patterns and statistics. These assessments usually take several years but can be accelerated to provide results markedly better than what is currently available. From these investigations, we can assess the likelihood and nature of strong shaking and ground failure over various time frames. The development of more resilient structures and infrastructure is a long-term goal, particularly in the face of economic limitations. Over the short-term, it is critical that the rebuilding effort be undertaken with an awareness of the potential for subsequent damaging events during the next months and years. It is essential that structures such as hospitals, schools, and critical facilities be reconstructed with greater resilience for the preservation of life and functionality.

Regional concerns: The experience of the Port-au-Prince, Haiti, earthquake reveals a need for better understanding of the nature and extent of earthquake and tsunami hazard in the Caribbean region. The arc of islands that forms the Lesser Antilles and Greater Antilles generally outlines the contact zone between the Caribbean and North American plates. This entire region is seismically active due to the relative motion between the plates and is prone to damaging earthquakes: a small-scale “ring of fire” like that encircling the Pacific ocean. Historical earthquakes greater than magnitude 7 have occurred in Puerto Rico, Jamaica, Dominican Republic, Martinique, and Guadeloupe. Along the northern coast of Venezuela, the juncture of the Caribbean and South American plates has caused damaging earthquakes in the vicinity of Trinidad and Tobago. Earthquake safety policy, including building codes throughout the region, should be based on thorough seismic hazard assessments.

You can access a current map of aftershocks at the M7.0 Haiti Earthquake and Aftershocks Web site, and you can listen to podcast interviews at the USGS CoreCast Web site.

USGS provides science for a changing world. For more information, visit www.usgs.gov.

Subscribe to USGS News Releases via our electronic mailing list or RSS feed.

**** www.usgs.gov ****

Links and contacts within this release are valid at the time of publication.

I dont doubt it, anything is possible and why not ?

Why So Many Earthquakes This Decade?

By Rycharde Manne | February 28th 2010 12:04 PM |

About Rycharde

Rycharde Manne is the internet pseudonym of Richard Mankiewicz. Author of The Story of Mathematics and contributing author to The Science Book, my...

In light of some comments below, and what appears to be an inability to follow a simple link, I accept it is time to rewrite this blog post as one seamless narrative. Thanks to those comments that helped solve the original problem.

19 April 2010, version 2.0

While Haiti is still sorting out the chaos from its January earthquake, the Earth suffers another massive quake in Chile. At a magnitude of 8.8 on the Richter scale this is one of the most powerful earthquakes ever recorded. Concerns about a tsunami spreading across the Pacific have abated and the Chilean authorities claim they have the resources to handle the catastrophe.

Why are we having so many earthquakes recently? Is it just that the media likes to report dramatic and tragic events, or has there been a quantitative increase? The graph below appears to tell a worrying story.


The graph legend states "USGS Worldwide Deadly&Destructive Earthquakes between Magnitudes 6 and 8" and plots data from 1900 to 2008. It appears to show a huge spike in major earthquakes starting some time around 1999. The conspiracy theorists have been all over this like a rash and numerous fingers are pointing to HAARP technology. Even the official literature states that starting in 1996 HAARP tested its capabilities for geological mapping using ELF waves by modulating the ambient current in the ionosphere using HF radio waves. Such a graph, showing a spike soon after HAARP started, seems to confirm the theorists' worse fears that not only has there been an increase in destructive earthquakes but that they may well be artificially created.

However, there's one problem with this theory: the graph does not show what it claims to show.

If you go to the URL referenced in the graph's title - http://earthquake.usgs.gov/earthquakes/world/historical.php - you will find the data upon which the graph is based. However, the subheading on that webpage reads:"Selected earthquakes of general historic interest." This is not a full data set but one selected by the USGS as being of historic interest. The above graph is therefore an artefact of this selection process. To claim that there has been a huge increase in major earthquakes based solely upon this graph is therefore false.

Luckily, another page at the USGS does have a full data set, although sadly only going back 30 years. I therefore created my own graph by calculating all the earthquakes above magnitude 6 for each year. The new graph looks like this:

USGS Major Earthquakes 1980-2009


Along the vertical axis are the number of such earthquakes per year and along the horizontal axis are the years 1980 to 2009. The line plotted is a rolling 10-year average to see if there is any trend. Admittedly, this is not 100 years worth of data but the concerns about the first graph were about a recent increase in major earthquakes so comparing the two is worthwhile.

As we can see, there was an upward trend in the 1990s but this has since stabilised at about 150 major earthquakes globally per year - or an average of 3 per week. Those earthquakes that make headline news are obviously those that cause chaos and destruction to humans. But there are many earthquakes around the world every single day, they just don't get elevated from local or national news onto the world stage.

If every earthquake was a harbinger of an impending apocalypse then I think I would go look for a different omen or live in perpetual disappointment. As for conspiracies, not all of them are wrong, but in this particular case, ditch that graph!

So, has there been a spike up in major earthquakes over the last decade? No.

Has there been any increase in major earthquakes in recent history? Some during the 1990s, although the data I have only covers the last 30 years. The USGS, who hold all the data, say that major earthquakes have been fairly constant.

Has something fundamentally changed in the motions of the Earth's tectonic plates? To get the answer to that question you'll have to consult a specialist.

The subject of this simple blog post was not geology or earthquakes or HAARP or conspiracies, but a simple question about finding the data to fit a graph. Whenever you see data being presented online have a look at the original source, and even then double check that the raw data has been correctly represented and interpreted.

For lessons in data visualisations, and on how to abuse them, there is nobody better than Edward Tufte.


==
Below is the original post (indeed v1.0 and v1.1 with the link). All comments before 19 April refer to this post, and would make little sense without this post as reference. That some comments may make little sense anyway I leave to the reader's judgement.
==

While Haiti is still sorting out the chaos from its January earthquake, the Earth suffers another massive quake in Chile. At a magnitude of 8.8 on the Richter scale this is one of the most powerful earthquakes ever recorded. Concerns about a tsunami spreading across the Pacific have abated and the Chilean authorities claim they have the resources to handle the catastrophe.

Why are we having so many earthquakes recently? Is it just that the media likes to report dramatic and tragic events, or has there been a quantitative increase? The graph below tells a worrying story.

The graph is compiled from data from the US Geological Survey (USGS), which monitors earthquakes throughout the globe. The data goes back over 100 years and looks as if this was compiled in 2007 or 2008. The URL which it points to has worldwide data on earthquakes but no longer has a graphical representation. Perhaps the graph is so alarming the USGS decided not to show data in this way. Just to fill in the recent data: 2008 saw 35 earthquakes of magnitude 6 and over; and 2009 saw a record-breaking 52, taking it way off the above scale - you can go count them yourself!


This alarming increase seems to have started in 1999. The conspiracy theorists have been all over this like a rash and numerous fingers are pointing to HAARP technology. There is increasing evidence that HAARP technology can alter the weather, but can it cause earthquakes? Even the official literature states that starting in 1996 HAARP tested its capabilities for geological mapping using ELF waves by modulating the ambient current in the ionosphere using HF radio waves. The official HAARP website has some interesting simulations of the fields created in the Earth's ionosphere-magnetosphere. Weather modification is another hornet's nest so I'd like to keep this to earthquakes.

However, this isn't a conspiracy website, so are there any scientists in this field who can explain this huge spike in earthquakes? An artefact of more measuring stations, surely not?

Update: we seem to have some answers! The above graph is an artefact of selective data. As some readers don't go through all the comments here is the link to the relevant comment and a new graph.

Could this by any chance, possibly be bible prophecy in action ?