
Earthquake devastation in Haiti (photo: Daily Mail UK)
Could the devastating earthquake in Haiti been acurately predicted? Could preventive measures been taken, people evacuated, lives saved?
A friend posted this excerpt on their blog today, from an online Haitian new site:
From HaitiXchange.com:
A recent article in Haiti’s Le Matin newspaper has quoted 65 year old geologist and former professor at the Geological Institute of Havana, Patrick Charles, as stating that “conditions are ripe for major seismic activity in Port-au-Prince. The inhabitants of the Haitian capital need to prepare themselves for an event which will inevitably occur…” According to him, the danger is imminent. He ads “Thank God that science has provided instruments that help predict these types of events and show how we have arrived at these conclusions.”
According to Patrick Charles, Port-au-Prince is traversed by a large fault which is part of the Enriquillo Fault Zone. The fault starts in Petionville and follows the Southern Peninsula ending at Tiburon. In 1751 and 1771, this town was completely destroyed by an earthquake. As proof to his claims, he referred to recent tremors that have occurred in Petionville, Delmas, Croix des Bouquets, and La Plaine. Minor tremors such as these usually signal a larger earthquake to come.
Although city officials often discuss this, it is noted that no measures have been put into place to address the situation. Mr. Charles mentions the following devastating scenarios: A giant tsunami reaching all the way to Lake Azuéi (aka Étang Saumâtre) flooding La Plaine, and the complete destruction of Morne l’Hopital which is currently dotted with flimsy shantytowns. If we thought the recent back-to-back hurricanes were devastating, they surely will pale in comparison to a major earthquake in the densely populated Haitian capital.
________________________________________
In mid-April of last year, New Scientist reported that geologists were predicting an earthquake in Iran for that same month (Ref 1). This scientist predicted the quake using 'pressure that builds up in rocks before an earthquake (which) causes electromagnetic disturbances influencing cloud formation overhead'. Did the prediction come true? Well, on April 3oth a mild quake shook southeast Iran - roughly the same location predicted by the scientist (Ref 2).
In their same article, New Scientist reported that an Italian scientist had successfully predicted an Italian quake (using another method involving the detection of radon gas), but his predictions were quelled by local authorities to prevent panic. This quake occurred, but the location and timing were slightly off.
So where does this anecdotal evidence really leave us? Can scientists reliably and accurately predict earthquakes in terms of location, strength and timing?
Volcanic eruptions and earthquakes occur along plate boundaries - those regions where the tectonic plates meet, either on land or under the sea. These plate boundaries are all over the earth (see map below), and the plates are constantly sliding past each other, typically a few centimeters per year.
Earthquakes occur at these sites on these plate boundaries that are called fault lines (perhaps most well-known being the San Andreas fault), named for the places where strain builds up between the tectonic plates and a sudden shift can occur, leading to the release of seismic energy which we call an earthquake.
In the US, areas where fault lines are prevalent are considered at higher risk for earthquakes:
As for accurate predictions of severity, time and place - scientists have a better job predicting in areas with a history of earthquakes. The San Francisco Bay area, for instance, has a 62% chance of a major earthquake in the next 30 years.
To make more precise predictions, scientists use various different methods of predicting the stress and strain at these fault lines, with varying degrees of accuracy and success (cloud formation, radon gas, satellite data, etc). There are several instances when scientists have made the prediction, sounded the alarm bells, and actions were taken to evacuate citizens and save lives (June 1991 in the Phillipines, and 2006 and 2007 quakes on the island of Reunion in the Indian Ocean). However the recent earthquake in Haiti illustrates how the current systems of earthquake detection are not always successful. As science progresses, technology improves, and with increased monitoring of locales known to be at high risk, perhaps the next Haiti disaster will be avoided.
References:
1. Iran quake prediction for April 2009:
http://www.newscientist.com/blogs/shortsharpscience/2009/04/quake-scientist-says-iran-will.html
2. Iran quake April 30, 2009 - prediction comes true:
http://www.usatoday.com/news/world/2009-04-30-iran-earthquake_N.htm
3. Can scientists predict natural disasters accurately?
http://www.newscientist.com/article/mg19926752.000
4. NASA on using satellites to predict earthquakes (2003 article):
http://science.nasa.gov/headlines/y2003/11aug_earthquakes.htm
5. Missing the mark on earthquake prediction:
http://www.abc.net.au/science/articles/2009/04/23/2550887.htm




Salon.com
Comments