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POSTED: Thu 14 January 2010 (Updated 28 Jan 2010)

RAPID ROUNDUP: Earthquake in Haiti - Experts respond

An earthquake measuring 7.0 that hit Haiti on Wed 13 January (Australian time) is feared to have resulted in the death of at least 170,000. Below Australian experts and several UK experts (courtesy of the Science Media Centre in London) respond.

The Geoscience Australia website has good basic information about earthquakes. Up-to-date seismic analysis by the British Geological Survey can also be found at their website:
www.earthquakes.bgs.ac.uk/recent_events/haiti_information_release.pdf

Feel free to use the quotes below in your stories. Any further comments will be posted here. If you would like to speak to an expert, please don’t hesitate to contact us on (08) 7120 8666 or by email.



Professor Sandy McFarlane is a psychiatry professor and Head of the Centre for Military & Veterans' Health at the University of Adelaide. He is a leading authority on post-traumatic stress disorder.

“Large-scale disasters such as the earthquake in Haiti create major challenges for the survival and long-term adjustment of the affected communities. However, in a country where there is widespread poverty and inadequate housing, these events only further compound the disadvantage and risk for the victims. In the absence of the disaster, the limited resources to deal with disadvantage and suffering are already major challenges in countries like Haiti. The health disadvantage and risks for the population are only compounded by such a major calamity.

For this reason many of the disaster plans for providing aid in a developed country require major adaptations. Particularly from a mental health perspective, the broader needs for improved services for a whole range of conditions other than posttraumatic stress disorder and bereavement require attention. The lack of adequate mental health services means there are few existing assets to built on. These disasters provide a genuine opportunity for aid to be directed towards assisting a sustainable infrastructure for mental health and social disadvantage in these communities.”

Dr Huilin Xing is from the Earth System Science Computational Centre at The University of Queensland

“The January 12, 2010, Haiti earthquake occurred as a left-lateral strike slip faulting on the Enriquillo-Plantain Garden fault system (EPGZ). This fault system accommodates about 8 mm per year, and it is the likely source of a series of historical large earthquakes in the region such as in 1751, 1761, 1770 and 1860.

However, it had been quite silent (locked) along the EPGZ afterwards until Magnitude 7 Haiti earthquake occurred on January 12, 2010. This earthquake and aftershocks are releasing the accumulated stress along it during the long time interval since the previous quake.”


Adjunct Professor Kevin McCue is President of the Australian Earthquake Engineering Society

“This was a major earthquake and was really a disaster waiting to happen. The capital of Haiti is between two major fault zones and they have not had a earthquake there for some time. The last major earthquake in this part of Haiti was1860. The plates are moving at about 7mm a year which is actually quite slow compared to the Australian plate, which is moving at ten times that speed. But even at 7mm a year, it will still bite you sometime.

This is a earthquake that has become a disaster because of the poverty of the people involved. The buildings simply weren’t designed and built to withstand earthquakes, so when you have a quake of this size, they just collapse. This is why in Australia and in other developed countries we have building codes to prevent similar disasters from occurring.”

Science Media Centre Round-up (UK)
FOR IMMEDIATE RELEASE

Expert reaction to the earthquake in Haiti

Up-to-date seismic analysis by the British Geological Survey can be found at their website:
http://www.earthquakes.bgs.ac.uk/recent_events/haiti_information_release.pdf

Professor Dave Petley of Durham University is blogging about the earthquake:
http://daveslandslideblog.blogspot.com/

Prof Roger Searle from the Earth Sciences Department at Durham University said:

“This quake was magnitude 7, equivalent to the energy release of about half a megaton of TNT. Earthquakes of this size can cause relatively slight damage in well-designed and constructed buildings, but considerable destruction in poor ones.

“The last major earthquake in this part of Haiti was 1860; in 1692, a major earthquake in Jamaica caused 2000 deaths. To date (1400GMT Jan 13) the USGS has recorded 33 aftershocks greater than magnitude 4.5 (large enough to cause at least minor damage).

“Earthquakes are complex processes that are very hard to predict. The earth’s crust is a complex system and at the boundaries of the tectonic plates there are networks of faults separating lots of smaller blocks. As the plates move, stress gradually builds up until one part of this complex system gives way, and an earthquake occurs. It’s a little bit like building a pile of stones: it gets steeper and steeper, and eventually the whole thing will give way, but it’s very hard to say just when and where. We can actually predict reasonably well where earthquakes will occur, but not when.

“Once an earthquake has occurred, we can calculate how that will affect the stress in the surrounding region: faults where the stress has increased are most likely to be the next to slip.”


Dr Sarada Sarma, Emeritus Reader of Engineering Seismology in the Department of Civil and Environmental Engineering at Imperial College London, said:

“Earthquakes are the most unpredictable of the natural disasters. Prediction of earthquakes requires us to know where and when they happen and how big they are. From the past history of earthquakes, it is relatively easy to say where an earthquake could occur and how big it might be, but almost impossible to say when. The only way to avoid death and destruction in big earthquakes is to build structures with proper seismic resistant design.”

Professor David Gordon, Director of the Townsend Centre for International Poverty Research at the University of Bristol, said:

"Our research for UNICEF showed that more than half of all children (2.1 million) in Haiti are severely shelter deprived. This means they were living in squalid and unsafe housing conditions. They had homes with mud floors, which often had inadequate walls and roofs, while many families also suffered from severely overcrowded living conditions with more than five people per room. It is this kind of poorly built housing that suffers great damage in earthquakes and results in many poor adults and children being killed or injured."

Dr Roger Musson, Seismologist at the British Geological Survey, said:

"The situation in Haiti is similar to the San Andreas Fault in California in that two plates are sliding past one another. The fault in this case is called the Enriquillo-Plantain Garden fault. This fault has been locked for the last 250 years gradually accumulating stress which has now been released in a single large earthquake."

Dr Brian Baptie, Seismologist at the British Geological Survey, said:

"Earthquakes of this size always have aftershocks that can last for many weeks. These always punch above their weight, affecting buildings that have already been damaged and hampering relief efforts."

Dr David Kerridge, Head of Earth Hazards at the British Geological Survey, said:

"With an earthquake of this size and the mountainous terrain there is a strong possibility of landslides which may have caused many causalities in more remote parts of the island. Due to disruptions in communications the full extent of the disaster might not be clear for a few days."

Dr Carmen Solana, volcanologist at the University of Portsmouth, said:

"The north Caribbean Islands are not frequently hit by large earthquakes like this, but occasionally large events occur on faults like the one that connects south Haiti with Jamaica, where the quake happened. The priority now should be rescuing victims, as after 48 hours the probabilities of finding people alive are much smaller. Haiti is a very poor country and a main concern is the outbreak of diseases such as cholera, related to broken pipes and lack of sanitation facilities."

Dr David Rothery, planetary scientist at the Open University, said:

"The earthquake that struck Haiti yesterday was so devastating because as well as being large (magnitude 7.0 on the Richter scale) its source was at a shallow depth of about 10 km. Closeness to the surface is a major factor contributing to the severity of ground shaking caused by an earthquake of any given magnitude. Furthermore, shaking tends to be greatest directly above the source. In this case the epicentre was only 15 km from the centre of the capital, Port au Prince, which therefore suffered very heavily.

"From the pictures I have seen, and from what I know of Haiti's impoverished economy, I doubt if buildings there have been constructed with earthquake-resistance in mind. They are at risk of further collapse caused by aftershocks, of which there have been several strong ones. The debris in the streets suggests that people would have been killed or injured by falling masonry if they tried to flee buildings while the ground was shaking, rather than sheltering under a table until motion had ceased. This is a basic measure for self-protection taught by schools in earthquake-prone regions. It is many decades since a comparably strong quake has hit Haiti, and I wonder if the population was adequately aware of what they could do to protect themselves.

"This earthquake was caused by sideways slip on a fault that marks part of the northern edge of the Caribbean Plate, which is grinding against the North American Plate. Further to the east the plate boundary changes direction and becomes a subduction zone that is the cause of the volcanoes of the Caribbean arc, including the currently-erupting Soufriere Hills volcano on Montserrat. No change in volcanic activity is to be expected as a result of this earthquake."

For further information, please contact the AusSMC on 08 7120 8666 (note new number) or email us.