The Haiti Earthquake: Science, Early
warning and mitigation
When we experience disasters like the earthquake in Haiti February
2010, we naturally ask the questions: Could we have known (early
warning)? Could we have been prepared (mitigation plans)?
There is no simple answer to that, because it relies on many
factors. Technically, Haiti could have been better prepared, in the
sense that we have the knowledge to build early warning systems and
disaster mitigation plans. In the case of Haiti, scientists knew
since 1998 (Timothy Dixon et al) that stress was building up fast and
ready to cause 7.0 earthquakes any time. Please note that when it
comes to earthquakes, any time means from 10-100 years, the timing is
not precise. As newly as 2008 the information about an eminent
earthquake was confirmed (by Paul Mann et al) at the Caribbean
Geological Conference. These scientists, who use GPS to monitor
tectonic plate movements, informed the Haitian authorities about this
danger. (see also other SB article). These two scientific papers are
both input in the risk assessment element of an early warning system
and mitigation plans.
Early Warning and Mitigation
The UN International Strategy for Disaster Reduction (UNISDR) has
defined what and early warning system is. (UNISDR, Living with Risk-a
global review of disaster reduction initiatives, 2004).
In general terms an early warning is the provision of timely and
effective information that allows individuals exposed to a hazard to
take action to avoid or reduce their risk and prepare for effective
response. An early warning system therefore consist of the following
4 elements:
Risk Knowledge - Understanding and mapping the hazard
Warning Service - Monitoring and Forecasting impending
events
Dissemination - Processing and disseminating understandable
warnings to political authorities and the population
Response Capability - Undertaking appropriate and timely
actions in response to the warnings.
A quick glance on this graphic tells us that knowing about the
risk is only part of the picture. The political, economic and social
conditions in Haiti ( http://www.unisdr.org/news/v.php?id=12398)
made it difficult to establish such an early warning system. More
importantly it prevented working out and implementing mitigation
plans based on risk assessments, which is fundamental to reduce
disasters. Mitigation plans would typically consist of urban planning
that regulates the quality of buildings as well as placements of
schools, hospitals, pipelines etc. Knowing is pivotal but only part
of the picture.
In the program The Science behind the Haiti Earthquake
(http://astrocast.tv/blog/?p=2784),
I let the International Centre for Geohazards explain in more details
how risk assessment is being done. I also talk to Prof. Tim Dixon
from the University of Miami about the Enriquillo-Plantain Garden
fault system in the Caribbean and have Prof. Bill Hammond from the
University of Nevada explain the difference between the Haitian,
Californian and Nevada's seismicity.
Science and Risk Assessment
From a purely scientific perspective, an earthquake is good news.
Today we have so many sensors installed picking up various signals
from natural events, that analysis of the data will boost our
knowledge. Seismic fault models can be validated or improved etc. An
earthquake like we saw in Haiti will not only fuel the scientific
knowledge production, the observations and scientific results are
also important input to an updated and renewed risk assessment of the
area.
Immediately after the Haiti earthquake the scientists mobilized. A
group of scientists that has specialized on the Enriquillo-Plantain
Garden fault (Tim Dixon representing the University of Miami group,
Eric Calais representing the Purdue University group and Paul Mann
representing the University of Texas group) sent a team of geodesists
to do GPS field survey in Haiti. Food and medicine is important, but
not the only life savers. The fact that the National Science
Foundation http://www.nsf.gov/index.jsp
supports this field trip is a good example on the hidden life saving
economic and professional support the scientific community provides.
In addition technical support is being provided by UNAVCO (
http://unavco.org/) , who also host
the so-called supersite for the Haiti earthquake
(http://supersites.unavco.org/haiti.php)
, a one stop site ( under the GEO umbrella) where you can find near
real-time data and analysis from groups involved in operating earth
observation infrastructure, both in-situ and space-based, as well as
modeling and analysis work.
I recommend reading the geodesists live blog from the field trip
for an excellent insight of the pleasures, challenges and risks that
scientists experience. http://haitigps.wordpress.com/
GPS field survey in the rubble after the Haiti earthquake.
Mitigating future disasters
Based on their extensive experience a number of UN bodies are
engaged in rebuilding the Haitian society. (Link to UNISDR). The
Haiti earthquake has engaged scores of other groups as well and
substantial relief support has been given from nations, organizations
and people around the globe. Some risk assessment experts, like
Conrad Lindholm from NORSAR, a …, that suggest that some of these
resources should be earmarked for disaster mitigation both in Haiti
(Times on suggestions for future mitigation in Haiti
http://www.time.com/time/specials/packages/article/0,28804,1953379_1953494_1958231,00.html),
but also for other mega cities with high risk and vulnerability.
Istanbul
The vibrant historical city of Istanbul is one of these places.
With its 11 mill inhabitants situated right on top of a seismic fault
in Turkey, the city sits on a natural hazard bomb that could blast
anytime creating a human and cultural disaster of unprecedented
dimensions. Just like in Haiti. Another megacity placed in an
earthquake prone area is the Indonesian capital Djakarta. Are the
authorities ready to handle a major earthquake there?
Norpils map of megacities?
Useful reading – in-depth material
Earthquakes deadliest disasters last decade:
http://www.unisdr.org/news/v.php?id=12470
Global assessment report on disaster risk reduction (2008):
http://www.preventionweb.net/english/hyogo/gar/report/index.php?id=1130&pid:34&pih:2
Global Geodetic Observing System:http://www.iag-ggos.org/
Group On Earth Observations: http://www.earthobservations.org/
GEO has established so-called communities of practice
(http://www.earthobservations.org/cop.shtml)
where geohazards is one out of 11 communities.
For more links check out The Science Behind the Haiti Earthquake.
http://astrocast.tv/blog/?p=2784
Selected references:
Tim Dixon et al.
Paul Mann et al.
The author is an expert on natural hazards.
