Following any damaging earthquake, seismologists are keen to deploy portable scientific instruments to record aftershocks. Such data is crucial for answering a number of key questions, including how shaking varies throughout an urban area due to differences in local geological conditions. Information like this is needed for what we call microzonation -- in short, the mapping of hazard levels throughout a metropolitan area. After the January 12, 2010, earthquake struck Haiti, there was an especially strong impetus to deploy portable instrumentation for this and other reasons; at the time of the quake, only a single educational seismometer was operating in the country. Looking at the shattered capital city with a seismological eye, it was also clear microzonation could substantially inform the rebuilding process.
Given the staggering scale of the devastation and the challenges of the recovery and relief efforts in Haiti, scientists were not able to rush in. My colleagues and I at the U.S. Geological Survey (USGS) devised a plan to collect vital data, including aftershock recordings and geological data from the fault zone. Before arriving in the country we felt pangs of doubt: How would we get into Port-au-Prince with our small mountain of instruments? Could we find suitable sites to install the seismometers? How experienced would our local counterparts be? Would we be able to record small aftershocks in the midst of the extremely noisy and still shattered urban area? At the beginning of March 2010, we arrived in Port-au-Prince to begin our investigations. Less than two months after the earthquake struck, the most horrific early days of the humanitarian crisis had passed, but we were still stunned by the scale and scope of the damage. While the earthquake did not knock down every building in Port-au-Prince, no corner of the sprawling city escaped unscathed.
In collaboration with the U.S. Embassy and with the support of the U.S. Agency for International Development (USAID), two USGS teams worked in Haiti to study the earthquake: a geology team, led by Carol Prentice, set out to look for evidence of fault movement along the Enriquillo Plantain Garden fault, the main fault through southern Haiti, and a team that I led to deploy portable seismometers.
The geology team combed the landscape west of Port-au-Prince and found no evidence of movement on the Enriquillo Plantain Garden fault. Other studies also confirmed the finding that, like the 1989 Loma Prieta earthquake near San Francisco, the earthquake had not occurred on the main fault as first signs indicated, but on complicated secondary faults. Carol and her colleagues continue to study what happened in the earthquake and try to understand the implications.
My team worked hard to clear our hurdles, joining forces with the extremely capable and highly motivated scientists of the Haitian Bureau des Mines et de l'Energie or Bureau of Mines and Energy (BME). Through our strong partnership, we have accomplished our initial goals and much more. We deployed 17 seismometers, eight outside of Port-au-Prince, and nine throughout the greater metropolitan area. Both my team and Carol's team published the initial results of our joint investigations in the November issue of Nature Geoscience.
Our interactions with the BME continue. Our two lead partners visited the USGS last December. The U.S. government is now contributing to the development of a permanent and sustainable seismic monitoring network. In a country where awareness of earthquake hazard had been almost non-existent, the USGS is working with other international agencies to help build a community of earthquake professionals who understand and can communicate the hazard to the Haitian public, media, and officials. This, I'm convinced, is the real key to the long process of improving seismic resilience in any country. With the training provided to-date our BME colleagues are able to deploy and operate seismometers on their own; on their own initiative they have developed outreach programs for local schools, and sought out contact with local officials. When the Nature Geoscience paper was published they took the lead in presenting the results at a local media briefing in Port-au-Prince. It has been truly a privilege to have had a chance to contribute to this process. What began as, by far, the most challenging project of my career has become, by far, the most gratifying.
The lessons of my experiences go well beyond the scientific conclusions. Like many who come to Haiti I have learned that there is so much more to the country than grim statistics. There is a deep resilience and determination; a vibrancy that resonates through the food and the music, the art, and the faces.
My colleagues and I look forward to continuing to work with the Haitian government as they step up to meet the challenge of reducing the vulnerability of their country to future earthquake disasters by building back better with the tools of scientific understanding.
Susan Hough is a senior seismologist with the USGS and led the Earthquake Disaster Assistance Team effort to deploy seismometers in Haiti following the January 2010 earthquake. In the fall of 2010, she was the first-ever U.S. Embassy Science Fellow in Port-au-Prince.