The interaction between physical sciences and humanities is nowhere more intricate than in the study of causes and effects of earthquakes. Obvious and not-soobvious interactions that change with time and space provide an amazingly fertile field for cultivating and harvesting people’s ingenuity and resilience. Who would think that there is a relationship between artesian wells and earthquakes? In his landmark lecture at the UK Institution of Civil Engineers in London in 1990, James Jackson (University of Cambridge) showed that earthquake fault movement may have caused the accumulation of underground water, which in turn attracted early civilizations to regions of the world that suffer repeatedly from earthquakes. The interaction between strong attractants and repellants was and still is in play, defining the location, and fate, of civilizations. California is an example of this intricate relationship, being the most seismic part of the United States, with strong and damaging earthquakes at about 20-year intervals, whilst being the largest state economy, and fluctuating between the sixth and ninth largest economy worldwide, had it been an independent state.
Armed with camera, notepad and pen, my journey of learning about the depth and breadth of earthquake risk started in September 1986, when I went on my first post-earthquake field mission in Southern Greece, following a ‘direct hit’ earthquake of very shallow depth and small magnitude, that caused extensive loss of life and livelihood in the Kalamata region at the southern tip of Peloponnesus in Greece. One striking memory was walking through the deserted streets, and passing by a toy and children’s clothes shop. Items were strewn across the shop floor, a wall fan was still rotating, and what I may have dramatized as some drops of blood were on the lower part of the wall. The lessons I learned from the locals exceeded those that I learned from the experts. Twenty years later, I am still learning new science and new humanities, as well as new linkages and interactions between the two.
This brings me to a recent and one of the most profound earthquakes: the Kashmir (Pakistan) earthquake of October 8, 2005. Early reports were alarming, and the picture grew bleaker as time passed. My long-term colleague and Journal of Earthquake Engineering partner Nick Ambraseys (Imperial College, London), arguably the founder of modern European engineering seismology, contacted me and provided some startling information. Early in 2005, he, with another leading international authority, Roger Bilham (Colorado School of Mines), published a paper on the “missing strain,” arguing that GPS measurements indicate that the average strain in the earth’s crust in the Himalayas is 18 inches per year, whilst the last several years of earthquake activity is estimated to have consumed about 5 inches per year, leaving a deficit that has to be released in future tremors. Their estimates were for imminent, albeit in geological terms, four or more earthquakes of magnitude larger than 8! And here we were just a few months after the publication, facing a Himalayan earthquake of magnitude about 7.6. First, this somewhat vindicates, in very short order, the Ambraseys and Bilham postulate, and second, what will happen next? After a short period of discussion amongst the Mid-America Earthquake Center (MAE) leadership, and with colleagues from Rice University, a field team was assembled, and frantic organization, for visas, flights and local support in Pakistan, got underway. Due to some security concerns, the team was rather small, comprising Ahmad Jan Durrani from Rice, Youssef Hashash and Sung Jig Kim, as well as the writer, from UI.
Arif Masud, also from UI, joined us there and remained behind for further information mopping-up. We covered approximately 1000 miles during our seven-day visit. We met and spoke with some 80 individuals from the Government, universities, the Army and private business. We took hundreds of pictures and several hours of video footage, but most of all, we learned or were reminded that earthquakes affect every single aspect of the functioning of societies, and as such their effects have to be mitigated comprehensively.
Our first encounter with earthquake damage was at Abbottabad, where several buildings collapsed, in spite of the fact that it is about 80 miles from the earthquake epicentral region. As we approached Muzaffarabad, the capital of Azad Kashmir Province, the extent of the disaster started to manifest itself, with tell-tale tent camps in many places, tens of mountain roads blocked and dust coming up from massive mountain slopes as the earth continued to move even 4-5 weeks after the earthquake. The human death toll was over 80,000 killed and 70,000 injured. The number of casualties was so high that one of the pressing needs in the region is permanent and accessible disabilities rehabilitation centers and short-term and long-term support for orphans and widows. It is devastating to note that a disproportionate number of children were killed in schools, a much higher percentage than in any other earthquake worldwide.
The structural, and more so, the geotechnical features of this event provide opportunities for expanding knowledge of earthquake effects. The extent and number of landslides are unprecedented in modern times and the effect of local ground conditions, from the soil as well as the surface topology viewpoints, calls for focused studies that would help reconstruction efforts. In two locations, in Balakot and Muzaffarabad, hilltop communities were wiped out, indicating strong topographical effects and providing lessons for town and urban planners. Even rivers changed their course or were completely blocked, creating precariously unstable lakes. On the structural side, the earthquake reiterated lessons learned over the years and unfortunately forgotten soon after damaging earthquakes. Heavy roofs, placed to protect against extremes of heat and cold, attract high earthquake forces and cause the collapse of residential units. Only a few fully engineered structures suffered extensive damage, one such structure being the modern Combined Forces Hospital, where high quality material was used, but poor construction practices deprived the structure from the benefits of the high quality material. The direct economic losses were estimated on the low side to be $5.2 billion. Most experts believe that the direct losses are higher, and that the indirect losses are perhaps twice the direct loss figure, adding up to an economic impact of around $15 billion or even more.
It has been my conviction never to undertake post-earthquake investigations unless I make the time and have the resources to report on the earthquake in a meaningful manner that adds to the literature, as opposed to travel logs and/or “Cook’s tour style” reports. We therefore immediately started working on our report which was issued in December 2005, a few weeks after our mission. The MAE Center report was very well received by the academic community and extensively referenced in other publications on the earthquake. It has also attracted considerable attention in Pakistan, and has resulted in high levels of visibility of the Civil and Environmental Department at UI, and the Mid-America Earthquake Center worldwide. My research group is continuing to work on the earthquake effects, and has recently completed a comprehensive study of old and modern reinforced concrete buildings from the area affected, to demonstrate the value of considered design and construction.
The effort and expense put towards the mission and follow-up work begs the question: how does the cost-benefit analysis of postearthquake field investigations look? This is not just an economics question, but is also a philosophical one. What is the price of knowledge, contribution to the education of vulnerable communities, education of our own students, renewing our appreciation of the real problems facing earthquake risk management, and building lasting relationships with colleagues from whom we learn, but more importantly, transfer our knowledge where it is most needed? Our field mission has resulted in a joint US-Pakistan research project, and contacts with various potential funding bodies and companies bidding for reconstruction projects. Hence even on the economics front, such missions are invaluable. Sung Jig Kim, PhD candidate at UI, and a member of the Kashmir earthquake field mission, contends that the trip and the follow-up work were lifetransforming for him, and underlined the importance of his studies, and the unique learning environment in our group, center, department and college. Similar testimonials from many of our students who shared in the tens of missions carried out in earthquake-hit regions abound, including the earthquake of Jogjakarta (Indonesia) of May 27, 2006.
Earthquakes will not reduce in number, unpredictability or intensity. Meantime, population increases are turning towns into cities, cities into megacities, rural into urban, and wilderness into inhabited. It is therefore incumbent on us all to continue a vigilant watch of earthquake effects and relentlessly seek mitigation, response and recovery measures. Central to our endeavors are field investigations that provide natural laboratory evidence and irreplaceable first-hand observational data. It is only through the interactive development and deployment of field observations, computer analysis and laboratory testing that the vulnerability of communities will be reduced and the wealth created by societies will be protected from future disasters.