Ph.D. Cambridge University, U.K., 1970
Professor, Geological Sciences
Bilham’s research includes: Application of space geodesy and strain and tilt instrumentation to monitor deformation of the Earth at plate boundaries, mostly in southern Asia and western North America; Design and operation of new geophysical instruments to monitor strain and tilt in the Earth; Archival research into historical earthquakes; Statistics of urban earthquakes and global seismic hazards.
Current Research: Buildings as Weapons of Mass Destruction
Global earthquake disasters are hardly new science, but 2010 brought the world to a new, shameful record—more people have died in catastrophic earthquakes in the first decade of the new millennium that in any decade in the history of civilization. Since 2000, more than 650,000 people died unnecessarily from earthquakes in Indonesia, India, Pakistan, Iran, China, Haiti, Chile, and a handful of other earthquake- prone countries.
The new record is shameful because seismologists have been aware, since the late 19th century, that building collapse is largely responsible for deaths from earthquakes. In a 2009 article on the seismic future of cities, I note that earthquake-resistant design is applied with rigor by very few countries. As a result of the rapid growth of cities in the developing world, the tenfold increase in global population since 1900 has been approximately matched by a tenfold increase in earthquake fatalities (Figure 1).
Earthquakes have not become more numerous in recent years, nor are they stronger. The 230,000 deaths of the Haiti Mw7 earthquake resulted from the release of elastic energy equivalent to a 2-megaton nuclear bomb, whereas the 802 deaths from the Chile Mw8.8 earthquake were caused by energy release equivalent to a 500-megaton bomb. The factor of 287 in the number of Haitain deaths compared to Chile was entirely due to Port au Prince’s virtual absence of earthquake resistance (illustrated with global data in Figure 2).
Throughout the epicentral region of the Haiti earthquake, it was evident that the buildings had been doomed from their inception. Every possible construction error was visible in the mangled steel and concrete of Port au Prince and Leogane—weak cement sometimes mixed with sea water or dirt, rounded aggregate, brittle steel often missing corrugations, and insufficient stirrups. Traditional wooden buildings fared better and stood like beacons surrounded by piles of rubble.
Professor Bilham is a professor at the University of Colorado Boulder.