Military history is hidden in the squiggles of a seismogram. During the Iraq war, earthquake-monitoring instruments at Baghdad鈥檚 seismic observatory also recorded wartime activity including car bombs, weapon rounds and improvised explosives.
鈥淗aving a seismometer right in the middle of Baghdad, right in the midst of all this fighting 鈥� it turned out we had this marvellous opportunity for forensic seismology,鈥� says at Washington University in St Louis, Missouri. 鈥淭his was just luck, in a sense.鈥�
Wysession and his colleagues looked at the data for traces of a big event on 10 October 2006, when rounds fired into an ammunition supply point set off a chain of explosions 7聽kilometres from the observatory.
Advertisement
They detected not just this 鈥渃ook-off鈥�, but also evidence of other nearby reported military activity. There were unique seismic signatures for each type of weapon. And vibrations from heavy air traffic were clear enough that they could discern the type and speed of helicopters flying past.
Such information could be useful for gathering military intelligence, says Stephen Arrowsmith at Sandia National Laboratories in Albuquerque, New Mexico.
鈥淲hat makes this study very unique and interesting to me is that it鈥檚 an actual set of measurements from actual military operations,鈥� Arrowsmith says. That makes the data harder to study and verify, but valuable for learning how to identify unknown events. 鈥淚t could be quite useful as a tool to characterize what鈥檚 going on in this type of environment.鈥�
Journal reference: Bulletin of the Seismological Society of America, DOI: 10.1785/0120140187
Image credit:聽Baz Ratner/Reuters
