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Institute for Crisis, Disaster, and Risk Management Crisis and Emergency Management Newsletter Website |
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December
2006
Volume
11 - Number 3 |
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By Clinton Freeman The magnitude 9.0 earthquake and subsequent tsunami that occurred off the Sumatra-Andaman islands of Indonesia caused massive loss of life and extensive property damage along the coastlines of Indonesia, Sri Lanka, Thailand, India and many small island nations within the Indian Ocean. However, initial estimates made by the Federal Australian Government’s geological survey, Geoscience Australia (GA), determined the epicenter of the earthquake to be on land, and therefore no tsunami was expected. This of course was a major embarrassment to both the organization and to the Government. Simply put, GA recorded earthquakes using seismometers located on Australian soil which limited the accuracy when calculating the epicenters of earthquakes elsewhere throughout the world. The identification of an earthquake’s epicenter is an iterative process, converging as calculations take into account recordings from seismographs further afield and at well-distributed azimuths about the epicenter. The vast geographical area of Australia and its surrounding oceans makes it incomprehensible to have seismometers spaced as close as those seismic networks within smaller geographical regions like California. To remedy this lack of seismological data, the Government invested A$70 million over four years to improve Australia’s tsunami warning system, which will be integrated with the developing Indian Ocean Tsunami Warning System. I was employed at GA as part of this effort, not directly involved with tsunamis, but rather to build a comprehensive database of earthquakes within south-west Western Australia. This will later serve as a template for all Australian earthquakes. I was part of the Earthquake and Tsunami Hazard Project, which along with other projects such as geodetic monitoring and geophysical networks, made a team of scientists and technicians to monitor and research seismicity within and around Australia. Before the tsunami and the subsequent disaster, only one scientist was employed within Australia (at GA) to study tsunamigenic earthquakes. Following the investment and instruction of the Government, this soon changed as scientists within GA and universities turned their efforts to contribute to the mitigation of future tsunamis that may strike Australia. Computer modelers began constructing inundation models to account for variables such as the continental shelf and irregular coastlines which impact the set of waves as they approach. Modeling how buildings impede and channel the water is also important. The computer processing resources needed to model dynamic systems should not be underestimated, and requires access to some of the world’s most powerful computers. Professional relationships were strengthened with other agencies such as the Bureau of Meteorology, which is tasked with deploying the sea level gauges to be used for detecting and tracking tsunami waves. Working with Federal Government personnel also presented a challenge because of cultural differences between scientists, politicians and bureaucrats. Personally, I was honored to have spent time working and interacting with leading scientists in a current, dynamic and exciting area of research – that of earthquake and tsunami hazards. Research takes considerable time, and extends much longer than timeframes bandied about in business and government circles. I attended a seminar given by a Professor from the University of Western Australia who was in Sri Lanka on that fateful day. He noted that many of those who drowned at the coast had been living there illegally, and as he ventured towards the seashore he ignored his own scientific intuition - tsunami waves are not singular but instead arrive in sets, and the first is not necessarily the highest. Geoscience Australia, (2005), Frequently Asked Questions about the Australian Tsunami Warning System, http://www.ga.gov.au/media/atws.jsp |