HR: 16:15h
AN: U44A-04    [Abstracts]
TI: Velocity and Spectral Analysis of Tide Gauge Records of the Indian Ocean Tsunami of December 26, 2004
AU: * Pulli, J J
EM: jpulli@bbn.com
AF: BBN Technologies, 1300 North 17th Street Suite 400, Arlington, VA 22209 United States
AB: Digital and analog tide gauge recordings of the Indian Ocean tsunami generated by the great Sumatra earthquake of December 26, 2004 were analyzed to estimate the tsunami's speed of propagation and spectral content. Digital recordings at a sampling rate of 1 sample per minute were obtained from the Australian National Tide Center; the tsunami arrivals were clearly recorded at its stations at Cocos Keeling Island (1702 km from the epicenter) and Hillary's Boat Harbor (4418 km from the epicenter). Spectral analyses of these signals indicate a primary tsunami period of 13.9 minutes at Cocos; this spectral line plus longer period lines up to 50 minutes are seen at Hillarys Harbor. Scans of analog tide gauge records were obtained from the Indian National Institute of Oceanography. These scans were enlarged to a resolution of 0.5 inches per hour and the first breaks of the tsunami arrivals were measured to within 5 minutes. Ten time-distance pairs across the Indian Ocean were used to obtain a tsunami propagation velocity of 657 km/hour. The theoretical value of the tsunami velocity for the average water depth in the Indian Ocean (3.4 km) is 653 km/hour.
DE: 4564 Tsunamis and storm surges
SC: Union [U]
MN: 2005 Joint Assembly