HR: 17:45h
AN: U32C-07    [PDF]
TI: Hawaiian Infrasound: A Mele of Fire, Wind, and Water
AU: * Garces, M
EM: milton@isla.hawaii.edu
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Hetzer, C
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Harris, A
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Johnson, J
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Willis, M
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Businger, S
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AU: Merrifield, M
AF: University of Hawaii, Manoa, 2525 Correa Road, Honolulu, HI 96822
AB: Some of the more interesting infrasonic signals the can be routinely observed in Hawaii are associated with volcanic activity, severe weather, and ocean processes. Kilauea volcano is one of the most active volcanoes in the world, and infrasonic observations from an expedition in November of 2002 strongly suggest that continuous infrasound in the 1-8 Hz frequency band may be generated from the lava tube system of Puu Oo and may correspond to pressure instabilities in the magma flow. The eruption signal we observed corresponds to low-level effusive activity, and appears to only propagate for a few tens of kilometers. In contrast, signals associated with severe weather in the ocean may propagate for thousands of kilometers. These infrasonic signals, known as microbaroms, are close relatives of microseisms and occupy the 0.1-0.6 Hz frequency band. We believe that these signals are generated by the nonlinear interaction of ocean surface waves generated by storms, and show some observations from hurricanes Daniel and Jimena. When these waves hit the Hawaiian coastline, they can produce world class surf as well as substantial infrasonic energy. We postulate that surf infrasound can be generated by the collapse of the wave upon itself (barreling), impact against a cliff, or slamming against a shallow reef, and show examples from the epic 2002-2003 Hawaiian winter. Our observations in Hawaii demonstrate how infrasound can provide useful information of solid earth-ocean-atmosphere interactions and can be integrated with other technologies to enhance our basic understanding of geophysical processes.
UR: http://www.inframatics.org
DE: 3307 Boundary layer processes
DE: 3360 Remote sensing
DE: 7299 General or miscellaneous
DE: 8419 Eruption monitoring (7280)
DE: 9810 New fields (not classifiable under other headings)
SC: U
MN: 2003 Fall Meeting