[SIO GP Seminars] Seminar at 3.15

[Urska Manners]

Geophysics Seminar Fans - 

Please join us this afternoon for this week's Geophysics Seminar.  
Please note the small CHANGE IN MEETING TIME from 3 to 3:15.  


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Friday, October 6, 3:15 PM 
  (refreshments served at 3:00 PM) 
  Munk Conference Room 
   
Elizabeth Cochran

  "Infrasound events detected with the Southern California Seismic 
Network" 
  
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ABSTRACT
We examine continuous data from the Southern California Seismic Network 
from 2003 and identify infrasound acoustic waves from 76 previously 
undetected events. Using waveform cross-correlation of the signal 
envelope functions, we determine their relative arrival times and 
estimate source locations. The waves travel at acoustic speeds of ~320 
m/s and are observed in seismic records up to 450 km from their 
probable source locations off the west coast of southern California. 
The dominant daylight occurrence of the events points to a man-made 
source related to military activity. The events are mostly recorded in 
the winter and spring when atmospheric conditions trap acoustic energy 
near the Earth's surface and favor propagation to the west. These 
results suggest that data from regional and global seismic networks can 
supplement observations from infrasound arrays for Comprehensive Test 
Ban Treaty monitoring and geophysical applications such as volcano 
monitoring, bolide detection, atmospheric acoustic sources and 
tomography.


Urška

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Urska Manners
Institute of Geophysics and Planetary Physics
Scripps Institution of Oceanography
University of California, San Diego
La Jolla, CA 92093-0225
umanners at ucsd.edu
(858) 534-8119
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