Analysis of Deep Seafloor Arrivals Observed on NPAL04
WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF GEOLOGY AND GEOPHYSICS
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This report gives an overview of the analysis that was done on Deep Seafloor Arrivals since they were initially presented in Stephen et al 2009. All of the NPAL04LOAPEX North Pacific Acoustic Laboratory, 2004 Long Range Ocean Acoustic Propagation Experiment data on three ocean bottom seismometers OBSs at 5,000m depth and the deepest element of the deep vertical line array DVLA at 4250m depth has been analyzed. A distinctive pattern of late arrivals was observed on the three OBSs for transmissions from T500 to T2300. The delays of these arrivals with respect to the parabolic equation predicted PEP path were the same for all ranges from 500 to 2300km, indicating that the delay was introduced near the receivers. At 500km range the same arrival was observed throughout the water column on the DVLA. We show that arrivals in this pattern converted from a PEP path to a bottom-diffracted surface reflected BDSR path at an off-geodesic seamount.
- Physical and Dynamic Oceanography