Ocean Bottom Seismometer Augmentation of the NPAL 2010-2011 Philippine Sea Experiment
Abstract
This project addresses the coherence and depth dependence of deep-water ambient noise and signals. Seafloor signals will be studied in the band from 50-400Hz and seafloor ambient noise will be studied in the band from 0.03 - 80Hz. On NPAL04 we observed a new class of arrivals in long-range ocean acoustic propagation that we call Deep Seafloor Arrivals (DSAs) because they are the dominant arrivals on ocean bottom seismometers (Mercer et al., 2009; Stephen et al., 2009; Stephen et al., 2008). They either were undetected or very weak on the deepest DVLA hydrophone located near the conjugate depth about 750m above the seafloor. It appears that at least part of the path for DSAs is through or on the seafloor perhaps as an interface wave. We will do a similar experiment in the Philippine Sea. The objective here is to understand the relationship between seafloor pressure and seafloor particle motion for both ambient noise and short- and long-range signals. What is the relationship between the seismic (ground motion) noise on the seafloor and the acoustic noise in the water column? What governs the trade-offs in contributions from local and distant storms and in contributions from local and distant shipping? How effective is seafloor bathymetry at stripping distant shipping noise from the ambient noise field?
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2010
- Accession Number
- ADA542047
Entities
People
- Peter F. Worcester
- Ralph Stephen
Organizations
- Woods Hole Oceanographic Institution