Sound Waves 03 USGS http://soundwaves.usgs.gov/2003/10/fieldwork.html Sound Waves 03 USGS map and learn more http://soundwaves.usgs.gov/2003/10/fieldwork.html <http://soundwaves.usgs.gov/2003/10/fieldwork.html> USGS: Mapping of the Puerto Rico Trench Sound Waves 03 USGS