Trawling and the Ocean Bottom Seismometer Project
|I am a research geologist with the U.S. Geological Survey in Anchorage, Alaska, and I mostly study earthquakes and tsunamis. I am also one of the Principle Investigators of a large National Science Foundation (NSF) funded geophysical experiment, which just deployed 75 ocean bottom seismometers (OBSs) offshore the coastline of part of Kodiak and the Alaska Peninsula in May and July of 2018. These instruments will sit on the sea bottom, record earthquakes, and will be retrieved in August and September of 2019. Pickup should be completed by about September 15th, 2019. These seismometers will record thousands of previously undetectable earthquakes, will show how the crust is deforming offshore, and the data should help scientists better understand the processes that lead to large earthquakes and tsunamis offshore Alaska. Before deployment, our research group consulted trawl-density maps to help guide where we dropped some of these instruments. However, given the vigor of bottom fishing in the waters of coastal Alaska, it seems impossible to completely avoid trawling areas. Also, the type of instrument deployed in these waters less than 200 fathoms has a Trawl Resistant Mount (TRM), which has a bit of a clamshell design, that should hopefully deflect fishing gear on the bottom (see attached photos). We would like to alert the trawling community to the location of the instruments to avoid having them get tangled. Attached above is a map showing the location of some of the instruments, and the latitude and longitude positions of those in less than 200 fathoms of water depth. If you have any questions regarding this deployment or instrument locations, please don't hesitate to contact me.
August 17, 2018
|For a .gpx file of the instrument locations, which can be imported into many chartplotters:
GPX file for chart plotters
|Peter J. Haeussler
U.S. Geological Survey
4210 University Dr.
Anchorage, AK 99508
|Click on the above photos to enlarge.|
|Alaska Amphibious Community Seismic Experiment
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