@article {6228, title = {Seep Detection Using E/V Nautilus Integrated Seafloor Mapping and Remotely Operated Vehicles on the United States West Coast}, year = {2017}, month = {December 11-15}, pages = {New Orleans, LA}, abstract = {

Exploration Vessel (E/V) Nautilus has been mapping the seafloor off the west coast of the United States, from Washington to California, for the past three years with a Kongsberg EM302 multibeam sonar. This system simultaneously collects bathymetry, seafloor and water column backscatter data, allowing an integrated approach to mapping to more completely characterize a region, and has identified over 1,000 seafloor seeps.

Hydrographic multibeam sonars like the EM302 were designed for mapping the bathymetry. It is only in the last decade that major mapping projects included an integrated approach that utilizes the seabed and water column backscatter information in addition to the bathymetry. Nautilus mapping in the Eastern Pacific over the past three years has included a number of seep-specific expeditions, and utilized and adapted the preliminary mapping guidelines that have emerged from research.

The likelihood of seep detection is affected by many factors:

Nautilus integrated seafloor mapping provided multiple indicators of seep locations, but it remains difficult to assess the probability of seep detection. Even when seeps were detected, they have not always been located during ROV dives. However, the presence of associated features (methane hydrate and bacterial mats) serve as evidence of potential seep activity and reinforce the transient nature of the seeps. Not detecting a seep in the water column data does not necessarily indicate that there is not a seep at a given location, but with multiple passes over an area and by the use of other contextual data, an area may be classified as likely or unlikely to host seeps.

}, keywords = {backscatter, bathymetry, e/v nautilus, multibeam, seep, water column}, url = {https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/289727}, author = {Lindsay Gee and Nicole A Raineault and Renato Kane and Miles Saunders and Erin Heffron and Robert W Embley and Susan G. Merle} }