Final Environmental Assessment

Researchers from the University of New Mexico and Western Washington University, with funding from the U.S. National Science Foundation (NSF), and in collaboration with researchers from the United States Geological Survey (USGS), Dalhousie University,and the Geological Survey of Canada, propose to conduct high-energy seismic surveys from the Research Vessel (R/V) Marcus G. Langseth (Langseth) at the Queen Charlotte Fault (QCF) in the Northeas tPacific Ocean during summer 2021. R/V Langseth is owned by Columbia University and operated by Lamont-Doherty Earth Observatory (L-DEO)of Columbia University. The proposed two-dimensional (2-D) seismic surveys would occur within Exclusive Economic Zones(EEZ)of Canada and the U.S., including Canadian Territorial Waters.The surveys would use a 36-airgun towed array with a total discharge volume of ~6600 in 3 and would occur in water depths ranging from 50to 2800 m. NSF, as the research funding and action agency, has a mission to “promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense...”. The proposed seismic survey would collect data in support of a research proposal that has been reviewed under the NSF merit review process and identified as an NSF program priority. They would provide data necessary to characterize crustal and uppermost mantle velocity structure, fault zone architecture and rheology, and seismicity of the QCF.