Multibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA

In 2015 the U.S. Geological Survey, Pacific Coastal and Marine Science Center, in cooperation with the Alaska Department of Fish and Game (ADFG), collected bathymetry and acoustic-backscatter data near Cross Sound in southeast Alaska using a Reson 7111 multibeam echosounder mounded to the ADFG R/V Solstice. The bathymetry and acoustic-backscatter data are provided as GeoTIFFs with 10-m spatial resolution; the navigational tracklines are provided in a polyline shapefile. All files have accompanying FGDC metadata. The survey was conducted to map the offshore expression of the Queen Charlotte fault system that runs for approximately 500 kilometers off the coast of southeast Alaska and British Columbia. This was the first in a series of surveys to map the entire offshore component of the fault. The fault system has generated numerous powerful earthquakes in the magnitude 7 and 8 range. This new mapping will help understand the fault's slip rate, earthquake recurrence intervals, and paleoseismic history.