Samuel Y Johnson

Seafloor Mapping - Geologic framework, hazards, and habitats


Sam Johnson is a Research Geologist in the U.S. Geological Survey Pacific Coastal and Marine Science Center (PCMSC), an organization of about 100 research and support staff based in Santa Cruz and Menlo Park, CA.  He served as PCMSC Center Director from 2003 to 2008. He currently designs, coordinates, and conducts research projects that focus on seafloor and benthic habitat mapping, coastal and marine geomorphology and geologic framework, coastal evolution, and coastal earthquake and tsunami hazards.  He helped plan and is the USGS lead for the multi-agency California Seafloor Mapping Program. His present research is focused on active tectonics and hazards offshore central California (Santa Barbara Channel to Cape Mendocino).


  • B.A. (1975) University of California, Santa Cruz (Earth Sciences)
  • M.S. (1978) University of Washington (Geological Sciences)
  • Ph.D. (1982) University of Washington Geological Sciences

 Professional Studies/Experience

  • 1982-1984 - Assistant Professor, Washington State University
  • 1984 to 2003 - Research Geologist, USGS Energy and Earthquake Hazards Programs
  • 2003 to 2008 - Center Director, USGS Pacific Coastal and Marine Science Center
  • 2008 to 2019 - Research Geologist, USGS Pacific Coastal and Marine Science Center
  • 2019 to present - Research Geologist Emeritus, USGS Pacific Coastal and Marine Science Center

Research Interests

  • Sea floor mapping and geomorphology
  • Coastal and marine sedimentology and stratigraphy
  • Active Tectonics
  • Geologic framework and hazards

Professional societies

  • Geological Society of America (Fellow) 
  • American Geophysical Union 
  • Society for Sedimentary Geology 
  • Seismological Society of America

Honors, awards, recognition, elected offices

  • Department of Interior Distinguished Service Award (2019)