Rob Witter, Ph.D.

I conduct geological detective work that uncovers clues about the location, size, and frequency of ancient earthquakes and tsunamis. If we prepare for these hazards we can prevent future earthquakes and tsunamis from becoming future disasters.


Research Focus

I study prehistoric earthquakes along the Pacific-North American plate boundary. I apply aspects of geomorphology, paleoseismology, geodesy, and sea-level studies to decipher the geologic record of ancient earthquakes. Most of my work focuses on great subduction earthquakes capable of generating tsunamis. What I find out contributes to seismic and tsunami hazards assessments used to strengthen building codes and reduce tsunami risk.

Research Highlights

Mind the Gap: New Evidence for Alaskan Tsunamis Found
LiveScience reporter Becky Oskin highlights USGS findings that help fill gaps in Alaska’s earthquake and tsunami history.

Unknown Tsunami Trigger Hides Along a Creeping Aleutian Fault
EOS writer Cody Sullivan reviews USGS tsunami research published in Geophysical Research Letters.

Uncharted: Exploring one of America’s fastest faults
A team of USGS scientists spent 10 days in the wilderness investigating the Fairweather Fault.

Return to the Alaska Wilderness
USGS Scientists visit one of North America’s fastest-moving faults.


BA in Biology, 1991, Whitman College, Walla Walla, WA
PhD in Geoscience, 1999, University of Oregon, Eugene, OR

Professional Experience

2011–present, Research Geologist, U.S. Geological Survey, Alaska Science Center, Anchorage, AK
2006–2011, Regional Coastal Geologist, Oregon Department of Geology and Mineral Industries, Newport, OR
1999–2006, Senior Project Geologist, William Lettis & Associates, Inc., Walnut Creek, CA

Recent Publications

Witter, R. C., Briggs, R. W., Engelhart, S. E., Gelfenbaum, G., Koehler, R. D., Nelson, A. R., La Selle, S., Corbett, D. R., Wallace, K. L., (2019) 131 (5-6): 707-729, Evidence for frequent, large tsunamis spanning locked and creeping parts of the Aleutian megathrust, Geological Society of America Bulletin, doi:10.1130/B32031.1.

Witter, R. C., LeWinter, A., Glennie, C., Hauser, D., Bender, A. M. and Finnegan, D., 2017, Digital Elevation Models of Glacier Bay National Park, Between Lituya Bay and Icy Point, Alaska, Derived from Airborne Lidar Data Acquired in September 2015: U.S. Geological Survey data release, doi:10.5066/F7W094D4.

Witter, R. C., LeWinter, A., Bender, A., Glennie, C., and Finnegan, D., 2017, Sculpted by water, elevated by earthquakes—The coastal landscape of Glacier Bay National Park, Alaska: U.S. Geological Survey General Information Product 177, doi:10.3133/gip177.

Priest, G. R., Witter, R. C., Zhang, Y. J., Goldfinger, C., Wang, K., Allan, J. C., 2017, New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites, Natural Hazards, doi:10.1007/s11069-017-2864-9.

Horton, B. P., Milker, Y., Dura, T., Wang, K., Bridgeland, W. T., Brophy, L., Ewald, M., Khan, N.S., Engelhart, S.E., Nelson, A.R., and Witter, R.C., 2017, Microfossil measures of rapid sea-level rise: Timing of response of two microfossil groups to a sudden tidal-flooding experiment in Cascadia. Geology, doi:10.1130/G38832.1.

Witter, R. C., Carver, G. A., Briggs, R. W., Gelfenbaum, G., Koehler, R. D., LaSelle, S., Bender, A. M., Engelhart, S. E., Hemphill-Haley, E., and Hill, R., 2016, Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust, Geophysical Research Letters, doi:10.1002/2015GL066083.

Nicolsky, D.J., Freymueller, J.T., Witter, R.C., Suleimani, E.N., Koehler, R.D., 2016, Evidence for shallow megathrust slip across the Unalaska seismic gap during the great 1957 Andreanof Islands earthquake, eastern Aleutian Islands, Alaska, Geophysical Research Letters, doi:10.1002/2016GL070704.

Milker, Y., Nelson, A. R., Horton, B. P., Engelhart, S. E., Bradley, L.-A., and Witter, R.C., 2016. Differences in coastal subsidence in southern Oregon (USA) during at least six prehistoric megathrust earthquakes. Quaternary Science Reviews, 142(C), 143–163. doi:10.1016/j.quascirev.2016.04.017.

Milker, Y., Horton, B. P., Vane, C. H., Engelhart, S. E., Nelson, A. R., Witter, R. C., Khan, N. S., Bridgeland, W. T., 2015, Annual and seasonal distribution of intertidal foraminifera and stable carbon isotope geochemistry, Bandon Marsh, Oregon, USA. Journal of Foraminiferal Research, doi:10.2113/gsjfr.45.2.146.

Haeussler, P. J., R. C. Witter, and K. Wang, 2015, Intertidal biological indicators of coseismic subsidence during the M7.8 Haida Gwaii, Canada, earthquake, Bulletin of the Seismological Society of America doi:10.1785/0120140197.

Kelsey, H. M., R. C. Witter, S. E. Engelhart, R. W. Briggs, A. R. Nelson, P. J. Haeussler, and R. Corbett, 2015, Beach ridges as paleoseismic indicators of abrupt coastal subsidence during subduction zone earthquakes, and implications for Alaska-Aleutian subduction zone paleoseismology, southeast coast of the Kenai Peninsula, Alaska, Quaternary Science Reviews, 113, 147-158, doi:10.1016/j.quascirev.2015.01.006.

Witter, R. C., 2015, Chapter 3.1, Pre-fieldwork surveys, in Shennan, I., Long, A.J., and Horton, B.P. (eds), Handbook of Sea-Level Research, Wiley-Blackwell, p. 29–46.

Witter, R.C., R.W. Briggs, S.E. Engelhart, G. Gelfenbaum, R.D. Koehler, and W.D. Barnhart, 2014, Little late Holocene strain accumulation and release on the Aleutian megathrust below the Shumagin Islands, Alaska, Geophysical Research Letters, doi:10.1002/2014GL059393.

Priest, G.R., Y. Zhang, R.C. Witter, K. Wang, C. Goldfinger, L. Stimely, 2014, Tsunami impact to Washington and northern Oregon from segment ruptures on the southern Cascadia subduction zone, Natural Hazards, doi:10.1007/s11069-014-1041-7.

Witter, R. C., Y. J Zhang, K. Wang, G. R. Priest, C. Goldfinger, L.Stimely, J. T. English, and P. A. Ferro, 2013, Simulated tsunami inundation for a range of Cascadia megathrust earthquake scenarios at Bandon, Oregon, USA, Geosphere, v. 9, no. 6, doi:10.1130/GES00899.1.

Engelhart, S. E., Horton, B. P., Nelson, A. R., Hawkes, A. D., Witter, R. C., Wang, K., Wang P.-L., and Vane, C. H., 2013, Testing the use of microfossils to reconstruct great earthquakes at Cascadia, Geology, doi:10.1130/G34544.1.

Wang, P.-L., S. E. Engelhart, K. Wang., A. D. Hawkes, B. P. Horton, A. R. Nelson, and R. C. Witter, 2013, Heterogeneous rupture in the great Cascadia earthquake of 1700 inferred from coastal subsidence estimates, Journal of Geophysical Research, doi:10.1002/jgrb.50101.

Engelhart, S. E., B. P. Horton, C. H. Vane, A. R. Nelson, R. C. Witter, S. R. Brody, and A. D. Hawkes, 2013, Modern foraminifera, δ13C, and bulk geochemistry of central Oregon tidal marshes and their application in paleoseismology, Palaeogeography, Palaeoclimatology, Palaeoecology, doi:10.1016/j.palaeo.2013.02.032.

Kelson, K., R. C. Witter, A. Tassara, I. Ryder, C. Ledezma, G. Montalva, D. Frost, N. Sitar, R. Moss, and L. Johnson, 2012, Coseismic tectonic surface deformation during the 2012 Maule, Chile, Mw 8.8 earthquake, Earthquake Spectra, v. 28, n. S1, p. 39-54.

Pilarczyk, J. E., Horton, B. P., Witter, R. C., Vane, C. H., Chagué-Goff, C., Goff, J., 2012, Sedimentary and foraminiferal evidence of the 2011 Tohoku-oki tsunami on the Sendai coastal plain, Japan. Sedimentary Geology. doi:10.1016/j.sedgeo.2012.08.011.

Richmond, B., W. Szczucinski, C.Chague-Goff, K. Goto, D. Sugawara, R. Witter, D.R. Tappin, B. Jaffe, S. Fujino, Y. Nishimura, and J. Goff, 2012, Erosion, deposition and landscape change on the Sendai coastal plain, Japan, resulting from the March 11, 2011 Tohoku-oki tsunami, Sedimentary Geology, doi:10.1016/j.sedgeo.2012.08.005.

Witter, R.C., Y.J. Zhang, K. Wang, C. Goldfinger, and G.R. Priest, 2012, Coseismic slip on the southern Cascadia megathrust implied by tsunami deposits in an Oregon lake and earthquake-triggered marine turbidites, Journal of Geophysical Research, 117, B10303, doi:10.1029/2012JB009404.

Witter, R. C., B. Jaffe, Y. Zhang, and G. R. Priest, 2012, Reconstructing Hydrodynamic Flow Parameters of the 1700 Tsunami at Cannon Beach, Oregon, USA, Natural Hazards, doi:10.1007/s11069-011-9912-7.

Allan, J., P. Komar, P. Ruggiero, and R.C. Witter, 2012, The March 2011 Tohoku tsunami and its impacts along the U.S. West Coast, Journal of Coastal Research, Journal of Coastal Research, v. 28, n. 5, p. 1142-1153, doi:10.2112/jcoastres-d-11-00115.1.

Goto, K., C. Chague-Goff, S. Fujino, J. Goff, B. Jaffe, Y. Nishimura, B. Richmond, D. Suguwara, W. Szczucinski, D.R. Tappin, R. Witter, and E. Yulianto, 2011, New insights of tsunami hazard from the 2011 Tohoku-oki event, Marine Geology, 290, 46-50.

Horton, B. P., Sawai, Y., Hawkes, A. D., and Witter, R. C., 2011, Sedimentology and paleontology of a tsunami deposit accompanying the great Chilean earthquake of February 2010: Marine Micropaleontology, v. 79, no. 3-4, p. 132–138.

Zhang, Y. J., R. C. Witter, and G. R. Priest, 2011, Tsunami-tide interaction in 1964 Prince William Sound tsunami, Ocean Modelling, v. 40, p. 246–259.