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.
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.
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
Education and Certifications
Ph.D. 1999 University of Oregon, Eugene, OR Geoscience
B.A. 1991 Whitman College, Walla Walla, WA Biology
Science and Products
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Minimal stratigraphic evidence for coseismic coastal subsidence during 2000 yr of megathrust earthquakes at the central Cascadia subduction zone Minimal stratigraphic evidence for coseismic coastal subsidence during 2000 yr of megathrust earthquakes at the central Cascadia subduction zone
Lithology and microfossil biostratigraphy beneath the marshes of a central Oregon estuary limit geophysical models of Cascadia megathrust rupture during successive earthquakes by ruling out >0.5 m of coseismic coastal subsidence for the past 2000 yr. Although the stratigraphy in cores and outcrops includes as many as 12 peat-mud contacts, like those commonly inferred to record subsidence...
Authors
Alan Nelson, Andrea Hawkes, Yuki Sawai, Ben Hotron, Robert C. Witter, Lee-Ann Bradley, Niamh Cahill
Identifying the greatest earthquakes of the past 2000 years at the Nehalem River Estuary, Northern Oregon Coast, USA Identifying the greatest earthquakes of the past 2000 years at the Nehalem River Estuary, Northern Oregon Coast, USA
We infer a history of three great megathrust earthquakes during the past 2000 years at the Nehalem River estuary based on the lateral extent of sharp (≤3 mm) peat-mud stratigraphic contacts in cores and outcrops, coseismic subsidence as interpreted from fossil diatom assemblages and reconstructed with foraminiferal assemblages using a Bayesian transfer function, and regional correlation...
Authors
Alan Nelson, Andrea Hawkes, Yuki Sawai, Simon Engelhart, Robert C. Witter, Wendy Grant-Walter, Lee-Ann Bradley, Tina Dura, Niamh Cahill, Benajamin Horton
Palaeotsunamis in the Sino-Pacific region Palaeotsunamis in the Sino-Pacific region
Palaeotsunami research in the Sino-Pacific region has increased markedly following the 2011 Tōhoku-oki tsunami. Recent studies encompass a variety of potential sources and cover a full range of research activities from detailed studies at individual sites through to region-wide data collation for the purposes of database development. We synthesise palaeotsunami data from around the...
Authors
James Goff, Robert C. Witter, James Terry, Michaela Spiske
Radiocarbon dating of tsunami and storm deposits Radiocarbon dating of tsunami and storm deposits
Radiocarbon age determinations can be an expedient and accurate means to assign age to deposits of tsunami or storm origin. Essential to the process of incorporating radiocarbon age determinations in tsunami or coastal storm investigations is an awareness on the part of the investigator that a sample will always return an age from a laboratory, but only carefully selected samples inform...
Authors
Harvey M. Kelsey, Robert C. Witter
Ground failure triggered by shaking during the November 30, 2018, magnitude 7.1 Anchorage, Alaska, earthquake Ground failure triggered by shaking during the November 30, 2018, magnitude 7.1 Anchorage, Alaska, earthquake
We developed an initial inventory of ground failure features from the November 30, 2018, magnitude 7.1 Anchorage earthquake. This inventory of 153 features is from ground-based observations soon after the earthquake (December 5–10) that include the presence or absence of liquefaction, landslides, and individual crack traces of lateral spreads and incipient landslides. This is not a...
Authors
Alex Grant, Randall Jibson, Robert C. Witter, Kate Allstadt, Eric Thompson, Adrian Bender
Preface to the focus section on the 30 November 2018 Mw 7.1 Anchorage, Alaska earthquake Preface to the focus section on the 30 November 2018 Mw 7.1 Anchorage, Alaska earthquake
On 30 November 2018, a magnitude (Mw) 7.1 intraslab earthquake occurred under the most densely populated area of Alaska, ∼12 km north of downtown Anchorage. It generated the strongest ground shaking in the greater Anchorage area since the 1964 Mw 9.2 Great Alaska earthquake. Although the 30 November 2018 earthquake did not cause deaths or serious injuries, its economical and...
Authors
Natalia Ruppert, Robert C. Witter
Non-USGS Publications**
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.
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.
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.
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.
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, doi:10.1016/j.marmicro.2011.02.001
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, doi:10.1016/j.ocemod.2011.09.005
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 18
No Result Found
Filter Total Items: 26
No results found.
Filter Total Items: 55
Minimal stratigraphic evidence for coseismic coastal subsidence during 2000 yr of megathrust earthquakes at the central Cascadia subduction zone Minimal stratigraphic evidence for coseismic coastal subsidence during 2000 yr of megathrust earthquakes at the central Cascadia subduction zone
Lithology and microfossil biostratigraphy beneath the marshes of a central Oregon estuary limit geophysical models of Cascadia megathrust rupture during successive earthquakes by ruling out >0.5 m of coseismic coastal subsidence for the past 2000 yr. Although the stratigraphy in cores and outcrops includes as many as 12 peat-mud contacts, like those commonly inferred to record subsidence...
Authors
Alan Nelson, Andrea Hawkes, Yuki Sawai, Ben Hotron, Robert C. Witter, Lee-Ann Bradley, Niamh Cahill
Identifying the greatest earthquakes of the past 2000 years at the Nehalem River Estuary, Northern Oregon Coast, USA Identifying the greatest earthquakes of the past 2000 years at the Nehalem River Estuary, Northern Oregon Coast, USA
We infer a history of three great megathrust earthquakes during the past 2000 years at the Nehalem River estuary based on the lateral extent of sharp (≤3 mm) peat-mud stratigraphic contacts in cores and outcrops, coseismic subsidence as interpreted from fossil diatom assemblages and reconstructed with foraminiferal assemblages using a Bayesian transfer function, and regional correlation...
Authors
Alan Nelson, Andrea Hawkes, Yuki Sawai, Simon Engelhart, Robert C. Witter, Wendy Grant-Walter, Lee-Ann Bradley, Tina Dura, Niamh Cahill, Benajamin Horton
Palaeotsunamis in the Sino-Pacific region Palaeotsunamis in the Sino-Pacific region
Palaeotsunami research in the Sino-Pacific region has increased markedly following the 2011 Tōhoku-oki tsunami. Recent studies encompass a variety of potential sources and cover a full range of research activities from detailed studies at individual sites through to region-wide data collation for the purposes of database development. We synthesise palaeotsunami data from around the...
Authors
James Goff, Robert C. Witter, James Terry, Michaela Spiske
Radiocarbon dating of tsunami and storm deposits Radiocarbon dating of tsunami and storm deposits
Radiocarbon age determinations can be an expedient and accurate means to assign age to deposits of tsunami or storm origin. Essential to the process of incorporating radiocarbon age determinations in tsunami or coastal storm investigations is an awareness on the part of the investigator that a sample will always return an age from a laboratory, but only carefully selected samples inform...
Authors
Harvey M. Kelsey, Robert C. Witter
Ground failure triggered by shaking during the November 30, 2018, magnitude 7.1 Anchorage, Alaska, earthquake Ground failure triggered by shaking during the November 30, 2018, magnitude 7.1 Anchorage, Alaska, earthquake
We developed an initial inventory of ground failure features from the November 30, 2018, magnitude 7.1 Anchorage earthquake. This inventory of 153 features is from ground-based observations soon after the earthquake (December 5–10) that include the presence or absence of liquefaction, landslides, and individual crack traces of lateral spreads and incipient landslides. This is not a...
Authors
Alex Grant, Randall Jibson, Robert C. Witter, Kate Allstadt, Eric Thompson, Adrian Bender
Preface to the focus section on the 30 November 2018 Mw 7.1 Anchorage, Alaska earthquake Preface to the focus section on the 30 November 2018 Mw 7.1 Anchorage, Alaska earthquake
On 30 November 2018, a magnitude (Mw) 7.1 intraslab earthquake occurred under the most densely populated area of Alaska, ∼12 km north of downtown Anchorage. It generated the strongest ground shaking in the greater Anchorage area since the 1964 Mw 9.2 Great Alaska earthquake. Although the 30 November 2018 earthquake did not cause deaths or serious injuries, its economical and...
Authors
Natalia Ruppert, Robert C. Witter
Non-USGS Publications**
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.
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.
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.
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.
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, doi:10.1016/j.marmicro.2011.02.001
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, doi:10.1016/j.ocemod.2011.09.005
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.