Walter A. Barnhardt, PhD
My scientific background is in marine geology and my passion is working on basic scientific problems that have societal and management implications. I focus on understanding how coasts have evolved through time and space, so we can better predict their future behavior and minimize losses due to storms, chronic erosion and sea-level rise.
I lead the Coastal and Shelf Geology Group at the Woods Hole Coastal and Marine Science Center. This internationally recognized team consists of about 25 scientists and technologists who apply state-of-the-art methods to map coastal/shelf environments and model the processes that shape them. Products and tools produced from our studies help resource managers to make sustainable, science-based decisions and mitigate the impacts of storms, sea-level rise, and human activities along the nation’s coasts. I have 30+ years of experience in New England, the Mid-Atlantic and Great Lakes, where I advise federal/state/local agencies, Tribal nations, and non-governmental organizations on coastal erosion strategies, environmental restoration projects, and offshore infrastructure development. I also oversee efforts to recruit students from under-represented groups to the USGS workforce through a speaker series and internship program with the City College of New York.
Professional Experience
2017-Present Research Geologist U.S. Geological Survey - Woods Hole, MA
2009-2017 Center Director U.S. Geological Survey - Woods Hole, MA
2004-2009 Research Geologist U.S. Geological Survey - Woods Hole, MA
2001-2004 Assistant Professor Univ. of North Carolina - Chapel Hill, NC
1998-2001 Adjunct Lecturer Santa Clara University – Santa Clara, CA
1996-2001 Research Geologist U.S. Geological Survey - Menlo Park, CA
1994-1996 Postdoctoral Researcher University of Maine - Orono, ME
Education and Certifications
1994 Ph.D., Geological Sciences University of Maine - Orono, ME
1992 M.S., Geological Sciences University of Maine - Orono, ME
1984 B.S. (with honors), Geology College of William & Mary - Williamsburg, VA
Science and Products
Filter Total Items: 31
Geophysical and sampling data from the inner continental shelf: Duxbury to Hull, Massachusetts
The U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM) have cooperated to map approximately 200 km² of the Massachusetts inner continental shelf between Duxbury and Hull. This report contains geophysical and geological data collected by the USGS on three cruises between 2006 and 2007. These USGS data are supplemented with a National Oceanic and Atmospheric
Authors
Walter A. Barnhardt, Seth D. Ackerman, Brian D. Andrews, Wayne E. Baldwin
Tectonic controls on nearshore sediment accumulation and submarine canyon morphology offshore La Jolla, Southern California
CHIRP seismic and swath bathymetry data acquired offshore La Jolla, California provide an unprecedented three-dimensional view of the La Jolla and Scripps submarine canyons. Shore-parallel patterns of tectonic deformation appear to control nearshore sediment thickness and distribution around the canyons. These shore-parallel patterns allow the impact of local tectonic deformation to be separated f
Authors
Nicolas Le Dantec, Leah J. Hogarth, Neal W. Driscoll, Jeffrey M. Babcock, Walter A. Barnhardt, William C. Schwab
Automated feature extraction and spatial organization of seafloor pockmarks, Belfast Bay, Maine, USA
Seafloor pockmarks occur worldwide and may represent millions of m3 of continental shelf erosion, but few numerical analyses of their morphology and spatial distribution of pockmarks exist. We introduce a quantitative definition of pockmark morphology and, based on this definition, propose a three-step geomorphometric method to identify and extract pockmarks from high-resolution swath bathymetry.
Authors
Brian D. Andrews, Laura L. Brothers, Walter A. Barnhardt
Coastal change along the shore of northeastern South Carolina— The South Carolina Coastal Erosion Study
The U.S. Geological Survey, in cooperation with the South Carolina Sea Grant Consortium, conducted a 7-year, multidisciplinary study of coastal erosion in northeastern South Carolina. Shoreline behavior along the coast of Long Bay is dictated by waves, tidal currents, and sediment supply that act within the overall constraints of the regional geologic setting. Beaches are thin ribbons of sand that
Authors
W. C. Schwab, P. T. Gayes, R.A. Morton, N. W. Driscoll, W. E. Baldwin, W. A. Barnhardt, J. F. Denny, M.S. Harris, M.P. Katuna, T.R. Putney, G. Voulgaris, J.C. Warner, E.E. Wright
High-Resolution Geologic Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts
The geologic framework of the Massachusetts inner continental shelf between Cape Ann and Salisbury Beach has been shaped by a complicated history of glaciation, deglaciation, and changes in relative sea level. New geophysical data (swath bathymetry, sidescan sonar and seismic-reflection profiling), sediment samples, and seafloor photography provide insight into the geomorphic and stratigraphic re
Authors
Walter A. Barnhardt, Brian D. Andrews, Seth D. Ackerman, Wayne E. Baldwin, Christopher J. Hein
Holocene reworking of a sand sheet in the Merrimack Embayment, Western Gulf of Maine
Recent bathymetric, backscatter, and seafloor sediment samples demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta (deposited 12 kya; currently at 45 m depth) and braid plain during the Holocene transgression. Asymmetric bedforms and distinct grain size distributions suggest the sand sheet is actively being reworked by inner-shel
Authors
C.J. Hein, D. M. FitzGerald, W. Barnhardt
Seismic stability of the Duwamish River Delta, Seattle, Washington
The delta front of the Duwamish River valley near Elliott Bay and Harbor Island is founded on young Holocene deposits shaped by sea-level rise, episodic volcanism, and seismicity. These river-mouth deposits are highly susceptible to seismic soil liquefaction and are potentially prone to submarine landsliding and disintegrative flow failure.
A highly developed commercial-industrial corridor, exten
Authors
Robert E. Kayen, Walter A. Barnhardt
Geologic framework of the long bay inner shelf: implications for coastal evolution in South Carolina
The inner continental shelf off northern South Carolina is a sediment-limited environment characterized by extensive hardground areas, where coastal plain strata and ancient channel-fill deposits are exposed at the sea floor. Holocene sand is concentrated in large shoals associated with active tidal inlets, an isolated shore-detached sand body, and a widespread series of low-relief sand ridges. Th
Authors
W. Barnhardt, J. Denny, W. Baldwin, W. Schwab, R. Morton, P. Gayes, N. Driscoll
Holocene evolution of the merrimack embayment, northern massachusetts, interperted from shallow seismic stratigraphy
Recent multi-beam, backscatter, and bottom sediment data demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta and braid plain (12 kya) during the Holocene transgression. Seismic data reveal the presence of widespread channel cut-and-fill structures landward of the delta suggesting that much of the sand sheet consists of braided st
Authors
C.J. Hein, D. M. FitzGerald, W. A. Barnhardt
Mapping the seafloor geology offshore of Massachusetts
Geologic and bathymetric maps help us understand the evolutionary history of the Massachusetts coast and the processes that have shaped it. The maps show the distribution of bottom types (for example, bedrock, gravel, sand, mud) and water depths over large areas of the seafloor. In turn, these two fundamental parameters largely determine the species of flora and fauna that inhabit a particular are
Authors
Walter A. Barnhardt, Brian D. Andrews
High-resolution geologic mapping of the inner continental shelf: Nahant to Gloucester, Massachusetts
This report presents high-resolution maps of the seafloor offshore of Massachusetts, from Nahant to Gloucester. Approximately 134 km² of the inner shelf were mapped with a focus on the nearshore region in water depths less than 40 m (fig. 1.1). The maps were prepared as part of a cooperative mapping program between the U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Mana
Authors
Walter A. Barnhardt, Brian D. Andrews, Bradford Butman
Shelf stratigraphy and the influence of antecedent substrate on Holocene reef development, south Oahu, Hawaii
Paired analyses of drill cores and high-resolution seismic reflection data show that development of Holocene framework reefs on the Oahu (Hawaii) shelf is limited to settings of low wave energy and to the period 8000 to 3000 yr BP. A prominent bounding surface that is mapped across much of the Oahu shelf is an erosion surface cut into Marine Isotope Stages 5 and 7 limestones that show extensive lo
Authors
E. E. Grossman, W. A. Barnhardt, P. Hart, B. M. Richmond, M.E. Field
Science and Products
Filter Total Items: 31
Geophysical and sampling data from the inner continental shelf: Duxbury to Hull, Massachusetts
The U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM) have cooperated to map approximately 200 km² of the Massachusetts inner continental shelf between Duxbury and Hull. This report contains geophysical and geological data collected by the USGS on three cruises between 2006 and 2007. These USGS data are supplemented with a National Oceanic and Atmospheric
Authors
Walter A. Barnhardt, Seth D. Ackerman, Brian D. Andrews, Wayne E. Baldwin
Tectonic controls on nearshore sediment accumulation and submarine canyon morphology offshore La Jolla, Southern California
CHIRP seismic and swath bathymetry data acquired offshore La Jolla, California provide an unprecedented three-dimensional view of the La Jolla and Scripps submarine canyons. Shore-parallel patterns of tectonic deformation appear to control nearshore sediment thickness and distribution around the canyons. These shore-parallel patterns allow the impact of local tectonic deformation to be separated f
Authors
Nicolas Le Dantec, Leah J. Hogarth, Neal W. Driscoll, Jeffrey M. Babcock, Walter A. Barnhardt, William C. Schwab
Automated feature extraction and spatial organization of seafloor pockmarks, Belfast Bay, Maine, USA
Seafloor pockmarks occur worldwide and may represent millions of m3 of continental shelf erosion, but few numerical analyses of their morphology and spatial distribution of pockmarks exist. We introduce a quantitative definition of pockmark morphology and, based on this definition, propose a three-step geomorphometric method to identify and extract pockmarks from high-resolution swath bathymetry.
Authors
Brian D. Andrews, Laura L. Brothers, Walter A. Barnhardt
Coastal change along the shore of northeastern South Carolina— The South Carolina Coastal Erosion Study
The U.S. Geological Survey, in cooperation with the South Carolina Sea Grant Consortium, conducted a 7-year, multidisciplinary study of coastal erosion in northeastern South Carolina. Shoreline behavior along the coast of Long Bay is dictated by waves, tidal currents, and sediment supply that act within the overall constraints of the regional geologic setting. Beaches are thin ribbons of sand that
Authors
W. C. Schwab, P. T. Gayes, R.A. Morton, N. W. Driscoll, W. E. Baldwin, W. A. Barnhardt, J. F. Denny, M.S. Harris, M.P. Katuna, T.R. Putney, G. Voulgaris, J.C. Warner, E.E. Wright
High-Resolution Geologic Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts
The geologic framework of the Massachusetts inner continental shelf between Cape Ann and Salisbury Beach has been shaped by a complicated history of glaciation, deglaciation, and changes in relative sea level. New geophysical data (swath bathymetry, sidescan sonar and seismic-reflection profiling), sediment samples, and seafloor photography provide insight into the geomorphic and stratigraphic re
Authors
Walter A. Barnhardt, Brian D. Andrews, Seth D. Ackerman, Wayne E. Baldwin, Christopher J. Hein
Holocene reworking of a sand sheet in the Merrimack Embayment, Western Gulf of Maine
Recent bathymetric, backscatter, and seafloor sediment samples demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta (deposited 12 kya; currently at 45 m depth) and braid plain during the Holocene transgression. Asymmetric bedforms and distinct grain size distributions suggest the sand sheet is actively being reworked by inner-shel
Authors
C.J. Hein, D. M. FitzGerald, W. Barnhardt
Seismic stability of the Duwamish River Delta, Seattle, Washington
The delta front of the Duwamish River valley near Elliott Bay and Harbor Island is founded on young Holocene deposits shaped by sea-level rise, episodic volcanism, and seismicity. These river-mouth deposits are highly susceptible to seismic soil liquefaction and are potentially prone to submarine landsliding and disintegrative flow failure.
A highly developed commercial-industrial corridor, exten
Authors
Robert E. Kayen, Walter A. Barnhardt
Geologic framework of the long bay inner shelf: implications for coastal evolution in South Carolina
The inner continental shelf off northern South Carolina is a sediment-limited environment characterized by extensive hardground areas, where coastal plain strata and ancient channel-fill deposits are exposed at the sea floor. Holocene sand is concentrated in large shoals associated with active tidal inlets, an isolated shore-detached sand body, and a widespread series of low-relief sand ridges. Th
Authors
W. Barnhardt, J. Denny, W. Baldwin, W. Schwab, R. Morton, P. Gayes, N. Driscoll
Holocene evolution of the merrimack embayment, northern massachusetts, interperted from shallow seismic stratigraphy
Recent multi-beam, backscatter, and bottom sediment data demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta and braid plain (12 kya) during the Holocene transgression. Seismic data reveal the presence of widespread channel cut-and-fill structures landward of the delta suggesting that much of the sand sheet consists of braided st
Authors
C.J. Hein, D. M. FitzGerald, W. A. Barnhardt
Mapping the seafloor geology offshore of Massachusetts
Geologic and bathymetric maps help us understand the evolutionary history of the Massachusetts coast and the processes that have shaped it. The maps show the distribution of bottom types (for example, bedrock, gravel, sand, mud) and water depths over large areas of the seafloor. In turn, these two fundamental parameters largely determine the species of flora and fauna that inhabit a particular are
Authors
Walter A. Barnhardt, Brian D. Andrews
High-resolution geologic mapping of the inner continental shelf: Nahant to Gloucester, Massachusetts
This report presents high-resolution maps of the seafloor offshore of Massachusetts, from Nahant to Gloucester. Approximately 134 km² of the inner shelf were mapped with a focus on the nearshore region in water depths less than 40 m (fig. 1.1). The maps were prepared as part of a cooperative mapping program between the U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Mana
Authors
Walter A. Barnhardt, Brian D. Andrews, Bradford Butman
Shelf stratigraphy and the influence of antecedent substrate on Holocene reef development, south Oahu, Hawaii
Paired analyses of drill cores and high-resolution seismic reflection data show that development of Holocene framework reefs on the Oahu (Hawaii) shelf is limited to settings of low wave energy and to the period 8000 to 3000 yr BP. A prominent bounding surface that is mapped across much of the Oahu shelf is an erosion surface cut into Marine Isotope Stages 5 and 7 limestones that show extensive lo
Authors
E. E. Grossman, W. A. Barnhardt, P. Hart, B. M. Richmond, M.E. Field