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Cordell Johnson

Physical Scientist with the USGS Pacific Coastal and Marine Science Center

Science and Products

High-resolution multichannel sparker seismic-reflection and chirp sub-bottom data acquired along the Cascadia margin during USGS field activity 2019-024-FA

High-resolution multichannel sparker seismic (MCS) data and chirp sub-bottom data were collected by the U.S. Geological Survey in collaboration with the University of Washington (UW) in the summer of 2019 along the Cascadia submarine forearc offshore Oregon and Washington. Data were acquired to characterize quaternary deformation and sediment dynamics along the central and northern Cascadia margin
By
Pacific Coastal and Marine Science Center

Aerial imagery and structure-from-motion data products from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA

This data release presents aerial imagery and structure-from-motion (SfM) data products from uncrewed aerial system (UAS) surveys conducted on the ocean beaches adjacent to the Columbia River Mouth at the Oregon-Washington border.  The surveys cover approximately 3 kilometers of Benson Beach at Cape Disappointment State Park north of the Columbia River mouth, in Washington, and 3 kilometers of the
By
Pacific Coastal and Marine Science Center

Nearshore bathymetry data from the Unalakleet River mouth, Alaska, 2019

This data release presents nearshore bathymetry data collected at the mouth of the Unalakleet River in Alaska, near the city of Unalakleet. The data were collected in August 2019 by the U.S. Geological Survey, Pacific Coastal and Marine Science Center. Nearshore bathymetry was measured along survey lines from the shore to a depth of approximately -7.4 m NAVD88 and in a portion of the estuary close
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Aerial imagery and structure-from-motion derived data products from UAS survey of the Liberty Island Conservation Bank Wildlands restoration site, Sacramento-San Joaquin Delta, California, October 2018

Unmanned aerial systems (UAS) were used to acquire high-resolution imagery of the Liberty Island Conservation Bank Wildlands restoration site in the Sacramento-San Joaquin Delta in California, with the goal of using structure-from-motion (SfM) photogrammetric techniques to derive a digital surface model, orthomosaic imagery, and a topographic point cloud. The survey was conducted using two Depart
By
Pacific Coastal and Marine Science Center

Permafrost Mapping in Two Wetland Systems North of the Tanana River in Interior Alaska 2014

Surface-based 2D electrical resistivity tomography (ERT) surveys were used to investigate the distribution of permafrost at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites contained habitat types characteristic of interior Alaska, including thermokarst bog, forested permafrost plateau, and a rich fen. These
By
Water Resources Mission Area

Electrical Resistivity Tomography Data at Fort Irwin National Training Center, San Bernardino County, California, 2015 and 2017

The U.S. Army Fort Irwin National Training Center (NTC), approximately 35 mi north-northeast of Barstow, California, covers approximately 1,177 square miles, and is comprised of ten groundwater basins, three of which have been subdivided into subbasins on the basis of additional hydrologic testing. Since the early 1990s, the U.S. Geological Survey (USGS) has been studying water resources issues at
By
California Water Science Center, Geology, Geophysics, and Geochemistry Science Center
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.
Polar bear walks across flooded barrier island during Arctic storm
Polar bear walks across flooded barrier island during Arctic storm
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

Polar bear walks across flooded barrier island during Arctic storm

Polar bear walks across flooded barrier island during Arctic storm

Adult polar bear walking across a recently overwashed barrier island during a large Arctic storm in September 2016. The barrier island is offshore of Barter Island on Alaska’s north coast.

By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Alaska Science Center
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

Polar bear walks across flooded barrier island during Arctic storm

Polar bear walks across flooded barrier island during Arctic storm

Adult polar bear walking across a recently overwashed barrier island during a large Arctic storm in September 2016. The barrier island is offshore of Barter Island on Alaska’s north coast.

By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Alaska Science Center
Polar bear lazes in a field on Barter Island, Alaska.
Polar bear lazes in a field on Barter Island, Alaska
Polar bear lazes in a field on Barter Island, Alaska
Polar bear lazes in a field on Barter Island, Alaska.

Polar bear lazes in a field on Barter Island, Alaska

Polar bear lazes in a field on Barter Island, Alaska

A polar bear rests in a field on Barter Island, Alaska.

By
Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
Polar bear lazes in a field on Barter Island, Alaska.

Polar bear lazes in a field on Barter Island, Alaska

Polar bear lazes in a field on Barter Island, Alaska

A polar bear rests in a field on Barter Island, Alaska.

By
Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
Photo of a floating platform with instruments on it, to collect water data.
Collecting data over a submarine groundwater vent
Collecting data over a submarine groundwater vent
Photo of a floating platform with instruments on it, to collect water data.

Collecting data over a submarine groundwater vent

Collecting data over a submarine groundwater vent

An inflatable boat floating above a submarine groundwater vent was used as a multi-day mooring platform for making time-series measurements of the naturally occurring groundwater tracers radon (222Rn) and thoron (220Rn). Gray surface buoys closer to the beach mark locations of thermistor arrays and wave/tide gauges.

By
Pacific Coastal and Marine Science Center
Photo of a floating platform with instruments on it, to collect water data.

Collecting data over a submarine groundwater vent

Collecting data over a submarine groundwater vent

An inflatable boat floating above a submarine groundwater vent was used as a multi-day mooring platform for making time-series measurements of the naturally occurring groundwater tracers radon (222Rn) and thoron (220Rn). Gray surface buoys closer to the beach mark locations of thermistor arrays and wave/tide gauges.

By
Pacific Coastal and Marine Science Center

Evaluation of the characteristics, discharge, and water quality of selected springs at Fort Irwin National Training Center, San Bernardino County, California

Eight springs and seeps at Fort Irwin National Training Center were described and categorized by their general characteristics, discharge, geophysical properties, and water quality between 2015 and 2017. The data collected establish a modern (2017) baseline of hydrologic conditions at the springs. Two types of springs were identified: (1) precipitation-fed upland springs (Cave, Desert King, Devoug
Authors
Jill N. Densmore, Drew C. Thayer, Meghan C. Dick, Peter W. Swarzenski, Lyndsay B. Ball, Celia Z. Rosecrans, Cordell Johnson
By
Water Resources Mission Area, California Water Science Center, Geology, Geophysics, and Geochemistry Science Center, Pacific Coastal and Marine Science Center

Permafrost mapping with electrical resistivity tomography in two wetland systems north of the Tanana River, Interior Alaska

Surface-based 2D electrical resistivity tomography (ERT) surveys were used to characterize permafrost distribution at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites were part of an ecologically-sensitive research area characterizing biogeochemical response of this region to warming and permafrost thaw, and
Authors
Christopher H. Conaway, Cordell Johnson, Thomas Lorenson, Merritt R. Turetsky, Eugénie S. Euskirchen, Mark Waldrop, Peter W. Swarzenski
By
Water Resources Mission Area

Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi

Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, to date an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; und
Authors
Ferdinand Oberle, Curt D. Storlazzi, Olivia Cheriton, Renee K. Takesue, Daniel J. Hoover, Joshua B. Logan, Christina M. Runyon, Christina A. Kellogg, Cordell Johnson, Peter W. Swarzenski
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Seasonal electrical resistivity surveys of a coastal bluff, Barter Island, North Slope Alaska

Select coastal regions of the North Slope of Alaska are experiencing high erosion rates that can be attributed in part to recent warming trends and associated increased storm intensity and frequency. The upper sediment column of the coastal North Slope of Alaska can be described as continuous permafrost underlying a thin (typically less than 1–2 m) active layer that responds variably to seasonal t
Authors
Peter W. Swarzenski, Cordell Johnson, Thomas Lorenson, Christopher H. Conaway, Ann E. Gibbs, Li H. Erikson, Bruce M. Richmond, Mark P. Waldrop
By
Pacific Coastal and Marine Science Center

Ground-truthing electrical resistivity methods in support of submarine groundwater discharge studies: Examples from Hawaii, Washington, and California

Submarine groundwater discharge (SGD) is an important conduit that links terrestrial and marine environments. SGD conveys both water and water-borne constituents into coastal waters, where these inflows may impact near-shore ecosystem health and sustainability. Multichannel electrical resistivity techniques have proven to be a powerful tool to examine scales and dynamics of SGD and SGD forcings. H
Authors
Cordell Johnson, Peter W. Swarzenski, Christina M. Richardson, Christopher G. Smith, Kevin D. Kroeger, Priya M. Ganguli
By
Pacific Coastal and Marine Science Center

Science and Products

High-resolution multichannel sparker seismic-reflection and chirp sub-bottom data acquired along the Cascadia margin during USGS field activity 2019-024-FA

High-resolution multichannel sparker seismic (MCS) data and chirp sub-bottom data were collected by the U.S. Geological Survey in collaboration with the University of Washington (UW) in the summer of 2019 along the Cascadia submarine forearc offshore Oregon and Washington. Data were acquired to characterize quaternary deformation and sediment dynamics along the central and northern Cascadia margin
By
Pacific Coastal and Marine Science Center

Aerial imagery and structure-from-motion data products from UAS surveys of the beaches at Fort Stevens State Park, OR, and Cape Disappointment State Park, WA

This data release presents aerial imagery and structure-from-motion (SfM) data products from uncrewed aerial system (UAS) surveys conducted on the ocean beaches adjacent to the Columbia River Mouth at the Oregon-Washington border.  The surveys cover approximately 3 kilometers of Benson Beach at Cape Disappointment State Park north of the Columbia River mouth, in Washington, and 3 kilometers of the
By
Pacific Coastal and Marine Science Center

Nearshore bathymetry data from the Unalakleet River mouth, Alaska, 2019

This data release presents nearshore bathymetry data collected at the mouth of the Unalakleet River in Alaska, near the city of Unalakleet. The data were collected in August 2019 by the U.S. Geological Survey, Pacific Coastal and Marine Science Center. Nearshore bathymetry was measured along survey lines from the shore to a depth of approximately -7.4 m NAVD88 and in a portion of the estuary close
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Aerial imagery and structure-from-motion derived data products from UAS survey of the Liberty Island Conservation Bank Wildlands restoration site, Sacramento-San Joaquin Delta, California, October 2018

Unmanned aerial systems (UAS) were used to acquire high-resolution imagery of the Liberty Island Conservation Bank Wildlands restoration site in the Sacramento-San Joaquin Delta in California, with the goal of using structure-from-motion (SfM) photogrammetric techniques to derive a digital surface model, orthomosaic imagery, and a topographic point cloud. The survey was conducted using two Depart
By
Pacific Coastal and Marine Science Center

Permafrost Mapping in Two Wetland Systems North of the Tanana River in Interior Alaska 2014

Surface-based 2D electrical resistivity tomography (ERT) surveys were used to investigate the distribution of permafrost at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites contained habitat types characteristic of interior Alaska, including thermokarst bog, forested permafrost plateau, and a rich fen. These
By
Water Resources Mission Area

Electrical Resistivity Tomography Data at Fort Irwin National Training Center, San Bernardino County, California, 2015 and 2017

The U.S. Army Fort Irwin National Training Center (NTC), approximately 35 mi north-northeast of Barstow, California, covers approximately 1,177 square miles, and is comprised of ten groundwater basins, three of which have been subdivided into subbasins on the basis of additional hydrologic testing. Since the early 1990s, the U.S. Geological Survey (USGS) has been studying water resources issues at
By
California Water Science Center, Geology, Geophysics, and Geochemistry Science Center
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.
Polar bear walks across flooded barrier island during Arctic storm
Polar bear walks across flooded barrier island during Arctic storm
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

Polar bear walks across flooded barrier island during Arctic storm

Polar bear walks across flooded barrier island during Arctic storm

Adult polar bear walking across a recently overwashed barrier island during a large Arctic storm in September 2016. The barrier island is offshore of Barter Island on Alaska’s north coast.

By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Alaska Science Center
Polar bear appears to walk on top of rippled gray water. Just behind it are very large breaking waves below a gray-blue sky.

Polar bear walks across flooded barrier island during Arctic storm

Polar bear walks across flooded barrier island during Arctic storm

Adult polar bear walking across a recently overwashed barrier island during a large Arctic storm in September 2016. The barrier island is offshore of Barter Island on Alaska’s north coast.

By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Alaska Science Center
Polar bear lazes in a field on Barter Island, Alaska.
Polar bear lazes in a field on Barter Island, Alaska
Polar bear lazes in a field on Barter Island, Alaska
Polar bear lazes in a field on Barter Island, Alaska.

Polar bear lazes in a field on Barter Island, Alaska

Polar bear lazes in a field on Barter Island, Alaska

A polar bear rests in a field on Barter Island, Alaska.

By
Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
Polar bear lazes in a field on Barter Island, Alaska.

Polar bear lazes in a field on Barter Island, Alaska

Polar bear lazes in a field on Barter Island, Alaska

A polar bear rests in a field on Barter Island, Alaska.

By
Natural Hazards, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
Photo of a floating platform with instruments on it, to collect water data.
Collecting data over a submarine groundwater vent
Collecting data over a submarine groundwater vent
Photo of a floating platform with instruments on it, to collect water data.

Collecting data over a submarine groundwater vent

Collecting data over a submarine groundwater vent

An inflatable boat floating above a submarine groundwater vent was used as a multi-day mooring platform for making time-series measurements of the naturally occurring groundwater tracers radon (222Rn) and thoron (220Rn). Gray surface buoys closer to the beach mark locations of thermistor arrays and wave/tide gauges.

By
Pacific Coastal and Marine Science Center
Photo of a floating platform with instruments on it, to collect water data.

Collecting data over a submarine groundwater vent

Collecting data over a submarine groundwater vent

An inflatable boat floating above a submarine groundwater vent was used as a multi-day mooring platform for making time-series measurements of the naturally occurring groundwater tracers radon (222Rn) and thoron (220Rn). Gray surface buoys closer to the beach mark locations of thermistor arrays and wave/tide gauges.

By
Pacific Coastal and Marine Science Center

Evaluation of the characteristics, discharge, and water quality of selected springs at Fort Irwin National Training Center, San Bernardino County, California

Eight springs and seeps at Fort Irwin National Training Center were described and categorized by their general characteristics, discharge, geophysical properties, and water quality between 2015 and 2017. The data collected establish a modern (2017) baseline of hydrologic conditions at the springs. Two types of springs were identified: (1) precipitation-fed upland springs (Cave, Desert King, Devoug
Authors
Jill N. Densmore, Drew C. Thayer, Meghan C. Dick, Peter W. Swarzenski, Lyndsay B. Ball, Celia Z. Rosecrans, Cordell Johnson
By
Water Resources Mission Area, California Water Science Center, Geology, Geophysics, and Geochemistry Science Center, Pacific Coastal and Marine Science Center

Permafrost mapping with electrical resistivity tomography in two wetland systems north of the Tanana River, Interior Alaska

Surface-based 2D electrical resistivity tomography (ERT) surveys were used to characterize permafrost distribution at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites were part of an ecologically-sensitive research area characterizing biogeochemical response of this region to warming and permafrost thaw, and
Authors
Christopher H. Conaway, Cordell Johnson, Thomas Lorenson, Merritt R. Turetsky, Eugénie S. Euskirchen, Mark Waldrop, Peter W. Swarzenski
By
Water Resources Mission Area

Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi

Pervasive and sustained coral diseases contribute to the systemic degradation of reef ecosystems, however, to date an understanding of the physicochemical controls on a coral disease event is still largely lacking. Water circulation and residence times and submarine groundwater discharge all determine the degree to which reef organisms are exposed to the variable chemistry of overlying waters; und
Authors
Ferdinand Oberle, Curt D. Storlazzi, Olivia Cheriton, Renee K. Takesue, Daniel J. Hoover, Joshua B. Logan, Christina M. Runyon, Christina A. Kellogg, Cordell Johnson, Peter W. Swarzenski
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Seasonal electrical resistivity surveys of a coastal bluff, Barter Island, North Slope Alaska

Select coastal regions of the North Slope of Alaska are experiencing high erosion rates that can be attributed in part to recent warming trends and associated increased storm intensity and frequency. The upper sediment column of the coastal North Slope of Alaska can be described as continuous permafrost underlying a thin (typically less than 1–2 m) active layer that responds variably to seasonal t
Authors
Peter W. Swarzenski, Cordell Johnson, Thomas Lorenson, Christopher H. Conaway, Ann E. Gibbs, Li H. Erikson, Bruce M. Richmond, Mark P. Waldrop
By
Pacific Coastal and Marine Science Center

Ground-truthing electrical resistivity methods in support of submarine groundwater discharge studies: Examples from Hawaii, Washington, and California

Submarine groundwater discharge (SGD) is an important conduit that links terrestrial and marine environments. SGD conveys both water and water-borne constituents into coastal waters, where these inflows may impact near-shore ecosystem health and sustainability. Multichannel electrical resistivity techniques have proven to be a powerful tool to examine scales and dynamics of SGD and SGD forcings. H
Authors
Cordell Johnson, Peter W. Swarzenski, Christina M. Richardson, Christopher G. Smith, Kevin D. Kroeger, Priya M. Ganguli
By
Pacific Coastal and Marine Science Center
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