Todd Hoefen
Todd Hoefen is a Geophysicist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 109
A method for quantitative mapping of thick oil spills using imaging spectroscopy
In response to the Deepwater Horizon oil spill in the Gulf of Mexico, a method of near-infrared imaging spectroscopic analysis was developed to map the locations of thick oil floating on water. Specifically, this method can be used to derive, in each image pixel, the oil-to-water ratio in oil emulsions, the sub-pixel areal fraction, and its thicknesses and volume within the limits of light penetra
Authors
Roger N. Clark, Gregg A. Swayze, Ira Leifer, K. Eric Livo, Raymond F. Kokaly, Todd Hoefen, Sarah Lundeen, Michael Eastwood, Robert O. Green, Neil Pearson, Charles Sarture, Ian McCubbin, Dar Roberts, Eliza Bradley, Denis Steele, Thomas Ryan, Roseanne Dominguez
A rapid method for creating qualitative images indicative of thick oil emulsion on the ocean's surface from imaging spectrometer data
This report describes a method to create color-composite images indicative of thick oil:water emulsions on the surface of clear, deep ocean water by using normalized difference ratios derived from remotely sensed data collected by an imaging spectrometer. The spectral bands used in the normalized difference ratios are located in wavelength regions where the spectra of thick oil:water emulsions on
Authors
Raymond F. Kokaly, Todd M. Hoefen, K. Eric Livo, Gregg A. Swayze, Ira Leifer, Ian B. McCubbin, Michael L. Eastwood, Robert O. Green, Sarah R. Lundeen, Charles M. Sarture, Denis Steele, Thomas Ryan, Eliza S. Bradley, Dar A. Roberts
Estimated minimum discharge rates of the Deepwater Horizon spill— Interim report to the flow rate technical group from the Mass Balance Team
All of the calculations and results in this report are preliminary and intended for the purpose, and only for the purpose, of aiding the incident team in assessing the extent of the spilled oil for ongoing response efforts. Other applications of this report are not authorized and are not considered valid. Because of time constraints and limitations of data available to the experts, many of their e
Authors
Victor F. Labson, Roger N. Clark, Gregg A. Swayze, Todd M. Hoefen, Raymond F. Kokaly, K. Eric Livo, Michael H. Powers, Geoffrey S. Plumlee, Gregory P. Meeker
A Method for Qualitative Mapping of Thick Oil Spills Using Imaging Spectroscopy
A method is described to create qualitative images of thick oil in oil spills on water using near-infrared imaging spectroscopy data. The method uses simple 'three-point-band depths' computed for each pixel in an imaging spectrometer image cube using the organic absorption features due to chemical bonds in aliphatic hydrocarbons at 1.2, 1.7, and 2.3 microns. The method is not quantitative because
Authors
Roger N. Clark, Gregg A. Swayze, Ira Leifer, K. Eric Livo, Sarah Lundeen, Michael Eastwood, Robert O. Green, Raymond F. Kokaly, Todd Hoefen, Charles Sarture, Ian McCubbin, Dar Roberts, Denis Steele, Thomas Ryan, Roseanne Dominguez, Neil Pearson
Examination of Libby, Montana, Fill Material for Background Levels of Amphibole from the Rainy Creek Complex Using Scanning Electron Microscopy and X-Ray Microanalysis
Natural background levels of Libby-type amphibole in the sediment of the Libby valley in Montana have not, up to this point, been determined. The purpose of this report is to provide the preliminary findings of a study designed by both the U.S. Geological Survey and the U.S. Environmental Protection Agency and performed by the U.S. Geological Survey. The study worked to constrain the natural backg
Authors
David T. Adams, William H. Langer, Todd M. Hoefen, Bradley S. Van Gosen, Gregory P. Meeker
Sample collection of ash and burned soils from the October 2007 southern California Wildfires
Between November 2 through 9, 2007 scientists from the U.S. Geological Survey (USGS) collected samples of ash and burned soils from 28 sites in six areas burned as a result of the Southern California wildfires of October 2007, including the Harris, Witch, Santiago, Ammo, Canyon, and Grass Valley Fires. The primary goal of this sampling and analysis effort was to understand how differences in ash a
Authors
Todd M. Hoefen, Raymond F. Kokaly, Deborah A. Martin, Carlton J. Rochester, Geoffrey S. Plumlee, Greg Mendez, Eric G. Reichard, Robert N. Fisher
Materials characterization of dusts generated by the collapse of the World Trade Center
The major inorganic components of the dusts generated from the collapse of the World Trade Center buildings on September 11, 2001 were concrete materials, gypsum, and man-made vitreous fibers. These components were likely derived from lightweight Portland cement concrete floors, gypsum wallboard, and spray-on fireproofing and ceiling tiles, respectively. All of the 36 samples collected by the USGS
Authors
Gregory P. Meeker, Stephen J. Sutley, Isabelle Brownfield, Heather Lowers, Amy M. Bern, Gregg A. Swayze, Todd M. Hoefen, Geoffrey S. Plumlee, Roger N. Clark, Carol A. Gent
Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse
Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain wa
Authors
Geoffrey S. Plumlee, Philip L. Hageman, Paul J. Lamothe, Thomas L. Ziegler, Gregory P. Meeker, Peter M. Theodorakos, Isabelle Brownfield, Monique G. Adams, Gregg A. Swayze, Todd M. Hoefen, Joseph E. Taggart, Roger N. Clark, S. Wilson, Stephen J. Sutley
Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack
The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with temperatures
Authors
Roger N. Clark, Gregg A. Swayze, Todd M. Hoefen, Robert O. Green, Keith E. Livo, Gregory P. Meeker, Stephen J. Sutley, Geoffrey S. Plumlee, Betina Pavri, Charles M. Sarture, Joe Boardman, Isabelle Brownfield, Laurie C. Morath
Reflectance spectroscopy of organic compounds: 1. Alkanes
Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first
Authors
R. N. Clark, J. M. Curchin, T.M. Hoefen, G.A. Swayze
Leachate Geochemical Results for Ash Samples from the June 2007 Angora Wildfire Near Lake Tahoe in Northern California
This report releases leachate geochemical data for ash samples produced by the Angora wildfire that burned from June 24 to July 2, 2007, near Lake Tahoe in northern California. The leaching studies are part of a larger interdisciplinary study whose goal is to identify geochemical characteristics and properties of the ash that may adversely affect human health, water quality, air quality, animal ha
Authors
Philip L. Hageman, Geoffrey S. Plumlee, Deborah A. Martin, Todd M. Hoefen, Monique Adams, Paul J. Lamothe, Todor I. Todorov, Michael W. Anthony
Leachate Geochemical Results for Ash and Burned Soil Samples from the October 2007 Southern California Wildfires
This report is the second release of leachate geochemical data included as part of a multidisciplinary study of ash and burned soil samples from the October 2007 wildfires in southern California. Geochemical data for the first set of samples were released in an Open-File Report (Plumlee and others, 2007). This study is a continuation of that work.
The objectives of this leaching study are to aid
Authors
Philip L. Hageman, Geoffrey S. Plumlee, Deborah A. Martin, Todd M. Hoefen, Gregory P. Meeker, Monique Adams, Paul J. Lamothe, Michael W. Anthony
Science and Products
Filter Total Items: 109
A method for quantitative mapping of thick oil spills using imaging spectroscopy
In response to the Deepwater Horizon oil spill in the Gulf of Mexico, a method of near-infrared imaging spectroscopic analysis was developed to map the locations of thick oil floating on water. Specifically, this method can be used to derive, in each image pixel, the oil-to-water ratio in oil emulsions, the sub-pixel areal fraction, and its thicknesses and volume within the limits of light penetra
Authors
Roger N. Clark, Gregg A. Swayze, Ira Leifer, K. Eric Livo, Raymond F. Kokaly, Todd Hoefen, Sarah Lundeen, Michael Eastwood, Robert O. Green, Neil Pearson, Charles Sarture, Ian McCubbin, Dar Roberts, Eliza Bradley, Denis Steele, Thomas Ryan, Roseanne Dominguez
A rapid method for creating qualitative images indicative of thick oil emulsion on the ocean's surface from imaging spectrometer data
This report describes a method to create color-composite images indicative of thick oil:water emulsions on the surface of clear, deep ocean water by using normalized difference ratios derived from remotely sensed data collected by an imaging spectrometer. The spectral bands used in the normalized difference ratios are located in wavelength regions where the spectra of thick oil:water emulsions on
Authors
Raymond F. Kokaly, Todd M. Hoefen, K. Eric Livo, Gregg A. Swayze, Ira Leifer, Ian B. McCubbin, Michael L. Eastwood, Robert O. Green, Sarah R. Lundeen, Charles M. Sarture, Denis Steele, Thomas Ryan, Eliza S. Bradley, Dar A. Roberts
Estimated minimum discharge rates of the Deepwater Horizon spill— Interim report to the flow rate technical group from the Mass Balance Team
All of the calculations and results in this report are preliminary and intended for the purpose, and only for the purpose, of aiding the incident team in assessing the extent of the spilled oil for ongoing response efforts. Other applications of this report are not authorized and are not considered valid. Because of time constraints and limitations of data available to the experts, many of their e
Authors
Victor F. Labson, Roger N. Clark, Gregg A. Swayze, Todd M. Hoefen, Raymond F. Kokaly, K. Eric Livo, Michael H. Powers, Geoffrey S. Plumlee, Gregory P. Meeker
A Method for Qualitative Mapping of Thick Oil Spills Using Imaging Spectroscopy
A method is described to create qualitative images of thick oil in oil spills on water using near-infrared imaging spectroscopy data. The method uses simple 'three-point-band depths' computed for each pixel in an imaging spectrometer image cube using the organic absorption features due to chemical bonds in aliphatic hydrocarbons at 1.2, 1.7, and 2.3 microns. The method is not quantitative because
Authors
Roger N. Clark, Gregg A. Swayze, Ira Leifer, K. Eric Livo, Sarah Lundeen, Michael Eastwood, Robert O. Green, Raymond F. Kokaly, Todd Hoefen, Charles Sarture, Ian McCubbin, Dar Roberts, Denis Steele, Thomas Ryan, Roseanne Dominguez, Neil Pearson
Examination of Libby, Montana, Fill Material for Background Levels of Amphibole from the Rainy Creek Complex Using Scanning Electron Microscopy and X-Ray Microanalysis
Natural background levels of Libby-type amphibole in the sediment of the Libby valley in Montana have not, up to this point, been determined. The purpose of this report is to provide the preliminary findings of a study designed by both the U.S. Geological Survey and the U.S. Environmental Protection Agency and performed by the U.S. Geological Survey. The study worked to constrain the natural backg
Authors
David T. Adams, William H. Langer, Todd M. Hoefen, Bradley S. Van Gosen, Gregory P. Meeker
Sample collection of ash and burned soils from the October 2007 southern California Wildfires
Between November 2 through 9, 2007 scientists from the U.S. Geological Survey (USGS) collected samples of ash and burned soils from 28 sites in six areas burned as a result of the Southern California wildfires of October 2007, including the Harris, Witch, Santiago, Ammo, Canyon, and Grass Valley Fires. The primary goal of this sampling and analysis effort was to understand how differences in ash a
Authors
Todd M. Hoefen, Raymond F. Kokaly, Deborah A. Martin, Carlton J. Rochester, Geoffrey S. Plumlee, Greg Mendez, Eric G. Reichard, Robert N. Fisher
Materials characterization of dusts generated by the collapse of the World Trade Center
The major inorganic components of the dusts generated from the collapse of the World Trade Center buildings on September 11, 2001 were concrete materials, gypsum, and man-made vitreous fibers. These components were likely derived from lightweight Portland cement concrete floors, gypsum wallboard, and spray-on fireproofing and ceiling tiles, respectively. All of the 36 samples collected by the USGS
Authors
Gregory P. Meeker, Stephen J. Sutley, Isabelle Brownfield, Heather Lowers, Amy M. Bern, Gregg A. Swayze, Todd M. Hoefen, Geoffrey S. Plumlee, Roger N. Clark, Carol A. Gent
Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse
Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain wa
Authors
Geoffrey S. Plumlee, Philip L. Hageman, Paul J. Lamothe, Thomas L. Ziegler, Gregory P. Meeker, Peter M. Theodorakos, Isabelle Brownfield, Monique G. Adams, Gregg A. Swayze, Todd M. Hoefen, Joseph E. Taggart, Roger N. Clark, S. Wilson, Stephen J. Sutley
Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack
The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with temperatures
Authors
Roger N. Clark, Gregg A. Swayze, Todd M. Hoefen, Robert O. Green, Keith E. Livo, Gregory P. Meeker, Stephen J. Sutley, Geoffrey S. Plumlee, Betina Pavri, Charles M. Sarture, Joe Boardman, Isabelle Brownfield, Laurie C. Morath
Reflectance spectroscopy of organic compounds: 1. Alkanes
Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first
Authors
R. N. Clark, J. M. Curchin, T.M. Hoefen, G.A. Swayze
Leachate Geochemical Results for Ash Samples from the June 2007 Angora Wildfire Near Lake Tahoe in Northern California
This report releases leachate geochemical data for ash samples produced by the Angora wildfire that burned from June 24 to July 2, 2007, near Lake Tahoe in northern California. The leaching studies are part of a larger interdisciplinary study whose goal is to identify geochemical characteristics and properties of the ash that may adversely affect human health, water quality, air quality, animal ha
Authors
Philip L. Hageman, Geoffrey S. Plumlee, Deborah A. Martin, Todd M. Hoefen, Monique Adams, Paul J. Lamothe, Todor I. Todorov, Michael W. Anthony
Leachate Geochemical Results for Ash and Burned Soil Samples from the October 2007 Southern California Wildfires
This report is the second release of leachate geochemical data included as part of a multidisciplinary study of ash and burned soil samples from the October 2007 wildfires in southern California. Geochemical data for the first set of samples were released in an Open-File Report (Plumlee and others, 2007). This study is a continuation of that work.
The objectives of this leaching study are to aid
Authors
Philip L. Hageman, Geoffrey S. Plumlee, Deborah A. Martin, Todd M. Hoefen, Gregory P. Meeker, Monique Adams, Paul J. Lamothe, Michael W. Anthony