Todd Hoefen
Todd Hoefen is a Geophysicist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 113
Discovery of Olivine in the Nili Fossae Region of Mars Discovery of Olivine in the Nili Fossae Region of Mars
We have detected a 30,000-square-kilometer area rich in olivine in the Nili Fossae region of Mars. Nili Fossae has been interpreted as a complex of grabens and fractures related to the formation of the Isidis impact basin. We propose that post-impact faulting of this area has exposed subsurface layers rich in olivine. Linear mixture analysis of Thermal Emission Spectrometer spectra shows...
Authors
T.M. Hoefen, R. N. Clark, J. L. Bandfield, M. D. Smith, J.C. Pearl, P. R. Christensen
USGS Digital Spectral Library splib05a USGS Digital Spectral Library splib05a
We have assembled a digital reflectance spectral library of spectra that covers wavelengths from the ultraviolet to near-infrared along with sample documentation. The library includes samples of minerals, rocks, soils, physically constructed as well as mathematically computed mixtures, vegetation, microorganisms, and man-made materials. The samples and spectra collected were assembled...
Authors
Roger N. Clark, Gregg A. Swayze, Richard K. Wise, Eric Livo, Todd M. Hoefen, Raymond F. Kokaly, Steve J. Sutley
Images of the World Trade Center site show thermal hot spots on September 16 and 23, 2001 Images of the World Trade Center site show thermal hot spots on September 16 and 23, 2001
No abstract available.
Authors
Roger N. Clark, Robert O. Green, Gregg A. Swayze, Todd M. Hoefen, K. Eric Livo, Betina Pavi, Chuck Sarcher, Joe Boardman, J. Sam Vance
Environmental studies of the World Trade Center area after the September 11, 2001 attack Environmental studies of the World Trade Center area after the September 11, 2001 attack
This web site describes the results of an interdisciplinary environmental characterization of the World Trade Center (WTC) area after September 11, 2001. Information presented in this site was first made available to the World Trade Center emergency response teams on September 18, 2001 (Thermal hot spot information), and September 27, 2001 (maps and compositional results). The Airborne...
Authors
Roger N. Clark, Robert O. Green, Gregg A. Swayze, Greg Meeker, Steve Sutley, Todd M. Hoefen, K. Eric Livo, Geoff Plumlee, Betina Pavri, Chuck Sarture, Steve Wilson, Phil Hageman, Paul Lamothe, J. Sam Vance, Joe Boardman, Isabelle Brownfield, Carol Gent, Laurie C. Morath, Joseph Taggart, Peter M. Theodorakos, Monique Adams
Detection of crystalline hematite mineralization on Mars by the Thermal Emission Spectrometer: evidence for near-surface water Detection of crystalline hematite mineralization on Mars by the Thermal Emission Spectrometer: evidence for near-surface water
The Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor (MGS) mission has discovered a remarkable accumulation of crystalline hematite (α-Fe2O3) that covers an area with very sharp boundaries approximately 350 by 350–750 km in size centered near 2°S latitude between 0° and 5°W longitude (Sinus Meridiani). Crystalline hematite is uniquely identified by the presence...
Authors
P. R. Christensen, J. L. Bandfield, R. N. Clark, K.S. Edgett, V.E. Hamilton, T. Hoefen, H. H. Kieffer, R.O. Kuzmin, M. D. Lane, M. C. Malin, R.V. Morris, J.C. Pearl, R. Pearson, T. L. Roush, S. W. Ruff, M. D. Smith
Science and Products
Filter Total Items: 113
Discovery of Olivine in the Nili Fossae Region of Mars Discovery of Olivine in the Nili Fossae Region of Mars
We have detected a 30,000-square-kilometer area rich in olivine in the Nili Fossae region of Mars. Nili Fossae has been interpreted as a complex of grabens and fractures related to the formation of the Isidis impact basin. We propose that post-impact faulting of this area has exposed subsurface layers rich in olivine. Linear mixture analysis of Thermal Emission Spectrometer spectra shows...
Authors
T.M. Hoefen, R. N. Clark, J. L. Bandfield, M. D. Smith, J.C. Pearl, P. R. Christensen
USGS Digital Spectral Library splib05a USGS Digital Spectral Library splib05a
We have assembled a digital reflectance spectral library of spectra that covers wavelengths from the ultraviolet to near-infrared along with sample documentation. The library includes samples of minerals, rocks, soils, physically constructed as well as mathematically computed mixtures, vegetation, microorganisms, and man-made materials. The samples and spectra collected were assembled...
Authors
Roger N. Clark, Gregg A. Swayze, Richard K. Wise, Eric Livo, Todd M. Hoefen, Raymond F. Kokaly, Steve J. Sutley
Images of the World Trade Center site show thermal hot spots on September 16 and 23, 2001 Images of the World Trade Center site show thermal hot spots on September 16 and 23, 2001
No abstract available.
Authors
Roger N. Clark, Robert O. Green, Gregg A. Swayze, Todd M. Hoefen, K. Eric Livo, Betina Pavi, Chuck Sarcher, Joe Boardman, J. Sam Vance
Environmental studies of the World Trade Center area after the September 11, 2001 attack Environmental studies of the World Trade Center area after the September 11, 2001 attack
This web site describes the results of an interdisciplinary environmental characterization of the World Trade Center (WTC) area after September 11, 2001. Information presented in this site was first made available to the World Trade Center emergency response teams on September 18, 2001 (Thermal hot spot information), and September 27, 2001 (maps and compositional results). The Airborne...
Authors
Roger N. Clark, Robert O. Green, Gregg A. Swayze, Greg Meeker, Steve Sutley, Todd M. Hoefen, K. Eric Livo, Geoff Plumlee, Betina Pavri, Chuck Sarture, Steve Wilson, Phil Hageman, Paul Lamothe, J. Sam Vance, Joe Boardman, Isabelle Brownfield, Carol Gent, Laurie C. Morath, Joseph Taggart, Peter M. Theodorakos, Monique Adams
Detection of crystalline hematite mineralization on Mars by the Thermal Emission Spectrometer: evidence for near-surface water Detection of crystalline hematite mineralization on Mars by the Thermal Emission Spectrometer: evidence for near-surface water
The Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor (MGS) mission has discovered a remarkable accumulation of crystalline hematite (α-Fe2O3) that covers an area with very sharp boundaries approximately 350 by 350–750 km in size centered near 2°S latitude between 0° and 5°W longitude (Sinus Meridiani). Crystalline hematite is uniquely identified by the presence...
Authors
P. R. Christensen, J. L. Bandfield, R. N. Clark, K.S. Edgett, V.E. Hamilton, T. Hoefen, H. H. Kieffer, R.O. Kuzmin, M. D. Lane, M. C. Malin, R.V. Morris, J.C. Pearl, R. Pearson, T. L. Roush, S. W. Ruff, M. D. Smith