Todd Hoefen
Todd Hoefen is a Geophysicist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 110
Compositional maps of Saturn's moon Phoebe from imaging spectroscopy Compositional maps of Saturn's moon Phoebe from imaging spectroscopy
The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within...
Authors
R. N. Clark, R. H. Brown, R. Jaumann, D. P. Cruikshank, R.M. Nelson, B. J. Buratti, T. B. McCord, J. Lunine, K. H. Baines, G. Bellucci, J.-P. Bibring, F. Capaccioni, P. Cerroni, A. Coradini, V. Formisano, Y. Langevin, D. L. Matson, V. Mennella, P. D. Nicholson, B. Sicardy, Christophe Sotin, T.M. Hoefen, J. M. Curchin, G. Hansen, K. Hibbits, K.-D. Matz
Reflectance spectroscopy as a rapid assessment tool for the detection of amphiboles from the Libby, Montana region Reflectance spectroscopy as a rapid assessment tool for the detection of amphiboles from the Libby, Montana region
No abstract available.
Authors
Roger N. Clark, Todd M. Hoefen, Gregg A. Swayze, K. Eric Livo, Greg P. Meeker, Steve J. Sutley, Steve Wilson, Isabelle K. Brownfield, J. Sam Vance
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
The composition and morphology of amphiboles from the Rainy Creek complex, near Libby, Montana The composition and morphology of amphiboles from the Rainy Creek complex, near Libby, Montana
Thirty samples of amphibole-rich rock from the largest mined vermiculite deposit in the world in the Rainy Creek alkaline-ultramafic complex near Libby, Montana, were collected and analyzed. The amphibole-rich rock is the suspected cause of an abnormally high number of asbestos-related diseases reported in the residents of Libby, and in former mine and mill workers. The amphibole-rich...
Authors
G.P. Meeker, A.M. Bern, I. K. Brownfield, H.A. Lowers, S. J. Sutley, T.M. Hoefen, J.S. Vance
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
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
Science and Products
Filter Total Items: 110
Compositional maps of Saturn's moon Phoebe from imaging spectroscopy Compositional maps of Saturn's moon Phoebe from imaging spectroscopy
The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within...
Authors
R. N. Clark, R. H. Brown, R. Jaumann, D. P. Cruikshank, R.M. Nelson, B. J. Buratti, T. B. McCord, J. Lunine, K. H. Baines, G. Bellucci, J.-P. Bibring, F. Capaccioni, P. Cerroni, A. Coradini, V. Formisano, Y. Langevin, D. L. Matson, V. Mennella, P. D. Nicholson, B. Sicardy, Christophe Sotin, T.M. Hoefen, J. M. Curchin, G. Hansen, K. Hibbits, K.-D. Matz
Reflectance spectroscopy as a rapid assessment tool for the detection of amphiboles from the Libby, Montana region Reflectance spectroscopy as a rapid assessment tool for the detection of amphiboles from the Libby, Montana region
No abstract available.
Authors
Roger N. Clark, Todd M. Hoefen, Gregg A. Swayze, K. Eric Livo, Greg P. Meeker, Steve J. Sutley, Steve Wilson, Isabelle K. Brownfield, J. Sam Vance
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
The composition and morphology of amphiboles from the Rainy Creek complex, near Libby, Montana The composition and morphology of amphiboles from the Rainy Creek complex, near Libby, Montana
Thirty samples of amphibole-rich rock from the largest mined vermiculite deposit in the world in the Rainy Creek alkaline-ultramafic complex near Libby, Montana, were collected and analyzed. The amphibole-rich rock is the suspected cause of an abnormally high number of asbestos-related diseases reported in the residents of Libby, and in former mine and mill workers. The amphibole-rich...
Authors
G.P. Meeker, A.M. Bern, I. K. Brownfield, H.A. Lowers, S. J. Sutley, T.M. Hoefen, J.S. Vance
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
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