Gregg A Swayze, Ph.D.
Gregg Swayze is a Research Geophysicist in Denver. Gregg received a Doctorate in Geology from the University of Colorado in 1997. Since joining the USGS in 1985, Gregg has devoted his career to studying Remote Sensing and specializes in Imaging Spectroscopy. Presently, his science focuses on environmental and mineral exploration applications of imaging spectroscopy.
Biography
Education
Ph.D. degree/Geology, University of Colorado, 1997
M.S. degree/Geology, Colorado School of Mines, 1985
B.S. degree/Geology, Grand Valley State University, 1982
Professional Experience
1985 to present, U.S. Geological Survey, Denver, Colorado
Research Interests
Over the years, Gregg has developed methods to spectrally map acid-mine drainage in Leadville, Colorado, naturally-occurring asbestos in the foothills of California, insulation asbestos in the World Trade Center dust, and oil emulsions formed during the 2010 BP oil spill. He has also developed a portable spectral fingerprinting technique to identify asbestos-bearing vermiculite in attic insulation. Gregg has used his imaging spectroscopy experience with relict hydrothermal systems in Nevada and Hawaii to help map similar mineral deposits on the surface of Mars with the NASA CRISM orbital spectrometer. His most recent focus is on spectrally mapping REE-bearing minerals at the Mt. Pass Mine in California. He was recently selected as a Co-Investigator of the NASA/JPL Earth Surface Mineral Dust Source Investigation (EMIT) team with the goal of putting an imaging spectrometer on the International Space Station to map the mineralogy of dust source regions on a global basis.
Professional Societies
AGU, GSA, Colorado Scientific Society, and Society of Economic Geologists
Science and Products
Spectroscopy and Hyperspectral Imaging of Critical Mineral Resources
Our project will characterize the primary critical minerals (minerals that contain critical elements in their base structure) that are not yet in the USGS Spectral Library. We propose to increase understanding of the spectral indicators of critical minerals using lab-based studies of hand specimens and drill core, hyperspectral field...
Spectroscopy and Principles of Spectroscopy
Extensive tutorial on reflectance spectroscopy, the causes of absorption bands, the absorption and scattering processes that occur when light encounters a particulate surface, and principles of spectroscopy including continuum analysis, grain size effects, mixtures, etc.
USGS High Resolution Spectral Library
The USGS Spectral Library contains reflectance spectra, including samples of minerals, rocks, soils, physically constructed as well as mathematically computed mixtures, plants, vegetation communities, microorganisms, and man-made materials. The samples and spectra collected were assembled for the purpose of using spectral features for the remote detection of these and similar materials. The...
Spectroscopy of Expanded Vermiculite Products and Insulation
This dataset contains descriptions and analytical data (i.e., electron microprobe, X-ray diffraction, spectral reflectance, and scanning electron microprobe analyses) for unexpanded and expanded vermiculite samples. These data are provided for 52 samples of vermiculite attic insulation, horticultural products, aggregate, and packing materials derived from mines near Enoree, So
Interactive USGS Spectral Library Version 7
Interactive website allowing users to search the contents of the USGS Spectral Library Version 7 data.
USGS Digital Spectral Library
References for material identification in remote sensing images. The library contains spectral reflectance data for of hundreds of materials, including minerals, vegetation, organic and volatile compounds, and man-made materials.
USGS Spectral Library Version 7 Data
This data release provides the U.S. Geological Survey (USGS) Spectral Library Version 7 and all related documents. The library contains spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns). Laboratory samples of specific minerals, plants, chemical compounds, and m
Quantifying uncertainty for remote spectroscopy of surface composition
Remote surface measurements by imaging spectrometers play an important role in planetary and Earth science. To make these measurements, investigators calibrate instrument data to absolute units, invert physical models to estimate atmospheric effects, and then determine surface properties from the spectral reflectance. This study quantifies the...
Thompson, David R.; Braverman, Amy; Brodrick, Philip; Candela, Alberto; Carmon, Nimrod; Clark, Roger N.; Connelly, David; Green, Robert O.; Kokaly, Raymond; Li, Longlei; Mahowald, Natalie; Miller, Ronald L.; Okin, Gregory S.; Painter, Thomas H.; Swayze, Gregg A.; Turmon, Michael; Susilouto, Jouni; Wettergreen, David Classification of oil spill by thicknesses using multiple remote sensors
Satellite Synthetic Aperture Radar (SAR) is an operational tool for monitoring and assessment of oil spills. Satellite SAR has primarily been used to detect the presence/absence of oil, yet its ability to discriminate oil emulsions within a detected oil slick has not been fully exploited. Additionally, one of the challenges in the past has been...
Garcia-Pineda, Oscar; Staples, Gordon; Jones, Cathleen E; Hu, Chuanmin; Holt, Benjamin; Kourafalou, Villy; Graettinger, George; DiPinto, Lisa; Ramirez, Ellen; Street, David; Cho, Jay; Swayze, Gregg A.; Sun, Shaojie; Garcia, Diana; Haces-Garcia, Francisco Isotopic ratios of Saturn's rings and satellites: Implications for the origin of water and Phoebe
Isotopic ratios have long been used to learn about physical processes acting over a wide range of geological environments, and in constraining the origin and/or evolution of planetary bodies. We report the spectroscopic detection of deuterium in Saturn's rings and satellites, and use these measurements to determine the (D/H) ratios in their near-...
Clark, Roger N.; Brown, Robert H.; Cruikshank, D.P.; Swayze, Gregg A. Spatial spectroscopic models for remote exploration
Ancient hydrothermal systems are a high-priority target for a future Mars sample return mission because they contain energy sources for microbes and can preserve organic materials (Farmer, 2000; MEPAG Next Decade Science Analysis Group, 2008; McLennan et al.,2012; Michalski et al.,2017). Characterizing these large,...
Thompson, David R.; Candela, Alberto; Wettergreen, David; Dobrea, E. Noe; Swayze, Gregg A.; Clark, Roger N; Greenberger, Rebecca Characterizing the source of potentially asbestos-bearing commercial vermiculite insulation using in situ IR spectroscopy
Commercially produced vermiculite insulation from Libby, Montana, contains trace levels of asbestiform amphibole, which is known to cause asbestos-related diseases. When vermiculite insulation is found in a building, evaluation for its potential asbestos content traditionally involves collecting a sample from an attic or wall and submitting it for...
Swayze, Gregg A.; Lowers, Heather A.; Benzel, William M.; Clark, Roger N.; Driscoll, Rhonda L.; Perlman, Zac S.; Hoefen, Todd M.; Dyar, M. Darby Spectral properties of anhydrous carbonates and nitrates
No abstract available.
Bishop, J.L.; King, S.J.; Lane, M.D.; Lafuente, B.; Brown, A.J.; Hiroi, T.; Swayze, Gregg A.; Lin, J.-F.
USGS Spectral Library Version 7
We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified...
Kokaly, Raymond F.; Clark, Roger N.; Swayze, Gregg A.; Livo, K. Eric; Hoefen, Todd M.; Pearson, Neil C.; Wise, Richard A.; Benzel, William M.; Lowers, Heather A.; Driscoll, Rhonda L.; Klein, Anna J. Discovery of alunite in Cross crater, Terra Sirenum, Mars: Evidence for acidic, sulfurous waters
Cross crater is a 65 km impact crater, located in the Noachian highlands of the Terra Sirenum region of Mars (30°S, 158°W), which hosts aluminum phyllosilicate deposits first detected by the Observatoire pour la Minéralogie, L’Eau, les Glaces et l’Activitié (OMEGA) imaging spectrometer on Mars Express. Using high-resolution data from the Mars...
Ehlmann, Bethany L.; Swayze, Gregg A.; Milliken, Ralph E.; Mustard, John F.; Clark, Roger N.; Murchie, Scott L.; Breit, George N.; Wray, James J.; Gondet, Brigitte; Poulet, Francois; Carter, John; Calvin, Wendy M.; Benzel, William M.; Seelos, Kimberly D. Oil slick morphology derived from AVIRIS measurements of the Deepwater Horizon oil spill: Implications for spatial resolution requirements of remote sensors
Using fine spatial resolution (~ 7.6 m) hyperspectral AVIRIS data collected over the Deepwater Horizon oil spill in the Gulf of Mexico, we statistically estimated slick lengths, widths and length/width ratios to characterize oil slick morphology for different thickness classes. For all AVIRIS-detected oil slicks (N = 52,100 continuous features)...
Sun, Shaojie; Hu, Chuanmin; Feng, Lian; Swayze, Gregg A.; Holmes, Jamie; Graettinger, George; MacDonald, Ian R.; Garcia, Oscar; Leifer, Ira Spectroscopy from Space: Chapter 10
No abstract available
Clark, Roger N.; Swayze, Gregg A.; Carlson, Robert R.; Grundy, Will; Noll, Keith Natural and unnatural oil slicks in the Gulf of Mexico
When wind speeds are 2 – 10 m s−1, reflective contrasts in the ocean surface make oil slicks visible to synthetic aperture radar (SAR) under all sky conditions. Neural network analysis of satellite SAR images quantified the magnitude and distribution of surface oil in the Gulf of Mexico from persistent, natural seeps and from the...
MacDonald, Ian R.; O. Garcia-Pineda; A. Beet; S. Daneshgar Asl; L. Feng; D. G. Graettinger; D. French-McCay; J. Holmes; C. Hu; F. Huffer; I. Leifer; F. Mueller-Karger; A. Solow; M. Silva; Swayze, Gregg A. Spectral properties of Ca-sulfates: Gypsum, bassanite, and anhydrite
This study of the spectral properties of Ca-sulfates was initiated to support remote detection of these minerals on Mars. Gypsum, bassanite, and anhydrite are the currently known forms of Ca-sulfates. They are typically found in sedimentary evaporites on Earth, but can also form via reaction of acidic fluids associated with volcanic activity....
Bishop, Janice L.; Lane, Melissa D.; Dyar, M. Darby; King, Sara J.; Brown, Adrian J.; Swayze, Gregg A.
Spectral Signature of Topaz
This shows the spectral signature (left) of the mineral topaz (right).
Spectral Signature of Plywood
This shows the spectral signature (left) of plywood (right).
USGS Scientists Develop New Tool to Determine if Vermiculite Insulation Contains Asbestos
U.S. Geological Survey scientists and partners have created an onsite, time-saving technique for building inspectors to ascertain whether vermiculite insulation contains amphibole asbestos. The findings are featured in the April 2 edition of American Mineralogist.
USGS Spectral Library gets Ultra- and Hyper- Revamp
We've got a library full of spectral signatures, like a police fingerprint library for minerals and other substances!