HR: 1340h
AN: S13B-0188    [Abstracts]
TI: Field Imaging Spectroscopy. Applications in Earthquake Geology
AU: * Ragona, D
EM: dragona@ucsd.edu
AF: IGPP-Scripps Institution of Oceanography, 9500 Gilman Dr, La Jolla, CA 92093 United States
AU: Minster, B
EM: jbminster@ucsd.edu
AF: IGPP-Scripps Institution of Oceanography, 9500 Gilman Dr, La Jolla, CA 92093 United States
AU: Rockwell, T K
EM: trockwell@geology.sdsu.edu
AF: San Diego State University, 5500 Campanile Dr, San Diego, CA 92182 United States
AU: Fialko, Y
EM: fialko@radar.ucsd.edu
AF: IGPP-Scripps Institution of Oceanography, 9500 Gilman Dr, La Jolla, CA 92093 United States
AU: Jussila, J
EM: jouni.Jussila@specim.fi
AF: Specim, Teknologiantie 6D, Oulu, 90570 Finland
AU: Blom, R
EM: ronald.blom@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: Field Imaging Spectroscopy in the visible and infrared sections of the spectrum can be used as a technique to assist paleoseismological studies. Submeter range hyperspectral images of paleoseismic excavations can assist the analyisis and interpretation of the earthquake history of a site. They also provide an excellent platform for storage of the stratigraphic and structural information collected from such a site. At the present, most field data are collected descriptively. This greatly enhances the range of information that can be recorded in the field. The descriptions are documented on hand drawn field logs and/or photomosaics constructed from individual photographs. Recently developed portable hyperspectral sensors acquire high-quality spectroscopic information at high spatial resolution (pixel size ~ 0.5 mm at 50 cm) over frequencies ranging from the visible band to short wave infrared. The new data collection and interpretation methodology that we are developing (Field Imaging Spectroscopy) makes available, for the first time, a tool to quantitatively analyze paleoseismic and stratigraphic information. The reflectance spectra of each sub-millimeter portion of the material are stored in a 3-D matrix (hyperspectral cube) that can be analyzed by visual inspection, or by using a large variety of algorithms. The reflectance spectrum is related to the chemical composition and physical properties of the surface therefore hyperspectral images are capable of revealing subtle changes in texture, composition and weathering. For paleoseismic studies, we are primarily interested in distinguishing changes between layers at a given site (spectral stratigraphy) rather than the precise composition of the layers, although this is an added benefit. We have experimented with push-broom (panoramic) portable scanners, and acquired data form portions of fault exposures and cores. These images were processed using well-known imaging processing algorithms, and the results have being compared with field descriptions and digital photography. We have shown that SWIR images can enhance layers that are not easily seen in the field and also make visible important features that are not visible to the human eye. Hyperspectral images also improved the results of stratigraphic correlations across the faults by using quantitative methods (spectral comparison) and image enhancing techniques.
DE: 7221 Paleoseismology (8036)
DE: 8036 Paleoseismology (7221)
SC: Seismology [S]
MN: Fall Meeting 2005