|
|
|
|
|
|
|
ASTER Project |
|
Remote sensing of Carhuarazo volcanic complex Using ASTER imagery in Southern Perú to detect alteration zones and volcanic structures *
The video clips show first results of spectral analysis of ASTER reflectance data in a region in southern Peru. The aim was to gain information about alteration zones related to caldera structures by detecting and mapping alteration minerals. Coordinates of the center of the Carhuarazo volcanic complex are 73,7°W and 14,3°S.
ASTER false colour image of the research area.
The clip shows the research area as a false colour composite RGB:321. Note that vegetation is shown in bright red colours due to the so called "red edge" in the spectra of plants refering to the region of rapid change in reflectance of chlorophyll in the near infrared range. The false colour image is draped over ASTER DEM with a two fold vertical exaggeration.
<< play animation video>> | 
| | Geological units of the research area.
The clip shows the geological units of the research area as a transparent layer over a PC-sharpened Landsat 7 image draped over ASTER DEM with a two fold vertical exaggeration.
Legend:  Volcanic center Huantica (Dacite, plagioclase)
 Volcanic centers Sillajasa, Huanchayoc, Orcochante
 Volcanic center Carhuarazo
 Volcanic center Palla Palla (andesite, plagioclase)
 Fm. Caudalosa (andesitic flows intercalated with andesitic breccia a. tuff)
 Dacite
 Tonalite
 Scoria
 Fluvio-glacial deposits
 Fluvio-glacial deposits (gravel, sand, calcereous sandstone)
 Glacial deposits
 Aluvial deposits (gravel, sand, calcareous to silicic cementation)
 Coluvial deposit (gravel, stones, silicic and calcareous cementation
 Fm. Arcurquina (limestone )
 Fm. Hualhuani
 Fm. Murco (sandstone, limestone, red mari)
 Fm. Puquio
 Formacion Andamarca
 Tacaza group
 Yura group - Fm. Cachios (calcareous sandstone, calcareous nodules)
 Yura group - Fm. Gramadal (grey limestone)
 Yura group - Fm. Labra (sandstone)
 Playa
|  << play animation video>> | PC sharpened Landsat 7 image of the research area showing the spectrally purest pixel of the scene.
The clip shows in a temporal sequence the vegetation mask applied, the results of pixel-purity-index calculation (bright green) and the selected area for matched filtering (for the selection process please refer to the paper text) in yellow.
<< play animation video>> | 
| PC sharpened Landsat 7 image of the research area showing matched filtering results for alunite.
The clip shows in a temporal sequence the results of matched filtering for alunite and kaosmectite. Calculated intensities are displayed in a scale from yellow to red (alunite) and bright green to dark green (kaosmectite: a mixture of kaolinite and smectites) from lower to higher values.
<< play animation video>> | 
| PC sharpened Landsat 7 image of the research area showing matched filtering results for nacrite.
The clip shows in a temporal sequence the results of matched filtering for nacrite and recforite. Calculated intensities are displayed in a scale from dark blue to bright blue (recforite) and yellow to red (nacrite) from lower to higher values.
<< play animation video>> | 
| PC sharpened Landsat 7 image of the research area showing matched filtering results for dickite.
The clip shows in a temporal sequence the results of matched filtering for kaolinite and dickite. Calculated intensities are displayed in a scale from bright blue to dark blue (kaolinite) and dark green to bright green (dickite) from lower to higher values.
<< play animation video>> | 
| PC sharpened Landsat 7 image of the research area showing matched filtering results for eugsterite.
The clip shows in a temporal sequence the results of matched filtering for eugsterite and natrolite. Calculated intensities are displayed in a scale trom dark blue to bright blue (natrolite) and yellow to red (eugsterite) from lower to higher values.
<< play animation video>> *Brandmeier, M. (2010): Remote sensing of Carhuarazo volcanic complex. Using ASTER imagery in Southern Peru to detect alteration zones and volcanic structures – a combined approach of image processing in ENVI and ArcGIS/ArcScene. Geocarto International 8/25. 629-648. DOI: 10.1080/10106049.2010.519787 http://www.informaworld.com/smpp/content~content=a926889342~db=all~jumptype=rss | 
| |
|
|
|
|
|
ASTER Project 
