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Volcano Symmetry Database Using SRTM Imagery and the ENVI Software. Daniel Hawkins Arkansas CSAPS REU 2005. Volcan Cerro Azul. Project Purpose. Find constraints on volcano symmetry (i.e. morphology, age, relative plate motion).
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Volcano Symmetry Database Using SRTM Imagery and the ENVI Software Daniel Hawkins Arkansas CSAPS REU 2005 Volcan Cerro Azul
Project Purpose • Find constraints on volcano symmetry (i.e. morphology, age, relative plate motion). • Create a database of volcanoes including age, axes lengths, location, and relative symmetry. • Prologue to solar system volcanoes database to find similarities among volcanoes on other celestial bodies.
The SRTM Mission • Flew on Endeavor in 2000 for 11 days. • Created high-quality images of most of the Earth, with less distortion than aerial photography. • Available in 90 meter resolution throughout the world, 30 meter resolution in the USA.
Unedited SRTM Image • SRTM Images come in 1 degree tiles. • All images are grayscale. • Images are opened with ENVI 4.1 geographic imaging software. • ENVI allows geographic coordinates, allowing volcanoes to be found easily. • This image is a tile 24 South, 68 West. • Area in red box is Volcan Laguna Verde in Chile.
Color Image • Used to show better detail. • Allows for color saturation function to find semi-major and semi-minor axes of volcano in SigmaScan. • Allows for more accurate geographic coordinates when switching between ENVI and SigmaScan. • This image is a close up of Volcan Laguna Verde in Chile.
ENVI Software • ENVI is a geographic imaging software. • Geographic coordinates are used to find specific areas on the 1 degree tiles. • Allows conversion from grayscale to color based on preset mathematical functions. • Outputs image in multiple formats for further study. • Negatives: Only uses best fit models for measuring odd shapes. Cannot accurately measure angles other than north-south or east-west.
SigmaScan • Allows use of color saturation to measure distances on oddly shaped objects. • Allows measure of distances on surfaces other than north-south or east-west. • Sends information directly into the database. • Negatives: Cannot read geographic coordinates or elevation. Cannot open base file from the USGS server.
Application • Currently, study has been done of 19 stratovolcanoes from Chile. • Plate motion azimuth versus the azimuth of the asymmetry of the volcano has been looked at for correlation. • The histogram shows those 19 volcanoes against the azimuth of plate motion. • There is a possibility of correlation of asymmetry parallel to plate movement, but not a large enough population to be conclusive.
Continuing Work • Continue adding volcanoes to database. Currently working with approximately 250. • Add relative plate motions to database, and look for correlations. • Compare volcano types to find correlations between type and relative symmetry. • Make a database of extraterrestrial volcanoes and compare to terrestrial volcanoes. • Add database to World Organization of Volcano Observatories website for use by other researchers.
Volcano Symmetry Database Using SRTM Imagery and the ENVI Software. Daniel Hawkins Arkansas CSAPS REU 2005