Create a database of volcanoes including age, axes lengths

1
Volcano Symmetry Database Using SRTM Imagery and
the ENVI Software

• Daniel Hawkins
• Arkansas CSAPS REU 2005

Volcan Cerro Azul
2
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.

3
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.

4
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.

5
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.

6
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.

7
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.

8
The Database
9
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.

10
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.

11
Volcano Symmetry Database Using SRTM Imagery and
the ENVI Software.

• Daniel Hawkins
• Arkansas CSAPS REU 2005