Cerro Blanco

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 26.789°S
  • 67.765°W

  • 4670 m
    15318 ft

  • 355210
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: May 2003 (BGVN 28:05) Citation IconCite this Report


Satellite surveys during May 1996-October 2000 indicate subsidence

A satellite-based interferometric synthetic aperture radar (InSAR) survey of the remote central Andes volcanic arc (Pritchard and Simons, 2002) revealed deformation in the Robledo caldera between May 1992 and October 2000 (figure 1). Subsidence was detected, with a maximum deformation rate in the radar line-of-sight of 2-2.5 cm/year. The subsidence rate seemed to be decreasing with time. The inferred source depth was 4.5-6 km below sea level. Additional details about the study and analysis are available in Pritchard and Simons (2002).

Figure (see Caption) Figure 1. Shaded relief topographic map of the central Andes with insets showing areas of deformation detected by Pritchard and Simons (2002). Interferograms (draped over shaded relief) indicate active deformation; each color cycle corresponds to 5 cm of deformation in the radar line-of-sight (LOS). The LOS direction from ground to spacecraft (black arrow) is inclined 23° from the vertical. Black squares indicate radar frames, and black triangles show potential volcanic edifices. Courtesy of Matthew Pritchard.

Reference. Pritchard, M., and Simons, M., 2002, A satellite geodetic survey of large-scale deformation of volcanic centres in the Central Andes: Nature, v. 418, p. 167-170.

Information Contacts: Matthew Pritchard and Mark Simons, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA (Email: matt@gps.caltech.edu, URL: http://www.gps. caltech.edu/).

The Global Volcanism Program has no Weekly Reports available for Cerro Blanco.

Bulletin Reports - Index


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

05/2003 (BGVN 28:05) Satellite surveys during May 1996-October 2000 indicate subsidence




Information is preliminary and subject to change. All times are local (unless otherwise noted)


May 2003 (BGVN 28:05) Citation IconCite this Report


Satellite surveys during May 1996-October 2000 indicate subsidence

A satellite-based interferometric synthetic aperture radar (InSAR) survey of the remote central Andes volcanic arc (Pritchard and Simons, 2002) revealed deformation in the Robledo caldera between May 1992 and October 2000 (figure 1). Subsidence was detected, with a maximum deformation rate in the radar line-of-sight of 2-2.5 cm/year. The subsidence rate seemed to be decreasing with time. The inferred source depth was 4.5-6 km below sea level. Additional details about the study and analysis are available in Pritchard and Simons (2002).

Figure (see Caption) Figure 1. Shaded relief topographic map of the central Andes with insets showing areas of deformation detected by Pritchard and Simons (2002). Interferograms (draped over shaded relief) indicate active deformation; each color cycle corresponds to 5 cm of deformation in the radar line-of-sight (LOS). The LOS direction from ground to spacecraft (black arrow) is inclined 23° from the vertical. Black squares indicate radar frames, and black triangles show potential volcanic edifices. Courtesy of Matthew Pritchard.

Reference. Pritchard, M., and Simons, M., 2002, A satellite geodetic survey of large-scale deformation of volcanic centres in the Central Andes: Nature, v. 418, p. 167-170.

Information Contacts: Matthew Pritchard and Mark Simons, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA (Email: matt@gps.caltech.edu, URL: http://www.gps. caltech.edu/).

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2300 BCE ± 160 years Unknown Confirmed 7 Radiocarbon (corrected)

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Photo Gallery


The circular light-colored area in the center of this Thematic Mapper image is the 6-km-wide Robledo caldera. The Cerro Blanco del Robledo rhyolitic lava dome on the southern rim of the caldera was extruded into a pumice cone (pale tones). The margins of pyroclastic flows erupted prior to extrusion of the lava dome are faintly visible on the caldera floor and on the NW flanks of the caldera. Satellite geodetic surveys in the central Andes showed subsidence of Robledo caldera in the 1990s.

Thematic Mapper image (de Silva and Francis, 1991; courtesy of Matthew Pritchard, California Institute of Technology).
See title for photo information.

Smithsonian Sample Collections Database


There are no samples for Cerro Blanco in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites