Cerro Blanco

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  • Volcanic Region
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  • Last Known Eruption
  • 26.789°S
  • 67.765°W

  • 4670 m
    15318 ft

  • 355210
  • Latitude
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Most Recent Bulletin Report: May 2003 (BGVN 28:05)


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 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.

Index of Bulletin Reports


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




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


05/2003 (BGVN 28:05) 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 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/).
Download or Cite this Report

The Cerro Blanco volcanic complex contains the 6-km-wide Cerro Blanco caldera (also known as the Robledo caldera) in NW Argentina and is is located 80 km SW of the much larger and better known Cerro Galán caldera. Cerro Blanco was the site of the largest known Holocene eruption in the Central Andes about 4200 years BP (Fernandez-Turiel et al., 2013). The rhyolitic eruption produced plinian ashfall deposits of about 110 cu km and widespread ignimbrite deposits. The Holocene Cerro Blanco del Robledo lava dome is located on the southern rim of the caldera and is surrounded by extensive rhyolitic pumice-fall deposits. Satellite geodetic surveys in the central Andes (Pritchard and Simons, 2002) showed subsidence of the caldera in the 1990s.

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.


Craters

Feature Name Feature Type Elevation Latitude Longitude
Blanco, Cerro
    Robledo
Caldera -26° 45' 37" S -67° 44' 29" W

Domes

Feature Name Feature Type Elevation Latitude Longitude
Blanco, Cerro
    Blanco del Robledo, Cerro
Dome 4670 m -26° 46' 51" S -67° 45' 27" W
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).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

de Silva S L, Francis P W, 1991. Volcanoes of the Central Andes. Berlin: Springer-Verlag, 216 p.

Fernandez-Turiel J, Rodriguez-Gonzalez A, Saavedra J, Perez-Torrado F, Carracedo J, Osterrieth M, Carrizo J, Esteban G, 2013. The largest Holocene eruption of the Central Andes found. Amer Geophys Union Fall meeting, San Francisco, Dec 9-13, 2013, abs V13D-2639.

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

Volcano Types

Caldera
Lava dome

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Rhyolite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
39
39
65
14,279

Affiliated Databases

Large Eruptions of Cerro Blanco Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.