Geochemistry, Geophysics, Geosystems

Decadal volcanic deformation in the Central Andes Volcanic Zone revealed by InSAR time series

Authors

  • S. T. Henderson,

    Corresponding author
    1. Department of Earth and Atmospheric Sciences, Cornell University 3162 Snee Hall, Ithaca, New York 14850, USA
    • Corresponding author: S. T. Henderson, Department of Earth and Atmospheric Sciences, Cornell University 3162 Snee Hall, Ithaca, New York 14850, USA (sth54@cornell.edu)

    Search for more papers by this author
  • M. E. Pritchard

    1. Department of Earth and Atmospheric Sciences, Cornell University 3162 Snee Hall, Ithaca, New York 14850, USA
    Search for more papers by this author

Abstract

[1] Decadal trends of volcanic deformation in the Central Andes Volcanic Zone (CVZ) are identified with Interferometric Synthetic Aperture Radar (InSAR) stacks and time series velocity maps covering an area 19°S–27°S and 66°W–69°W. We combine over 750 ERS and Envisat interferograms from two descending and three ascending tracks. These tracks cover 100,000 km 2 and span 1992–2011. Our analysis extends observations at Cerro Blanco, Uturuncu, and Lazufre volcanic centers and uncovers two previously undocumented deformation centers: Cerro Overo in Northern Chile and Putana Volcano in Southwest Bolivia. Cerro Overo exhibits a transition from steady −0.4 cm/yr deflation to 0.5 cm/yr inflation over several years. Putana Volcano underwent a short-lived episode of uplift between 13 September 2009 and 31 January 2010, with a maximum uplift of 4.0 cm. Cerro Blanco continues −1.0 cm/yr deflation since 1995. Uplift at Lazufre began between 1997 and 2000 and has gradually accelerated to 3.5 cm/yr since 2005. Uturuncu volcano continues 1.0 cm/yr monotonic uplift since 1992 and shows evidence for a broad moat of subsidence surrounding the uplifting region. Four of the nine deformation events in the CVZ are not obviously associated with a particular volcanic edifice. Furthermore, there is significant spatial and temporal variability of these deformation events within a small geographic area.

Ancillary