Cotopaxi

Volcano number:352050
Region:South America
Country:Ecuador
Geodetic measurements?Yes
Deformation observation?Yes
Measurement method(s):InSAR, GPS - continuous, Tiltmeter, EDM
Duration of observation:1991-2006 (EDM), 2006-2008 (InSAR), 2009-present (GPS, tilt)
Inferred cause of deformation:Magmatic
Characteristics of deformation:

During a period of seismic unrest in 2001-2002, EDM recorded contraction of up to 8 cm on the northeast flank of Cotopaxi. The deformation source was best fit by a oblate spheroid at 3 km depth south of the summit, hypothesised to be a magma body (Hickey et al., 2015). Waveform modelling of VLP earthquakes during this period gave a source location to the north of the summit, which has been attributed to both magmatic and hydrothermal activity (Molina et al., 2008; Hickey et al., 2015).

No deformation was detected at Cotopaxi between 2006 and 2008 during an ALOS survey of Latin American volcanoes (Fournier et al., 2010).

Current GPS measurements are available online on the IG-EPN website, and appear to show ~1 cm of inflation since April 2015.

 

Reference:Hickey, J., J. Gottsmann, and P. Mothes (2015), Estimating volcanic deformation source parameters with a finite element inversion: The 2001–2002 unrest at Cotopaxi volcano, Ecuador. J. Geophys. Res. Solid Earth, 120, 1473–1486. doi: 10.1002/2014JB011731.
Reference:Indira Molina, Hiroyuki Kumagai, Alexander García-Aristizábal, Masaru Nakano, Patricia Mothes, Source process of very-long-period events accompanying long-period signals at Cotopaxi Volcano, Ecuador, Journal of Volcanology and Geothermal Research, Volume 176, Issue 1, 10 September 2008, Pages 119-133, ISSN 0377-0273, http://dx.doi.org/10.1016/j.jvolgeores.2007.07.019.
Reference:Fournier, T. J., M. E. Pritchard, and S. N. Riddick (2010), Duration, magnitude, and frequency of subaerial volcano deformation events: New results from Latin America using InSAR and a global synthesis, Geochem. Geophys. Geosyst., 11, Q01003, doi:10.1029/2009GC002558.
Reference:IG-EPN website: http://www.igepn.edu.ec/cotopaxi/deformacion-cotopaxi
Location:-78.436, -0.677

View of Cotopaxi from the north. Photo: David Arnold, 2014 (University of Bristol).

Change in distance between two EDM stations northeast of the summit (Molina et al., 2008). The distance between the two points is 6.038 km.