San Miguel

Volcano number:343100
Region:Mexico and Central America
Country:El Salvador
Geodetic measurements?Yes
Deformation observation?Yes
Measurement method(s):InSAR, GPS - continuous
Duration of observation:2007-2010 (ALOS InSAR), 2014 (COSMO-SkyMed InSAR), 2014 (GPS)
Inferred cause of deformation:Magmatic
Characteristics of deformation:

7 cm uplift were observed in ALOS inSAR at San Miguel between March and October 2007, followed by 6 cm of deflation from October 2007 to January 2008 (Schiek et al., 2008). However, Pritchard et al. (2010) concluded the data regarding ground deformation was inconclusive, and Ebmeier et al. (2013) did not observe any deformation at San Miguel (detection threshold 2.4 cm/year) in ALOS data from 2007 to 2010.

Eruptive activity in December 2013 – January 2014 was accompanied by 25 mm of uplift from February to August 2014, observed in both COSMO-SkyMed InSAR and GPS measurements (Bignami et al., 2015).

Reference:Schiek, C. G., J. M. Hurtado, A. A. Velasco, S. M. Buckley, and D. Escobar (2008), Determining volcanic deformation at San Miguel volcano, El Salvador by integrating radar interferometry and seismic analyses, Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract U51A-0018.
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, 1003, doi:10.1029/2009GC002558.
Reference:Ebmeier, S. K., J. Biggs, T. A. Mather, and F. Amelung (2013), On the lack of InSAR observations of magmatic deformation at Central American volcanoes, J. Geophys. Res. Solid Earth, 118, 2571–2585, doi:10.1002/jgrb.50195.
Reference:Bignami, C., C. Tolomei, A. Lugari, A. Bonforte, V. Siniscalchi, S. Borgstrom, F. Guglielmino, G. Puglisi, and S. Stramondo (2015), Inferring surface displacement of the San Miguel (aka Chaparrastique, El Salvador) during the 2014 volcanic crises, ESA FRINGE workshop, At ESA ESRIN, Frascati, Italy, March. doi: 10.13140/RG.2.1.1524.8809
Location:-88.269, 13.434

View of San Miguel from the southwest. Photo: Lee Siebert, 1999 (Smithsonian Institution).