|Duration of observation:||2006-2014|
|Inferred cause of deformation:||Magmatic|
|Characteristics of deformation:|
No deformation was detected at Santa Isabel between 2006 and 2009 during ALOS surveys of Latin American volcanoes (Fournier et al., 2010, Parks et al., 2011). An ALOS interferogram from Jan. 2008 to Mar 2011 also did not find any deformation (detection threshold < 1 cm/year) (Lundgren et al., 2015).
Radarsat 2 interferograms between Dec. 2011 and Dec 2014 show inflation at a maximum linear rate of 3-4 cm/year, centred approximately below Santa Isabel (Lundgren et al., 2015). While the centre of deformation was located closer to Santa Isabel, seismicity and stress modelling lead the authors to attribute the deformation to the magmatic system of Nevado del Ruiz located ~15 km to the northeast.
|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:||Parks, M. M., J. Biggs, T. A. Mather, D. M. Pyle, F. Amelung, M. L. Monsalve, and L. Narváez Medina (2011), Co-eruptive subsidence at Galeras identified during an InSAR survey of Colombian volcanoes (2006–2009), Journal of Volcanology and Geothermal Research 202, no. 3, 228-240, doi:10.1016/j.jvolgeores.2011.02.007|
|Reference:||Lundgren, P., S. V. Samsonov, C. M. López Velez, and M. Ordoñez (2015), Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations. Geophys. Res. Lett., 42, 4816–4823. doi: 10.1002/2015GL063858.|
View of Santa Isabel taken from the northeast, from the summit of Nevado del Ruiz. Photo: Norm Banks, 1985 (U.S. Geological Survey).