|Measurement method(s):||InSAR, GPS - continuous, Levelling, Tiltmeter, EDM|
|Duration of observation:||1985-1988 (EDM, Tilt, Levelling), 2006-2011 (ALOS InSAR), 2010-2012 (cGPS), 2011-2014 (Radarsat 2 InSAR)|
|Inferred cause of deformation:||Magmatic, Uncertain|
|Characteristics of deformation:|
A dense network of tiltmeters, EDM and levelling lines were installed at Nevado del Ruiz just before and following the November 1985 eruption. No long term deformation was detected between 1985 and 1988, but annual cycles of inflation and deflation were recorded by some tiltmeters (Banks et al., 1990). The deformation was temporally correlated with seasonal rainfall changes, and attributed to be due to changes in groundwater levels.
No deformation was detected at Nevado del Ruiz 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 ~15 km south of Nevado del Ruiz (Lundgren et al., 2015). The deformation was modelled by an inflating mogi and spheroidal source at 14 km depth. Continuous GPS installed in 2010 also detected ~6 cm of inflation at Nevado del Ruiz during 2012 (Ordoñez et al., 2015).
|Reference:||Banks, N. G., C. Carvajal, H. Mora, and E. Tryggvason (1990), Deformation monitoring at Nevado del Ruiz, Colombia: October 1985-March 1988, J. Volcanol. Geotherm. Res., 41, 269-295, doi:10.1016/0377-0273(90)90092-T.|
|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.|
|Reference:||Ordoñez, M., C. López, J. Alpala, L. Narváez, D. Arcos, and M. Battaglia (2015), Keeping watch over Colombia’s slumbering volcanoes, Eos, 96, doi:10.1029/2015EO025079|
View of Nevado del Ruiz from the east-southeast. Photo: Norm Banks, 1985 (USGS).