Source model of deformation at Lazufre volcanic center, central Andes, constrained by InSAR time series

Abstract

[1] Recent interferometric synthetic aperture radar (InSAR) observations of the Lazufre region, central Andes, show large-scale uplift at a rate of about 3 cm/yr, beginning between 1998 and 2002. The initiation of this activity during the ERS satellite mission and its proximity to active volcanoes have made Lazufre the focus of several studies aimed at understanding its source geometry, its relation to nearby volcanoes, and whether or not the source area is expanding. There now exists a longer time series from multiple ERS/ENVISAT satellite tracks that allows a more comprehensive examination of the source geometry and its temporal and spatial variation, if any. We processed 15 years of InSAR data from three separate tracks; modeling the different look geometries provided greater resolution of source depth and geometry. We conclude that the source is a shallowly dipping sill at a depth of about 8 km, with no evidence of lateral expansion. Citation: Pearse, J., and P. Lundgren (2013), Source model of deformation at Lazufre volcanic center, central Andes, constrained by InSAR time series,

Source model for the Copahue volcano magma plumbing system constrained by InSAR surface deformation observations

“…It is worth noting at this point that although our interpretation is but one scenario (Figure ) the highly elongated shape and orientation of the deeper source, pointing from beneath the shallower source toward the center of the caldera, favors a zone of magma transfer (and volume change) from a central caldera source. The lack of a detectable geodetic signature from this deeper caldera source implies that its volume change during this time interval was insignificant relative to its depth, although other volcanoes in the central and northern Andes have produced detectable deformation from deeper sources [ Pritchard and Simons , ; Fialko and Pearse , ; Pearse and Lundgren , ; Remy et al ., ; Lundgren et al ., ].…”

Persistent uplift of the Lazufre volcanic complex (Central Andes): New insights from PCAIM inversion of InSAR time series and GPS data

“…Figure shows some adjusted LOS displacement maps spanning different time intervals during the 2003–2010 period. These maps exhibit a conspicuous large‐wavelength elliptical displacement pattern that corresponds in location to the large uplift already described in previous studies [ Pritchard and Simons , ; Froger et al ., ; Ruch et al ., ; Anderssohn et al ., ; Henderson and Pritchard , ; Pearse and Lundgren , ]. When considering the whole time series, the extent and amplitude of the displacement pattern increases as a function of time.…”

“…The LOS velocity maxima at the center of the displacement pattern for the track 282, 318, and 404 are estimated to be: −3, −3.2, and −2.75 cm yr −1 toward the satellite. The value estimated for track 282 is in agreement with those given in previous studies [ Froger et al ., ; Ruch et al ., ; Anderssohn et al ., ; Henderson and Pritchard , ; Pearse and Lundgren , ].…”

“…They also revealed an increasing of uplift rate up to 3 cm yr −1 in the satellite line of sight (LOS) direction; over 3 times faster than the previously observed inflation rate. The same deformation behavior and displacement rate was also reported by subsequent studies [ Ruch et al ., ; Anderssohn et al ., ; Ruch et al ., ; Henderson and Pritchard , ; Pearse and Lundgren , ]. Several lines of evidences point to this ongoing uplift being related to the presence of a large quantity of magma within the crust.…”

Repeated magmatic intrusions at El Hierro Island following the 2011–2012 submarine eruption

“…During the December 2013 intrusion, the maximum vertical uplift was ~8 cm measured over only six days with an estimated volume change of 0.04 km 3 at ~10 km depth for a point pressure source. by an inflating sill (Pearse and Lundgren, 2013). Extensive magmatic intrusions were also observed in different areas beneath the Eyjafjallajökull volcano, Iceland, in 1994 and 1999 prior to the 2010 eruption (Pedersen and Sigmundsson, 2004;Pedersen and Sigmundsson, 2006).…”