|Region:||Mexico and Central America|
|Measurement method(s):||InSAR, Levelling|
|Duration of observation:||1979-1980 (Levelling), 2007-2010 (ALOS InSAR), 2010-2011 (UAVSAR)|
|Inferred cause of deformation:||Magmatic, Surface deposits|
|Characteristics of deformation:|
Campaign levelling surveys at Pacaya in 1979 and 1980 recorded up to 196 mm of deflation over 6 months, followed by 19 mm of inflation, again over 6 months (Eggers, 1983). Combining the deformation measurements with gravity surveys leads to the conclusion that the deformation is caused by the movement of magma beneath the volcano.
No deformation was detected at Pacaya (detection threshold 3 cm/yr) during an ALOS survey of Central American volcanoes (Ebmeier et al., 2013).
UAVSAR surveys conducted in 2010 and 2011 detect up to 2 m of ground motion at Pacaya. A two week UAVSAR interferogram suggests that the deformation is due to slope instability (Lundgren., 2013
|Reference:||Eggers, A. A. (1983), Temporal gravity and elevation changes at Pacaya volcano, Guatemala, J. Volcanol. Geotherm. Res., 19, 223-237, doi:10.1016/0377-0273(83)90111-7.|
|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:||Lundgren, P. (2013) Application of UAVSAR to active volcanoes, presentation given at the 2013 UAVSAR Workshop, JPL. Available online at: http://uavsar.jpl.nasa.gov/science/workshops/presentations2013/UAVSAR_WorkShop2013_Volcanoes_(Lundgren).pdf|
View of Pacaya looking from the north over Guatamala City. Photo: Bill Rose, 1981 (Michigan Technological University).