Two separate studies (Chaussard et al, 2013; Gonzalez et al, 2015) have utilised ALOS (Advanced Land Observation Satellite) data to perform InSAR studies on the regions surrounding the Singkut caldera. While neither study was centred on Singkut, focusing instead on the nearby Sinabung and Toba edifices, both noted a small amount of deformation at Sibayak, a stratovolcanic cone of Singkut.
Chaussard et al performed their study using data acquired between February 2007 and January 2011, and noted that the observed deformation at Sibayak was ‘not significant’, totalling less than 2cm in small cycles of uplift and subsidence over the four years. This deformation was deemed negligible enough that the measurements were used as a baseline against which more significant deformation at Mt Sinabung might be measured.
The findings of the 2015 Gonzalez et al study (January 2007 – August 2010) corroborated these measurements, but also noted a poorly defined area of subsidence centred around Mt Sibayak, which the authors suggested could be caused by active degassing processes. The average subsidence at the caldera was estimated at approximately 10 mm/yr, at a relatively constant rate.
Both studies utilised data from ALOS track 495, covering a rectangular area between 2.6 N 98.2 E and 3.8 N 99.0 E.