|Measurement method(s):||InSAR, Strainmeter, Tiltmeter|
|Duration of observation:||02/1981-02/1986; 2008-2011|
|Inferred cause of deformation:||Hydrothermal, Magmatic|
|Characteristics of deformation:|
Uplift was first observed at Tangkubanparahu (also called Tangkuban Perahu) by Dvorak et al between 1981 and 1986. Their study used tiltmeter (spirit level) measurements positioned around the edges of the summit craters, and from 1981-1983 they noted an average tilt rate of 40-50 micro-radians per year. This uplift decreased by a factor of five following the onset of phreatic activity at the volcano in 1983; between 1981 and 1983 the approximate volume of uplift was 3 million m3 per year, while from 1984 to 1986 it was 0.4 million m3 per year. The authors therefore link the deformation to the eruptive activity, suggesting possible causes as increased pressure within a very shallow magma body, or heating and expansion of a confined aquifer.
Tangkubanparahu was also included in a 2008-2011 InSAR survey performed by Salvi et al, published in 2015. This study utilised a combination of SBAS InSAR technique (using ALOS-1 data) and Persistent Scatter Interferometry (PSI) to build a large-scale database of deformation covering the entire Bandung basin and some of the surrounding regions, including Tangkubanparahu to the north. However, no significant deformation was observed at the volcano during the study period.
|Reference:||Dvorak, J. et al. 1990. Recent uplift and hydrothermal activity at Tangkuban Parahu Volcano, W-Java. Bull.Volcanol., 53, 20-28|
|Reference:||Salvi, S. et al. 2015. Use of multitemporal InSAR data to develop geohazard scenarios for Bandung, Western Java, Indonesia. EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.13161|
Photo by Tom Casadevall, 1987 (U.S. Geological Survey). From Smithsonian Institution Global Volcanism Program: Tangkubanparahu