3:30 PM - 3:45 PM
[SVC45-21] Crustal deformation around Azumayama Volcano
Keywords:volcanic activity, crustal deformation, GNSS
Japan Meteorological Agency (JMA) deploys 6 continuous GPS sites around the volcano. The data are processed using the precise point positioning strategy (Zumberge et al., 1997) of GIPSY-OASIS II ver. 6.2 with IGS08 precise ephemerides and GMF mapping functions (GMF, Boehm et al., 2006). Since the wide area of northeastern Japan still suffers the long lasting postseismic deformation following the 2011 Tohoku-oki earthquake (M9.0), we try to extract volcanic deformation related to the unrest of the volcano by fitting an approximation function of time consisting of linear, logarithmic, annual, and semi-annual terms. The coefficients of each term are estimated by the least-squares method for the period between April, 2011 and September, 2014.
Resulting displacements around the volcano for the period between October to December, 2014 show radial expansion and slight uplifting, which can be roughly modeled with an point pressure source at a depth of 3.4 km just beneath the summit of Issaikyozan.
Authors are grateful to the Japan Meteorological Agency and the Geospatial Information Authority of Japan for providing GNSS data used in this paper.
Boehm et al. (2006), GRL, 33, L07304, doi:10.1029/2005GL025546.
Japan Meteorological Agency (2013), http://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/souran_eng/menu.htm
Japan Meteorological Agency (2014a), http://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/kaisetsu/CCPVE/shiryo/