Slow deformation of Mt. Baekdu stratovolcano observed by satellite radar interferometry

Mt. Baekdu is a Cenozoic stratovolcano, where a series of micro-seismic events and gaseous emissions have been reported recently. Two-pass DInSAR technique was applied to detect possible displacement. Most interferometric phases out of 58 JERS-1 differential interferograms show concentric fringe patterns that correlate with elevation. From an analysis of fringe-duration relation, the fringe patterns can be interpreted mostly as an atmospheric contamination by stratified troposphere. To estimate the tropospheric delay, we used the data in Mt. Sobaek that is located about 20 km away from the summit of Mt. Baekdu and whose diameter is about 5 km. After removing the tropospheric effect, about 3 mm/yr of inflation was detected from 1992 to 1998. Although the volcanic inflation is not conclusive because of the large r.m.s. error, the results indicate that there exists a possibility of a slow upward deformation around the volcano.