Three-dimensional density modeling of the EGM2008 gravity field over the Mount Paekdu volcanic area

Here we use the global gravity field data set EGM2008 for 3-D crustal density modeling of the Mount Paekdu stratovolcano and surrounding area located on the border between North Korea and China. Curvature analysis and Euler deconvolution are used to assist interpretation, and the 3-D model is constrained by multiple geological and geophysical data sets. Mount Paekdu is characterized by a low Bouguer anomaly of -110x10(-5)m/s(2), which is caused by the combined gravity effects of (1) a depth to the Moho of about 40km, (2) a zone with lower P wave velocity and density than the surrounding, (3) low density volcanic rocks on the surface, and (4) the presence of a magma chamber that has not previously been identified. The modeled magma chamber has a mean thickness of 5km and a density of about 2350kg/m(3) and is located <10km from the surface. Magma chambers are also modeled beneath Mount Wangtian and Mount Nampotae. However, the results of the 3-D density modeling do not confirm the existence of a previously proposed midcrustal low-velocity zone in the area 70km to the north of Mount Paekdu. Since the Pliocene, volcanic activity in the Mount Paekdu region has migrated from the east coast of North Korea to the northwest, following the path of NW-SE trending faults.