 |
| Titel |
3-D density modeling of Mt. Paekdu (N Korea/China) stratovolcano and its evolution by a combination of EGM2008/terrestrial gravity field |
| VerfasserIn |
Hans-Jürgen Götze, Sungchan Choi |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104665
|
| Publikation (Nr.) |
 EGU/EGU2015-4093.pdf |
|
|
|
|
|
| Zusammenfassung |
| We combined the global gravity dataset EGM2008 and a local terrestrial gravity data survey
to conduct constrained 3-D crustal density modeling of a strato-volcanic complex and the
surrounding area located close to the border of North Korea and China. The independent
geophysical (seismic, seismology, geochemistry) and petrological constraints will be
presented together with the preprocessing of data base by curvature analysis and Euler
deconvolution. The multiple data base is used to assist a general interpretation of the
investigated area, and the 3D density model (modelled by the in-house IGMAS+ software).
Mt. Paekdu is characterized by a low of Bouguer anomaly of some –110 x 10-5 m/s2, which
is caused by the combined gravity effects of (1) Moho depth of about 40 km, (2) a zone with
both lower P-wave velocity and density than the surrounding, (3) low density volcanic rocks
at the surface, and (4) the presence of a magma chamber that has not previously been
identified.
The terrestrial gravity field measured along the seismic profile shows a remarkable
anomaly descending from the southern- to the northern flank of the Mt. Paekdu volcano,
which should be a typical anomaly pattern generally observed over the active volcanic area in
the world (e.g. the Yellow Stone volcano). The trend is interpreted to be caused by a
prominent density difference between a serious of high density mid crustal sill
beneath the southern flank and a predicted partial melted zone locating in the northern
flank. With the help of several geoscientific observations (seismic, electromagnetic,
gravity and geochemistry) and the 3D density model we conclude that a high density
sill was formed in Pliocene and early Pleistocene after pre-shield plateau-forming
eruption. Since the Pliocene, volcanic activity in the Mt. Paekdu region might be
migrated from the southeastern of North Korea to the northwest, following the path of
NW–SE-trending faults. Recently observed seismic tremors can be explained by the vertical
movement of the partial melted magma chamber beneath the northern part of the Mt.
Baekdu volcanic area, which is confirmed by vertical stress change calculation. |
|
|
|
|
|
|