Distribution and gravity anomalies of the mud diapirs and mud volcanoes off southwest Taiwan

Presenter: Yu-Tse Lin

Date: 2017/03/02

Abstract

In order to identify the mud diapirs and mud volcanoes off SW Taiwan, the study has examined ~1500 km Long MCS profiles and related marine geophysical data. Results show ten quasi-linear mud diapirs, oriented NNE–SSW to N–S directions. Thirteen mud volcanoes are identified from the multibeam bathymetric data. These mud volcanoes generally occur on tops of the diapiric structures. Moreover, the active mud flow tracks out of mud volcanoes MV1, MV3 and MV6 are observed through the high backscatter intensity stripes on the sidescan sonar images. The Kaoping Canyon and Fangliao Canyon have developed mainly controlled by mud diapiric intrusions. In another study, processing the gravity anomalies associated with the mud diapirs off SW Taiwan. Results show that the density contrasts of the submarine mud diapirs with respect to the surroundings are generally positive. Because the study area is in a tectonically compressive regime and the gas plume venting from the submarine mud volcanoes is very active, also density contrasts of the submarine mud diapirs with respect to the surroundings are generally positive, thus infer that mechanically the mud diapirs off SW Taiwan have been formed mainly due to the tectonic compression on the underlying sediments of high pore-fluid pressure, instead of the buoyancy of the buried sediments.

Reference

Chen, S.-C. et al., 2014. Distribution and characters of the mud diapirs and mud volcanoes off southwest Taiwan, J. Asian Earth Sci., 92, 201–214.

Doo, W.-B. et al., 2015. Gravity anomalies of the active mud diapirs off southwest Taiwan, Geophy. J. Int., 203, 2089–2098.