关键词: 南极,布兰斯菲尔德海峡,海磁异常,深部地质,西向漂移

Abstract:

The expression of ΔT in the Southern Hemisphere presented in this paper. The survey area is located in 63°S ,so where it is characterized by positive anomaly, and negative anomaly in the south. Data processed by reducing to pole and matched filtering, the deep and shallow source anomalies are obtained. Three deep source anomaly belts are related to South Shetland Islands, the Bransfield Strait and Antarctic Peninsula, the north and south belts are positive and negative one in the middle. The two shallow source anomaly belts are related to two faults in north and south edge of the Bransfield Strait. The deep source anomalies are referred to relief of the magnetic basement, because of subduction of the Pacific plate in the South Shetland Islands, where deep background is characterized by high basic composition and the value of deep and shallow source anomalies are higher than that in the south. The faults which are vertical to the trending of the Bransfield Strait are recognized by shallow source anomalies. According to the results of the research on the landform, rock ages and seismic velocity distribution, westward drift of the Antarctic Peninsula had probably happened in history.