Seismological Implication to the Tectonic Evolution of the Lützow-Holm Bay Region (East Antarctica)

• Main Author: Kanao, Masaki
• Format: Book Part
• Language: English
• Published: IntechOpen 2018
• Subjects: Science / Earth Sciences / Geology; bisacsh:SCI031000; East Antarctica; Lützow-Holm Bay; Antarc*; Antarctica; Ice Sheet
• Online Access: https://openresearchlibrary.org/viewer/43eb8365-3898-4101-8d5b-a07ce2eabb03; https://openresearchlibrary.org/ext/api/media/43eb8365-3898-4101-8d5b-a07ce2eabb03/assets/external_content.pdf; https://doi.org/10.5772/intechopen.71972

Passive source studies using teleseismic events demonstrated heterogeneous structure in the Lützow-Holm Bay (LHB) region, East Antarctica. Depth variations of upper mantle discontinuities (410 and 660 km) were derived from long-period receiver functions by local array stations. Shallow depths in topography of upper mantle discontinuity were cleared beneath the continental ice sheet back azimuth. These results reflect a paleo-upwelling of the mantle plume associated with Gondwana breakup. Lithospheric mantle anisotropy derived by shear waves’ (SKS) splitting anticipated a relationship between “fossil” anisotropy and the past tectonics in NE-SW orientation. Origin of mantle anisotropy was assumed to be caused by supercontinent assembly rather than present asthenospheric flow parallel with absolute plate motion. The deep seismic surveys by active sources, moreover, were carried out over continental ice sheet and provided clear information on crust-mantle boundary, together with inner lithospheric mantle reflections. The extracted lithospheric cross-sectional images by seismic reflection analyses implied tectonic influence of compressive stress during Pan-African age.