Project Summary
The Japanese Antarctic Research Expedition (JARE) deployed few broadband seismic stations both on the outcrop of Lützow-Holm Bay region, together with on the ice sheet of Mizuho Plateau in the vicinity of the Syowa Station, East Antarctica.
The Antarctica`s GAmburtsev Province / GAmburtsev Mountain SEISmic experiment (AGAP / GAMSEIS; IPY # 147) is an internationally coordinated deployment by few tens of broadband seismic stations over the crest of Gambursev Mountains (Dome-A) – Dome-F area. Two of these stations (GM06 and GM07 (Dome-F)) were contributed by Japanese participants (M. Kanao and A. Watanabe).
b. Principal Science Objectives
The seismological investigations by JARE provide detail information on structure and dynamics of crust - mantle – deep interior of the Earth viewed from the Lützow-Holm Bay – Mizuho Plateau – Dome-F region. The detection of ice-related seismic signals caused by environmental movement of sea-ice, ice-berg, continental ice-sheet, and coastal glaciers around the target area in East Antarctica would be detected involving global warming.
The GAMSEIS deployment gives constraints on the origin of the Gamburtsev Mountains with more broad structure and evolution of the East Antarctic craton and subglacial environment. The detection of seismic signals from phenomenon at the base of the ice sheet, such as outburst floods from subglacial lakes could be expected from detailed analyses.
The broadband deployment in East Antarctica during IPY2007-2008 was an unique opportunity for implementing to the Federation of Digital Seismographic Network (FDSN) in southern high latitude, in addition to contribute to the POLENET.
c. Research Highlights
From JARE data, shear wave splitting and anisotropy of the upper mantle and the lowermost mantle (D” zones) were obtained. Upper mantle structure by using long period receiver functions were also achieved by using broadband data around the LHB region. Ice related signals around the Bay region were also detected at the outcrop stations associated with environmental variations.
From GAMSEIS data obtained in 2008-09, local and regional seismic signals involving ice sheet and atmosphere variations were recorded, in addition to the significant number of teleseismic events. Phenomenon relating ice-sheet movement, such as basal sliding and outburst floods from sub-glacial lakes would be expected from detailed analyses.
|
|
