Icequakes around Syowa Station, Antarctica

Three types of icequakes were observed by the tripartite seismological network at Japanese Antarctic station, Syowa during the period from February 1976 to January 1977. The types are (1) shocks with a sharp initial phase (named Type I), (2) shocks with a small or unidentified amplitude of initial p...

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Bibliographic Details
Main Authors: Katsutada KAMINUMA, Toshio HANEDA
Format: Article in Journal/Newspaper
Language:English
Published: National Institute of Polar Research 1979
Subjects:
geo
Online Access:https://doi.org/10.15094/00008064
https://doaj.org/article/95e0676ee672430a8468bcacb81acd66
Description
Summary:Three types of icequakes were observed by the tripartite seismological network at Japanese Antarctic station, Syowa during the period from February 1976 to January 1977. The types are (1) shocks with a sharp initial phase (named Type I), (2) shocks with a small or unidentified amplitude of initial phase (named Type II), and (3) swarms. More than 80000 shocks of Type I and about 80 of Type II occurred through the year. A large number of shocks of Type I occurred in the austral winter season, whereas the number of Type II shocks was larger in summer than in winter. No correlations are identified between the icequake occurrence and the air temperature change, and between that and the sea level change. The features of icequakes suggest that the shocks of Type II are caused by fractures in the ice near the shelf edge of ice sheet, giving rise to the calving of icebergs and so on. Swarms are estimated to be caused by the temperature changes.