Explosion earthquakes of Mount Erebus, Antarctica

• Main Authors: Katsutada Kaminuma, Megumi Baba, Kazuo Shibuya, R.R. Dibble
• Format: Report
• Language: English
• Published: National Institute of Polar Research 1985
• Subjects: Mount Erebus; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1783; http://id.nii.ac.jp/1291/00001783/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1783&item_no=1&attribute_id=18&file_no=1

The characteristics of explosions of Mount Erebus, Antarctica are analyzed using the data of the seismic network operated by the International Mount Erebus Seismic Study (IMESS). About 70 earthquakes have been located by the network between 16 February and 29 June 1982. An aseismic zone is recognizable in the southeastern part of Mount Erebus on the vertical projection of hypocenter distributions. The aseismic zone seems to suggest the existence of a magma reservoir which is estimated to be located beneath the summit. Three types of explosions are recognizable by the seismic and the infrasound signals. The types are named α-, β- and γ-types and characterized as follows : 1) the α-type explosion has high infrasound frequency and high frequency spectra of explosion earthquakes, 2) the β-type has low infrasound frequency and low frequency spectra of explosion earthquakes and 3) the γ-type has low infrasound frequency and small elastic vibrations at the summit station. About 110 explosion earthquakes of both α- and β-types are counted and 14 clear γ-type events were recognized during the period.