![]() In: Civetta L, Gasparini P, Luongo G, Rapolla A (eds) Physical Volcano- logy. Kubotera A (1974) Volcanic tremors at Aso volcano. Kienle J, Rowe CA, Kaminuma K, Shibuya K, Kyle PR, Mcintosh WE, Dibble RR (1985) Eruption of Mount Erebus, and Ross Island seismicity (1984–1985). Special issue of bulletin of volcanic eruptions. Katsui Y (ed) (1971) List of the world active volcanoes. Mem Natl Inst Polar Res Spec Iss 37: 40–47 Kaminuma K, Baba M, Shibuya K, Dibble RR (1985) Explosion earthquakes of Mount Erebus, Antarctica. Presented at the 23rd general assembly of IASPEI meeting, F10–20, Tokyo Hamaguchi H, Zana N (1985) Distribution of hotspot volcanoes: “HINEP” lines as an evidence for deep mantle plumes. Mem Natl Inst Polar Res, Spec Iss 37: 29–39ĭibble RR, Kienle J, Kyle PR, Shibuya K (1984) Geophysical studies of Erebus volcano, Antarctica, from 1974 December to 1982 January. This process is experimental and the keywords may be updated as the learning algorithm improves.īaba M, Kaminuma K, Koyama E, Ueki S (1985) Seismic activity of Mount Erebus, Antarctica in 1983–1984. These keywords were added by machine and not by the authors. Considering all types together, the dominant seismic frequency increases in a general way with reported focal depth, and a similar increase in the spectrum of the source time function is postulated. Hence, there must be a transition in the generating mechanism from β- to hybrid to tremor type. Groups I and II are connected by a hybrid type, which has a seismic signal of tremor type, and an infrasonic signal of β-type. ![]() Reported focal depths range from 4 km below the summit (sea level) to 15 km. High-frequency types have ordinary earthquake onsets, and a dominant frequency of 12 Hz. Although they have no infrasonic onset, they occur during medium to high infrasonic noise levels. Tremor types have an emergent onset, a narrow spectral peak of 5.0–5.4 Hz, and a duration of 20–30 s. They are considered to be generated by the bursting of 200–300 m diameter low pressure bubbles at shallow depth in the lava lake. Γ-Types have a large infrasonic but very small seismic onset at the summit station. Reported focal depths range from 1.5–4 km below the summit. The onset portion of the seismic power spectrum, defined as having the duration of the infrasonic signal, has a dominant frequency lower than 3–4 Hz, whereas the coda has a dominant frequency of 5–10 Hz. Β-Types have a large onset of both seismic and infrasonic waves with a sinusoidal waveform at the summit station. Reported focal depths range from 3 to 5 km. The seismic power spectrum extends up to 15 Hz. Α-Types have a sharp infrasonic pressure pulse of 0.05–0.35 s, and a rarefaction tail of 1.5–3.5 s duration. On the basis of infrasonic and seismic waveforms, we classify volcanic earthquakes at Erebus volcano into Group-I events accompanied by infrasonic signals of eruptions, and Group-II without eruption signals.
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