REFLECTION PROFILES OF THE ACTIVE SEISMIC AND VOLCANIC REGION OFF THE EAST-COAST OF IZU PENINSULA

被引：3

作者：

KASAHARA, K

YAMAMIZU, F

TAKAHASHI, A

IKAWA, T

机构：

[1] National Research Institute for Earthscience and Disaster Prevention

[2] JAPEX Geoscience Institute, Inc., Tokyo 107, Minato-ku

来源：

JOURNAL OF PHYSICS OF THE EARTH | 1991年 / 39卷 / 01期

关键词：

D O I：

10.4294/jpe1952.39.361

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

VIBROSEIS reflection explorations profiled the crustal structure under the east coast of Izu Peninsula where a seabed volcano erupted on July 13, 1989. Profiles along two exploration lines show a common feature that consists of three layers. The uppermost layer is floored with relatively intense reflections from shallow depths within 0.5 s of two-way travel time, the next one is rather transparent layer, and the last is the basement ceiled with weaker reflections around 1.0 s. The shallower reflectors are seen to be broken here and there. The depth of deeper reflector correctly coinsides with the upper limit of the earthquake swarm which is concentrated to the depth range of 2-4 km. It is the most interesting that narrow spot-like high velocity bodies are found in the shallowest crust near the seismic swarm area. We suppose that those bodies may be interpreted as aged magma intrusions, and may create an asperity of the major earthquake of M5.5 prior to the submarine volcanic eruption.

引用

页码：361 / 370

页数：10

共 10 条

[1] Anderson R.G., McMechan G.A., Weighted stacking of seismic data using amplitude-decay rates and noise amplitudes, Geophys. Prospect., 38, pp. 365-380, (1990)
[2] Fukuyama E., Kinoshita S., Yamamizu F., Unusual high-stress drop subevent during the M5.5 earthquake, the largest event of the 1989 Ito-oki swarm activity, Geophys. Res. Lett., (1991)
[3] Ikawa T., Nakagome O., Okazaki K., Reflection seismic exploration in geothermal areas—Present technology and future—, J. Jpn. Geotherm. A., 24, pp. 60-72, (1987)
[4] Klemperer S.L., Seismic noise-reduction techniques for use with vertical stacking: an empirical comparison, Geophysics, 52, pp. 322-334, (1987)
[5] Okada Y., Yamamoto E., A model for the 1989 seismo-volcanic activity off Ito, central Japan, derived from crustal movement data, J. Phys. Earth, 39, pp. 177-195, (1991)
[6] Sheriff R.E., Geldart L.R., Exploration Seismology, 1, (1982)
[7] Suzuki H., Kasahara K., Ohtake M., Takahashi A., Ikawa T., Abe S., Kawabe Y., Magmatic activity of Izu-Oshima Volcano, Japan, as inferred from a seismic reflection survey, J. Volcanol. Geotherm. Res., (1991)
[8] Ueki S., Morita Y., Nishimura T., Horiuchi S., Hamaguchi H., The seismicity accompanying the eruption of a submarine volcano off Izu Peninsula, Japan, EOS. Trans. Am. Geophys. Union, 71, (1990)
[9] Wright P.M., Ward S.H., Ross H.P., West R.C., State-of-the-art geophysical exploration for geothermal resources, Geophysics, 50, pp. 2666-2699, (1985)
[10] Yoshii T., Asano S., Kubota S., Sasaki Y., Okada H., Masuda T., Moriya T., Murakami H., Crustal structure in Izu Peninsula, central Japan, as derived from explosion seismic observations 2. Ito-Matsuzaki profile, J. Phys. Earth, 33, pp. 435-451, (1985)

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