Observations of seismic signals induced by snow avalanches

Nobuyuki IMANISHI; Kouichi NISHIMURA; Takeo MORIYA; Tomomi YAMADA

doi:10.5331/seppyo.66.3

地震動の観測による雪崩の研究

今西伸行, 西村浩一, 森谷武男, 山田知充

著者情報

キーワード: 震動波形, 卓越周波数, 雪崩発生点, 雪崩の質量

ジャーナルフリー

2004 年 66 巻 1 号 p. 3-10

DOI https://doi.org/10.5331/seppyo.66.3

詳細

発行日: 2004/01/15 受付日: 2003/09/16 J-STAGE公開日: 2009/08/07 受理日: 2003/10/22 早期公開日: - 改訂日: -
訂正情報
訂正日: 2009/08/07 訂正理由: - 訂正箇所: 論文抄録訂正内容: Wrong : Since a seismic wave associated with a snow avalanche may contain considerable information about the avalanche itself, seismic observation using 4 seismographs was carried out at Toikanbetsu (N45°, E142°), Northern Hokkaido, Japan during 80 days from January to April 2001. This paper first discusses the characteristics of the sesmic signals. Second techniques to estimate the avalanche release point and its scale are developed. As a result of this observation, totally 50 seismic waves from full-depth avalanches were obtained. They correspond to 86% of all observed avalanches, which indicates that monitoring of avalanches with seismographs is useful. The shapes of waves from avalanches released at the same point are similar to each other. From frequency analyses of the seismic signals, a negative correlation is found between the dominant frequencies of the seismic signals and the distance from the avalanche release point to the location of the seismograph. On the other hand, the positive correlation is found between the total energy of the seismic wave and the avalanche mass. The results indicate that the avalanche release point and avalanche mass can be estimated.
Right : Since a seismic wave associated with a snow avalanche may contain considerable information about the avalanche itself, seismic observation using 4 seismographs was carried out at Toikanbetsu (N45°, E142°), Northern Hokkaido, Japan during 80 days from January to April 2001. This paper first discusses the characteristics of the sesmic signals. Second techniques to estimate the avalanche release point and its scale are developed. As a result of this observation, totally 50 seismic waves from full-depth avalanches were obtained. They correspond to 86% of all observed avalanches, which indicates that monitoring of avalanches with seismographs is useful. The shapes of waves from avalanches released at the same point are similar to each other. From frequency analyses of the seismic signals, a negative correlation is found between the dominant frequencies of the seismic signals and the distance from the avalanche release point to the location of the seismograph. On the other hand, the positive correlation is found between the total energy of the seismic wave and the avalanche mass. The results indicate that the avalanche release point and avalanche mass can be estimated.

訂正日: 2009/08/07 訂正理由: - 訂正箇所: 所属機関情報訂正内容: Wrong :
1) Institute of Low Temparature Science, Hokkaido University
2) Nagaoka Institute of Snow and Ice Studies, National Research Institute for Earth Science and Disaster Prevention
3) Division of Earth and Planetary Science, Graduate School of Science, Hokkaido University

Right :
1) Institute of Low Temparature Science, Hokkaido University
2) Nagaoka Institute of Snow and Ice Studies, National Research Institute for Earth Science and Disaster Prevention
3) Division of Earth and Planetary Science, Graduate School of Science, Hokkaido University

訂正日: 2009/08/07 訂正理由: - 訂正箇所: 引用文献情報訂正内容: Wrong : Lawrence, W. and Williams, T. R., 1976 : Seismic signals associated with avalanches. Journal of Glaciology,17(77), 521-526.
Leprettre, J. P., Navarre, J-P. and Taillefer, A., 1996 : First results from a pre-operational system for automatic detection and recognition of seismic signals associated with avalanches. Journal of Glaciology, 42(141), 352-363.
Leprettre, J. P., Navarre, J-P., Panel, J. M., Touvier, F., Taillefer, A. and Roulle, J., 1998 : Prototype for operational seismic detection of natural avalanches. Annals of Glaciology, 26, 313-318.
Nishimura, K. and Izumi, K., 1997 : Seismic signals induced by snow avalanche flow. Natural Hazard, 15, 89-100.
Sabot, F., Naaim, M., Granada, F., Surinach, E., Planet, P. and Furdada, G., 1998: Study of avalanche dynamics by seismic methods, image-processing techniques and numerical models. Annals of Glaciology, 26, 319-323.
Salway, A. A., 1978: A seismic and pressure transducer system for monitoring velocities and impact pressures of snow avalanches. Arctic and Alpine Research, 10(4), 769-774.
Suriñach, E., Sabot, F., Furdada, G. and Vilaplana, J. M., 2000: Study of seismic signals of artificially released snow avalanches for monitoring purposes. Phys. Chem. Earth (B), 25(9), 721-727.
Suriñach, E., Furdada, G., Sabot, E, Biescas, B. and Vilaplana, J. M., 2001 : On the characterization of seismic signals generated by snow avalanche for monitoring purposes. Annals of Glaciology, 32, 268-274.

Right : Lawrence, W. and Williams, T. R., 1976 : Seismic signals associated with avalanches. Journal of Glaciology,17(77), 521-526.
Leprettre, J. P., Navarre, J-P. and Taillefer, A., 1996 : First results from a pre-operational system for automatic detection and recognition of seismic signals associated with avalanches. Journal of Glaciology, 42(141), 352-363.
Leprettre, J. P., Navarre, J-P., Panel, J. M., Touvier, F., Taillefer, A. and Roulle, J., 1998 : Prototype for operational seismic detection of natural avalanches. Annals of Glaciology, 26, 313-318.
Nishimura, K. and Izumi, K., 1997 : Seismic signals induced by snow avalanche flow. Natural Hazard, 15, 89-100.
Sabot, F., Naaim, M., Granada, F., Surinach, E., Planet, P. and Furdada, G., 1998: Study of avalanche dynamics by seismic methods, image-processing techniques and numerical models. Annals of Glaciology, 26, 319-323.
Salway, A. A., 1978: A seismic and pressure transducer system for monitoring velocities and impact pressures of snow avalanches. Arctic and Alpine Research, 10(4), 769-774.
Suriñach, E., Sabot, F., Furdada, G. and Vilaplana, J. M., 2000: Study of seismic signals of artificially released snow avalanches for monitoring purposes. Phys. Chem. Earth (B), 25(9), 721-727.
Suriñach, E., Furdada, G., Sabot, E, Biescas, B. and Vilaplana, J. M., 2001 : On the characterization of seismic signals generated by snow avalanche for monitoring purposes. Annals of Glaciology, 32, 268-274.

抄録

雪崩発生に伴う地震動の特徴を把握するとともに,雪崩の発生地点と規模を推定する手法を確立するため,4台の地震計を用いて,2001年1月から4月までの80日間,北海道大学天塩研究林内で観測を行った.期間中に,対象域で確認された雪崩の86%にあたる50例の震動波形を得ることができ,地震計によって高い確率で雪崩発生のモニタリングが可能であることが判った.ほぼ同地点で発生した雪崩による震動は類似した波形を示すこと,震動の卓越周波数と地震計から雪崩発生点までの距離との間には負の相関があり,これから発生点の推定が可能であること,また雪崩の運動エネルギーと位置エネルギーとの関係を用いて,雪崩質量の推定が可能であることが示された.

責任著者(Corresponding author)

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