Shallow P-wave Velocity Structure of Shirane Pyroclastic Cone, Kusatsu-Shirane Volcano Derived from a Controlled Seismic Experiment

• ONIZAWA Shinya

  Kusatsu-Shirane Volcano Observatory, Volcanic Fluid Research Center, Tokyo Institute of Technology

• MORI Takehiko

  Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University:(Present address)Institute for Geothermal Sciences, Graduate School of Science, Kyoto University

• TSUTSUI Tomoki

  Faculty of Engineering and Resource Science, Akita University

• HIRABAYASHI Junichi

  Kusatsu-Shirane Volcano Observatory, Volcanic Fluid Research Center, Tokyo Institute of Technology

• NOGAMI Kenji

  Kusatsu-Shirane Volcano Observatory, Volcanic Fluid Research Center, Tokyo Institute of Technology

• OGAWA Yasuo

  Kusatsu-Shirane Volcano Observatory, Volcanic Fluid Research Center, Tokyo Institute of Technology

• MATSUSHIMA Takeshi

  Institute of Seismology and Volcanology, Faculty of Sciences, Kyushu University

• SUZUKI Atsuo

  Usu Volcano Observatory, Institute of Seismology and Volcanology, Graduate School of Science, Hokkaido University

• 西村 太志

Bibliographic Information

Other Title

• 人工地震探査より推定した草津白根火山白根火砕丘表層のP波速度構造
• ジンコウ ジシン タンサ ヨリ スイテイ シタ クサツ シラネ カザン シラネ カサイキュウ ヒョウソウ ノ Pハ ソクド コウゾウ

Abstract

P-wave velocity structure at a summit area of Kusatsu-Shirane volcano is investigated by using first arrival time data of a controlled seismic experiment conducted in 2003. The objectives of this study are to reveal a shallow P-wave velocity structure of Shirane pyroclastic cone and to make correlation of the resultant velocity model to geological information. The first arrival times for two dynamite shots recorded by 59 temporal seismic stations are used for investigating a two-layered velocity model. The first layer velocity is estimated by using arrivals at stations close to a shot point. The second layer velocity and depths of the interface are inferred by the time-term analysis. Estimated velocities of the first and second layers are 1.1km/s and 2.9km/s, respectively. Thickness of the first layer varies from almost 0m at surface exposures of lavas to about 100m at the summit of the pyroclastic cone. The first layer is interpreted as pyroclastic deposits covering the surface of the Shirane pyroclastic cone and the second is the uppermost subsurface lavas, by comparing to surface and borehole geological information and P-wave velocity of borehole core samples.

Journal

• BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN

  BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN 50 (1), 9-16, 2005

  The Volcanological Society of Japan

Keywords

• Kusatsu-Shirane volcano
• Shirane pyroclastic cone
• controlled seismic experiment
• P-wave velocity structure

Details

• CRID: 1390001204303702016
• NII Article ID: 110003041522
• NII Book ID: AN10512786
• DOI: 10.18940/kazan.50.1_9
• ISSN: 21897182
• ISSN: 04534360
• NDL BIB ID: 7266455
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7266455
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • CiNii Articles
  • KAKEN
  • Crossref
• Abstract License Flag: Disallowed