High-Resolution, Low-Altitude Helicopter-Borne Aeromagnetic Survey over Unzen Volcano

• OKUBO, Ayako

• TANAKA, Yoshikazu

• UTSUGI, Mitsuru

• KITADA, Naoto

• SHIMIZU, Hiroshi

• MATSUSHIMA, Tekeshi

Bibliographic Information

Other Title

• 雲仙火山における低高度な高密度空中磁気探査

Abstract

On September 18, 2002, we conducted a high-resolution, low-altitude helicopter-borneaeromagnetic survey over Unzen Volcano. Therefore, we conducted a magnetization intensitymapping on the volcano, on the assumption that the magnetic anomalies are caused by the terrainmagnetized in the same direction as the present Earth's magnetic field and the magnetizationintensity varies only laterally. This map shows good agreement with the geologic features, especially the hydrothermal alteration zone and the collapsed pyroclastic deposits. In addition, even in the area covered by lavas, the magnetization intensities show various values correspondingto each eruption event. Local magnetization lows on Heisei-Shinzan suggest that theHeisei lava produced by the 1991-1995 eruption has not yet been cooled enough.

Journal

• Disaster Prevention Research Institute Annuals. B

  Disaster Prevention Research Institute Annuals. B 47 (B), 735-742, 2004-04-01

  京都大学防災研究所

Keywords

• Unzen volcano
• helicopter-borne magnetic surveys
• aeromagnetic anomalies
• magnetization intensity map

Details

• CRID: 1050001202113224832
• NII Article ID: 120002514948
• NII Book ID: AN00027784
• ISSN: 0386412X
• HANDLE: 2433/129198
• Text Lang: ja
• Article Type: departmental bulletin paper
• Data Source:
  • IRDB
  • CiNii Articles
  • KAKEN