Study on Rupture Initiation by Broadband Records for Local Earthquakes.

当地地震宽带记录的破裂引发研究。

• 批准号: 02640310
• 负责人: KIKUCHI Masayuki
• 金额: $ 0.9万
• 依托单位: Yokohama City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640310/
• 关键词: Broadband Record; Inversion; Rupture Process; Stress drop; 応帯域地震記録; インバ-ジョン; 小田原地震

Body wave data recorded at a network of broadband seismograph stations were analysed to investigate local events with focal depths deeper than about 50 km. For these events the initial portion of P wave displacement represents well the source time function, but only if the amplitude is normalized to the maximum moment rate. The magnitudes of the analysed earthquakes range from Mw=3.1 to 6.5. It is shown than the seismic moment Mo and the pulse width T are well correlated as Mo/T^3=const., indicating that the stress drop is largely constant. This dynamic similarity seems to be valid for a vast range of earthquake sizes : Mw=1-8. Closer inspection of Mo/T^3 indicates that the stress drop slightly depends on the source depth while it is almost independent of whether the source is an inter-plate event or an intra-plate event. It is also shown that source complexity such as a multiple shock nature is not a characteristic of large earthquakes but is often observed even for small earthquakes.

对宽带地震台网络记录的体波数据进行分析，以调查震源深度超过约 50 公里的局部事件。对于这些事件，P 波位移的初始部分很好地代表了源时间函数，但前提是振幅被归一化为最大矩速率。分析的地震震级范围为 Mw=3.1 至 6.5。结果表明，地震矩Mo和脉冲宽度T有很好的相关性，为Mo/T^3=const.，表明应力降基本上是恒定的。这种动态相似性似乎适用于大范围的地震震级：Mw=1-8。对 Mo/T^3 的仔细检查表明，应力降稍微依赖于源深度，而几乎与源是板间事件还是板内事件无关。研究还表明，震源的复杂性（例如多次震波性质）并不是大地震的特征，但即使是小地震也经常观察到。

项目成果

Kikuchi,M.and H.Kanamori: "Reーexamination of the source process of the 1976 Guatemala earth quahe" 1990 Western Pacific Geophysics Meeting. A32A-9 (1990)

Kikuchi, M. 和 H. Kanamori：“重新审视 1976 年危地马拉地震的来源过程”1990 年西太平洋地球物理学会议 A32A-9 (1990)。

石田 瑞穂・菊地 正幸: "神奈川県西部に発生したM5.4の地震の解析" 1990地震学会秋季大会予稿集. 141 (1990)

Mizuho Ishida和Masayuki Kikuchi：“神奈川县西部发生的M5.4地震的分析”日本地震学会1990年秋季会议记录141（1990）。

Kikuchi,M.: "Strain drop and apparent strain for lange carthquakes" Tectonophysics. 211. 107-113 (1992)

Kikuchi,M.：“兰格迦特地震的应变下降和表观应变”构造物理学。

Ishida,M.and M.Kikuchi: "A possible fare shock of a future large earthquake near Odawara,central Japan" Geophys.Res.Lett.19. 1695-1698 (1992)

Ishida,M. 和 M.Kikuchi：“日本中部小田原附近未来大地震可能造成的费用冲击”Geophys.Res.Lett.19。

Ishida,M.and M.Kikuchi: "A possible foreshock of a future large earthquake near Odawara,central Japan" Geophys.Res.Letters.

Ishida,M. 和 M.Kikuchi：“日本中部小田原附近未来大地震可能发生的前震”Geophys.Res.Letters。