著者 阿部 邦昭
雑誌名 日本歯科大学紀要. 一般教育系
巻 41
ページ 13‑18
発行年 2012‑03‑20
URL http://doi.org/10.14983/00000059
Creative Commons : 表示 ‑ 非営利 ‑ 改変禁止 http://creativecommons.org/licenses/by‑nc‑nd/3.0/deed.ja
2007 Ô\ƌĦ¨ƱĮĬ&Ĭĸ!&łá
Source and characteristic properties of the 2007 Chuetsu-oki Earthquake Tsunami
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üĈĝŖ²¶úļőĆ²¶
Kuniaki ABE
Nippon Dental University College at Niigata
Abstract
A small tsunami was excited by the 2007 Chuetsu-oki Earthquake (M=6.8), generated under Japan Sea on July 16, 2007. It was detected by tide gages installed at the coast of Honshu, Japan. We analyzed the initial and the maximum waves after correcting of tidal level and response of the tide gages. A source area was estimated on arrival times using inverse refraction diagram and space distribution of period observed in the initial wave was related to the source area. The estimated source is approximated by an ellipse of 31 km in long axis and 19 km in short axis, and determined to be located nearest to the coast. The long period of 30-36 minutes is attributed to wave radiated in a direction of the long axis and short one of 10-18 minutes is attributed to wave radiated in a direction of the short axis. Space distribution of the maximum amplitude showed a decay larger than the case of cylindrical wave on a constant sea depth. It is characteristic to propagation along a sloping sea bottom. This source does not conflict with displacement field of fault model estimated from tectonic deformation on land.
Key Words : 2007 Chuetsu-oki earthquake tsunami, source, initial wave, maximum wave, period
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Fig. 2 Tsunami waveforms observed at some tide stations. Tide and response corrections were conducted.
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Fig. 3 Travel time curve of the 2007 Chuetsu-oki earthquake tsunami.
Tide stations north (open square) and south (solid square) to the epicenter.
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Fig. 7 Decay curve of maximum double amplitude plotted in log-log scale. One-dimensional relation is obtained using a least-square method and shown in the figure.
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Fig. 9 Comparison of the estimated tsunami source (Figure 4) with a fault model (Geodetic Survey Institute, 2007). The numerals on the fault are vertical displacements estimated by the fault model.
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ƆÆ VƟŵƆjVƧƠƞĀiŚuĨÓňƉĨ ÆňĜ¹20082007ÔúļŐ\ƌĦ¨ƱĮĬ&ĖĽ ſƣĮĬͶœŘ¬2595-106
Namegaya,Y.,Y.Tanioka,K.Abe,K.Satake,K.Hirata,M .Okada and Aditya R.Gusman, 2009, In situ
measurements of tide gauge response and corrections of tsunami waveforms from the Niigataken Chuetsu-oki Earthquake in 2007, Pure Applied Geophys., 166, 97-116.
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