| Reporter: | Wenbo Zhang |
| Title: |
Bard T. Aagaard, John F. Hall, and Thomas H. Heaton (2004) Effects of Fault Dip and Slip Rake Angles on Near-Source Ground Motions: Why Rupture Directivity Was Minimal in the 1999 Chi-Chi, Taiwan, Earthquake Bull. Seism. Soc. Am., 94(1), 155-170. |
| Summary: | In this paper, the authors study how the fault dip and slip rake angles affect near-source ground motions using 10 earthquake scenarios (five fault geometries with different combinations of fault dip and rake angles). They point out that rupture directivity and proximity to the fault are two factors controlling the amplitude of near-source ground motions. Strong shear-wave directivity requires that (1) the observer is located in the direction of rupture propagation and (2) the rupture propagates parallel to the direction of the fault slip vector. Their simulation results show that the ground motions generated by the scenario whose geometry is similar to the Chi-Chi earthquake are much smaller than the ground motions generated by the other scenarios. This is because that this scenario (geometry similar in the Chi-Chi earthquake) is a thrust fault with predominant along-strike rupture. The rupture propagates perpendicular to the slip vector and the rupture propagates in the direction of a node in the shear-wave radiation pattern. |
| Reporter: | 松波 孝治 [Koji Matsunami] |
| Title: |
Yutaka Mamada, and Hiroshi Takenaka (2004). Strong Attenuation of Shear Waves in the Focal Region of the 1997 Northwestern Kagoshima Earthquakes, Japan Bull. Seism. Soc. Am., 94(2), 464-478. |
| Summary: | 準備中 [In Preparation] |