Analysis on some strong ground motion records from the 2016 Kumamoto earthquake series

[摘要] The 2016 Kumamoto earthquake sequence started with an MJMA 6.5 earthquake in Kumamoto Prefecture on April 14, 2016, which is the foreshock. And a larger earthquake of MJMA 7.3 occurred on April 16, which is the mainshock. We analyzed the data of K-NET stations to get the distribution characteristics of PGA[3]. The characteristics of foreshock and mainshock is a little different. This phenomenon may be caused by fault directivity effect. We selected strong motion recordings and calculated the curve based on the fourier amplitude H/V spectrum ratio method [2], then identified the predominant frequency to analyze the nonlinear site effect.

[发布机构] Key Laboratory of Earthquake Engineering and Engineering Vibration, Institute of Engineering Mechanics, China Earthquake Administration, China^1

[效力级别] 经济学

[关键词] Directivity effect;Distribution characteristics;Earthquake sequences;Earthquake series;Fourier amplitudes;Predominant frequency;Spectrum ratio;Strong ground motion