图  1   台风路径及佘山台位置示意图(a)和佘山台四分量钻孔应变仪第一分量(150°方向)在台风“浣熊”及“海葵”经过期间的原始记录数据(b)

Figure  1.   The paths of typhoons and location of Sheshan station (a) and the original records from the first component of FCBS at Sheshan station during the typhoons "Neoguri" and "Haikui" (b)

图  2   第一分量(150°方向)在2014年7月台风“浣熊”经过期间6个频段记录的小波分解(上)及平均FFT幅值(下)

Figure  2.   Wavelet decomposition (upper) and mean FFT spectrum amplitude (lower) of 150° strain records over the six frequency bands during the typhoon "Neoguri" (2014-07-03—2014-07-15)

(a) 2—4 min; (b) 4—8 min; (c) 8—16 min; (d) 16—32 min; (e) 32—64 min; (f) 64—128 min

图  3   台风“浣熊”和“海葵”经过期间佘山台4个分量2—4 min频段的平均FFT幅值

Figure  3.   Mean FFT spectrum amplitude over the frequency band 2—4 min of four component records during the typhoons "Neoguri" and "Haikui"

图  4   2014年7月佘山台四分量钻孔应变仪2—8 min频段连续频谱记录在台风“浣熊”经过期(a)与无台风发生的平静期(b)的对比

Figure  4.   Comparison of temporal frequency spectra over the frequency band 2—8 min of FCBS at Sheshan station during the typhoon "Neoguri" (a) and without influences of typhoon (b)

图  5   台风“浣熊”经过时佘山台四分量钻孔应变仪在2—4 min频段各方向1小时平均FFT幅值(10^-8)平均振幅(蓝色曲线)及优势振动方向(红色线段)

(a) 2014年7月7日2—3时，台风来临前; (b) 2014年7月10日2—3时，台风强盛期; (c) 2014年7月13日2—3时，台风逐渐远离后

Figure  5.   Mean FFT spectrum amplitude (10^-8) in all directions (blue curve) and the predominant polarization direction (red line) of FCBS records at Sheshan station during the typhoon "Neoguri"

(a) From 2:00 to 3:00 on July 7, 2014 when the typhoon "Neoguri" was far away; (b) From 2:00 to 3:00 on July 10, 2014 when the typhoon "Neoguri" was impacting; (c) From 2:00 to 3:00 on July 13, 2014 after the typhoon "Neoguri" leaving away

图  6   台风“浣熊”经过期间佘山台四分量钻孔应变仪6个频段每隔1小时的各方向最大振幅(10^-8)及振动方向示意图

线段长度表示最大振幅，线段指向表示最大振动方向，玫红色表示台风来临前(7月3—7日)，红色表示台风强盛期间(7月8—10日)，蓝色表示台风逐渐远离台站后(7月11—14日)

Figure  6.   The maximum amplitudes (10^-8) and the predominant polarization directions over the six frequency bands with time for all one hour time series based on FCBS records at Sheshan station during the typhoon "Neoguri"

The lines with larger length represent relatively larger amplitudes. Rose red represents "Neoguri" was far away in July 3—7, red represents "Neoguri" was impacting in July 8—10, and blue represents "Neoguri" had left the station in July 11—14 (a) 2—4 min; (b) 4—8 min; (c) 8—16 min; (d) 16—32 min; (e) 32—64 min; (f) 64—128 min

图  7   台风“浣熊”经过期间佘山台四分量钻孔应变仪在6个频段的优势方向角随时间的变化

Figure  7.   The variations of predominant polarization directions over time for the six frequency bands based on FCBS records at Sheshan station during the typhoon "Neoguri"

(a) 2—4 min; (b) 4—8 min; (c) 8—16 min; (d) 16—32 min; (e) 32—64 min; (f) 64—128 min

图  8   佘山台所处海岸形态示意图

蓝色箭头代表近岸长重力波的大致入射和反射方向，黄色曲线代表光滑凹形的海岸形态

Figure  8.   The topographic condition near Sheshan station

The blue arrows represent incident and reflected directions of infragravity waves near coastline, the yellow arc represents the smooth concave shape of the coast

图  9   台风“浣熊”(a)和“海葵”(b)经过期间2—4 min平均FFT幅值与风速对比

Figure  9.   Comparison of the mean FFT spectrum amplitude over the frequency band 2—4 min with the nearby wind speed data during the typhoons "Neoguri" and "Haikui"