Compressional Wave Speed Dispersion and Attenuation in Carbonate Sediments, Kaneohe Bay, Oahu, HI
Compressional Wave Speed Dispersion and Attenuation in Carbonate Sediments, Kaneohe Bay, Oahu, HI
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DOI：
10.1109/joe.2008.920212
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发表时间：
2008-09
影响因子：
4.1
通讯作者：
E. Nosal;Chunhui Tao;S. Baffi;S. Fu;M. Richardson;R. Wilkens
中科院分区：
文献类型：
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作者：
E. Nosal;Chunhui Tao;S. Baffi;S. Fu;M. Richardson;R. Wilkens
现场压缩波的速度和衰减之间的20和100千赫的测量在两个碳酸盐沉积物的网站在卡内奥赫湾，在夏威夷的奥克尼岛的迎风面。速度随频率增加，从1691至1708米/秒，在粗沉积物网站（HC，孔隙度=0.45），从1579至1585米/秒，在细粒沉积物网站（HF，孔隙度=0.56）。有效衰减随频率增加，HC从15 dB/m增加到75 dB/m，HF从22 dB/m增加到62 dB/m。在这些网站的声速值的范围内的文献中报道的相同孔隙度的硅酸盐砂。这些礁源碳酸盐砂的衰减值高于文献中报道的许多硅酸盐砂的衰减值，并且它们似乎与频率呈线性相关（<$=0.65f）。声速和衰减数据进行了比较，两个沉积物的地质声学模型，生物斯托尔和颗粒剪切（GS）的预测。在这两个模型中，两个未知参数变化，以找到最适合在每个网站：1）衰减和声速数据和2）声速数据。这两种模型产生了类似的拟合，这与测量数据有显着差异。
In situ compressional wave speed and attenuation measurements between 20 and 100 kHz were made at two carbonate sediment sites in Kaneohe Bay, on the windward side of the Hawaiian island of Oahu. Velocities increased with frequency from 1691 to 1708 m/s at a coarse sediment site (HC, porosity=0.45) and from 1579 to 1585 m/s at a fine-grained sediment site (HF, porosity=0.56). Effective attenuation increased with frequency from 15 to 75 dB/m at HC and from 22 to 62 dB/m at HF. Values of sound speed at these sites are within the range of those reported in the literature for silicate sands of the same porosity. Attenuation values of these reef-derived carbonate sands are higher than many of those reported in the literature for silicate sands and they appear to be linearly related to frequency (¿=0.65f). Sound-speed and attenuation data were compared to predictions of two sediment geoacoustic models, Biot-Stoll and grain shearing (GS). In both models, two unknown parameters were varied to find best fits at each site to: 1) both attenuation and sound-speed data and 2) sound-speed data only. Both models yielded similar fits, which differ significantly from the measured data.