南海浅海海底沉积物的声衰减

Seabed sediment acoustic attenuation in shallow seas of the South China Sea

报道了南海浅海海底沉积物的声衰减性质。给出了测量和计算海底沉积物声衰减的方法。分析讨论了不同频率下的声衰减以及与若干个海底沉积物物理参数的关系，结果表明，同一类型沉积物在高频段时的声衰减要比低频段的声衰减大；同一频段下粗颗粒沉积物的声衰减要比细颗粒的声衰减大；北部湾海底浅层沉积物声衰减在低频100kHz下为80～150dB／m，在高频1MHz下为150～360dB／m；海南岛南部外海海底浅层沉积物声衰减在低频下为66～160dB／m，在高频1MHz下为190～350dB／m；高频段的数据与台湾海峡北部海底表层沉积物声衰减测量分析数据比较接近，而低频段的数据与台湾海峡北部海底表层沉积物声衰减测量分析数据有较大的差别。

Seabed sediment acoustic attenuation properties in shallow seas of the South China Sea were reported, a new way to measure and calculate the seabed sediment acoustic attenuation was presented, the results from two different frequencies were analyzed and the relation among several physical parameters of seabed sediment was discussed. Results show that the acoustic attenuation at the high frequency is much higher than that at the low frequency in the same type sediment; the acoustic attenuation of coarse granule sediment is higher than that of fine-particle sediment at the same measuring frequency. The acoustic attenuation is respectively 80～150 / 150～360 dB/m at low/high frequencies in the shallow sea seabed sediment of the Beibu Gulf and in the shallow sea seabed sediment of the southern Hainan Province, and the attenuation result is respectively 66～160 / 190～350 dB/m at low / high measuring frequencies. Comparing results with data from acoustic attenuation measurement of surface sediments in the northern Taiwan Strait, the data at the high frequency approach to it, but other data at the low frequency have much difference from it.