在北冰洋加拿大盆地正常发生的底部和下底部反射
Nicholas P Chotiros1, Matthew Dzieciuch2
1Applied Research Laboratories, The University of Texas at Austin, Texas, Austin 78758, USA.
The Journal of the Acoustical Society of America
|December 30, 2025
概括
北极海底反射是稳定的,每年有所变化. 底下分析揭示了潜在的气体水合物和粗的沉积物地下层接口,这对于了解北冰洋声学至关重要.
科学领域:
- 海洋学 海洋学 海洋学
- 地震学 地震学
- 声学 声学 在声学上
背景情况:
- 对北冰洋海底声学属性的分析对于了解水下声音传播至关重要.
- 之前的研究已经探讨了海底的反射性,但在深北极盆地进行的长期现场测量是有限的.
研究的目的:
- 用声信号分析北极海底的正常发射反射系数.
- 调查一年周期内底部和下底部反射的稳定性和可变性.
- 描述下底层,包括潜在的气体水合物和沉积物地下层接口.
主要方法:
- 来自配色声源和垂直线阵列的声学信号被使用.
- 从加拿大盆地的一个停泊处收集的数据 (约. 4000米深) 超过一年.
- 分析 35 Hz 的脉冲正弦波传输和记录的基带调节信号.
主要成果:
- 底部反射稳定,平均损失为13.5dB,每年变化较小 (0.15dB).
- 检测到三个低于底部的回报.
- 第一个底下回归表明底部模拟反射器具有相位逆转,可能是由于水合物层下方的自由气体.
- 在前两个亚底部回报的波动归因于不断变化的亚水化合物泡种群.
- 第三个下底回归显示出高变性,表明粗的沉积物-地下室接口.
结论:
- 北极海底在底部接口表现出稳定的声学反射性.
- 下底分析提供了气体水合物存在的证据和相关的自由气体.
- 海底下回报的变化凸显了海底下的动态过程,例如泡种群和接口粗度.
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