ISTerre, CNRS, Université de Savoie, Campus Scientifique, 73376 Le Bourget du Lac Cedex, France.
J Acoust Soc Am. 2012 Jan;131(1):80-91. doi: 10.1121/1.3662051.
The dispersion of flexural waves propagating in the Arctic sea ice cover is exploited in order to locally measure the ice thickness. The observed dispersion, for waves filtered in the 4-20 s period interval, at up to 4 broad-band seismometers deployed in Spring 2007 near the North Pole, is compared to a parameterized model that accounts for a complex wavefield made of a superposition of independent plane waves with different amplitudes and back-azimuth angles. The parameterization, that includes finding the best modeled ice thickness, is performed by using the cross-correlation functions between the seismometers. The ice thickness is estimated to 2.5 ± 0.2 m for the ~1 km-large floe the seismic stations were deployed on, which is coherent with other, independent measurements at this site. This study thus demonstrates the feasibility of using broad-band seismometers deployed on the sea-ice in order to passively measure the ice thickness, without requiring active sources nor human intervention.
利用在北极海域冰层中传播的弯曲波的频散特性，可以局部测量冰层厚度。在 2007 年春季，我们在北极附近使用多达 4 个宽带地震仪，在 4-20 秒的时间段内对波进行滤波，将观测到的频散与一个参数化模型进行了比较，该模型考虑了由具有不同幅度和背向方位角的独立平面波叠加而成的复杂波场。该参数化模型包括寻找最佳模拟冰层厚度，通过地震仪之间的互相关函数来实现。对于地震台站所在的约 1 公里大小的浮冰块，估计冰层厚度为 2.5 ± 0.2 米，这与该地点的其他独立测量结果一致。因此，本研究证明了在海冰上部署宽带地震仪以被动测量冰层厚度的可行性，无需使用主动源或人工干预。
