美国密苏里科技大学Fansheng KONG团队研究了北冰洋盖克尔海脊的微震：JASMInE海底地震实验结果。相关论文于2025年3月18日发表在《中国科学：地球科学》杂志上。

为了表征北冰洋的大洋中部微震并探索北极变暖的潜在地震环境噪声印记，研究组分析了2021年8月北极科学联合大洋中脊洞察探险（JASMInE）期间沿东盖克尔海脊部署的九个海底地震仪（OBS）的地震记录。在单频微震的周期带（10-20秒）内，通常由直接撞击海岸线的海浪产生，没有观察到明显的光谱峰值。

在双频微震（DFM）周期带（2-10秒）内，光谱功率比开阔海洋中的能量低约20-40 dB，特别是对于部署在盖克尔海脊轴外的OBS。这种极弱的DFM可归因于常年海冰覆盖的存在，这阻碍了大气与海洋的相互作用，从而阻碍了DFM的产生。根据瑞利波的极化分析以及DFM功率和海浪高度的相关性，海底记录的弱DFM可能来自巴伦支海北部和邻近地区。作为北极变暖的热点，巴伦支海北部从北极内部输入的海冰正在减少，这增强了大气与海洋的相互作用。

在该地区，海洋数据记录的方向变化很大的风驱动波和常年海冰覆盖的存在可能会促进沿几乎相反方向传播的波列的形成，这种非线性相互作用激发了DFM。这些DFM在传播过程中由于地震衰减而不断失去功率，变得如此微弱，以至于部署在山脊轴外的OBS在DFM周期带中没有检测到明显的光谱峰值。相比之下，沿脊轴的OBS在2-5s的短周期DFM带中显示出更高的能量，这可归因于厚松散沉积层引起的局部DFM放大。

附：英文原文

Title: Microseisms at the Gakkel Ridge, Arctic Ocean: Results from the JASMInE ocean bottom seismic experiment

Author: Zhangju LIU, Jiabiao LI, Fansheng KONG, Xiongwei NIU, Weiwei DING, Tao ZHANG, Pingchuan TAN, Yulong ZHOU, Mei XUE, Yinxia FANG

Issue&Volume: 2025/03/18

Abstract: To characterize mid-ocean microseisms in the Arctic Ocean and explore potential seismic ambient noise imprint of Arctic warming, this study analyzes seismic records from nine ocean bottom seismometers (OBSs) deployed along the eastern Gakkel Ridge during the Joint Arctic Scientific Middle-ocean ridge Insight Expedition (JASMInE) in August 2021. In the period band of single frequency microseisms (10–20s), typically produced by ocean waves directly impacting coastlines, no prominent spectral peaks are observed. In the double frequency microseism (DFM) period band (2–10s), spectral powers are far less energetic than those in the open oceans by approximately 20–40dB, especially for OBSs deployed off the Gakkel Ridge axis. This dramatically weak DFMs can be attributed to the presence of the perennial sea-ice cover, which hinders atmosphere-ocean interactions and thus obstructs the generation of DFMs. Based on polarization analyses of Rayleigh waves and correlations of DFM power and ocean wave height, the weak DFMs recorded on the seafloor likely originate from the northern Barents Sea and adjacent regions. As an Arctic warming hotspot, the northern Barents Sea is experiencing reduced sea-ice import from the interior Arctic which enhances atmosphere-ocean interactions. In this region, wind-driven waves with highly variable directions as documented by oceanographic data and the presence of the perennial sea-ice cover may promote the formation of wave trains propagating in nearly opposite directions, which nonlinear interactions excite DFMs. These DFMs continuously lose power due to seismic attenuation during propagation, becoming so weak that the OBSs deployed off the ridge axis detect no noticeable spectral peaks in the DFM period band. The OBSs along the ridge axis, by contrast, reveal more energetic power in the short-period DFM band of 2–5s, which can be attributed to local DFM amplification caused by the thick unconsolidated sediment layer.

DOI: 10.1007/s11430-024-1528-7

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-024-1528-7