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

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

机构地区：[1]State Key Laboratory of Submarine Geoscience,Hangzhou,310012,China [2]Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou,310012,China [3]Geology and Geophysics Program,Missouri University of Science and Technology,Rolla,MO,65409,USA [4]State Key Laboratory of Marine Geology,School of Ocean and Earth Science,Tongji University,Shanghai,200092,China

出　　处：《Science China Earth Sciences》2025年第4期1223-1235,共13页中国科学(地球科学英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42330308,42406069);the Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(Grant Nos.QNRC2201,JB2401);the Zhejiang Provincial Natural Science Foundation(Grant Nos.LR24D060001,LZ23D060004)。

摘　　要：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(JASMIn E)in August 2021.In the period band of single frequency microseisms(10–20 s),typically produced by ocean waves directly impacting coastlines,no prominent spectral peaks are observed.In the double frequency microseism(DFM)period band(2–10 s),spectral powers are far less energetic than those in the open oceans by approximately 20–40 dB,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 shortperiod DFM band of 2–5 s,which can be attributed to local DFM amplification caused by the thick unconsolidated sediment layer.

关 键 词：MICROSEISMS Gakkel Ridge Arctic Ocean Ocean bottom seismometer Seismic ambient noise 

分 类 号：P73[天文地球—海洋科学]