Double-Frequency Microseisms on the Thick Unconsolidated Sediments in Eastern and Southeastern Coasts of United States: Sources and Applications on Seismic Site Effect Evaluation  

作　　者：Zhen Guo Yu Huang Adnan Aydin 

机构地区：[1]College of Civil Engineering,Tongji University,Shanghai 200092,China [2]Shanghai Sheshan National Geophysical Observatory,Shanghai 201602,China [3]Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China [4]Department of Geology and Geological Engineering,the University of Mississippi,MS 38677,USA

出　　处：《Journal of Earth Science》2021年第5期1190-1201,共12页地球科学学刊（英文版）

摘　　要：This study presents a systematic analysis of double-frequency(DF) microseisms recorded on the unconsolidated sediments in the eastern and southeastern coasts of United States. For all recordings, the site effect parameters(predominant frequency(f_(0)), amplification factor and unconsolidated sediment thickness(UST)) are obtained by Nakamura method and the DF spectra are classified into five groups in terms of the DF peak patterns and the recording locations relative to the coastline. The frequencies and energy levels of the DF peaks in horizontal direction and the amplification factors are associated with the UST which is resulted from seismic site effect. By polarization analysis, the primary vibration directions of the DF peaks are identified and presented as great circles passing through the recording stations intersecting mainly along the continental slope. Correlation analyses of time histories of the DF energy and the ocean wave climate observed at buoys show that the low(<0.2 Hz) and high(>0.2 Hz) frequency DF microseisms are generated in the deep ocean and the continental shelf respectively. It is concluded that the continental slope plays a significant role in the generation of DF microseisms as it causes reflection of waves from the open ocean, initiating standing waves.

关 键 词：seismic site effect double-frequency microseisms unconsolidated sediments continental slope ocean wave 

分 类 号：TU435[建筑科学—岩土工程]