气候变化领域集成服务门户(CCPortal): Temporal Modulation of the Local Microseism in the North Sea

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DOI	10.1029/2020JB019770
	Temporal Modulation of the Local Microseism in the North Sea
	Becker D.; Cristiano L.; Peikert J.; Kruse T.; Dethof F.; Hadziioannou C.; Meier T.
发表日期	2020
ISSN	21699313
卷号	125 期号:10
英文摘要	Primary and secondary microseism originating in the world oceans and peaking at around 14 and 7 s, respectively, characterize the Earth's background noise in that frequency range. Microseism generated in marginal seas with partly shorter periods and higher spatial and temporal variability is less studied and requires stations in immediate proximity to the source to be observed. Such studies can help to elucidate the exact microseism generation areas and mechanisms in a constrained area. We analyze 15 years of broadband data recorded at the seismic station on Helgoland island in the marginal North Sea. In addition to remote primary (RPM) and secondary microseism (RSM) originating in the North Atlantic, we observe strong and dominant local secondary microseism (LSM) with on average higher frequencies above 0.2 Hz, in accordance with shorter wave periods of about 4–8 s in the shallow North Sea. During times with low RSM activity we observe local primary microseism (LPM) at frequencies in agreement with local ocean wave periods. The higher horizontal to vertical (H/V) ratio of LPM with respect to LSM indicates a major non-Rayleigh wave contribution. LSM and LPM show a strong modulation with local semidiurnal ocean tides and microseism energy maxima preceding the water level maximum by 2.5 and 1.5 hr, respectively. This time shift might be influenced by stronger currents during rising than falling tides. Active sources of tide-modulated microseism migrate along the North Sea coast in sync with the ocean tidal signal as evidenced by comparison of LSM maxima at stations distributed along the coast. ©2020. The Authors.
英文关键词	ocean microseism; ocean tides; seismic noise; seismic noise sources
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187589
作者单位	Institute of Geophysics, Centre for Earth System Research and Sustainability (CEN), Universität Hamburg, Hamburg, Germany; Department of Geosciences, Christian-Albrechts-Universität zu Kiel, Kiel, Germany; Now at GFZ German Research Centre for Geosciences, Potsdam, Germany
推荐引用方式 GB/T 7714	Becker D.,Cristiano L.,Peikert J.,et al. Temporal Modulation of the Local Microseism in the North Sea[J],2020,125(10).
APA	Becker D..,Cristiano L..,Peikert J..,Kruse T..,Dethof F..,...&Meier T..(2020).Temporal Modulation of the Local Microseism in the North Sea.Journal of Geophysical Research: Solid Earth,125(10).
MLA	Becker D.,et al."Temporal Modulation of the Local Microseism in the North Sea".Journal of Geophysical Research: Solid Earth 125.10(2020).