JpGU-AGU Joint Meeting 2017

講演情報

[EJ] ポスター発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG71] [EJ] 海洋底地球科学

2017年5月24日(水) 13:45 〜 15:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:沖野 郷子(東京大学大気海洋研究所)

[SCG71-P18] Estimating bottom current velocities from ocean-bottom-seismometer records

*Simon C Staehler1,2Mechita Schmidt-Aursch3Wolfgang Roeder1Robert Mars1 (1.Leibniz-Institute for Baltic Sea Research, Rostock, Germany、2.Ludwig Maximilians University of Munich, Germany、3.Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany)

キーワード:Ocean bottom seismology, Benthic zone, Currents

Current velocities in the lowermost meters of the ocean are poorly understood and not often measured. At the same time, they strongly affect the stability of benthic ecosystems.
Ocean-bottom-seismometers (OBS) are long-term installations of seismic sensors on the sea floor, which typically last for months and which have covered various parts of the global oceans in the last decades. The German OBS type LOBSTER has a peculiar design choice in the form of a ten-meter long head buoy cable that is very susceptible to current strumming. While this signal may be a nuisance for seismological observations, it does contain information: We present a method to estimate the current velocity in the lowermost ten meters from the noise created by that cable and compare noise-estimated current velocities with measurements of a colocated acoustic profiler.
Since this seismometer type has been widely used in different settings and depths worldwide in the last decade, this data may be a valuable and completely novel observable for physical oceanography and biology.