Records of the tsunami induced by the 2010 Chilean earthquake from Xiaoqushan seafloor observatory in the East China Sea

Abstract

Sea-level variation can be induced by periodic tides, stochastic wind, air pressure, and swell. Larger sea-level variation has the potential to cause coastal disasters. In this paper, real-time continuous data obtained by the Xiaoqushan seafloor observatory in the East China Sea were analyzed employing frequency power spectral and tidal harmonic methods to extract the major components and periodicities of sea-level change. The sea-level anomaly (sla) was calculated by subtracting the tidal components from the observed sea level data. In the study period, the correlation between sla and the local north-south wind speed was high with a correlation coefficient of 0.65 at the 95% confidence level. The local wind-induced sea-level anomaly (sla wind ) was therefore computed through linear fitting. Although sla wind is one of the main components of sla, the residual sea-level anomaly (sla residual ) obtained by subtracting sla wind from sla is not zero, suggesting that there are other factors besides wind. Detailed analysis of the sea-level data at the time of the 8.8-magnitude Chilean earthquake on February 27, 2010 showed a peak sla residual value of 0.48 m at around 15:00 on February 28, which was highly coincident with the tsunami arrival time forecast by the Pacific Tsunami Warning Center. The peak sla residual event is therefore linked with the tsunami induced by the 2010 Chilean earthquake. This is the first time that a tsunami has been detected using real-time continuous data recorded by a seafloor observatory in the sea off China. Such observations are expected to improve tsunami forecast models and promote the development of a tsunami warning system and a seafloor observatory network in the East China Sea. sea-level anomaly, seafloor observatory, tide, wind, Chilean earthquake Citation:

A Sensor Control Model for Cabled Seafloor Observatories in the East China Sea

“…An initial analysis of some in situ observation data sets from the Xiaoqushan Seafloor Observatory demonstrated that long-term measurements contributed to comprehensive studies on the mechanisms of ocean dynamics and environmental variations under different weather conditions [ 23 ]. Another initial outcome was the observatory data record and analysis of the tsunami induced by the 2010 Chilean earthquake [ 32 ], which also confirmed the practical performance of ESOCS from the perspective of data acquisition and application.…”

Development of a Plug-and-Play Monitoring System for Cabled Observatories in the East China Sea

“…An initial analysis of some in situ observation data sets from the Xiaoqushan Seafloor Observatory [ 13 ] demonstrated that the long-term measurements contributed to comprehensive studies on the mechanisms of ocean dynamics and environmental variations under different weather conditions. Another initial outcome was the observatory data record and analysis of the tsunami induced by the 2010 Chilean earthquake [ 27 ], which also confirmed the practical performance of ESOMS from the perspective of data provision and usage. In this study, data sets obtained by the Xiaoqushan Seafloor Observatory were analyzed to extract periodicities of sea-level change and sea level anomaly (sla) was calculated based on the observed sea level data.…”

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