Detecting the 11 March 2011 Tohoku tsunami arrival on sea-level records in the Pacific Ocean: application and performance of the Tsunami Early Detection Algorithm (TEDA)

Abstract

Abstract. Real-time detection of a tsunami on instrumental sea-level records is quite an important task for a Tsunami Warning System (TWS), and in case of alert conditions for an ongoing tsunami it is often performed by visual inspection in operational warning centres. In this paper we stress the importance of automatic detection algorithms and apply the TEDA (Tsunami Early Detection Algorithm) to identify tsunami arrivals of the 2011 Tohoku tsunami in a real-time virtual exercise. TEDA is designed to work at station level, that is on sea-level data of a single station, and was calibrated on data from the Adak island, Alaska, USA, tide-gauge station. Using the parameters' configuration devised for the Adak station, the TEDA has been applied to 123 coastal sealevel records from the coasts of the Pacific Ocean, which enabled us to evaluate the efficiency and sensitivity of the algorithm on a wide range of background conditions and of signal-to-noise ratios. The result is that TEDA is able to detect quickly the majority of the tsunami signals and therefore proves to have the potential for being a valid tool in the operational TWS practice.

A new real‐time tsunami detection algorithm

“…Successively, Bressan and Tinti [] proposed estimating the long‐term average slope induced by the tide signal within the sea level record using first‐order polynomial fitting, and then comparing this slope to the short‐term average slope of the time series. In a successive paper, this technique was applied to the March 2011 Tohoku tsunami tide gauges data [ Bressan and Tinti , ].…”

Evaluating HF Coastal Radar Site Performance for Tsunami Warning

“…Equations (8) and (9) represent two equations in two unknowns: the tsunami wave height and the orbital velocity. These can be combined to eliminate either of the unknowns, resulting in a second-order partial differential equation, either for the tsunami shallow-water wave height or the wave orbital velocity.…”

“…The detection of the earthquake itself of course gave a general warning of the danger, but in this case, no local warning of the magnitude of the impending disaster was available. There are now many methods used in tsunami detection: the continuous monitoring of seismic events with modeling, changes in the tide level, detection by open-ocean buoys and coastal tide gauges and by using pressure recorders located on the ocean floor [1][2][3][4][5][6][7][8][9][10][11]. In this paper, we describe the quantitative modeling of local tsunami behavior and its detection using a shore-based HF radar system.…”

Tsunami arrival time detection system applicable to discontinuous time series data with outliers

“…Because the DART algorithm does not provide information on tsunami height but only on arrival time, Beltrami (2011) extended the length of the interval between the actual and prediction times. Bressan and Tinti (2012) proposed a tsunami early detection algorithm (TEDA) designed to detect an anomalous water level based on two slope-based algorithms: tsunami detection and secure detection. The TEDA was successfully calibrated and tested on both synthetic tsunamis and historical tsunami records (Bressan and Tinti, 2012;Bressan et al, 2013).…”

“…Bressan and Tinti (2012) proposed a tsunami early detection algorithm (TEDA) designed to detect an anomalous water level based on two slope-based algorithms: tsunami detection and secure detection. The TEDA was successfully calibrated and tested on both synthetic tsunamis and historical tsunami records (Bressan and Tinti, 2012;Bressan et al, 2013). Pérez et al (2013) introduced a real-time automatic tsunami detection algorithm based on a variance method that was developed within the TRANSFER (Tsunami Risk and Strategies for the European Region) project.…”