Articles | Volume 11, issue 5
Nat. Hazards Earth Syst. Sci., 11, 1499–1521, 2011

Special issue: New developments in tsunami science: from hazard to risk

Nat. Hazards Earth Syst. Sci., 11, 1499–1521, 2011

Research article 19 May 2011

Research article | 19 May 2011

Structure and performance of a real-time algorithm to detect tsunami or tsunami-like alert conditions based on sea-level records analysis

L. Bressan and S. Tinti L. Bressan and S. Tinti
  • Physics Department, University of Bologna, Bologna, Italy

Abstract. The goal of this paper is to present an original real-time algorithm devised for detection of tsunami or tsunami-like waves we call TEDA (Tsunami Early Detection Algorithm), and to introduce a methodology to evaluate its performance. TEDA works on the sea level records of a single station and implements two distinct modules running concurrently: one to assess the presence of tsunami waves ("tsunami detection") and the other to identify high-amplitude long waves ("secure detection"). Both detection methods are based on continuously updated time functions depending on a number of parameters that can be varied according to the application. In order to select the most adequate parameter setting for a given station, a methodology to evaluate TEDA performance has been devised, that is based on a number of indicators and that is simple to use. In this paper an example of TEDA application is given by using data from a tide gauge located at the Adak Island in Alaska, USA, that resulted in being quite suitable since it recorded several tsunamis in the last years using the sampling rate of 1 min.