THE TOHOKU TSUNAMI OF 11 MARCH 2011 AS RECORDED ON THE RUSSIAN FAR EAST

Abstract

The source region of the catastrophic Tohoku tsunami of 11 March 2011 was near the Russian Far East, thus a warning was issued for threatened coasts of the Kuril Islands and Kamchatka. The tsunami was clearly recorded by a number of coastal tide gauges and by bottom pressure stations (including the Russian DART 21401). The recordings by these instruments were used to estimate the major characteristics of the tsunami waves, including arrival times, maximum heights, duration of signals and main wavelength periods. Further analysis indicated significant differences in the spectral characteristics of the waves propagating eastward toward North America from those directed in a northwest direction, towards the Russian Far East. The main peaks of the eastward propagating tsunami waves were of relatively high frequency, while those propagating in a northwest direction, were mainly of low frequency. At far-field stations, the resonant periods associated with local topographic effects were predominant in the spectra.

Keywords

• tsunami
• open-ocean DART station
• coastal station
• arrival time
• maximum height
• spectra
• wavelet analysis