Characteristics of the 2011 Great Tohoku Tsunami on the Russian Far East Coast: Deep-Water and Coastal Observations

The source region of the catastrophic Tohoku tsunami of 11 March 2011 was not far from the Russian Far East coast. The Sakhalin Tsunami Warning Center at Yuzhno-Sakhalinsk issued an Alert for threatened coasts of the Kuril Islands and Kamchatka; the observed tsunami heights were up to 2–2.5 m along the Pacific coast of the Kuril Islands. The tsunami was clearly recorded by a number of coastal tide gauges and by deep-ocean bottom pressure stations located in the vicinity of the Kuril Islands, as well as by the Russian open-ocean DART station 21401, located eastward from the South Kuril Islands. The data from other DART stations, in particular those located near Japan and the Aleutian Islands, were used for comparison. The records from these instruments were used to estimate the major characteristics of the tsunami waves, including arrival times, maximum heights, durations of the signal and main wavelength periods, as well as for comparison with the results of numerical modelling. In contrast to deep-sea stations where the first waves were the highest, at Russian coastal sites the highest waves occurred several hours after the arrival of the first tsunami wave. Further analysis indicated significant differences in spectral characteristics of tsunami waves propagating eastward toward North America and those directed in the northeast direction towards the Russian Far East. The main peaks of the eastward propagating tsunami waves were relatively high-frequency (periods ranging from 6–8 to 15–20 min), while those propagating in the northeast direction were mainly low-frequency (ranging from 25–40 to 60–80 min). Additionally, pronounced spectral peaks with similar long periods were found in the “middle-field” records at Hanasaki (on the northeastern coast of Hokkaido Island), at Yuzhno-Kurilsk (Kunashir Island) and at Malokurilsk (Shikotan Island). At remote stations, the resonant periods associated with local topographic features were predominant in the spectra.

Год публикации: 2014

Ключевые слова: Tsunami measurements, tsunami warning service, Kuril Islands, long waves, resonant mode, tide gauges, bottom pressure stations, DART, spectral analysis, numerical modelling, tsunami source

Авторы: Shevchenko, G.V., Ivelskaya, T.N., Loskutov, A.V.

Библиографическая ссылка: Shevchenko, G.V., Ivelskaya, T.N., Loskutov, A.V. Characteristics of the 2011 great Tohoku tsunami on the Russian Far East coast: deep-water and coastal observations // Pure and Aapplied geophysics. – 2013. – Vol. 171., – № 12. – P. 3329-3350.

Исследование цунами по данным глубоководных и прибрежных регистраторов

Рассматриваются некоторые аспекты натурных измерений уровня моря на примере сети донных регистраторов ИМГиГ ДВО РАН в при-брежной зоне во взаимосвязи с регистрацией цунами в открытом океане системой DART. Отмечены возможности теоретического анализа длинных гравитационных волн по натурным записям и роль подобных измерений в проблеме заблаговременного предупреждения и моделирования цунами. Отражены некоторые результаты исследования цунами с использованием уровенных данных.

Год публикации: 2013

Ключевые слова: цунами, уровень моря, донный датчик, источник, DART, дисперсия, спектры, численное моделирование, запись, сигнал, вейвлеты.

Авторы: Лоскутов Артём Владимирович

Библиографическая ссылка: Лоскутов А.В. Исследование цунами по данным глубоководных и прибрежных регистраторов // Вестник ДВО РАН. – 2013. – Т.169, №3 – С.84-91.

Tsunami measurements in bays of Shikotan Island

Bottom pressure gauges deployed in bays of Shikotan Island (South Kuril Islands) recently recorded two tsunamis: the Simushir (Kuril Islands) tsunami of January 13, 2007 generated by a local earthquake with magnitude M w = 8.1 and the Peruvian tsunami of August 15, 2007 generated by a distant earthquake, M w = 8.0. The records enabled us to investigate the properties of these two tsunamis and to estimate the effect of the regional and nearshore topography on arriving tsunami waves. Eigen periods and spatial structure of resonant oscillations in particular bays were examined based on results of numerical modeling. Significant amplification of the fundamental (Helmholtz) resonant modes in Malokurilskaya Bay (19 min) and in Krabovaya Inlet (29 min) and some secondary modes was caused by the Simushir tsunami. The considerably different geometry and bottom topography of these bays, located on the inner coast of the island, determine the differences in their eigen periods; the only mutual peak, which was found in both basins, had a period of 5 min and was probably related to the source features. The Peruvian tsunami was clearly recorded by the bottom pressure gauge in Tserkovnaya Bay on the outer (oceanic) coast of the island. Three dominant periods in the tsunami spectrum at this bay were 60, 30 and 19 min; the latter period was found to be related to the fundamental mode of the bay, while the other two periods appear to be associated with the shelf resonant amplification of tsunami waves arriving in the region of the South Kuril Islands. The prevalence of low-frequency components in the observed tsunami spectrum is probably associated with the large extension of the initial source area and faster decay of short period waves during the long trans-oceanic tsunami propagation.

Год публикации: 2011

Ключевые слова: Tsunami measurements, Kuril Islands, long waves, Eigen oscillations, resonant mode, bottom pressure gauge, spectral analysis, seiches, numerical modeling

Авторы: Shevchenko G., Shishkin A., Bogdanov G., Loskutov A.

Библиографическая ссылка: 3. Shevchenko G., Shishkin A., Bogdanov G., Loskutov A. Tsunami measurements in bays of Shikotan Island // Pure and Applied Geophysics. – 2011. – Vol. 168. – P. 2011-2021.

Регистрация цунами у берегов Сахалина и Курильских островов

После продолжительного перерыва ИМГиГ ДВО РАН возобновил работы по экспериментальному изучению длинноволновых процессов у берегов Сахалина и Южных Курильских островов. В процессе измерений, выпол- ненных в 2006-2007 гг., получены записи Симуширского (15.11.2006 г.) и Невельского (02.08.2007 г.) цунами в порту г. Холмск, Симуширского цунами (13.01.2007 г.) в бухтах Крабовая и Малокурильская (о-в Шикотан), Перуанского цунами (16.08.2007 г.) в бухтах Малокурильская и Малая Церковная. В статье проанализированы особенности волнового режима, связанные с цунами и обусловленные характером топографии в районе поста- новки станции.

Год публикации: 2008

Авторы: Шевченко Г.В., Ковалев П.Д., Богданов Г.С., Шишкин А.А., Лоскутов А.В., Чернов А.Г.

Библиографическая ссылка: 1. Шевченко Г.В., Ковалев П.Д., Богданов Г.С., Шишкин А.А., Лоскутов А.В., Чернов А.Г. Регистрация цунами у берегов Сахалина и Курильских островов // Вестник ДВО РАН. – 2008. – № 6. – С. 23-33.