Propagating tsunami wave and subsequent resonant response signals detected by HF radar in the Kii Channel, Japan

Hinata, Hirofumi; Fujii, Satoshi; Furukawa, Keita; Kataoka, Tomoya; Miyata, Masafumi; Kobayashi, Takashi; Mizutani, Masahiro; Kokai, Takahiro; Kanatsu, Nobuyoshi

doi:10.1016/j.ecss.2011.08.009

Cited by 49 publications

(17 citation statements)

References 16 publications

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“…The velocity amplitudes of these waves increased again to 20 cm/s. This characteristic is similar to the waves seen in the Kii Channel (Hinata et al, ), which indicate a shift in the oscillation pattern.…”

Section: Spatiotemporal Variation Of Tsunami Wavessupporting

confidence: 82%

“…The 2011 Tohoku tsunami waves were observed by HF radars not only in the near field of the Japan coast (Hinata et al, 2011) but also in the far field, across the Pacific Ocean to the coast of Hawaii (Benjamin et al, 2016;Dzvonkovskaya et al, 2011;Lipa et al, 2011Lipa et al, , 2012a. Lipa et al (2011) described how HF radars installed in Hokkaido, Japan, and California detected the tsunami's approach by averaging the resolved radial velocities perpendicular to the depth contours.…”

Section: Introductionmentioning

confidence: 99%

“…Other tsunami detection techniques were examined by statistical methods (Fuji & Hinata, 2017) and the development of new algorithms for Doppler spectra of radar (Grilli et al, 2015). Hinata et al (2011) showed that the radial velocities and sea surface heights obtained from the Kii Channel, Japan, and its shelf indicated natural oscillations induced by the tsunami waves.…”

Section: Introductionmentioning

confidence: 99%

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Tsunami Waves and Tsunami‐Induced Natural Oscillations Determined by HF Radar in Ise Bay, Japan

2018

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Tsunami waves and the subsequent natural oscillations generated by the 2011 Tohoku earthquake were observed by two high‐frequency (HF) radars and four tidal gauge records in Ise Bay. The radial velocity components of both records increased abruptly at approximately 17:00 (JST) and continued for more than 24 h. This indicated that natural oscillations followed the tsunami in Ise Bay. The spectral analyses showed that the tsunami wave arrivals had periods of 16–19, 30–40, 60–90, and 120–140 min. The three longest periods were remarkably amplified. Time‐frequency analysis also showed the energy increase and duration of these periods. We used an Empirical Orthogonal Function (EOF) to analyze the total velocity of the currents to find the underlying oscillation patterns in the three longest periods. To verify the physical properties of the EOF analysis results, we calculated the oscillation modes in Ise Bay using a numerical model proposed by Loomis. The results of EOF analysis showed that the oscillation modes of 120–140 and 60–90 min period bands were distributed widely, whereas the oscillation mode of the 30–40 min period band was distributed locally. The EOF spatial patterns of each period showed good agreement with the eigenmodes calculated by the method of Loomis (1975). Thus, the HF radars were capable of observing the tsunami arrival and the subsequent oscillations.

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Section: Spatiotemporal Variation Of Tsunami Wavessupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Tsunami Waves and Tsunami‐Induced Natural Oscillations Determined by HF Radar in Ise Bay, Japan

2018

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“…The detection of tsunamis by HF radars was first proposed by (Barrick 1979), but it is only in the aftermath of the IO 2004 tsunami that this possibility was confirmed by numerical simulations (e.g., Lipa et al 2006;Heron et al 2008;Gurgel et al 2011;Fuji and Hinata 2017), and following the Tohoku 2011 tsunami in a posteriori reanalyses of radar data (e.g., Hinata et al 2011;Lipa et al 2011Lipa et al , 2012aBenjamin et al 2016). HF radars can measure properties of the ocean surface (e.g., radial surface current, significant wave height,...) beyond the horizon, over a large sweep area reaching up more than 100 km offshore (depending on frequency, antenna power, and environmental noise), with a ∼120 degree or greater aperture.…”

mentioning

confidence: 93%

Tsunami detection by high-frequency radar in British Columbia: performance assessment of the time-correlation algorithm for synthetic and real events

et al. 2018

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“…Once the tsunami velocity can be measured by the ship velocity component in the direction normal to the ship heading, it is worth carrying out inversion for real-time tsunami forecast to estimate source and tsunami height. Fuji et al (2013) examined a tsunami inversion/forecast experiment using pseudo observation of tsunami current derived from coastal ocean radars (Hinata et al 2011;Lipa et al 2012;Benjamin et al 2016). They employed the tsunami current instead of tsunami height for the inversion for the tsunami source.…”

Section: Tsunami Inversion/forecastmentioning

confidence: 99%

Measuring offshore tsunami currents using ship navigation records

Inazu

Ikeya

Waseda

et al. 2018

Prog Earth Planet Sci

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We investigated ship navigation records known as Automatic Identification System (AIS) data near the source region of the 2011 Tohoku, Japan, tsunami. The AIS data of 16 ships in the offshore navigation could be compiled by about 40 min after the tsunami generation. Most of the AIS data showed notable deviation of the ship heading from the course over ground during the tsunami passage. There was good agreement in terms of amplitude/phase between the ship velocity and the simulated tsunami velocity in the direction normal to the ship heading. An equation of motion due to wave drag and inertia forces was examined for an offshore movable floating body. We explain that the ship movement in the direction normal to the heading immediately responds to the tsunami current, and relative velocity between the ship and the tsunami current asymptotically become zero. This indicates the movement velocity of navigating ships in the direction normal to the heading derived from AIS data will work as an offshore tsunami current meter. We examined the AIS data during the 2011 Tohoku tsunami and showed these data could be useful for tsunami source estimation and forecast. The AIS data in the current framework will possibly be a crowd-sourced tool for monitoring offshore tsunami current and tsunami forecast.

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Propagating tsunami wave and subsequent resonant response signals detected by HF radar in the Kii Channel, Japan

Cited by 49 publications

References 16 publications

Tsunami Waves and Tsunami‐Induced Natural Oscillations Determined by HF Radar in Ise Bay, Japan

Tsunami Waves and Tsunami‐Induced Natural Oscillations Determined by HF Radar in Ise Bay, Japan

Tsunami detection by high-frequency radar in British Columbia: performance assessment of the time-correlation algorithm for synthetic and real events

Measuring offshore tsunami currents using ship navigation records

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