A dislocation model of the 1933 Sanriku earthquake consistent with the tsunami waves.

Abe, Kuniaki

doi:10.4294/jpe1952.26.381

Cited by 21 publications

(13 citation statements)

References 11 publications

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“…Several outer‐rise earthquakes with normal fault mechanism that generated large tsunami occurred in March 1933 in Sanriku, Japan ( Mw 8.4) [ Kanamori , ; Abe , ], August 1977 in Sumba ( Mw 8.2) [ Gusman et al ., ], January 2007 at Kuril Islands ( Mw 8.0) [ Tanioka et al ., ], and September 2009 at Samoa Islands ( Mw 8.1) [ Lay et al ., ; Tonini et al ., ]. An outer‐rise earthquake with reverse fault mechanism occurred on 31 August 2012 in the Philippines ( Mw 7.6) (USGS) generated a small tsunami.…”

Section: Discussionmentioning

confidence: 99%

A methodology for near‐field tsunami inundation forecasting: Application to the 2011 Tohoku tsunami

et al. 2014

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Existing tsunami early warning systems in the world can give either one or a combination of estimated tsunami arrival times, heights, or qualitative tsunami forecasts before the tsunami hits near-field coastlines. A future tsunami early warning system should be able to provide a reliable near-field tsunami inundation forecast on high-resolution topography within a short time period. Here we describe a new methodology for near-field tsunami inundation forecasting. In this method, a precomputed tsunami inundation and precomputed tsunami waveform database is required. After information about a tsunami source is estimated, tsunami waveforms at nearshore points can be simulated in real time. A scenario that gives the most similar tsunami waveforms is selected as the site-specific best scenario and the tsunami inundation from that scenario is selected as the tsunami inundation forecast. To test the algorithm, tsunami inundation along the Sanriku Coast is forecasted by using source models for the 2011 Tohoku earthquake estimated from GPS, W phase, or offshore tsunami waveform data. The forecasting algorithm is capable of providing a tsunami inundation forecast that is similar to that obtained by numerical forward modeling but with remarkably smaller CPU time. The time required to forecast tsunami inundation in coastal sites from the Sendai Plain to Miyako City is approximately 3 min after information about the tsunami source is obtained. We found that the tsunami inundation forecasts from the 5 min GPS, 5 min W phase, 10 min W phase fault models, and 35 min tsunami source model are all reliable for tsunami early warning purposes and quantitatively match the observations well, although the latter model gives tsunami forecasts with highest overall accuracy. The required times to obtain tsunami forecast from the above four models are 8 min, 9 min, 14 min, and 39 min after the earthquake, respectively, or in other words 3 min after receiving the source model. This method can be useful in developing future tsunami forecasting systems with a capability of providing tsunami inundation forecasts for locations near the tsunami source area.

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Section: Discussionmentioning

confidence: 99%

A methodology for near‐field tsunami inundation forecasting: Application to the 2011 Tohoku tsunami

et al. 2014

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“…As previously outlined, many source models have been proposed for the 2011 event (e.g., Ammon et al 2011;Koper et al 2011;Fujii et al 2011;Romano et al 2012;Yokota et al 2012;Satake et al 2013); The source model of Satake et al (2013) was adopted in the present study for the simulation of the tsunami because their source model reproduces better offshore wave profiles of the tsunami. The characteristics of the other two sources have also been investigated based on observed earthquake and tsunami records (e.g., Obana et al 2017;Satake et al 2017;Okal et al 2016;Abe 1973Abe , 1978. Kanamori (1971), for example, proposed a source model of the 1933 event based on observed seismic data.…”

Section: Numerical Modeling Of Tsunami Propagation and Inundationmentioning

confidence: 99%

“…Kanamori (1971), for example, proposed a source model of the 1933 event based on observed seismic data. However, Abe (1978) demonstrated that Kanamori's model (1971) was insufficient in explaining the initial motion of the 1933 tsunami that was observed on the Sanriku coast and proposed a new source model. Okal et al (2016) developed a source model of the event that considered the aftershock distribution according to the earthquake and global tsunami records.…”

Section: Numerical Modeling Of Tsunami Propagation and Inundationmentioning

confidence: 99%

Frequency-dependent amplification of the Sanriku tsunamis in Ryori Bay

Yamanaka

Nakamura

2020

Earth Planets Space

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In the present study, the local tsunami amplification observed in Ryori Bay, located on the Sanriku coast of Japan, was investigated using numerical simulations. Large-scale tsunami propagation simulations and tsunami inundation simulations for the bay were systematically conducted to estimate and model the 2011, 1933, and 1896 tsunamis that occurred off the Sanriku coast and which resulted in large run-ups. The simulation results, which are moderately consistent with observations, presented larger run-up heights and inundations for the 1933 and 1896 tsunamis (which followed relatively small earthquakes) compared to those of the 2011 tsunami (which followed a larger earthquake). Furthermore, the frequency analysis indicated that the former two tsunamis comprised higher predominant components. A tsunami inundation simulation using parametrized synthetic waveforms was conducted to identify the contributing factors associated with the large amplification and run-ups. The results indicated that the predominant components are significantly amplified in the bay and the initial decrease in the water surface elevation prior to the primary waves of the two tsunamis leads to an increase in their run-up heights. Furthermore, the simulated waveforms of the tsunamis revealed that the 1933 and 1896 tsunamis had their wavefronts changed into a steep wavefront, i.e., a bore-like wave, during their wave developments in the bay, attributed to shoaling, narrowing bay width, and the nonlinear effect of the wave. These results, therefore, indicate that bores which are known to generate large run-up heights were generated in the bay during the two tsunamis.

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“…On the other hand, if we assume a shortening ratio consistent with GPS observation (− 0.10 ppm/year), baseline change due to the 1894 Shonai earthquake reduces to about − 19 mm (− 3.7 ppm). From GPS observation, the interseismic (2005) 1933/3/3 Sanriku 8.4 − 3.5 − 3.0 Abe (1978) 1936/11/3 Miyagi-oki 7.2 + 0.6 + 0.1 Yamanaka and Kikuchi (2004) 1937/7/27 Miyagi-oki 7.1 + 0.1 0.0 Yamanaka and Kikuchi (2004) 1938/5/23-1938/11/7 Shioyazaki-oki 7.0, 7.5, 7.3,7.4, 6.9 − 0.6 − 0.4 Abe (1977 1962/4/30 Northern Miyagi 6.2 + 0.5 + 0.6 Sato (1989) 1964/6/16 Niigata 7.6 + 8.0 + 3.0 Abe (1975) 1968/5/16 Tokachi-oki 8.2 − 0.4 − 0.5 Aida (1978) 1970/10/16 SE Akita 6.2 − 0.2 0.0 Mikumo (1974) 1978/6/12 Miyagi-oki 7.5 + 1.5 − 0.5 Seno et al (1980) 1983/5/26 Japan Sea 7.7 − 1.1 − 0.4 Sato (1985) 2003 / shortening ratio can be as small as 0 based on GPS observation before 2011. However, if we assume no interseismic deformation, coseismic length change of the 1894 Shonai earthquake is estimated to be negative, which we consider unlikely.…”

Section: Re-survey Of the Shionohara Baselinementioning

confidence: 99%

Triangulation scale error caused by the 1894 Shonai earthquake: a possible cause of erroneous interpretation of seismic potential along the Japan Trench

Sagiya

Matta

Ohta

2018

Earth Planets Space

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Horizontal crustal strain in the Tohoku area during the twentieth century based on triangulation showed N-S extension and E-W contraction was not significant. This feature was one of the reasons why the 2011 Tohoku-oki earthquake was unexpected for many scientists. The first triangulation conducted in the late nineteenth century used a length scale defined by baseline surveys, direct measurements of short (2-10 km) baselines with steel rods. The Shionohara baseline in the Yamagata prefecture was measured in May-July 1894 and the 1894 Shonai (M7.0) earthquake occurred in its western neighbor 3 months after the measurement. The earthquake possibly elongated the baseline by as large as 5 cm or 10 ppm. However, the original length measured before the earthquake was used for the network adjustment of the entire triangulation network, causing extensive underestimation of the length scale of the network as large as 5-10 ppm in northeast Japan. The scale error effect was comparable to tectonic deformation signal over 100 years. The baseline length was re-surveyed in 2012, 1 year after the Tohoku-oki earthquake, and the result is consistent with the hypothesis of scale bias considering interseismic deformation.

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A dislocation model of the 1933 Sanriku earthquake consistent with the tsunami waves.

Cited by 21 publications

References 11 publications

A methodology for near‐field tsunami inundation forecasting: Application to the 2011 Tohoku tsunami

A methodology for near‐field tsunami inundation forecasting: Application to the 2011 Tohoku tsunami

Frequency-dependent amplification of the Sanriku tsunamis in Ryori Bay

Triangulation scale error caused by the 1894 Shonai earthquake: a possible cause of erroneous interpretation of seismic potential along the Japan Trench

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