scholarly journals Influence of normal tide and the Great Tsunami as recorded through hourly-resolution micro-analysis of a mussel shell

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuji Sano ◽  
Tomoyo Okumura ◽  
Naoko Murakami-Sugihara ◽  
Kentaro Tanaka ◽  
Takanori Kagoshima ◽  
...  
Keyword(s):  
Tohoku Earthquake ◽  
Organic Layer ◽  
Growth Line ◽  
Mussel Shell ◽  
The 2011 Tohoku Earthquake ◽  
Northeastern Japan ◽  
The Pacific ◽  
Endogenous Clock ◽  
Mediterranean Mussel ◽  
Cyclic Changes

AbstractWe report here hourly variations of Mg/Ca, Sr/Ca, and Ba/Ca ratios in a Mediterranean mussel shell (Mytilus galloprovincialis) collected at the Otsuchi bay, on the Pacific coast of northeastern Japan. This bivalve was living in the intertidal zone, where such organisms are known to form a daily or bidaily growth line comprised of abundant organic matter. Mg/Ca ratios of the inner surface of the outer shell layer, corresponding to the most recent date, show cyclic changes at 25–90 μm intervals, while no interpretable variations are observed in Sr/Ca and Ba/Ca ratios. High Mg/Ca ratios were probably established by (1) cessation of the external supply of Ca and organic layer forming when the shell is closed at low tide, and (2) the strong binding of Mg to the organic layer, but not of Sr and Ba. Immediately following the great tsunami induced by the 2011 Tohoku earthquake, Mg/Ca enrichment occurred, up to 10 times that of normal low tide, while apparent Ba/Ca enrichment was observed for only a few days following the event, therefore serving a proxy of the past tsunami. Following the tsunami, periodic peaks and troughs in Mg/Ca continued, perhaps due to a biological memory effect as an endogenous clock.

Hourly-resolution Analysis of a Mussel Shell: Influence of Normal Tide and the Great Tsunami

2021 ◽  
Author(s):  
Yuji Sano ◽  
Tomoyo Okumura ◽  
Naoko Murakami-Sugihara ◽  
Kentaro Tanaka ◽  
Takanori Kagoshima ◽  
...  
Keyword(s):  
Tohoku Earthquake ◽  
Growth Line ◽  
Mussel Shell ◽  
The 2011 Tohoku Earthquake ◽  
Northeastern Japan ◽  
The Pacific ◽  
Endogenous Clock ◽  
Mediterranean Mussel ◽  
Resolution Analysis ◽  
Cyclic Changes

Abstract We report here hourly variations of Mg/Ca, Sr/Ca and Ba/Ca ratios in a Mediterranean mussel shell (Mytilus galloprovincialis) collected at the Otsuchi bay, on the Pacific coast of northeastern Japan. This bivalve was living in the intertidal zone, where such organisms are known to form a daily or bidaily growth line comprised of abundant organic matter. Mg/Ca ratios of the inner surface of the outer shell layer, corresponding to the most recent date, show cyclic changes at 25-90 mm intervals, while no valuable variations are observed in Sr/Ca and Ba/Ca ratios. High Mg/Ca ratios were probably established when the bivalve was located at low tide with a reduced supply of Ca from seawater. Immediately following the great tsunami induced by the 2011 Tohoku earthquake, Mg/Ca enrichment occurred, up to 10 times that of normal low tide, while apparent Ba/Ca enrichment was observed for only a few days following the event, implementing a proxy of the past tsunami. Following the tsunami, periodic peaks and troughs in Mg/Ca continued, perhaps due to a biological memory effect as an endogenous clock.

scholarly journals Middle-Scale Ionospheric Disturbances Observed by the Oblique-Incidence Ionosonde Detection Network in North China after the 2011 Tohoku Tsunamigenic Earthquake

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 1000
Author(s):  
Jin Wang ◽  
Gang Chen ◽  
Tao Yu ◽  
Zhongxin Deng ◽  
Xiangxiang Yan ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Oblique Incidence ◽  
North China ◽  
Tohoku Earthquake ◽  
Ionospheric Disturbances ◽  
Doppler Measurement ◽  
The 2011 Tohoku Earthquake ◽  
Tsunamigenic Earthquake ◽  
The Pacific ◽  
The Pacific Ocean

The 2011 Tohoku earthquake and the following enormous tsunami caused great disturbances in the ionosphere that were observed in various regions along the Pacific Ocean. In this study, the oblique-incidence ionosonde detection network located in North China was applied to investigate the inland ionospheric disturbances related to the 2011 tsunamigenic earthquake. The ionosonde network consists of five transmitters and 20 receivers and can monitor regional ionosphere disturbances continuously and effectively. Based on the recorded electron density variations along the horizontal plane, the planar middle-scale ionospheric disturbances (MSTIDs) associated with the 2011 Tohoku tsunamigenic earthquake were detected more than 2000 km west of the epicenter about six hours later. The MSTIDs captured by the Digisonde, high-frequency (HF) Doppler measurement, and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellite provided more information about the far-field inland propagation characteristics of the westward propagating gravity waves. The results imply that the ionosonde network has the potential for remote sensing of ionospheric disturbances induced by tsunamigenic earthquakes and provide a perspective for investigating the propagation process of associated gravity waves.

scholarly journals Seawater-leaching Testing for Arsenic and Heavy Metals in Tsunami Deposits Produced by the 2011 off the Pacific Coast of Tohoku Earthquake, Northeastern Japan

2014 ◽  
Vol 123 (6) ◽  
pp. 835-853 ◽  
Author(s):  
Takahiro WATANABE ◽  
Noriyoshi TSUCHIYA ◽  
Shin-ichi YAMASAKI ◽  
Ryoichi YAMADA ◽  
Nobuo HIRANO ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Pacific Coast ◽  
Tohoku Earthquake ◽  
Tsunami Deposits ◽  
Northeastern Japan ◽  
The Pacific

Nutrient status of Otsuchi Bay (northeastern Japan) following the 2011 off the Pacific coast of Tohoku Earthquake

2015 ◽  
Vol 72 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Hideki Fukuda ◽  
Ryosuke Katayama ◽  
Yanhui Yang ◽  
Hiroyuki Takasu ◽  
Yuichiro Nishibe ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Tohoku Earthquake ◽  
Nutrient Status ◽  
Otsuchi Bay ◽  
Northeastern Japan ◽  
The Pacific

Site-Specific Behavior of 2011 Tohoku Earthquake Tsunami Influenced by Artificial Changes of Coastal Environments

2012 ◽  
Vol 7 (sp) ◽  
pp. 485-490
Author(s):  
Chiharu Mizuki ◽  
◽  
Kazuomi Hirakawa ◽  
Keyword(s):  
Land Use ◽  
Pacific Coast ◽  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
Coastal Environments ◽  
Specific Behavior ◽  
The 2011 Tohoku Earthquake ◽  
Site Specific ◽  
The Pacific ◽  
Artificial Changes

Many aspects affect local tsunami behavior. A drastic change in behavior in the 2011 Tohoku Earthquake at specific sites in relation to coastal conditions in Hokkaido. These include coastal constructions such as jetty ports, digging formula ports, types of seawall, etc., in addition to land use for fisheries. Examples of site-specific behavior in the 2011 Tohoku Earthquake along the Pacific coast of Hokkaido are introduced in order to help future tsunami disasters.

Impact of the 2011 Tohoku earthquake tsunami on zooplankton community in Otsuchi Bay, northeastern Japan

2015 ◽  
Vol 72 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Yuichiro Nishibe ◽  
Hiroshi Isami ◽  
Hideki Fukuda ◽  
Shuhei Nishida ◽  
Toshi Nagata ◽  
...  
Keyword(s):  
Zooplankton Community ◽  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
The 2011 Tohoku Earthquake ◽  
Otsuchi Bay ◽  
Northeastern Japan

Damage Assessment on Electric Power Failures During the 2011 off the Pacific Coast of Tohoku Earthquake

2012 ◽  
Vol 7 (sp) ◽  
pp. 491-499 ◽  
Author(s):  
Gaku Shoji ◽  
◽  
Dai Takahashi ◽  
Takuya Tsukiji ◽  
Satoshi Naba ◽  
...  
Keyword(s):  
Electric Power ◽  
Web Sites ◽  
Pacific Coast ◽  
Tohoku Earthquake ◽  
Damage Functions ◽  
Power Company ◽  
Northeastern Japan ◽  
The Pacific ◽  
Branch Office ◽  
Office Personnel

We collected data on the March 11, 2011, Great East Japan Earthquake by surveying web sites related to power failures during 2011 off the Pacific coast of Tohoku (northeastern Japan) and, in addition, by interviewing local government sectors and Tokyo Electric Power Company (TEPCO) branch office personnel. We quantify two damage ratios for power failures for subject municipalities defined by the ratio of the number of affected households and houses in a city to the number of related households and houses. This revealed the dependence of damage ratios on seismic intensities induced in subject municipalities. Damage functions related to power failures are then developed.

Empirical Fragility Curves of Buildings in Northern Miyagi Prefecture During the 2011 off the Pacific Coast of Tohoku Earthquake

2016 ◽  
Vol 11 (6) ◽  
pp. 1253-1270 ◽  
Author(s):  
Hao Wu ◽  
◽  
Kazuaki Masaki ◽  
Kojiro Irikura ◽  
Susumu Kurahashi ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Fragility Curves ◽  
Ground Motions ◽  
Strong Motion ◽  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
The 2011 Tohoku Earthquake ◽  
Kobe Earthquake ◽  
The Pacific ◽  
Miyagi Prefecture

In this study, empirical fragility curves expressed in terms of relationship between damage ratio indices of buildings and ground motion indices were developed in northern Miyagi prefecture located in near-field areas during the 2011 off the Pacific coast of Tohoku Earthquake. The ground motion indices were evaluated from observed ground motions at strong-motion stations and estimated at sites at which no strong-motion accelerometers were deployed during the mainshock. The ground motions at the non-instrumental sites were estimated using the empirical Green’s function method based on bedrock motions inverted from observed records on surfaces from small events that occurred inside the source fault, transfer functions due to underground velocity structures identified from microtremor H/V spectral ratios, and a short-period source model of the mainshock. The findings indicated that the empirical fragility curves as functions of Japan Meteorological Agency (JMA) instrumental seismic intensity during the 2011 Tohoku Earthquake almost corresponded to those during the 1995 Kobe Earthquake and the seven disastrous earthquakes that occurred between 2003 and 2008. However, the empirical fragility curves as functions of peak ground velocity were the lowest. A possible reason for this is that the response spectra of the ground motions in the period ranging from 1.0 s to 1.5 s were small during the 2011 Tohoku Earthquake. Another reason could be the seismic resistant capacities of buildings in the studied districts involved during the 2011 Tohoku Earthquake exceeded those in the cities affected during the 1995 Kobe Earthquake.

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