Earthquake and Volcano Hazards Observation and Research Program: An Overview

2020 ◽  
Vol 15 (2) ◽  
pp. 70-75
Author(s):  
Naoyuki Kato ◽  
Takeshi Nishimura ◽  
◽  
Keyword(s):  
Research Program ◽  
Disaster Response ◽  
Tohoku Earthquake ◽  
Volcanic Eruptions ◽  
Fiscal Year ◽  
The 2011 Tohoku Earthquake ◽  
The Pacific ◽  
Volcano Hazards ◽  
Scientific Results ◽  
Volcanic Data

The Earthquake and Volcano Hazards Observation and Research Program was from Japanese fiscal year 2014 to 2018. This national program succeeded the Research Program for Earthquake and Volcanic Eruption Prediction (2009–2013). However, mainly because of the disaster caused by the 2011 earthquake off the Pacific coast of Tohoku, known as the 2011 Tohoku Earthquake, the basic policy of the program changed drastically. It changed from research for predicting earthquakes and volcanic eruptions to comprehensive research for mitigating disasters on the basis of scientific results related to the mechanisms of earthquakes and volcanic eruptions and their forecasts. The program was planned to be multidisciplinary in nature. In addition to Earth scientists working to get a scientific understanding of earthquakes and volcanic eruptions, historians, archaeologists, human and social scientists, and engineers took part in the program aimed at collecting pre-instrumental earthquake and volcanic data, understanding earthquake and volcano disasters, risk evaluation, and research into disaster response and preparedness. In this article, we review the basic concept of the 2014–2018 program and its main achievements. In the end, we summarize the problems left for future studies.

Special Issue on Earthquake and Volcano Hazards Observation and Research Program

2020 ◽  
Vol 15 (2) ◽  
pp. 69-69
Author(s):  
Yuichiro Tanioka ◽  
Shingo Yoshida ◽  
Takao Ohminato ◽  
Aitaro Kato ◽  
Noriko Kamaya
Keyword(s):  
Research Program ◽  
Disaster Response ◽  
Volcanic Eruptions ◽  
Special Issue ◽  
Social Scientists ◽  
New Findings ◽  
New Ideas ◽  
Earthquake Generation ◽  
Volcano Hazards ◽  
Volcanic Data

The Earthquake and Volcano Hazards Observation and Research Program (2014–2018) carried out comprehensive research to mitigate disasters related to earthquakes and volcanic eruptions. The program selected multidisciplinary research in which earth scientists who study the processes of earthquake generation and volcanic eruptions, historians, archaeologists, human and social scientists, and engineers were all involved. The program aimed to collect pre-instrumental and pre-historical earthquake and volcanic data to understand earthquake and volcano disasters, to find risk evaluation techniques, and to evaluate disaster response and preparedness. Active collaborations between researchers from different science fields inspired new ideas and have driven various research in the program. New findings from the program have also created international collaborations and recognitions. Most of the results and new findings in the program have already been published in various internationally recognized journals and have greatly influenced scientific communities. We believe that it is important to compile our findings from the last five years of the program and to publish the essence of our findings and published papers in this special issue. We hope that this special issue will be of value to researchers who are interested in multidisciplinary studies of mitigation of disasters such as earthquakes, volcanic eruptions, and related phenomena.

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.

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.

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.

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.

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.

Postseismic Uplift Along the Pacific Coast of Tohoku and Kanto Districts Associated with the 2011 off the Pacific Coast of Tohoku Earthquake

2018 ◽  
Vol 13 (3) ◽  
pp. 496-502
Author(s):  
Takeshi Iinuma ◽  
Keyword(s):  
Pacific Coast ◽  
Tohoku Earthquake ◽  
Fault Creep ◽  
The 2011 Tohoku Earthquake ◽  
Sanriku Coast ◽  
The Past ◽  
The Pacific ◽  
Kanto District ◽  
Coseismic Subsidence ◽  
Gps Observations

The 2011 off the Pacific coast of Tohoku earthquake (M9.0) produced up to 1.2 m subsidence along the Pacific coast in northeastern Japan. Based on Global Positioning System (GPS) observations, continuing postseismic coastal uplift has been detected in the past six years after the main shock. By applying a 3D spherical Earth viscoelastic finite element model using the postseismic seafloor and terrestrial GPS observations as constraints, I demonstrate that this uplift is mainly caused by the postseismic viscoelastic relaxation of the asthenosphere. Although the model was constrained only based on horizontal crustal deformation, the vertical displacements predicted for six years after the 2011 Tohoku earthquake agree reasonably well with the time series of the observed uplift at sites along the Pacific coast including the southern Sanriku coast and Kanto district. I estimated the time at which the cumulative postseismic uplift will fully compensate the coseismic subsidence. The results show that large coseismic coastal subsidence on the southern Sanriku coast will be fully offset by the postseismic uplift within several decades. To the immediate north, the model underpredicts the postseismic uplift and possibly indicates unaccounted postseismic fault creep. Farther south, the postseismic uplift of the coast of the Kanto district has already exceeded the small amount of coseismic subsidence over the past six years, as predicted by the model. To prepare for future earthquakes, especially with respect to the coastal construction at fishery ports, it is important to construct a comprehensive rheological structure model based on geophysical observations including GNSS positioning.

scholarly journals Evolution of the 2011 Tohoku Earthquake Tsunami on the Pacific Coast of Hokkaido

2012 ◽  
Vol 54 (1) ◽  
pp. 1250002-1-1250002-17 ◽  
Author(s):  
Yasunori Watanabe ◽  
Yuta Mitobe ◽  
Ayumi Saruwatari ◽  
Tomohito Yamada ◽  
Yasuo Niida
Keyword(s):  
Pacific Coast ◽  
Tohoku Earthquake ◽  
2011 Tohoku Earthquake ◽  
The 2011 Tohoku Earthquake ◽  
The Pacific

scholarly journals Seismogravity processes observed in the course of development of the 2011 Tohoku earthquake

2020 ◽  
Vol 2 (2) ◽  
pp. 39-47
Author(s):  
Leonid Sobisevich ◽  
Alexey Sobisevich ◽  
Konstantin Kanonidi
Keyword(s):  
Seismic Event ◽  
Tohoku Earthquake ◽  
Original Data ◽  
Northern Caucasus ◽  
The 2011 Tohoku Earthquake ◽  
Russian Academy Of Sciences ◽  
Federal Research ◽  
Scientific Results ◽  
Academy Of Sciences ◽  
Schmidt Institute

The analysis of the seismogravity processes accompanying the process of development of the tsunamigenic Great East Japan (Tohoku) Earthquake is carried out. Original data and most of the scientific results were obtained at the Geophysical Observatory in Northern Caucasus operated by the Schmidt Institute of Physics of the Earth, Russian Academy of Sciences in collaboration with the Federal Research for Geophysical Service of the Russian Academy of Sciences. Specific attention is focused on the analysis of the structure of the registered seismic processes and the accompanying gravitomagnetic disturbances observed immediately prior to the main seismic event.

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