Great East Japan Earthquake Research Articles

Attachment and adjustment in expatriate reactions to the 2011 Tohoku disasters

Attachment and adjustment in expatriate reactions to the 2011 Tohoku disasters

Preliminary analysis of certified disaster-related death in the affected area of the Fukushima Daiichi nuclear power plant accident following the Great East Japan Earthquake: an observational study

Preliminary analysis of certified disaster-related death in the affected area of the Fukushima Daiichi nuclear power plant accident following the Great East Japan Earthquake: an observational study

Responses from Businesses in Rural Communities Recovering from the 2011 Tohoku Disasters during the 2020 Tokyo Olympics

Summary The 2011 Great East Japan Earthquake (GEJE) significantly impacted the Tohoku Region in north-eastern Japan, leading to a large number of human casualties and environmental devastation. It exacerbated pre-existing economic and demographic decline. Tourism development was promoted as part of economic recovery and revitalization efforts. With Japan securing the winning bid for the 2020 Tokyo Olympics, it was hoped that having some of the Olympic activities hosted in Tohoku would contribute to recovery efforts. This case study examines the perspectives of businesses in areas located near the Olympic venues in Tohoku, on what kind of effects the Olympics had on their operations. Information © The Authors 2023

Association Between Changes in Alcohol Consumption Before and After the Great East Japan Earthquake and Risk of Hypertension: A Study Using the Ministry of Health, Labour and Welfare National Database.

The 2011 Great East Japan Earthquake has resulted in a nuclear accident, forcing residents of the surrounding areas to evacuate. To determine any association between excessive drinking and hypertension in the setting of disaster, we assessed whether the proportion of excessive drinkers increased and if post-disaster excessive drinking was a risk factor for hypertension. This retrospective study assessed data from the Japanese National Database. Cumulative population data for Fukushima Prefecture (3,497,576 people) were analyzed by categorizing residents into four areas-evacuation, coastal, central, and mountainous-to calculate the proportion of excessive, heavy (equivalent to binge drinking), and at-risk drinkers for 2008-2017. The hazard ratios (HRs) for the incidence of hypertension for 2012-2017 were examined in association with changes in drinking status pre- and post-disaster, which included 136,404 people who received specific health checkups pre-disaster (2008-2010) and post-disaster (2011-2012). The proportion of excessive drinkers among women increased after the disaster in all areas examined. The association between excessive drinking and the incidence of hypertension was determined among men and women in all areas; it was stronger among women in the evacuation areas, with the sex- and age-adjusted HRs for the incidence of hypertension of 1.41 for pre-disaster excessive drinking, 2.34 for post-disaster excessive drinking, and 3.98 for pre- and post-disaster excessive drinking, compared with not excessive drinking pre- and post-disaster. Excessive drinking post-disaster may be associated with an increased risk of hypertension among men and women, especially among women in the evacuation areas.

Community Insights: Citizen Participation in Kamaishi Unosumai Decade-Long Recovery from the Great East Japan Earthquake

Numerous scholars and researchers have long advocated for citizen engagement in post-disaster recovery and reconstruction initiatives, although unique opportunities and challenges in effectively implementing citizen engagement still exist. It has been 12 years since the Great East Japan Earthquake, where the government called for a citizen-centered recovery and reconstruction process, and reconstruction in most areas in the Tohoku region has almost been concluded. Using qualitative data acquired through interviews with the residents, field observations during the World Bosai Walk, and questionnaire and archival research, this study aimed to discuss the overall reconstruction of Unosumai in Iwate Prefecture, giving the residents’ perspective on the benefits and challenges they faced in participating in recovery planning and reconstruction and how the community has been able to strengthen their participation in disaster reduction initiatives since the earthquake and tsunami. This discussion is crucial as it would effectively offer lessons on engaging residents in post-disaster recovery and reconstruction after mega-disasters.

Genome‐wide association study of brain MRI and other phenotypes in the Tohoku Medical Megabank Organization

AbstractBackgroundThe Tohoku Medical Megabank Organization (ToMMo) is a large cohort study and biobank established in 2013 in the Miyagi Prefecture of Northern Japan following the Great East Japan Earthquake and Tsunami. ToMMo enrolled 150K individuals in a planned longitudinal study aiming to reveal numerous and diverse biological, psychological, and lifestyle characteristics associated with important diseases, and it collects and analyzes a rich set of biological data, including genomics, from participants to support innovative research on these diseases. Importantly, aging and Alzheimer’s disease are key areas of our research agenda, but little is known about common genetic variants that affect quantitative traits related to AD in Japanese people. MRI brain scans and cognitive screening on 12,164 cohort participants were collected at baseline (the TMM Brain‐MRI Study) since 2014 to 2019.MethodThe TMM Brain‐MRI study acquired multiple MRI sequences, including T1‐weighted imaging (T1WI). The ADNI Phantom was used, and each scan’s quality was checked. Following pre‐processing steps, Freesurfer (v7.2.0) was used with the Destrieux or Desikan‐Killiany atlas to parcellate multiple anatomical brain regions and derive cortical thickness data. We conducted a Genome‐Wide Association Study (GWAS) on all Brain‐MRI Study participants who were also genetically profiled with a Japanese‐oriented microarray (Japonica‐Array® v1, v2 and NEO) and WGS.ResultAlong with the other data types, the genotyping data for the TMM Brain‐MRI study participants represented etiological characteristics. The attached Figure shows the age distribution by decile for 7,630 male and female participants who were profiled with the Japonica‐Array® v2. The usable archived volumetric T1WI data demonstrated inverse correlations between brain volume and age, as well as very good agreement with correlations observed in previous clinical studies. We identified nominally genome‐wide significant loci (P < 5×10‐8) associated with imaging phenotypes in this sample consisted of Japanese adults as the discovery stage of the study.ConclusionThe ToMMo MRI and genetic data provide insights into the genetic architecture of the brain that are relevant to understanding brain aging and AD. Our results require some replication stages and meta‐analyses using samples of Japanese individuals in other studies.

Adjoint Inversion of Near‐Field Pressure Gauge Recordings for Rapid and Accurate Tsunami Source Characterization

AbstractWe explore the potential of the adjoint‐state tsunami inversion method for rapid and accurate near‐field tsunami source characterization using S‐net, an array of ocean bottom pressure gauges. Compared to earthquake‐based methods, this method can obtain more accurate predictions for the initial water elevation of the tsunami source, including potential secondary sources, leading to accurate water height and wave run‐up predictions. Unlike finite‐fault tsunami source inversions, the adjoint method achieves high‐resolution results without requiring densely gridded Green's functions, reducing computation time. However, optimal results require a dense instrument network with sufficient azimuthal coverage. S‐net meets these requirements and reduces data collection time, facilitating the inversion and timely issuance of tsunami warnings. Since the method has not yet been applied to dense, near‐field data, we test it on synthetic waveforms of the 2011 Mw 9.0 Tohoku earthquake and tsunami, including triggered secondary sources. The results indicate that with a static source model without noise, using the first 5 min of the waveforms yields a favorable performance with an average accuracy score of 93%, and the largest error of predicted wave amplitudes ranges between −5.6 and 1.9 m. Using the first 20 min, secondary sources were clearly resolved. We also demonstrate the method's applicability using S‐net recordings of the 2016 Mw 6.9 Fukushima earthquake. The findings suggest that lower‐magnitude events require a longer waveform duration for accurate adjoint inversion. Moreover, the estimated stress drop obtained from inverting our obtained tsunami source, assuming uniform slip, aligns with estimations from recent studies.

Exploring the role of language ideology in disaster contexts: case study of the 2011 Great East Japan Earthquake and Tsunami

Abstract During/after disasters, language communication (or the lack thereof) can be a matter of life or death, particularly for “Indigenous/Tribal, Minority and Minoritized languages and peoples” (ITMs). Disaster and language studies have identified language barriers as critical because some ITMs do not understand basic risk communication, evacuation warnings, and recovery information. There are three major approaches to lowering these barriers in disaster contexts: (1) disseminating warnings and critical information in multilingual formats; (2) using bi/multilingual translators/interpreters and automated translator; and (3) using simplified language(s). However, this top–down approach is insufficient because ITMs need more than just selective information to cope with adversities. The basic communication rights to know, “talk about it,” and express one’s feelings after a traumatic event should not be a taken-for-granted privilege for speakers of the majority languages. The root causes of disaster linguicism, which focuses on the unique social vulnerabilities confronted by ITMs, have not been properly addressed. Drawing from our qualitative research, this article explores the role of Japanese language ideology in relation to the experiences of ITMs in the 2011 Great East Japan Earthquake and Tsunami.

Estimation of wave velocity and analysis of dispersion characteristics based on wavelet decomposition

Due to the complexity of the crustal medium and stratigraphic boundaries, seismic waves typically exhibit attenuation and dispersion after propagation through the medium. By studying the regularity of seismic wave dispersion, soil layer information can be extracted. Current spectral decomposition techniques take less account of signal filtering processing of seismic waves, and the complexity of the stratigraphy tends to reduce the accuracy of dispersion analysis. Based on the above, a new method for calculating the dispersion characteristics of a site from surface and downhole ground vibration recordings is proposed, which is simpler than the spectra analysis of surface waves (SASW) method and eliminates the need for multiple pickups and additional equipment. This method is based on wavelet decomposition and seismic wave filtering, and a numerical simulation example is established to verify the effectiveness of the method. Then, the records of the Tohoku earthquake on March 11, 2011 are used as actual strong earthquake examples for filtering and dispersion analysis. Finally, it is concluded that the seismic wave dispersion analysis method based on wavelet decomposition can effectively filter and analyze seismic waves in specific frequency bands.

Spatiotemporal variations in seismic activity in and around the focal region of the 2021 [formula omitted]7.3 and 2022 [formula omitted]7.4 Fukushima-Oki earthquakes, Japan

The spatiotemporal evolution of seismic activity is presented for a broad region surrounding the focal areas of the 2021 M7.3 and 2022 M7.4 Fukushima-Oki earthquakes, which occurred within the subducting slab off the Pacific coast of Fukushima Prefecture, northeastern Japan. This study investigates the spatiotemporal variations in seismic activity during the periods before the 2021 M7.3 earthquake, between the 2021 M7.3 and 2022 M7.4 earthquakes, and after the 2022 M7.4 earthquake using the b-value of the Gutenberg–Richter relation, the aftershock decay rate (p-value), and changes in the seismicity rate (Z-value). The study area is also divided into two depth sections to investigate the depth variations in these seismicity parameters relative to the plate interface. The b-values in the deeper section (intraslab) are generally lower than those in the shallower section (around the plate interface) throughout the entire analysis period, including the hypocentral areas of the M7.3 and M7.4 earthquakes. The aftershock decay rates for the M7.3 and M7.4 earthquakes also show depth-dependent characteristics, with a slower decay rate (p < 1.0) at many grid nodes in the deeper section than in the shallower section. Furthermore, seismic quiescence was noted in the hypocentral area of the M7.3 earthquake about two years before the occurrence of this mainshock. The locations of the M7.3 and M7.4 earthquakes around the down-dip edge of the slip area of the 2011 M9.0 Tohoku earthquake suggests that the variations in seismic activity detected in this study mainly reflect stress increases due to the coseismic slip and postseismic deformation of this great earthquake. The present study suggests that the effect of viscoelastic relaxation is a dominant factor in the deeper section. Furthermore, the variations in seismicity may also reflect heterogeneous structures within the slab.

Spatiotemporal Variations of Intermediate‐Depth Earthquakes Before and After 2011 Tohoku Earthquake Revealed by a Template Matching Catalog

AbstractWe investigate spatiotemporal changes of intermediate‐depth earthquakes in the double seismic zone beneath Central and Northeastern Japan before and after the 2011 magnitude 9 Tohoku earthquake. We build a template‐matching catalog 1 year before and 1 year after the Tohoku earthquake using Hi‐net recordings. The new catalog has a six‐fold increase in earthquakes compared to the Japan Meteorological Agency catalog. Our results show no significant change in the intermediate‐depth earthquake rate prior to the Tohoku earthquake, but a clear increase in both planes following the Tohoku earthquake. The regions with increased intermediate‐depth earthquake activity and the post‐seismic slips following the Tohoku earthquake are spatially separate and complementary with each other. Aftershock productivity of intermediate‐depth earthquakes increased in both planes following the Tohoku earthquake. Overall, aftershock productivity of the upper plane is higher than the lower plane, likely indicating that stress environments and physical mechanisms of intermediate‐depth earthquakes in the two planes are distinct.

Idobata-Nagaya: a community housing solution for socially isolated older adults following the great East Japan earthquake.

Following the Great East Japan Earthquake, the living environment of socially isolated older adults has become a pressing concern. In response, Nagaya, a collective housing program, was established in Soma City, Fukushima, Japan to address social isolation among older adults and support their long-term health. This study aimed to identify characteristics of individuals in Nagaya and examine the sustainability of this initiative. We conducted a retrospective analysis of residents who were relocated to Nagaya, emphasizing their characteristics, the continuity of their stay in Nagaya, and their care certification levels, using data up to December 31, 2022. We employed Kaplan-Meier curves to analyze the duration for which residents continued to reside in Nagaya and the time leading up to the requiring care-level certification. Of 65 people who moved to Nagaya after the disaster, 30 people (46.2%) continued to live there, 21 (32.3%) died during their stay, and 14 (21.5%) moved out. The overall duration of occupancy averaged 6.39 years (SD 3.83 years). The proportion of requiring care-level certification occurrences per person-year was 0.0577 for those without care certification and 0.3358 for those with requiring support level at the time of moving in. In summary, Nagaya-style communal housing may offer suitable living environments for older adults with diverse needs during disasters and serve as a valuable tool for developing public policies in aging societies.

Dynamic discrete choice model and its estimation algorithm with dynamic inconsistent expected utility in an uncertain situation

Decision making in terms of travel behavior is always dynamic; however, the future behavior of an individual is often inconsistent with their present plan. Therefore, this study aims to incorporate dynamic inconsistency into the expected utility of dynamic sequential choices with a novel structural estimation approach. The incorporation of dynamic heterogeneity into expected utility enables the illustrative modeling of more types of decision making because decision making often involves dynamic inconsistent expected utilities. However, the existing approaches for dynamic discrete choice suppose an equilibrium situation and cannot evaluate these dynamic inconsistent situations. In this study, we propose a novel dynamic discrete choice model with dynamic inconsistency in its expected utility and an empirical algorithm for parameter estimation. We formulate a heterogeneous expected utility as a range constraint near the dynamic consistent expected utility for model identification. Our algorithm, which applies a mathematical program to inequality constraints, enables parameter estimation with dynamic heterogeneity. The proposed model and algorithm were applied to the problem of evacuation departure choice in the city of Rikuzentakata during the Great East Japan Earthquake and Tsunami of 2011. The case study demonstrated the validity of introducing dynamic heterogeneity via likelihood comparisons; it was also found that dynamic heterogeneity is distributed around the dynamic consistent expected utility.

Validation and modification of the AFHCHDC7 risk score for predicting the long-term cardiovascular disease risk after the Great East Japan Earthquake: The Fukushima Health Management Survey

ObjectivesThis study aimed to evaluate the predictive performance of the AFHCHDC7 risk score, developed for post-disaster cardiovascular disease (CVD) risk management, for 6-year CVD risk in Fukushima Prefecture after the Great East Japan Earthquake compared to the Suita CVD risk score and to modify the AFHCHDC7 risk score. MethodsThe present study comprised 14,779 individuals aged 30–79 years with no history of CVD at baseline who underwent the comprehensive health checkup and completed the mental health and lifestyle survey in 2011. Its primary outcome was CVD onset (myocardial infarction, stroke). Logistic regression analyses were used to construct a prediction model. The calibration performance and discrimination performance according to area under the curve (AUC) values were evaluated for each model. ResultsThe AFHCHDC7 risk score had lower AUC values than the Suita CVD risk score from baseline for 6 years (AUC: 0.65). The modified AFHCHDC7 risk score (age-stratified, adding sex and smoking) had higher predictive performance than the Suita CVD risk score from baseline for 6 years (AUC: 0.74 vs. 0.73). ConclusionsThe modified AFHCHDC7 score may be useful as a simple tool for identifying individuals’ long-term CVD risk in disaster evacuees. The utility of this score needs to be carefully evaluated in future studies.

Development of the global tsunami forecasting system considering the dynamic interaction of tide-tsunami around the Korean Peninsula

Tsunamis are extreme natural events that pose a significant threat to coastal communities, making a comprehensive understanding of tsunami propagation mechanisms necessary for forecasting and evacuation purposes. While previous forecasting models have successfully examined several factors influencing tsunami propagation, the impact of the dynamic interaction between tides and tsunamis has yet to be investigated thoroughly. The Yellow Sea is characterized by high tidal elevations and strong tidal currents, which can accelerate the tsunami impacts on the Korean coasts. This study developed a regional tide-tsunami interaction model based on the shallow water equation model to quantitatively investigate the dynamic tide-tsunami interaction and evaluate its influence on tsunami propagation and amplification mechanism. High-resolution numerical tests were conducted for two worst-case tsunami scenarios that occurred in the Korean Peninsula, including the 2010 Chilean tsunami (far-field forecasting) and the 2011 Tohoku tsunami (near-field forecasting). The performance of the numerical model was validated utilizing the observational tide data collected along the Korean coasts. The numerical model effectively reproduces the horizontal distribution of instantaneous free surface displacement and velocity. The results reveal that the dynamic tide-tsunami interaction induced by these tsunamis generally reduces the water level and velocity in the ocean while amplifying these quantities as the tsunamis approach the coastal regions. However, due to the complex and arbitrary features of the topography, the impact of the dynamic tide and tsunami interaction on water elevation and velocity is inconsistent even compared with measurements from the adjacent tidal gauges, which suggests that the dynamic interaction can play an opposite role during the propagation and amplification process. Furthermore, the different arrival times of tsunamis along the Korean coasts are dominated by the corresponding phase of the local tidal currents that develop in each region.

Understanding memory transmission in disaster risk reduction practices: A case study from Japan

“Disasters strike when they have faded from memory”, is a powerful quote from the Japanese geophysicist Terada Torahiko (1878–1935). This sentence, often used when addressing the need to improve disaster resilience, is a powerful reminder of the role that local memories of past disasters play in ensuring the safety of communities exposed to hazards. Twelve years from the Great East Japan Earthquake and Tsunami (GEJET) that hit Japan Tohoku's East Coast, this article aims at understanding how the transmission of local knowledge and experiences of past disasters contributes to increasing community resilience to tsunami risks. Based on field research along the coast of the Japanese prefectures of Iwate, Miyagi and Fukushima, this study analyses 11 semi-structured in-depth interviews, to investigate the role of memory transmission in preparing for tsunami risks such as the GEJET. The data was analysed following a narrative approach and through thematic coding with the use of NVivo. Coding structures led to the identification of disaster memory transmission practices in the case study areas and allowed the testing of the relevance of the theoretical framework to community disaster resilience studies. Results are aligned with the theoretical framework and show that disaster memorials are more likely to influence community resilience if passed down using a combination of oral transmission and interpretation together with the use of backup memory archives and physical objects. Such practices are recommended as they allow both the communicability and durability of lessons-learned. Transmitting and maintaining a constant interaction between these two forms of memory is the responsibility of those institutions that oversee the keeping alive of memories, by continuously repurposing and renewing them while engaging with exposed communities.

Abstract 12510: Spatial and Temporal Effects on Human Health Following a Serious Natural Disaster

Introduction: The effects of disasters can be classified into direct effects and indirect effects. Although direct effects of disasters have been extensively reported, the reports on indirect effects are scarce. We analysed the long-term spatiotemporal effects of The Great East Japan Earthquake, which occurred on March 11, 2011, to elucidate its direct and indirect effects. Methods: The spatial analyses and the temporal analyses were performed using the data from Japanese Diagnosis Procedure Combination (DPC) database from August 01, 2010 to March 31, 2015. Results: The number of patients in DPC-participating hospitals showed apparent decrease with odds ratio of 0.46 (25th-75th percentile 0.10-0.80) immediately after the earthquake (Figure1), and the crude death ratio increased significantly with odds ratio of 1.78 (25th-75th percentile 1.13-2.26), lasting for 12 months (Figure2). This change was not only seen in the disaster area but in the broader area of Japan. The proportion of patients admitted to hospitals due to malignant disease largely decreased (53.8% before earthquake, 34.8% within 1 year after earthquake, odds ratio 0.65), and the proportion of patients admitted to hospitals due to cardiovascular disease largely increased (13.1% before earthquake, 28.5% after earthquake, odds ratio 2.17) within 1 year after the earthquake. Conclusions: A wide-scale natural disaster affects the number of patients and mortality prominently in the disaster area for at least 1 year, especially in patients with cardiovascular disease. The results of this study provide important information for development of future disaster control measures.

Multi-dimensional landscape ecological risk assessment and its drivers in coastal areas

The eastern coastal areas of Japan are threatened by multiple ecological risks due to frequent natural disasters, climate changes, human activities, etc. Identification spatio-temporal variations and driving mechanisms of landscape ecological risk could be used as significant basis for policymakers. In this study, taking the eastern coastal areas of Japan affected by the 2011 Great East Japan Earthquake and Tsunami Disaster as the study area, the “Nature-Landscape Pattern-Human Society” (NA-LP-HS) multi-dimensional ecological risk assessment framework was established to analyze the spatio-temporal patterns, and identity driving factors using spatial cluster analysis and spatial principal component analysis (SPCA) based on ArcGIS from 2009 to 2021. The findings revealed the distinct geographic patterns in landscape ecological risk, with a noticeable decline from the southwest to the northeast. During the period from 2009 to 2015, the driving factors leading to a sharp risk increase were natural disasters and vegetation coverage. These high-risk areas were concentrated in Sendai Bay and its surroundings. From 2015 to 2021, ecological instability was primarily attributed to a reduction in vegetation coverage, the occurrence of natural disasters, and heightened rainfall erosion. These high-risk areas were mainly clustered within the Tokyo-centered urban agglomeration. Spatial clustering of ecological risks was obvious across all time periods. The key factors contributing to the clustering of high ecological landscape risks focused on the “landscape pattern” criterion, specifically including vegetation coverage, land use land cover. This study demonstrated the ability of multi-dimensional ecological risk assessment to identify high-risk areas and driving factors, and these results could provide a visual analysis and decision-making basis for sustainable development of coastal areas.

Assessment of drug needs and contributions of pharmacists in the aftermath of the 2011 triple disaster in Fukushima, Japan: A combined analysis

After a major disaster, drug logistics are crucial for maintaining medical care. Although pharmacists play a vital role in healthcare institutions, their role is not well defined, and their recognition from other healthcare professionals is lacking. This was evident at Minamisoma Municipal General Hospital in Fukushima, Japan, which was affected by the Great East Japan earthquake, tsunami, and nuclear power plant accident. The supply of drugs and related information was severely disrupted. In response, two pharmacists were interviewed and the data was analyzed through a thematic approach. Additionally, prescription data collected by pharmacists was analyzed quantitatively. The results from the qualitative survey showed that pharmacists made efforts to supply drugs and collect information, despite facing various psychological challenges, such as confidence, responsibility, anguish, and conflicts. The “leadership” of the hospital's upper managers was instrumental in supporting the pharmacists. The prescription data revealed that drug supply continued for approximately one month without interruption, and the demand for antihypertensive and psychiatric drugs increased. A majority (72.3 %) of the patients (N = 3,518) were 60 years of age or older, which might have contributed to the demand for chronic disease drugs. This study provides an example of the role of pharmacists and drug logistics during major disaster situations, including nuclear accidents.

JMorp: Japanese Multi-Omics Reference Panel update report 2023.

Modern medicine is increasingly focused on personalized medicine, and multi-omics data is crucial in understanding biological phenomena and disease mechanisms. Each ethnic group has its unique genetic background with specific genomic variations influencing disease risk and drug response. Therefore, multi-omics data from specific ethnic populations are essential for the effective implementation of personalized medicine. Various prospective cohort studies, such as the UK Biobank, All of Usand Lifelines, have been conducted worldwide. The Tohoku Medical Megabank project was initiated after the Great East Japan Earthquake in 2011. It collects biological specimens and conducts genome and omics analyses to build a basis for personalized medicine. Summary statistical data from these analyses are available in the jMorp web database (https://jmorp.megabank.tohoku.ac.jp), which provides a multidimensional approach to the diversity of the Japanese population. jMorp was launched in 2015 as a public database for plasma metabolome and proteome analyses and has been continuously updated. The current update will significantly expand the scale of the data (metabolome, genome, transcriptome, and metagenome). In addition, the user interface and backend server implementations were rewritten to improve the connectivity between the items stored in jMorp. This paper provides an overview of the new version of the jMorp.