scholarly journals Two-Step Seismic Noise Reduction Saused by COVID-19 Induced Reduction in Social Activity in Metropolitan Tokyo, Japan

2020 ◽  
Author(s):  
Suguru Yabe ◽  
Kazutoshi Imanishi ◽  
Kiwamu Nishida
Keyword(s):  
Noise Reduction ◽  
Frequency Band ◽  
Metropolitan Area ◽  
Seismic Noise ◽  
Social Activity ◽  
State Of Emergency ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
The World ◽  
40 Hz

Abstract The COVID-19 pandemic that started at the end of 2019 forced populations around the world to reduce social and economic activities; it is believed that this can prevent the spread of the disease. In this paper, we report a seismic noise analysis during such an induced social activity reduction taking the Tokyo Metropolitan area, Japan. Using seismic data obtained from 18 stations in the Metropolitan Seismic Observation Network (MeSO-net), a two-step seismic noise reduction in the frequency bands 1–20 Hz and 20–40 Hz was observed during the timeline of COVID-19 in Tokyo. The first noise reduction occurred at the beginning of March in the frequency band 20–40 Hz. This corresponded with the request of the Prime Minister of Japan for a nationwide shutdown of schools. Although social activity was not reduced significantly at this juncture, local reduction of seismic wave excitation in the high frequency band, 20–40 Hz, was recorded at some MeSO-net stations located in school properties. The second reduction of seismic noise occurred at the end of March to the beginning of April 2020 in the frequency band 1–20 Hz. This timing corresponds to when the Governors of the Tokyo Metropolitan area requested citizens to stay home and when the state of emergency was declared for the Tokyo Metropolitan area by the government, respectively. The estimated population at train stations abruptly dropped since this timing, which suggests that social activity was severely reduced. Such large-scale change in social activity affects the seismic noise level in the low frequency bands. The seismic noise level started to increase from the middle of May correlating with increase in population at the train stations. This suggests that social activity restarted even before the state of emergency was lifted at the end of May. The two-step seismic noise reduction observed in this study has not been reported in other cities around the world. Unexpected reduction of social activity due to COVID-19 provided us a rare opportunity to investigate the characteristics of seismic noise caused by human activities.

scholarly journals Two-step Seismic Noise Reduction caused by COVID-19 Induced Reduction in Social Activity in metropolitan Tokyo, Japan

2021 ◽  
Author(s):  
Suguru Yabe ◽  
Kazutoshi Imanishi ◽  
Kiwamu Nishida
Keyword(s):  
Noise Reduction ◽  
Frequency Band ◽  
Metropolitan Area ◽  
Noise Level ◽  
Seismic Noise ◽  
Social Activity ◽  
State Of Emergency ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
The World

Abstract The COVID-19 pandemic that started at the end of 2019 forced populations around the world to reduce social and economic activities; it is believed that this can prevent the spread of the disease. In this paper, we report an analysis of the seismic noise during such an induced social activity reduction in the Tokyo metropolitan area, Japan. Using seismic data obtained from 18 stations in the Metropolitan Seismic Observation Network (MeSO-net), a two-step seismic noise reduction was observed during the timeline of COVID-19 in Tokyo. The first noise reduction occurred at the beginning of March 2020 in the frequency band of 20–40 Hz. This corresponded with the request by the Prime Minister of Japan for a nationwide shutdown of schools. Although social activity was not reduced significantly at this juncture, local reduction of seismic wave excitation in the high frequency band, 20–40 Hz, was recorded at some MeSO-net stations located in school properties. The second reduction of seismic noise occurred at the end of March to the beginning of April 2020 in a wider frequency band including lower frequency bands of 1–20 Hz. This timing corresponds to when the Governors of the Tokyo metropolitan area requested citizens to stay home and when the state of emergency was declared for the Tokyo metropolitan area by the government, respectively. Since then, the estimated population at train stations abruptly dropped, which suggests that social activity was severely reduced. Such large-scale changes in social activity affect the seismic noise level in low frequency bands. The seismic noise level started to increase from the middle of May correlating with increase in population at the train stations. This suggests that social activity restarted even before the state of emergency was lifted at the end of May. The two-step seismic noise reduction observed in this study has not been reported in other cities around the world. Unexpected reduction of social activity due to COVID-19 provided a rare opportunity to investigate the characteristics of seismic noise caused by human activities.

scholarly journals Two-step seismic noise reduction caused by COVID-19 induced reduction in social activity in metropolitan Tokyo, Japan

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Suguru Yabe ◽  
Kazutoshi Imanishi ◽  
Kiwamu Nishida
Keyword(s):  
Noise Reduction ◽  
Frequency Band ◽  
Metropolitan Area ◽  
Noise Level ◽  
Seismic Noise ◽  
Social Activity ◽  
State Of Emergency ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
The World

Abstract The COVID-19 pandemic that started at the end of 2019 forced populations around the world to reduce social and economic activities; it is believed that this can prevent the spread of the disease. In this paper, we report an analysis of the seismic noise during such an induced social activity reduction in the Tokyo metropolitan area, Japan. Using seismic data obtained from 18 stations in the Metropolitan Seismic Observation Network (MeSO-net), a two-step seismic noise reduction was observed during the timeline of COVID-19 in Tokyo. The first noise reduction occurred at the beginning of March 2020 in the frequency band of 20–40 Hz. This corresponded with the request by the Prime Minister of Japan for a nationwide shutdown of schools. Although social activity was not reduced significantly at this juncture, local reduction of seismic wave excitation in the high-frequency band, 20–40 Hz, was recorded at some MeSO-net stations located in school properties. The second reduction of seismic noise occurred at the end of March to the beginning of April 2020 in a wider frequency band including lower frequency bands of 1–20 Hz. This timing corresponds to when the Governors of the Tokyo metropolitan area requested citizens to stay home and when the state of emergency was declared for the Tokyo metropolitan area by the government, respectively. Since then, the estimated population at train stations abruptly dropped, which suggests that social activity was severely reduced. Such large-scale changes in social activity affect the seismic noise level in low-frequency bands. The seismic noise level started to increase from the middle of May correlating with increase in population at the train stations. This suggests that social activity restarted even before the state of emergency was lifted at the end of May. The two-step seismic noise reduction observed in this study has not been reported in other cities around the world. Unexpected reduction of social activity due to COVID-19 provided a rare opportunity to investigate the characteristics of seismic noise caused by human activities.

scholarly journals Two-step Seismic Noise Reduction caused by COVID-19 Induced Reduction in Social Activity in metropolitan Tokyo, Japan

2020 ◽  
Author(s):  
Suguru Yabe ◽  
Kazutoshi Imanishi ◽  
Kiwamu Nishida
Keyword(s):  
Noise Reduction ◽  
Frequency Band ◽  
Metropolitan Area ◽  
Noise Level ◽  
Seismic Noise ◽  
Social Activity ◽  
State Of Emergency ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
The World

Abstract The COVID-19 pandemic that started at the end of 2019 forced populations around the world to reduce social and economic activities; it is believed that this can prevent the spread of the disease. In this paper, we report an analysis of the seismic noise during such an induced social activity reduction in the Tokyo metropolitan area, Japan. Using seismic data obtained from 18 stations in the Metropolitan Seismic Observation Network (MeSO-net), a two-step seismic noise reduction was observed during the timeline of COVID-19 in Tokyo. The first noise reduction occurred at the beginning of March 2020 in the frequency band of 20–40 Hz. This corresponded with the request by the Prime Minister of Japan for a nationwide shutdown of schools. Although social activity was not reduced significantly at this juncture, local reduction of seismic wave excitation in the high frequency band, 20–40 Hz, was recorded at some MeSO-net stations located in school properties. The second reduction of seismic noise occurred at the end of March to the beginning of April 2020 in a wider frequency band including lower frequency bands of 1–20 Hz. This timing corresponds to when the Governors of the Tokyo metropolitan area requested citizens to stay home and when the state of emergency was declared for the Tokyo metropolitan area by the government, respectively. Since then, the estimated population at train stations abruptly dropped, which suggests that social activity was severely reduced. Such large-scale changes in social activity affect the seismic noise level in low frequency bands. The seismic noise level started to increase from the middle of May correlating with increase in population at the train stations. This suggests that social activity restarted even before the state of emergency was lifted at the end of May. The two-step seismic noise reduction observed in this study has not been reported in other cities around the world. Unexpected reduction of social activity due to COVID-19 provided a rare opportunity to investigate the characteristics of seismic noise caused by human activities.

scholarly journals Characterizing Risk Communication and Awareness for Sustainable Society: The Case of Foreign Residents in the Tokyo Metropolitan Area of Japan

2021 ◽  
Vol 13 (11) ◽  
pp. 5786
Author(s):  
Bismark Adu-Gyamfi ◽  
Rajib Shaw
Keyword(s):  
Risk Communication ◽  
Metropolitan Area ◽  
Disaster Preparedness ◽  
Primary Data ◽  
Disaster Prevention ◽  
Sustainable Society ◽  
Vulnerable Group ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
The World

Many disasters occur in Japan, and therefore many initiatives to educate and integrate foreign residents into its society to overcome systematic barriers and enhance disaster preparedness have been implemented. Nevertheless, studies have highlighted foreign residents as a vulnerable group who are at risk of disasters in the country. The country anticipates and prepares for potential mega-disasters in the future; therefore, effective risk communication is vital to creating the required awareness and preparation. Therefore, this study looked at the changing foreigner–Japanese population mix in the Tokyo Metropolitan Area to ascertain its level of diversity and risk communication characteristics. It used secondary and primary data to analyze how heterogeneity among foreigners translates into a different understanding of their awareness. The study reveals that the 23 special wards within the Tokyo Metropolitan area can be compared to other recognized diverse cities in the world, with Shinjuku city, Minato city, Arakawa, and Taito cities being the most heterogeneous cities in Tokyo. Nevertheless, diversity within foreign residents creates diversity in information-gathering preferences, disaster drill participation preferences, and the overall knowledge in disaster prevention. The study suggests the use of these preferences as a tool to promote targeted risk communication mechanisms.

scholarly journals Impact of COVID-19 on Stroke Admissions and the Medical Care System in the Tokyo Metropolitan Area

2020 ◽  
Vol 11 ◽  
Author(s):  
Takahiro Ota ◽  
Yoshiaki Shiokawa ◽  
Teruyuki Hirano
Keyword(s):  
Medical Care ◽  
Acute Stroke ◽  
Metropolitan Area ◽  
The State ◽  
Medical Care System ◽  
State Of Emergency ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
Multicenter Survey ◽  
Care System

Aims: This study aimed to assess the number of patients with acute stroke seeking medical emergency care since the declaration of the state of emergency in the COVID-19 pandemic in the Tokyo metropolitan area of Japan.Methods: In this combined retrospective and prospective multicenter survey, data on the numbers of hospital admissions due to acute ischemic stroke, of large vessel occlusion (LVO) cases, and of reperfusion therapies performed from February to July 2020, restrictions of the medical care system, and comprehensive stroke center (CSC) scale scores were collected in 19 stroke centers in Tokyo.Results: In the survey period, 3,456 patients were admitted with acute stroke. There was a decrease in the number of admissions (−22%), LVO (−22%), thrombolysis (−6%), and thrombectomy (−23%) during the state of emergency, but the ratio of thrombectomy to LVO cases was not different. The acceptance of acute stroke cases by emergency transport and emergent operations in the central eastern area of Tokyo, was also significantly decreased to <50% and remains <60%. According to CSC scores, each hospital restricted their infrastructure or educational activities according to their medical resources. There was only one stroke case with COVID-19 (thrombectomy case) in all 3,456 patients in this study.Conclusion: The COVID-19 pandemic had a major impact on stroke care in Tokyo, including stroke admissions and medical care systems, resulting in a significant reduction in thrombolysis and thrombectomy. The extent of the drop may be the result of the number of COVID-19 patients.

Results of the Tokyo Metropolitan Area Convection Study for Extreme Weather Resilient Cities (TOMACS)

2019 ◽  
Vol 100 (10) ◽  
pp. 2027-2041 ◽  
Author(s):  
Ryohei Misumi ◽  
Yoshinori Shoji ◽  
Kazuo Saito ◽  
Hiromu Seko ◽  
Naoko Seino ◽  
...  
Keyword(s):  
High Resolution ◽  
Metropolitan Area ◽  
Extreme Weather ◽  
Polarimetric Radar ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
Social Experiments ◽  
Urban Impacts ◽  
X Band ◽  
The World

AbstractThe Tokyo Metropolitan Area Convection Study for Extreme Weather Resilient Cities (TOMACS) began as a Japanese domestic research project in 2010 and aimed to elucidate the mechanisms behind local high-impact weather (LHIW) in urban areas, to improve forecasting techniques for LHIW, and to provide high-resolution weather information to end-users (local governments, private companies, and the general public) through social experiments. Since 2013, the project has been expanded as an international Research and Development Project (RDP) of the World Weather Research Programme (WWRP) of the World Meteorological Organization (WMO). Through this project, the following results were obtained: 1) observation data for LHIW around Tokyo were recorded using a dense network of X-band radars, a C-band polarimetric radar, a Ku-band fast-scanning radar, coherent Doppler lidars, and the Global Navigation Satellite System; 2) quantitative precipitation estimation algorithms for X-band polarimetric radars have been developed as part of an international collaboration; 3) convection initiation by the interaction of sea breezes and urban impacts on the occurrence of heavy precipitation around Tokyo were elucidated by a dense observation network, high-resolution numerical simulations, and different urban surface models; 4) an “imminent” nowcast system based on the vertically integrated liquid water derived from the X-band polarimetric radar network has been developed; 5) assimilation methods for data from advanced observation instruments such as coherent Doppler lidars and polarimetric radars were developed; and 6) public use of high-resolution radar data were promoted through the social experiments.

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