scholarly journals Temporal changes in anthropogenic seismic noise levels associated with economic and leisure activities during the COVID-19 pandemic

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji
Keyword(s):  
Seismic Noise ◽  
Ambient Noise ◽  
Anthropogenic Activities ◽  
Leisure Activities ◽  
Time Of Day ◽  
Noise Levels ◽  
Economic Activities ◽  
State Of Emergency ◽  
Tokyo Metropolitan Area ◽  
Day Of The Week

AbstractSeismic ambient noise with frequencies > 1 Hz includes noise related to human activities. A reduction in seismic noise during the COVID-19 pandemic has been observed worldwide, as restrictions were imposed to control outbreaks of the SARS-CoV-2 virus. In this context, we studied the effect of changes in anthropogenic activities during COVID-19 on the seismic noise levels in the Tokyo metropolitan area, Japan, considering time of day, day of the week, and seasonal changes. The results showed the largest reduction in noise levels during the first state of emergency under most conditions. After the first state of emergency was lifted, the daytime noise reverted to previous levels immediately on weekdays and gradually on Sundays. This was likely because economic activities instantly resumed, while non-essential outings on Sundays were still mostly avoided. Furthermore, the daytime noise level on Sundays was strongly reduced regardless of changes on weekdays after the second state of emergency, which restricted activities mainly at night. Sunday noise levels gradually increased from the middle of the second state of emergency, suggesting a gradual reduction in public concern about COVID-19 following a decrease in the number of infections. Our findings demonstrate that seismic noise can be used to monitor social activities.

scholarly journals Temporal changes in anthropogenic seismic noise levels associated with economic and leisure activities during the COVID-19 pandemic

2021 ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji
Keyword(s):  
Seismic Noise ◽  
Ambient Noise ◽  
Anthropogenic Activities ◽  
Leisure Activities ◽  
Time Of Day ◽  
Noise Levels ◽  
Economic Activities ◽  
State Of Emergency ◽  
Tokyo Metropolitan Area ◽  
Day Of The Week

Abstract Seismic ambient noise with frequencies > 1 Hz includes noise related to human activities. A reduction in seismic noise during the COVID-19 pandemic has been observed worldwide, as restrictions were imposed to control outbreaks of the SARS-CoV-2 virus. In this context, we studied the effect of changes in anthropogenic activities during COVID-19 on the seismic noise levels in the Tokyo metropolitan area, Japan, considering time of day, day of the week, and seasonal changes. The results showed the largest reduction in noise levels during the first state of emergency under most conditions. After the first state of emergency was lifted, the daytime noise reverted to previous levels immediately on weekdays and gradually on Sundays. This was likely because economic activities instantly resumed, while non-essential outings on Sundays were still mostly avoided. Furthermore, the daytime noise level on Sundays was strongly reduced regardless of changes on weekdays after the second state of emergency, which restricted activities mainly at night. Sunday noise levels gradually increased from the middle of the second state of emergency, suggesting a gradual reduction in public concern about COVID-19 following a decrease in the number of infections. Our findings demonstrate that seismic noise can be used to monitor social activities.

scholarly journals Temporal changes in anthropogenic seismic noise levels associated with economic and leisure activities during the COVID-19 pandemic

2020 ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji
Keyword(s):  
Seasonal Variation ◽  
Human Activities ◽  
Seismic Noise ◽  
Anthropogenic Activities ◽  
Leisure Activities ◽  
Noise Levels ◽  
Economic Activities ◽  
State Of Emergency ◽  
Tokyo Metropolitan Area ◽  
School Activities

Abstract Seismic noise of frequencies >1 Hz includes noise that is strongly related to human activities. Reduction in seismic noise during the COVID-19 pandemic has been observed worldwide as restrictions were imposed on numerous human activities to control outbreaks of the virus. In this context, we studied the effect of reduced anthropogenic activities during COVID-19 on the noise levels in the Tokyo metropolitan area, Japan, considering seasonal variation. A significant reduction in noise was observed during the emergency, including that of frequencies >20 Hz, which was associated with school activities. After lifting the state of emergency, noise reverted to previous levels immediately for weekdays, but gradually for Sunday. This was likely because economic activities instantly resumed post-emergency on weekdays; however, most people still continued to avoid non-essential outings on Sunday. We also observed seasonal variation related to school holidays, energy consumption, and industrial activity. Noise levels in the frequency range of 1–5 Hz were found to be related to construction activity, which increased in winter and gradually decreased from 2017. Our findings demonstrate that seismic noise can be used to monitor economic activities and movement of people at a local scale.

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 Soundscape and ambient noise levels of the Arctic waters around Greenland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Ladegaard ◽  
Jamie Macauley ◽  
Malene Simon ◽  
Kristin L. Laidre ◽  
Aleksandrina Mitseva ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Anthropogenic Activities ◽  
Open Water ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Underwater Noise ◽  
Noise Levels ◽  
Greenland Sea ◽  
Mammal Species ◽  
Seismic Surveys

AbstractA longer Arctic open water season is expected to increase underwater noise levels due to anthropogenic activities such as shipping, seismic surveys, sonar, and construction. Many Arctic marine mammal species depend on sound for communication, navigation, and foraging, therefore quantifying underwater noise levels is critical for documenting change and providing input to management and legislation. Here we present long-term underwater sound recordings from 26 deployments around Greenland from 2011 to 2020. Ambient noise was analysed in third octave and decade bands and further investigated using generic detectors searching for tonal and transient sounds. Ambient noise levels partly overlap with previous Arctic observations, however we report much lower noise levels than previously documented, specifically for Melville Bay and the Greenland Sea. Consistent seasonal noise patterns occur in Melville Bay, Baffin Bay and Greenland Sea, with noise levels peaking in late summer and autumn correlating with open water periods and seismic surveys. These three regions also had similar tonal detection patterns that peaked in May/June, likely due to bearded seal vocalisations. Biological activity was more readily identified using detectors rather than band levels. We encourage additional research to quantify proportional noise contributions from geophysical, biological, and anthropogenic sources in Arctic waters.

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 The effect of confinement due to COVID-19 on seismic noise in Mexico

Solid Earth ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 1411-1419
Author(s):  
Xyoli Pérez-Campos ◽  
Víctor H. Espíndola ◽  
Daniel González-Ávila ◽  
Betty Zanolli Fabila ◽  
Víctor H. Márquez-Ramírez ◽  
...  
Keyword(s):  
Signal Processing ◽  
Mexico City ◽  
Noise Level ◽  
Seismic Noise ◽  
Noise Levels ◽  
Traffic Light ◽  
Economic Activities ◽  
Seismic Stations ◽  
The World ◽  
The City

Abstract. The world experienced the beginning of the COVID-19 pandemic by the end of 2019 to the beginning of 2020. Governments implemented strategies to contain it, most based on lockdowns. Mexico was no exception. The lockdown was initiated in March 2020, and with it, a reduction in the seismic noise level was witnessed by the seismic stations of the national and Valley of Mexico networks. Stations located in municipalities with more than 50 000 people usually experience larger seismic noise levels at frequencies between 1 and 5 Hz, associated with human activity. The largest noise levels are recorded in Mexico City, which has the largest population in the country. The largest drop was observed in Hermosillo, Sonora; however, it was also the city with the fastest return to activities, which seems to correlate with a quick increase in confirmed COVID-19 cases. Mexico initiated a traffic-light system to modulate the re-opening of economic activities for each state. Therefore, since 1 June, noise levels have generally reflected the colour of the state traffic light. Furthermore, the reduction in the noise level at seismic stations has allowed identification of smaller earthquakes without signal processing. Also, people in cities have perceived smaller or more distant quakes.

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 Effect of coronavirus lockdowns on the ambient seismic noise levels in Gujarat, northwest India

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ketan Singha Roy ◽  
Jyoti Sharma ◽  
Santosh Kumar ◽  
M. Ravi Kumar
Keyword(s):  
Urban Areas ◽  
Seismic Noise ◽  
Anthropogenic Activities ◽  
Anthropogenic Activity ◽  
Noise Levels ◽  
Geological Conditions ◽  
Northwest India ◽  
Almost All ◽  
Cultural Noise ◽  
The Impact

AbstractThe Covid-19 pandemic created havoc and forced lockdowns in almost all the countries worldwide, to inhibit social spreading. In India as well, as a precautionary measure, complete and partial lockdowns were announced in phases during March 25 to May 31, 2020. The restricted human activities led to a drastic reduction in seismic background noise in the high frequency range of 1–20 Hz, representative of cultural noise. In this study, we analyse the effect of anthropogenic activity on the Earth vibrations, utilizing ambient noise recorded at twelve broadband seismographs installed in different environmental and geological conditions in Gujarat. We find that the lockdowns caused 1–19 dB decrease in seismic noise levels. The impact of restricted anthropogenic activities is predominantly visible during the daytime in urban areas, in the vicinity of industries and/or highways. A 27–79% reduction in seismic noise ground displacement (drms) is observed in daytime during the lockdown, in populated areas. However, data from station MOR reveals a drastic decrease in drms amplitude both during the day (79%) and night times (87%) since factories in this area operate round the clock. The noise at stations located in remote areas and that due to microseisms, shows negligible variation.

scholarly journals The effect of confinement due to COVID-19 on seismic noise in Mexico

2020 ◽  
Author(s):  
Xyoli Pérez-Campos ◽  
Víctor H. Espíndola ◽  
Daniel González-Ávila ◽  
Betty Zanolli Fabila ◽  
Víctor H. Márquez-Ramírez ◽  
...  
Keyword(s):  
Signal Processing ◽  
Mexico City ◽  
Noise Level ◽  
Seismic Noise ◽  
Noise Levels ◽  
Traffic Light ◽  
Economic Activities ◽  
Seismic Stations ◽  
The World ◽  
The City

Abstract. The world experienced the beginning of the COVID-19 pandemic by the end of 2019, beginning of 2020. Governments implemented strategies to contain it, most based on lockdowns. Mexico was not the exception. The lockdown was initiated in March 2020 and with it, a reduction on the seismic noise level was witnessed by the seismic stations of the national and the Valley of Mexico networks. Stations located in municipalities with more than 50,000 people usually experience larger seismic noise levels at frequencies between 1 to 5 Hz, associated with human activity. The largest noise levels are recorded in Mexico City, with the largest population in the country. The largest drop was observed in Hermosillo, Sonora, however, it was also the city with the fastest return to activities, which seems to correlate with a quick increase in confirmed COVID-19 cases. Mexico initiated a traffic-light system to modulate the re-opening of economic activities for each state. Therefore, since 1 June, noise levels reflect, in general, the colour of the state traffic light. Furthermore, the reduction in the noise level at seismic stations has allowed identification of smaller earthquakes without signal processing. Also, people in cities have perceived smaller or distant quakes.

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