Using Seismic Noise Levels to Monitor Social Isolation: An Example From Rio de Janeiro, Brazil

2020 ◽  
Vol 47 (16) ◽  
Author(s):  
Fábio L. Dias ◽  
Marcelo Assumpção ◽  
Pedro S. Peixoto ◽  
Marcelo B. Bianchi ◽  
Bruno Collaço ◽  
...  
Geophysics ◽  
1975 ◽  
Vol 40 (6) ◽  
pp. 1066-1072 ◽  
Author(s):  
H. M. Iyer

A seismic noise experiment was conducted in the East Mesa area of Imperial Valley, California, by the U.S. Geological Survey (USGS) in May 1972. There is a pronounced heat flow anomaly over the area, and between July 1972 and the present five deep test wells have been drilled over the anomaly by the U.S. Bureau of Reclamation (U.S. Bureau of Reclamation, 1974). At the time of our survey, we were aware of results from a preliminary seismic noise survey in East Mesa by Teledyne Geotech (Douze and Sorrells, 1972). A detailed noise survey was conducted by Teledyne Geotech soon after our experiment (Geothermal Staff of Teledyne Geotech, 1972). Both the Teledyne Geotech surveys show noise levels (in the 3.0 to 5.0 hz band) 12–18 db higher over the area where the thermal gradients and heat flow reach maximum values than in the surroundings. Our results, on the other hand, show that the seismic noise field in the area is dominated by cultural noise, and it is impossible to see a noise anomaly that can be related to the geothermal phenomena in East Mesa. We think that it is important to take into account this disagreement between the two results in order to make a critical evaluation of the utility of seismic noise as a geothermal prospecting tool. The purpose of this note is to put our findings on record.


2019 ◽  
Vol 109 (2) ◽  
pp. 610-620 ◽  
Author(s):  
Erik E. Ramírez ◽  
J. Antonio Vidal‐Villegas ◽  
M. Alejandra Nuñez‐Leal ◽  
Jorge Ramírez‐Hernández ◽  
Adán Mejía‐Trejo ◽  
...  

Geophysics ◽  
1974 ◽  
Vol 39 (4) ◽  
pp. 389-400 ◽  
Author(s):  
H. M. Iyer ◽  
Tim Hitchcock

In September and October, 1972 the U. S. Geological Survey made an investigation of seismic noise associated with the known geothermal phenomena in Yellowstone National Park. Eighty‐four stations, each recording for at least 48 hours, were operated. All major geyser basins were covered by the experiment. L-shaped three‐element arrays, three‐component stations, and single vertical component stations were operated. Four eight‐element mobile arrays were operated to study propagation characteristics of the noise. Preliminary analysis of data shows that high noise levels are associated with all the major thermal areas in the park. An elongated band of high noise envelops Lower and Upper Geyser Basins; noise levels are high around Norris Basin, Mammoth Hot Springs, Sulphur Mountain, and Mud Volcano; and a strong noise field exists around Lower and Upper Falls of the Yellowstone River. The seismic waves generated by the waterfalls have very different spectral characteristics from the waves associated with geothermal activity. The geothermal noise is predominantly in the spectral band of 2–8 hz, whereas the waterfall noise is predominantly around 2 hz. A mobile array operated near Norris Basin showed coherent wave trains radiating from seismic sources in the basin. Seismic noise measured around 50 m from Old Faithful Geyser showed amplitude fluctuations that followed the eruption cycles of the geyser. A few minutes after each eruption, the noise level starts rising slowly in ramplike fashion. Twenty to thirty minutes before the next eruption, sharp bursts of noise activity occur with increasing rapidity and continue for a few minutes after the eruption. The predominant energy of seismic noise generated by Old Faithful is at frequencies well above 8 hz. We postulate that only such high frequency noise is generated by the surface activity of geysers and hot springs and that the lower frequency noise found in and around the geyser basins is generated by a deeper convection system associated with the geothermal activity.


2020 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Natália Loureiro Rocha ◽  
Alcilea Barbosa de Andrade Sora ◽  
Alessandra Da Terra Lapa ◽  
Daniele Durval Dos Santos

O presente relato de experiência visa destacar a vivência dos autores na construção do Projeto Cuidadosamente em uma universidade privada localizada no município do Rio de Janeiro. Objetiva-se com esse estudo apontar a sua inserção prática, bem como, retratar a importância de um projeto desta magnitude no cuidado à saúde psíquica dos acadêmicos de enfermagem, principalmente no contexto atual de isolamento social pela pandemia de COVID-19. Conclui-se que a ação possibilita a construção de uma rede de apoio entre os próprios colegas de classe que estão experenciando as mesmas dificuldades com esse isolamento social e ameniza situações que possam maximizar ou desencadear algum tipo de transtorno mental, a exemplo de ansiedade e depressão, através de uma escuta qualificada, que é atribuição importante do enfermeiro nos diferentes níveis de assistência. Building the Project Mindfully: reflection on the mental health of nursing students in front of COVID-19The present experience report aims to highlight the authors’ experience in the construction of the Project Mindfully in a private university located in the city of Rio de Janeiro. The objective of this study is to point out its practical insertion, as well as, to portray the importance of a project of this magnitude in the care of the psychic health of nursing students, especially in the current context of social isolation by the pandemic of COVID-19. It is concluded that the action makes it possible to build a support network among the classmates themselves who are experiencing the same difficulties with this social isolation and alleviates situations that can maximize or trigger some type of mental disorder, such as anxiety and depression, through qualified listening, which is an important role of nurses at different levels of care.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji

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.


2021 ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji

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.


2020 ◽  
Vol 9 (10) ◽  
pp. e8849109317
Author(s):  
Otto Gabriel Fernandes de Oliveira Cavalcante ◽  
Janks Karbdalla Leal de Paiva ◽  
André Haubrichs de Freitas e Silva ◽  
Brenda dos Santos Costa ◽  
Pedro Marques Miguel da Costa ◽  
...  

Many debates about environmental issues surfaced with the advent of the new coronavirus and social distancing. Therefore, the present article aimed to investigate air quality impacts in Rio de Janeiro, during social isolation period. In order to confirm air pollutants, decrease, for example NO and particulate material, documents such as legislations, technical standards, scientific articles published in this period, were analyzed during the studied period. Furthermore, the article sought to bring awareness about the short temporality of the air quality improvement, since without more sustainable forms of production, in a little while, those pollutants may increase again.


2020 ◽  
Author(s):  
Hiro Nimiya ◽  
Tatsunori Ikeda ◽  
Takeshi Tsuji

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.


Solid Earth ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 2127-2144
Author(s):  
Mario Arroyo-Solórzano ◽  
Diego Castro-Rojas ◽  
Frédérick Massin ◽  
Lepolt Linkimer ◽  
Ivonne Arroyo ◽  
...  

Abstract. A noticeable decrease in seismic noise was registered worldwide during the lockdown measures implemented in 2020 to prevent the spread of COVID-19. In Central America, strong lockdown measures started during March of 2020. In this study, we used seismic stations from Costa Rica, Guatemala, El Salvador, and Nicaragua to study the effects of these measures on seismic records by characterizing temporal variations in the high-frequency band (4–14 Hz) via spectral and amplitude analyses. In addition, we studied the link between the reduction in seismic noise and the number of earthquake detections and felt reports in Costa Rica and Guatemala. We found that seismic stations near the capitals of Costa Rica, Guatemala, and El Salvador presented a decrease in their typical seismic noise levels, from 200 to 140, from 100 to 80, and from 120 to 80 nm, respectively. Our results showed that the largest reduction of ∼ 50 % in seismic noise was observed at seismic stations near main airports, busy roads, and densely populated cities. In Nicaragua, the seismic noise levels remained constant (∼ 40 nm), as no lockdown measures were applied. We suggest that the decrease in seismic noise levels may have increased earthquake detections and the number of felt reports of low-magnitude earthquakes. However, the variations observed in several seismic parameters before and after the lockdown are not significant enough to easily link our observations or separate them from other contributing factors. Our results imply that the study of seismic noise levels can be useful to verify compliance with lockdown measures and to explore their effects on earthquake detection and felt reports.


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