Silence of Canadian Cities: COVID19 Lockdown and Seismic Vibrations

[nvikas]

TL;DR Summary

COVID19 Lockdown and the resulting decrease in human activities had an impact on the earth's seismic vibrations. In all the cities (Toronto, Montreal, Edmonton, Calgary and Yellowknife), the seismic vibrations decreased between 14% – 44%. In the 3 densely packed cities of the population over 1 million -Toronto, Montreal, and Calgary, the seismic vibrations dropped by over 30%. The source of data was the seismic stations of the Canadian National Seismograph Network (CNSN).

On 11 March 2020, the World Health Organization (WHO) declared Coronavirus disease (COVID-19) as a pandemic. By then it had spread to at least 110 countries. The announcement made by WHO had a cascading effect. Cities, territories, and countries around the world ended up declaring states of emergency. Schools, universities, malls, non-essential services, government, and private offices were closed putting cities under siege. Canada was no exception. All Canadian provinces and territories — implemented some public or health emergency measures to check the spread of COVID-19.

This was the best time to analyze the impact of the reduction in human activities brought by COVID19 lockdown on the seismic vibration of the Earth.

The ground vibrations sampling rate of many seismic stations is over 100 readings a second. I ended up with a dataset of over 10 billion values from 6 seismic stations across Canada which I had to analyze using #python to measure the changes.

View the graphs of changes in Seismic Vibrations at https://hotpoprobot.com/2020/07/25/the-silence-of-canadian-cities-and-oceans-the-impact-of-covid19-lockdown/

 

[berkeman]

I would guesstimate that the large majority of that reduction was due to the decrease in ground traffic (cars, trucks, trains, etc.). Do you have any research data on the breakdown?

https://i.cbc.ca/1.5511296.15852521...iginal_780/empty-streets-downtown-moncton.jpg

 

[Vanadium 50]

Do you have any research data on the breakdown?

There are a few papers in the literature. For example, https://science.sciencemag.org/content/early/2020/07/22/science.abd2438 They say " everyday human activity is recorded as a near-continuous signal especially on seismometers in urban environments. ".

 

[nvikas]

I would guesstimate that the large majority of that reduction was due to the decrease in ground traffic (cars, trucks, trains, etc.). Do you have any research data on the breakdown?

https://i.cbc.ca/1.5511296.15852521...iginal_780/empty-streets-downtown-moncton.jpg

View attachment 266939

Thanks. I do not have the data of how traffic reduced during the lockdown. But usually noise about 1Hz is classified as noise from human activities. I have provided a baseline, ie ground vibrations before the lockdown to get a measure of natural + human made seismic vibrations prior to the lockdown. During the lockdown, the natural noise remained but human-made noise (likely traffic, construction in cities) reduced causing the likely dip in total vibrations measured.

 

[nvikas]

There are a few papers in the literature. For example, https://science.sciencemag.org/content/early/2020/07/22/science.abd2438 They say " everyday human activity is recorded as a near-continuous signal especially on seismometers in urban environments. ".

Absolutely. And for this study, I selected cities that had a seismic station nearby to get a good measure of the reduction in this near-continuous activity. In 5 out of 6 cities, the seismic noise dipped.