Have you been also wondering if the number of earthquakes has increased in recent months, or loosely since the beginning of the coronavirus-led lockdown? And does this increase has something to do with our restricted movement?
Let’s dive into what is actually happening.
Our Earth is made up of many pieces — called tectonic plates — which keep moving around slowly, but are stuck at their edges (plate boundaries) due to friction. An earthquake is what happens when two of such pieces of the Earth suddenly slip past one another, overcoming the friction that holds them together. This leads to a release of energy, which radiates in all directions in the form of waves called seismic waves. These waves reach the surface of the earth and make the ground shake.
There are human-induced earthquakes too, which are caused by activities such as extraction of mining products, groundwater, oil and gas. They are also caused by building reservoirs behind dams that leads to increased fluid pressure on the surface of the Earth. Other activities include explosion from underground bombs, nuclear tests or injecting fluids back to the Earth, also known as fracking.
But what about our daily activities, like getting up, walking, driving a car, traveling by train or taking a bus? Do these activities also contribute to an earthquake?
The answer is No.
The daily activities that humans perform cause small vibrations that lead to anthropogenic seismic noises, but these are not responsible for earthquakes. Now you must be wondering, why are we suddenly hearing more news about earthquakes this year than any other year?
Well, I have to say, some of it is psychological, some the responsibility of the media and the Godly search-engine Google, which uses your data to show personalised content, while the rest may only be because you started to read more to cope up with the lockdown boredom.
Let’s walk over some figures.
According to the Earthquake Catalogue of the United States Geological Survey (USGS), the number of quakes with a magnitude of more than 4.5 in a specific time frame is tabulated below:
Reacting to this data, Celeste Labedz, a PhD student at the California Institute of Technology Seismological Laboratory, says, “All earthquakes are at a totally normal level…nothing different this year than any other year for earthquakes.”
“If you’re trying to write a story on earthquakes being different this year, they are not. That would be a very boring story,” she jokes.
On being asked if this is a marginal drop in the earthquake rate, Labedz says, “It is a random distribution, sometimes there are a little bit more earthquakes, sometimes less.”
This leads us to our conclusion that daily human activities or changes in behavioral patterns due to the COVID-19 lockdown are not responsible for the occurrence of any earthquakes. Further, the USGS website says, “The increasing number of earthquakes in recent years is not because there are more earthquakes, but because there are more seismic instruments and they are able to record more earthquakes.”
It adds, “As a result of the improvements in communications and the increased interest in natural disasters, the public now learns about earthquakes more quickly than ever before.”