Fault zones play a key role in shaping the deformation of the Earth's crust. All of these zones contain fluids, which heavily influence how earthquakes propagate. In an article published in Nature Communications, Chiara Cornelio, a PhD student at EPFL's Laboratory of Experimental Rock Mechanics (LEMR), shows how the viscosity of these fluids directly affects an earthquake's intensity.

After running a series of laboratory tests and simulations, Cornelio developed a physical model to accurately calculate variables such as how much energy an earthquake needs to propagate - and, therefore, its force - according to the viscosity of subsurface fluids.

The study formed part of wider research into geothermal energy projects which, like other underground activities, can trigger earthquakes - a process known as induced seismicity, as opposed to natural seismicity, where earthquakes occur without human intervention.

"Subsurface exploration projects such as geothermal power, injection wells and mining all involve injecting pressurized fluids into fractures in the rock," explains Cornelio. "Studies like this show how a better understanding of the properties and effects of fluids is vital to preventing or attenuating induced earthquakes. Companies should factor these properties into their thinking, rather than focusing solely on volume and pressure considerations."

Like soap
Cornelio ran 36 experiments, simulating earthquakes of varying intensity, and propagating at different speeds, in granite or marble, with fluids of four different viscosities. Her findings demonstrated a clear correlation between fluid viscosity and earthquake intensity.

"Imagine these fluids working like soap, reducing the friction between your hands when you wash them, or like the oil you spray on mechanical parts to get them moving again," explains Marie Violay, an assistant professor and the head of the LEMR.

"Moreover, naturally occurring earthquakes produce heat when the two plates rub together. That heat melts the rock, creating a lubricating film that causes the fault to slip even further. Our study also gives us a clearer picture of how that natural process works."

Research paper

Related Links
Ecole Polytechnique Federale De Lausanne
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest

Tweet

Thanks for being here; We need your help. The Space Media Network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceMediaNetwork Contributor $5 Billed Once credit card or paypal		SpaceMediaNetwork Monthly Supporter $5 Billed Monthly paypal only

New earthquaking-sensing method could give earlier warnings
Washington (UPI) Mar 11, 2019
Scientists in Japan have developed a new method for sensing earthquakes. Their analysis suggests subtle gravitational signatures precede an earthquake's earliest tremors. The new detection strategy could help earthquake warning systems sound an alarm before a quake begins, providing people more time to evacuate buildings and seek safe ground. Scientists at the University of Tokyo's Earthquake Research Institute were inspired by a recent Italian research paper suggesting earthquakes could ... read more