The United States Geological Survey (USGS) has released its annual earthquake hazards map for the contiguous US, and somewhat surprisingly, the likelihood of you – an American – experiencing a significant seismic event in 2017 is actually slightly lower than it was last year. That is, of course, unless you like in Oklahoma.
There are plenty of ways earthquakes can happen, and you can click here to see our summary of them.
One underappreciated source of terrifying tremors is wastewater injection, wherein waste products from oil and gas exploration, and occasionally fracking, are disposed of underground; this can sometimes trigger earthquakes. This type of event is known as an “induced earthquake”.
A fair bit of evidence is coming to light that definitely links oil and gas exploration, as well as fracking, with seismic activity, and states that engage in plenty of it are more likely to experience 3.0M events than others. It is no coincidence that oil/gas exploration-heavy Oklahoma is shown to be at a higher risk of major quakes in 2017.
“Induced seismicity poses the highest hazard in two areas, which are Oklahoma/southern Kansas and the Colorado/New Mexico area known as the Raton Basin,” the USGS summarize in their statement. “In those areas, there is a significant chance that damaging levels of ground motion will occur in 2017.”
All in all, 4 million Americans are at risk of experiencing a significant seismic event this year, and 3.5 million of these live in states that engage in fracking. The overall US hazard risk is lower in 2017 compared to last year though, as more states overall have scaled back their fracking operations and are far more quake free than they used to be.
“The significantly decreased number of earthquakes in north Texas and Arkansas was not expected, and this was likely due to a decline in injection activity,” the USGS add.
The 2017 hazard map of Oklahoma. USGS
It’s important to note that such quakes, although shallow, are not thought to be as dangerous as natural quakes. One of the largest induced earthquakes in recent history was 2016’s 5.8M tremor in Oklahoma – following on from a 5.6M in 2011 – but most seem to hover around the 3.0M mark, and at present, there are several of these every week.
However, there’s a lot science is yet to discover about induced earthquakes, and ramping up fracking and oil and gas exploration without knowing the related earthquake risks (among others) is a little reckless.