Something odd is going on just north of Weaverville, NC. Since Sunday, there have been 15 microquakes within a mile radius. What could be going on?
The magnitude of these quakes have been between M1.1 to as high as M 2.5. They all have been very shallow as well. While it is not unusually to have small quakes in the Western Carolinas this many over such a short period and centered over such a small area is odd.
My suspicion is this might be due to mining, drilling or construction in the area. There was a similar swarm near Boone where they were blasting part of the mountain away for the HWY 321 widening. To my knowledge though I don’t know of any there. There are no waste water injection wells in this area, so that is not the cause. It could just be natural as well as mountains settle and shifts over time.
Update: It’s likely Drought Conditions:
One of my suspicions seems to make the most sense. Ground water and surface water levels are extremely low in this area. Satellite data shows this exact parts of Western North Carolina extremely low ground water levels. The lake of water and weight from surface water in this area might be triggering some shifting or reducing weight on an ancient fault. This seems to be the most plausible reason but with two more quakes in the past 24 hrs, it will interesting to see how long they go on for.