A 5.1 magnitude earthquake struck the town of Sparta, North Carolina, on August 9, 2020. The community saw widespread damage along the landscape and is still discovering damaged parts of their town. A 1.5-mile-long crack along the surface was recently discovered and has left scientists fascinated by new information the crack may hold.
Researchers found that the earthquake was generated from a reverse fault line, which pushes one part of the plate on top of the other. The southern end of Sparta was slightly raised following the earthquake. The crack runs through a sizable portion of the community, including deep forests, open fields, and commercial buildings.
Seismic activity has been more active since the 2020 quake, with two earthquakes around a 2.0 magnitude, and there is evidence of seismic activity in the past. One thing that makes this earthquake interesting to researchers is its shallowness. While most earthquakes occur 5-7 miles below the surface and are too deep to cause damage, this one occurred merely ¾ of a mile from the surface, damaging cell towers, power lines, and buildings, among other things.
The team of researchers included U.S Geological representative and lead author Paula M. Figuereido, who told reporters, “It’s very rare that a moderate magnitude earthquake will create a rupture at the surface.” Researchers have named the newly discovered fault “Little River Fault.”
There are many questions at play here that scientists do not quite understand yet. “These less active faults ... tend to move when there are pressure changes on the surface above them. These pressure changes can be due to things like sediment or water being added or released over time,” Figueiredo stated. “But these characteristics don’t apply in the Sparta region, which means that there may be something else at play that we don’t fully understand yet.”
The team of researchers is continuing to study the crack, hoping to uncover new information. This 1.5-mile-long crack could potentially lead to groundbreaking discoveries regarding shallow earthquakes around the world.