By The Washington Post · Matthew Cappucci · NATIONAL, SCIENCE-ENVIRONMENT
Many were evacuated from the airport, where the Federal Aviation Administration issued a ground stop for all inbound flights. Social media video emerged of damaged pipes gushing water from the ceiling in the airport.
Within an hour of the initial quake, at least a dozen aftershocks greater than 3.0 in magnitude struck in the immediate vicinity.
According to the U.S. Geological Survey, there is a roughly 1 in 5 chance of an aftershock greater than 5.0 in magnitude occurring.
The earthquake was shallow, occurring only about six or seven miles below the surface, which may have maximized shaking at the surface.
According to Utah's Division of Emergency Management, it was the strongest earthquake to strike the state since 1992.
Rocky Mountain Power reported 55,000 customers without power in the Salt Lake region after the quake.
There were reports of structural damage. Cracked walls, toppled furniture and other minor damage was reported at the homes of many residents across the state capital.
Initial data suggests the earthquake was associated with "normal faulting," which occurs when one tectonic plate slides down the side of another.
In addition, there was probably some strike-slipping, which means one plate slid a bit past the other side-to-side.
The quake is likely to have occurred along the Wasatch fault. It parallels the Wasatch Range, which is no surprise, considering the mountains were formed by it. The plate to the east rises, while that to the west dips below.
According to the USGS, the Wasatch fault zone can be divided into 10 smaller segments of faulting, about half of which have been active for 10,000 years. The USGS estimates that those segments produced quakes reaching 7.0 in magnitude about every 900 to 1,300 years.