An intense earthquake swarm is taking place near the Salton Sea in Southern California, U.S. on June 5, 2021, starting with M2.2 at 08:05 UTC (01:05 LT).
The USGS has registered 285 earthquakes by 21:24 UTC. The swarm is still in progress and new earthquakes are being registered every few minutes, sometimes 2 or 3 within 1 minute. (Update: 805 earthquakes were registered by 21:29 UTC on June 6)
The strongest so far was M5.3 at 17:55 UTC (10:55 LT). The quake struck 11 km (7 miles) W of Calipatria and 11 km N of Westmorland at a depth of 5.8 km (4.6 miles).
3 000 people are estimated to have felt strong shaking, 9 000 moderate, and 201 000 light.
More than 1 050 people submitted 'I felt it' reports.
Image credit: TW/SAM, Google
M2.5+ earthquakes on June 5, 2021. Image credit: TW/SAM, Google
The USGS earthquake scientists said earthquake swarms in this area are not really unusual.
"We last had a swarm right near today’s activity in 2005. And the entire region surrounding the Salton Sea is known for having swarms; we had two just last fall."
According to the USGS forecast, over the next 7 days there is an 8% chance of one or more aftershocks that are larger than magnitude 5.3. It is likely that there will be smaller earthquakes, with 2 to 46 magnitude 3 or higher aftershocks. Magnitude 3 and above are large enough to be felt near the epicenter. The number of aftershocks will drop off over time, but a large aftershock can increase the numbers again, temporarily.
The chance of an earthquake of magnitude 3 or higher is > 99 %, and it is most likely that as few as 2 or as many as 46 such earthquakes may occur in the case that the sequence is re-invigorated by a larger aftershock. The chance of an earthquake of magnitude 5 or higher is 13 %, and it is most likely that as few as 0 or as many as 2 such earthquakes may occur. The chance of an earthquake of magnitude 6 or higher is 1 %, such an earthquake is possible but with a low probability. The chance of an earthquake of magnitude 7 or higher is 1 in 700, such an earthquake is possible but with a low probability.
Featured image credit: TW/SAM, Google