The USGS in California stated late last night that the chance of an earthquake aftershock of magnitude 5 or higher is 99% within the next week in southern California.

The chance of an earthquake of magnitude 6 or higher is 61 %, and it is most likely that as few as 0 or as many as 5 such earthquakes may occur [between now and 7/13/19].”

– USGS yesterday, July 5th at 10:36pm PT

The USGS also stated last night that the chances of an earthquake of magnitude of 6 or higher is 61% and chances of a 7 or higher is 11%.

Our detailed aftershock forecast:
– The USGS estimates the chance of more aftershocks as follows: Within the next 1 Week until 2019-07-13 04:10:00 (UTC):
+ The chance of an earthquake of magnitude 3 or higher is > 99 %, and it is most likely that as few as 250 or as many as 3,600 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 > 99 %, and it is most likely that as few as 2 or as many as 37 such earthquakes may occur.
+ The chance of an earthquake of magnitude 6 or higher is 61 %, and it is most likely that as few as 0 or as many as 5 such earthquakes may occur.
+ The chance of an earthquake of magnitude 7 or higher is 11 %, and it is most likely that as few as 0 or as many as 2 such earthquakes may occur.

– USGS yesterday, July 5th at 10:36pm PT

California experienced its 12th largest earthquake on record last night (July 4th at 8:19pm) – a 7.1-magnitude quake with the epicenter in Ridgecrest (150 miles north of Los Angeles, and 150 miles south of Mammoth Lakes).

This was the largest earthquake in Southern California in 20-years and occurred only 1 day after a 6.4-magnitude earthquake that occurred in the same exact region on July 4th.

Constant aftershocks have occurred between the two large quakes and since the latest 7.1-magnitude quake.

Ridgecrest is experiencing 1 aftershock per minute today.

The largest aftershock was a 5.5-magnitude earthquake that occurred at 8:47pm PT on July 5th – only 28-minutes after the large 7.1-magnitude quake.

Preliminary Event: M 5.5 – 15km ESE of Little Lake, CA: ShakeMap – V , DYFI? – VI, Time – 2019-07-06 03:47:53 UTC (2019-07-05 19:47:53 -08:00 at epicenter), Location: 35.903°N 117.746°W, Depth: 3.37 km (2.09 mi)

– USGS today, July 6th at 12:33am

USGS AFTERSHOCK FORECAST:

Aftershock Forecast
Updated 2019-07-06 04:37:56 (UTC)

Be ready for more earthquakes:
– More earthquakes than usual (called aftershocks) will continue to occur near the mainshock.

– When there are more earthquakes, the chance of a large earthquake is greater which means that the chance of damage is greater.

– The USGS advises everyone to be aware of the possibility of aftershocks, especially when in or around vulnerable structures such as unreinforced masonry buildings.

– This earthquake is part of a sequence. An earthquake sequence may have larger and potentially damaging earthquakes in the future, so remember to: Drop, Cover, and Hold on.

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What we think will happen next:
– According to our forecast, over the next week starting on July 6, 2019 at 04:10 UTC, there is a 9% chance of one or more aftershocks that are larger than magnitude 7.1. It is likely that there will be smaller earthquakes over the next 1 Week, with 250 to 3,600 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.

– More details about the earthquake forecast are provided in the section “Our detailed aftershock forecast” below.

About this earthquake and related aftershocks:
– This forecast is based purely on experience with past sequences in geothermal areas of California, including in this area.

– So far in this sequence there have been 0 magnitude 3 or higher earthquakes, which are strong enough to be felt, and 0 magnitude 5 or higher earthquakes, which are large enough to do damage.

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Our detailed aftershock forecast:
– The USGS estimates the chance of more aftershocks as follows: Within the next 1 Week until 2019-07-13 04:10:00 (UTC):
+ The chance of an earthquake of magnitude 3 or higher is > 99 %, and it is most likely that as few as 250 or as many as 3,600 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 > 99 %, and it is most likely that as few as 2 or as many as 37 such earthquakes may occur.
+ The chance of an earthquake of magnitude 6 or higher is 61 %, and it is most likely that as few as 0 or as many as 5 such earthquakes may occur.
+ The chance of an earthquake of magnitude 7 or higher is 11 %, and it is most likely that as few as 0 or as many as 2 such earthquakes may occur.

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About our earthquake forecasts:
– No one can predict the exact time or place of any earthquake, including aftershocks. Our earthquake forecasts give us an understanding of the chances of having more earthquakes within a given time period in the affected area. We calculate this earthquake forecast using a statistical analysis based on past earthquakes.

– Our forecast changes as time passes due to decline in the frequency of aftershocks, larger aftershocks that may trigger further earthquakes, and changes in forecast modeling based on the data collected for this earthquake sequence.

This forecast was issued: 2019-07-06 04:03:05 (UTC)
This forecast will be updated on or before 2019-07-13 04:03:05 (UTC)