The data below are the most preferred data available
The data below have been reviewed by a scientist
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 could be 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.
What we think will happen next
According to our forecast, over the next 1 Week there is a < 1 % chance of one or more aftershocks that are larger than magnitude 7.0. It is likely that there will be smaller earthquakes over the next 1 Week, with 28 to 64 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
Our forecast is based on observations of the aftershocks that have occurred so far, as well as the general behavior of past aftershock sequences.
So far in this sequence there have been 216 magnitude 3 or higher earthquakes, which are strong enough to be felt, and 5 magnitude 5 or higher earthquakes, which are large enough to do damage.
Our detailed aftershock forecast
The USGS estimates the chance of more aftershocks as follows: Within the next 1 Week until 2018-12-14 16:00:01 (UTC):
The chance of an earthquake of magnitude 3 or higher is > 99 %, and it is most likely that as few as 28 or as many as 64 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 36 %, and it is most likely that as few as 0 or as many as 3 such earthquakes may occur.
The chance of an earthquake of magnitude 6 or higher is 4 %, such an earthquake is possible but with a low probability.
The chance of an earthquake of magnitude 7 or higher is 1 in 200, such an earthquake is possible but with a low probability.
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: 2018-12-07 16:05:39 (UTC)
This forecast will be updated on or before 2018-12-14 16:05:39 (UTC)