Hi All. I got to wondering if the M>5.4 Big Bear City quake could in some way be related to the M>7.3 Landers quake of 1992. I didn’t find anything that would lead me to believe that it is, but there is a possibility that it could be related to the M>6.4 at Big Bear Lake in 1992. If you remember it is felt that this quake was triggered by the Landers quake.

I used the ANSS quake catalog as I felt this would have the revised (if any) location of the Big Bear City. There was a difference of about 4 miles with the new location to the west of the computer-generated epicenter. I plotted the epicenter of the quakes on a topo map.

The 1994 fault map shows there are a number of small faults in the area of the M>5.4 quake. All are unnamed and are listed as being older then 1.6 million years, but should not be considered inactive.

The Big Bear Lake of 1992 also appears to be located on some unnamed faults that are younger then 1.6 million years old and show some activity. The Santa Ana fault could be the principle fault for the Big Bear Lake quake as it is about 4 miles south of the epicenter to the quake. There is about a 12-mile separation between the Big Bear City quake and the Big Bear Lake quake. The map doesn’t show any connection between the two in regards to faults, but that doesn’t mean there isn’t one.

When I plotted the quakes above M>3.0 there appears to be a NNW by SSE trending. This is close to the direction of the faults north of Big Bear Lake/Big Bear City.

Now I’m not 100% sure about this, but I think there was some talk about some of the strain from the Landers quake may have triggered the M>6.4. If that is the case the transfer of some of that strain could also have caused the M>5.4 quake.

It sure is going to be interesting to see how this ends. Take Care…Don in creepy town