Here is a NY Times article on these two earthquakes and 1,000's of other earthquakes that followed them.
This article has some great visualizations, showing the location/size of earthquakes on a map, during and after the recent two big ones, rolling out in the order that they occurred in.
The earthquakes are shown on a map of the affected area, as well as a larger scale version for the whole state (not showing the size-to-strength relationship).
Here is a non-motion screen capture of the graphic:
Watching these earthquakes appear on the maps, makes one think of how earlier quakes locations might be triggering later ones.
The article says:
“Once a large earthquake has happened, the odds of another large earthquake are as high as you’re ever going to see,” said Susan Hough, a seismologist at the United States Geological Survey.
That’s because powerful earthquakes often trigger more quakes nearby. Each of the thousands of aftershocks triggered by the July 5 earthquake has a tiny chance of being strong but is much more likely to be weak. More aftershocks mean more rolls of the dice, increasing the odds that at least one aftershock will be severe.
One thing the visualizations did not show was the direction of movement where the quakes were located (little arrows on the circles would have been informative for example).
To me, it looks like as the earthquakes occur (presumably releasing crustal tension) the tension might build up in neighboring areas, where (there might be an increased likelihood of) another earthquake being occurring, releasing its local tension.
The area of these two quakes looks to me like a zone of interacting fissures getting mashed between the neighboring plates, kind of like a bunch of rubble being pushed around between tow large blocks.
How does this compare to "normal" geological thought?
Is there deeper research on this? I have not heard of it.
