[Steve S in SF]

Interesting line of earthquakes along Sacramento River in Northern California.
Thinking they might be related to replenishment of aquifer/ ground water from a wet year after years of drought.?  
5 to 35 kilometers in depth.
Have not seen earthquakes in past shown here.
USGS.gov earthquakes map

[Skywise]

The drought certainly caused a lot of reservoirs to drain to record low levels. Now they're all filled up, or nearly so. What affect does that unloading and reloading have? Especially across multiple reservoirs simultaneously.

Brian

[Island Chris]

Filling a reservoir can trigger earthquakes. I am not bothering to Google it, but there was a rather large one some decades ago in California, that was linked to (I think) filling Oroville reservoir. It is more the pore fluid pressure in faults increasing than the mass of the water that is known to weaken faults. The question is whether filling a reservoir at the surface can increase pore pressure in a fault at the depth the earthquake initiates. Similarly, one would expect there to be a limit to the horizontal distance where reservoir level would affect seismicity.
Chris

[Steve S in SF]

(07-30-2017, 12:15 AM)Island Chris Wrote: Filling a reservoir can trigger earthquakes. I am not bothering to Google it, but there was a rather large one some decades ago in California, that was linked to (I think) filling Oroville reservoir. It is more the pore fluid pressure in faults increasing than the mass of the water that is known to weaken faults. The question is whether filling a reservoir at the surface can increase pore pressure in a fault at the depth the earthquake initiates. Similarly, one would expect there to be a limit to the horizontal distance where reservoir level would affect seismicity.
Chris

Yes- 1975 Oroville Earthquake after they first filled the resevior.