[Strategerist]

Do not mild earthquakes indicate normal movement (i.e. relieving of stress)?

Earthquakes of this size relieve basically no stress whatsoever.

It would take ONE THOUSAND quakes of this size (M 4.0) to relieve the same amount of stress as an M 6 quake.

[Dog Gone]

Every earthquake on a fault line relieves stress.

[Michael.SF.]

It would take ONE THOUSAND quakes of this size (M 4.0) to relieve the same amount of stress as an M 6 quake.

Actually it sounds like you are confirming what I stated, rather than disputing it. Consider that the map in post seven shows 386 earthquakes occurring in California in the last week. So how many is that over a period of time?

At that rate that is about 20,000 earthquakes in a year. Given that rate may be unusually high, but even if it is off by a factor of 2, that is still 10,000 quakes in a year.

As I said, I would be more concerned of a big one if we were not having any small ones.