OK, so I’m watching quakes and things, and this tiny little
issue comes up. There are a bunch of them down in Baja. The
energy from them tends to wander up my way after a while, so I
like to keep tabs on them. Then we got a couple of small ones up
by Mammoth “Lakes” a bit north of Death Valley… that’s actually
a volcanic Caldera and can get really nasty if it blows it’s
top. Think “small super volcano” (if there can be such a thing
as a ‘small one’ of them…) The geology of Southern California
can be a bit, er, complex… There is a subducted spreading zone
(that starts as a Pacific floor spreading area) and then some of
it gets sucked under the North American plate. This “has issues”
like spreading out the Basin and Range area a bit and making
Utah and Nevada larger… as they sink a little. But a lot of it
goes into “other places”. For example, Death Valley. It is below
sea level as it is being slowly pulled open into a rift in the
continent. How much of a rift? The passive margin switched to
active margin in th