First, think of the ground surface,
and then let's start having a mass of very hot molten rock,
which we call magma,
moving up towards the surface.
As it moves up, it starts to break the overlying rock.
And those breaks basically are earthquakes.
So in the area, on the ground surface,
above the molten rock, which is moving up,
there will be hundreds to thousands
of earthquakes per day.
And those earthquakes will probably be in the 4.5
magnitude range or larger.
The other thing that occurs
as this gets close to the surface,
the ground starts to deform.
It actually gets bent.
So in the area of the earthquakes,
you should also see significant ground deformation.
Sometimes up to a yard a year may occur
preceding an eruption.
Also, we would expect to see changes
in the hot water features,
the geysers and hot springs,
as this molten rock gets near the surface.
And we would expect to see changes
in the geothermal gases that come from the ground.
Now, do we have earthquake swarms in the park?
Definitely.
Do we have ground deformation?
Definitely.
Does the hydrothermal system change?
Every day.
But are those signs of an impending eruption?
No.
All these things have to be coincident, in the same area,
and very concentrated, at greater magnitude,
and many more of them than we currently see.
So having an earthquake swarm near Norris
and ground deformation in the White Lake area,
and changes in the thermal system in Mammoth,
they're all part of the normal vital signs of this volcano.
And there has been nothing that has been indicated
that there is an impending eruption.