Jake Lowenstern: I'm Jake Lowenstern of the US Geological
Survey and I'm Scientist-in-Charge of the Yellowstone
Volcano Observatory. Today, we're going to talk about
the Yellowstone Volcano Observatory, what it does,
who makes it up and what we do, what are the monitoring
techniques that we use to look at volcanic activity
at Yellowstone.
The Yellowstone Volcano Observatory is a virtual observatory.
There is no building. We're a partnership of three different
organizations. There is the USGS, my organization which runs
the volcano observatories.
Then, there's the University of Utah and they run the seismic
and ground deformation networks, and they're doing the
geophysics involved with volcano monitoring. And finally,
we have the land manager, Yellowstone National Park, and
their group of scientists who're out looking at the
hydrothermal activity and the other geological
activity at Yellowstone.
The main systems that we use for monitoring at Yellowstone
are the seismic and the GPS ground deformation systems.
The seismic system is about 27 different seismic stations.
They are spread out all over Yellowstone and they allow us
to look at the size of earthquakes, the timing of
earthquakes and the magnitude, how big they are,
how much energy they release. Beyond that, we have GPS
stations and the GPS stations are on very fixed monuments
that are put into the ground. And they're averaging
their location over many, many days and are taking
data constantly. And that allows us to get very precise
locations and to see how any spot on the ground is
moving over time. And with a result of having this
technique, we can see that the ground at Yellowstone,
for example in this area right here, has moved about
20 centimeters or something around 12 inches upwards
over the last four and half years.
[Scoring Text: How are satellites used to study deformation?]
We have two primary methods of looking at ground deformation, one, we've already talked
about, the use of satellites
and the GPS system. And there we can look at one point in
space or one point on the ground and see how it moves over time.
We have another technique that allows us to look at
all of the ground surface at the same time, and that's
called InSAR or Interferometric Synthetic Aperture Radar.
In this case, you get two radar images that are taken
maybe a year apart. And you can't see what happened
over that year but you can see the amount of movement
everywhere within the park over that one-year time shift.
We do look at the geysers as well in some locations,
but we don't have the data in real time. Instead, we
have data loggers, which show the temperature of different
stream outlets and geyser outflows and pool temperatures.
And we can go collect that data and put it in an archive
and look at the changes in the temperature of different
features over time.
Another thing that we have is the park has contracted
with various different university groups to fly over
Yellowstone and take thermal images of the park.
And what they're trying to do with those thermal images
is look at how the park changes over time and see if
some of the thermal areas are shrinking and
other ones are growing.
[Scoring Text: Swarms of earthquakes and ground deformation at Yellowstone.]
Ever since people started coming to Yellowstone there've
been lots of earthquakes. And ever since we started
putting up a seismic network, we've seen that there
are swarms. That sometimes there's a swarm every few
months somewhere in the park. The biggest one that we
know of was in 1985, there's been smaller ones since then.
Also we know that there's been the ground moving up
and down over time. Between the 1920's and the 1970's,
there was a shift in Yellowstone Lake and that caused
areas in the south to be drowned. And there was about
80 centimeters of upward movement of the caldera floor
up in this region and so we know that there's been this
kind of activity. When people have looked at lake
levels in the past, they've seen over the past 10,000
years there are even bigger uplifts and down warps
that had been occurring at Yellowstone.
So this clearly is the kind of activity that is
always happening at Yellowstone. You go around calderas
in other places in the world, and we can even find
more extreme examples of ground deformation, of swarms,
also without any volcanic activity.
So in general, anytime we see a swarm or we see bit
of ground deformation, we don't necessarily think
that this is indicating a volcanic eruption. There's a lot of things that go on at Yellowstone.
It's an active place. That's what makes it so special.
We don't necessarily tie every single anomalous bit
of activity into a volcanic eruption.
So, YVO includes a couple different people working
from the U.S. Geological Survey, a couple of people
working at Yellowstone National Park, and a group of
people working at the University of Utah on the
geophysical data, the seismic and GPS data. In general,
it's a relatively small operation because there's a lot
of volcanoes in the United States. We have well over
100 that have erupted in the last 10,000 years, and so
there's a lot of activity to watch. In Alaska, there
are about 80 different volcanoes and probably about a
quarter of them have erupted in the last 50 to 100 years.
So there's a lot that we need to look out for.
Yellowstone is an important part of the volcano program,
but it's not the only part. And so we also need to
make sure that we have people out looking at the
Cascades volcanoes in Washington, Oregon and California,
at the Long Valley Observatory also in California,
and then in Alaska and Hawaii.
If you go to our website, which is volcanoes.usgs.gov/yvo, you'll see that we put out a monthly update.
And that update summarizes everything that we've seen
in terms of the ground deformation, in terms of earthquakes
over that monthly period. Anytime anything else happens,
there might be a hydrothermal explosion, there's a swarm
of earthquakes, there's maybe faster ground motion,
we'll put out an information release.
And that information release will also get put right there
in the front page of our website and will provide
information on what's happening right now. That all goes into an archive so you can look
back at the
last six months or nine months or eventually many, many
years of information releases and monthly updates and
get a view of what's been happening at Yellowstone over time.