(upbeat music)
- Hi everybody.
I'm Mike Poland, the scientist-in-charge
of the Yellowstone Volcano Observatory
and this is the monthly update for May 1st, 2022.
I'm coming to you today,
from the Cascades Volcano Observatory
in Vancouver, Washington.
CVO is one of five observatories
operated by the U.S. Geological Survey in the United States.
The others are in Hawaii, and Alaska, California,
and of course, Yellowstone.
Now, unlike the other four,
Yellowstone is a virtual volcano observatory,
it exists only online.
Well, there are some USGS scientists
who work in Yellowstone based at California
and Cascades Observatories.
And we also have scientists that are based
in various state geologic surveys, universities,
and research agencies around the country,
because YVO is a consortium of nine different institutions,
scientists that study Yellowstone
based all over the western United States.
Because we're a virtual observatory,
all of the information, all of our work happens online.
So you can actually go to the YVO webpage
and look at any kind of monitoring data that are collected,
whether it's seismic data or ground deformation data,
where the ground is going up or down, even geyser activity.
We also try to put a lot of reports
and compilations of information online.
And one of those reports is available this week.
This is the YVO Annual Report for 2021.
It's got all kinds of information about seismic activity
during the year 2021, ground deformation,
even research activities like geologic mapping,
or studies of Yellowstone Lake.
So if you're interested in what happened
in Yellowstone in 2021, what kind of research,
what kind of activity, check out this report.
It's available free online starting now.
All right, now let's talk about what happened
in Yellowstone during the month of April 2022.
The University of Utah Seismograph Stations,
which is responsible for the operation and maintenance
of the Yellowstone seismic network,
located 141 earthquakes in the Yellowstone region
during the month of April,
and this is pretty typical for the Yellowstone area.
The largest earthquake of the month
was a magnitude 2.5 earthquake,
that occurred north of West Yellowstone on April 30th.
Now included in these 141 earthquakes
were three small swarms.
In the middle of April,
there were 24 earthquakes that occurred
to the north of West Yellowstone.
Also in mid-April,
another 20 earthquakes occurred in this little cluster here,
to the north, northeast of West Yellowstone.
And finally in early April,
a small cluster of 14 earthquakes occurred
to the south of West Thumb and Lewis Lake area,
in the south part of Yellowstone National Park.
This sort of swarm activity happens all the time
in Yellowstone.
In fact, about 50% of all Yellowstone earthquakes occur
as part of these small swarms,
most of them between the Hebgen Lake
and Norris Junction area.
This is the most seismically active part
of Yellowstone National Park.
Ground deformation has seen a continuation of the patterns
that have been going on now for several years.
Now, this is vertical deformation
at the White Lake GPS station,
on the east side of the caldera, Sour Creek resurgent dome.
Each blue dot represents one day of data.
The entire plot spans the past two years.
When you see upward trends that's uplift
and downward trends indicate subsidence.
And over the past two years, and in fact,
extending all the way back to 2015,
the trend has been dominantly subsidence,
interrupted during summer months by a pause
in that subsidence or a slight amount of uplift.
And that's due to groundwater
that percolates from runoff into the subsurface.
The trend of subsidence is continuing into today.
It's occurring at a rate of about one inch or so per year.
Moving to the other side of the caldera,
the Mallard Lake resurgent dome.
This is from a GPS site near Old Faithful
and we see the same sorts of trends.
Now, the signal gets much, much better here
in September of 2020, when some of the trees
around the site were removed, there was a fire nearby
and some of the trees were removed
to reduce the fuel load in the area.
You can see this overall subsidence,
interrupted during summer months by a pause
or a slight amount of uplift, and then subsidence again.
This period in December of 2020
shows a small deviation from that,
and that's because snow covered the antenna
during a particularly intense winter storm.
And then finally,
there's the GPS site near the Norris Geyser Basin.
We haven't seen much at all
over the past two years at this particular site,
very, very minor trends in either direction up or down.
Then there's this large deviation again here
in December of 2021,
again, due to snow covering the antenna.
So not a whole lot of deformation
in the immediate vicinity of Norris Geyser Basin.
And finally turning to Steamboat Geyser,
everybody's favorite geyser,
tallest geyser in the world.
We went month without an eruption,
a major eruption at Steamboat.
This is the temperature record
in the Steamboat outflow channel.
All of these rises and falls
are the daily temperature variations.
And then towards the middle of the month of April
we started to see a little bit more fuzziness
to this record.
And that's due to minor eruptive activity.
We tend to see more and more minor eruptive activity
before a major eruption.
So it doesn't look like Steamboat is done
putting on a show quite yet.
Hopefully this minor activity will culminate
in a major eruption at some point during the month of May,
and we'll hopefully see even more major eruptions
during the summer months.
It's a spectacular site.
So hopefully Steamboat's not done just yet.
Well, that does it for the May 1st 2022 monthly report.
Now, remember if you have any questions at all,
you can feel free to email us at YVO web team,
that's all one word at usgs.gov.
And next month, we're gonna be coming to you
from Yellowstone National Park itself.
All of the scientists that work
as part of the Yellowstone Volcano Observatory
are gonna be getting together
in our first in person meeting in four years.
So next month we'll be reporting from Yellowstone,
talking about activity there and introducing you
to some of the scientists that work as part of YVO.
So until then stay safe, stay healthy,
we'll see you again real soon, bye bye.
(upbeat music)