(gentle music)
Hi, everybody.
I'm Mike Poland, the scientist in charge of
the Yellowstone Volcano Observatory.
And this is the YVO monthly update
for May 1st of 2021.
It's May, and that means it's field season in Yellowstone.
The roads are finally mostly open
and enough of the snow is melted
that geologists and geophysicists, geochemists,
can get in and start doing some of the work
that they've been planning for the last several months,
and the field work is going to start next week.
There's a team headed to Yellowstone that will
be deploying a temporary GPS network.
Now we do have a continuous GPS network in Yellowstone.
It operates 24/7, 365 days a year.
That's denoted by these green circles
throughout the Yellowstone region.
But we like to densify that network
during the summer months.
So every May we deploy temporary sites
and then we collect those in October.
The sites are very low profile, low power,
and they aren't radio connected.
So we have to actually pick them up in October
before the snow falls in order to download them
and get the data.
That's one of the sites here that's being installed a couple
of years ago, and you can see we sometimes have to dig
through quite a lot of snow to get down to the ground.
But there's a solar panel
and a battery pack that powers the instrumentation.
And then the GPS antenna sits quite close to the ground.
So this gets deployed every May
and it'll get picked up again
later this year in October before the snow starts to fall.
We'll also do some maintenance
on the Norris temperature monitoring network.
Now, this is a network of temperature monitoring stations
deployed at nine areas throughout the Norris region.
For example, Steamboat Geyser, Echinus Geyser.
Here's a photo of Steamboat erupting
from a couple of years ago.
All that water flows down this outwash channel
and our temperature loggers sits in the channel.
So whenever hot water from an eruption goes over
our temperature sensor
it records a spike in temperature.
So this provides a way to monitor what these
features might be doing over time.
All this data is radioed in real time
to a base station and then put online.
So you can follow along from the YVO website.
So we need to go in once a year
and usually do battery swaps,
check some of the thermal probes,
make sure that everything is functioning properly.
So that'll happen next week also.
But this is really just the opening phase of a lot
of field work that's planned for the summer of 2021.
And that's going to include the installation
of a temporary experimental gas monitoring station
near Mud Volcano.
A lot of geologic field work mapping different areas
throughout the park, upgrades to seismic stations
and the seismic radio network to make sure we're
always getting seismic data back to be processed
at the University of Utah.
And even the National Park Service is going to
continue their hydrothermal feature survey
where they are mapping out
and documenting every hydrothermal feature in the park.
So a real full field season coming up
in the next few months
2021 is going to be just as busy as ever.
Okay with that, let's talk about what happened
in Yellowstone during the month of April.
The University of Utah seismograph stations
which is responsible for the operation and maintenance
of the Yellowstone seismic network, located just 43 earthquakes
in the Yellowstone National Park region
during the month of April 2021.
There were no swarms in the region.
You can see the earthquakes are widely dispersed
throughout the area.
And the largest magnitude event was a magnitude 2.5
that occurred on April 27th
about halfway between Hebgen Lake and Norris Geyser basin.
This area is typically where we see the most seismicity
in the region.
In terms of deformation we haven't seen much in the way of
real changes either over the last several years.
This is vertical deformation over the last two years
at the White Lake GPS station
which is located on the east side of the caldera,
the Sour Creek resurgent dome.
Each one of these dots is one day's worth of data.
Upward trends indicate uplift
and downward trends indicate subsidence of the ground.
And you can see over this past two year period
the dominant trend has been one of subsidence
by about two or three centimeters per year.
That's about an inch per year.
During the summertime however there are these
brief periods of uplift.
You can see in 2019 here, in 2020 here,
and possibly beginning in 2021,
these little periods of uplift typically start
in April or May.
And they're caused by recharge
of the groundwater system from all the snow melt.
That's putting a lot of meltwater into the subsurface.
So we may expect to see this transition to become more clear
in the months to come.
Switching to the other side of the caldera
the west side of the caldera and the Mallard Lake resurgent
dome near Old Faithful.
We see the same overall trend
of ground subsidence by a couple of centimeters per year,
a little less than an inch per year
with some possible localized uplift occurring
during the summer months.
And we may be seeing the transition to that
happening right now.
At the Norris Geyser basin
there really hasn't been any deformation at all
since early 2020.
This is vertical uplift over the last two years at Norris.
And the fact that there really hasn't been any change
in this trend here since early 2020 suggests that
there's just no deformation happening in the Norris region
at this time.
Finally turning to Steamboat Geyser,
everyone's favorite geyser.
Eruptions there continue.
This is a plot of the temperature of
the outflow channel at Steamboat.
Every time the temperature increases that's a sign
of minor geyser activity occurring and those minor
eruptions culminate with a major eruption.
And then the geyser goes dry.
The temperature drops to background air temperature levels
and then minor eruptions begin again.
We had three major eruptions of Steamboat Geyser
during the month of April.
One here just right at the end of April 4th,
another here on April 16th,
and the third here on April 23rd.
And you can see from the trends towards the end of the month
that we're building again to another major eruption
that should happen in early May.
So May and hopefully throughout the summer,
we will continue to see the spectacular geyser eruptions
occurring at Steamboat.
Well, that does it for the YVO monthly update for
May 1st of 2021.
Now, remember if you have any questions
you can email us anytime at YVOwebteam,
all one word at usgs.gov.
And next month we will coming
to you from Yellowstone National Park.
So until then stay safe, stay healthy.
We'll see you again soon.
Bye bye.
(gentle music)