(upbeat guitar music)
Hi everybody, I'm Mike Poland, the Scientist-in-Charge
of the Yellowstone Volcano Observatory,
and I'm here with the update for March of 2020.
We're gonna talk about what's been happening in the park
over the last month or so.
Before we dive into the data,
I wanted to wish a happy birthday
to Yellowstone National Park.
It was March 1st of 1872 when President Grant
signed the Yellowstone Protection Act,
establishing the park, so to Yellowstone,
happy 148th birthday.
All right, let's dive in and look at what's happened
over the past month in Yellowstone.
The University of Utah seismograph stations,
which is responsible for the operation and maintenance
of the Yellowstone seismic network,
located 222 earthquakes during the month of February, 2020.
You can see them here on this map,
distributed more or less randomly throughout the region.
The largest event occurred on February 10th
on the north side of Yellowstone Lake,
it was a magnitude 2.4.
In addition to the random seismicity throughout the region,
there were three swarms that were recorded during the month.
The largest in terms of numbers of earthquakes
was this cluster right here, just a few miles to the west
of the Norris Geyser Basin.
That occurred during February 17th to the 24th,
and it included 68 earthquakes, the largest of which
was a magnitude 2.1.
A slightly smaller swarm occurred down here
on the Pitchstone Plateau.
That included 38 events, largest of that sequence
was a magnitude 2.3, and those occurred
during February 11th to 12th.
And finally, there was a cluster right up here
just to the east of Hebgen Lake,
in an area where we've seen, historically,
quite a lot of seismicity.
There were 13 events there
that occurred February 3rd and 4th,
and the largest was a magnitude 1.2.
So the seismicity included quite a few swarm events,
and that's pretty normal for Yellowstone,
where about half of all of the earthquakes
that are recorded are part of seismic swarms.
In terms of deformation, we've seen trends
that have been established over the last several years
continue over the last few months.
So this is a plot of deformation
from GPS station on White Lake,
which is at the Sour Creek resurgent dome.
Each dot is a day of data,
it's vertical, so downward trends are subsidence
and upward trends are uplift.
So over the last two years,
the Sour Creek resurgent dome has been subsiding,
and those trends continued over the last month.
The rates are about a few centimeters,
maybe an inch a year or so.
Moving to the Mallard Lake resurgent dome,
this is a GPS site that's near Old Faithful,
and the same sort of trend applies,
aside from some seasonal up and downs,
the overall trend is one of subsidence over time,
few centimeters, about an inch a year.
And finally, we can go to the Norris Geyser Basin.
Now, Norris had been uplifting from 2015 to 2018.
In this plot that just spans the last two years,
you can see the uplift that began in 2015,
here it is continuing through 2018,
but it pauses in late 2018,
and by 2019 there appears to be some subsidence,
especially towards the end of 2019.
Now, since the beginning of 2020,
that appears to have more or less paused,
so we haven't seen really a lot of significant deformation
of the Norris area in the last few months.
And finally, we'll move to everyone's favorite geyser,
Steamboat Geyser, it erupted four times
during the month of February.
This is a temperature record
in the outlet channel for the geyser,
so every time you see temperature spikes,
that's geyser activity.
So that spike there represents an eruption on February 1st.
It also erupted on February 12th.
Another eruption occurred right about here
on February 21st, unfortunately the temperature recorder
was out at that time, so we caught the build up
to the eruption, but not the eruption itself.
And finally, the last eruption of the month
was on February 28th, late in the night.
So four eruptions of Steamboat Geyser in February,
bringing the grand total of eruptions
for the year, 2020, so far to six.
Well, that does it for the March update
for the Yellowstone Volcano Observatory.
Now remember, if you have any questions,
feel free to email us anytime,
at yvowebteam, all one word, @usgs.gov.
Have a great March, and we'll see you in April.
(upbeat guitar music)