(cheerful instrumental music)
Hi everybody.
I'm Mike Poland, the scientist-in-charge
of the Yellowstone Volcano Observatory
and this is the monthly update for November 1st of 2022.
Now November is Native American Heritage Month,
so it seems like a good opportunity,
to acknowledge the long history,
of Indigenous people in the Yellowstone region.
I'm standing next to Nez Perce Creek
and that's named after a tribe,
a small band of which was fighting a running battle,
with the US Army in the late 1870s.
In fact, they crossed Yellowstone National Park,
in an attempt to escape to Canada.
One of the myths about Yellowstone,
is that people really haven't been in the area much at all,
until recently, and we know that's just not true.
Archeological evidence shows that people were in the park,
for at least the past 11,000 years.
We also know that they were using resources in the park,
because obsidian arrowheads
and other artifacts have been found as far away,
as the Ohio River Valley,
but they originated from rock in Yellowstone,
so clearly some of the Indigenous peoples,
who worked in this area traded with people from the outside.
Another enduring myth,
is that people were afraid of Yellowstone,
so there weren't many Indigenous people,
in the region at all anyway and that's just not true either.
Most people did leave the area,
during the very harsh winters,
but there was one group that stayed year round,
a tribe of Shoshoni called the Sheepeaters,
because much of what they needed to survive,
they derived from mountain bighorn sheep.
So a lot of these sort of myths in the last few years,
we've been able to break down really substantially,
thanks to archeological evidence
and the cultural traditions,
of these Indigenous people themselves.
All right, now let's talk about the seismic, deformation,
and geyser activity,
that's occurred over the last month,
here in Yellowstone National Park.
October seismicity in the Yellowstone region,
was dominated by earthquakes in one specific area,
between Mammoth Hot Springs and Norris Geyser Basin.
That's a cluster of earthquakes,
that's been ongoing since late July.
Now during the month of October,
238 earthquakes were located in part of this swarm.
Over a thousand earthquakes have occurred
since the summertime and this actually is not that unusual,
there have been many swarms in Yellowstone,
that have had thousands of earthquakes.
This one has been a long lived one,
percolating along with 238 earthquakes during the month,
out of the overall total of 334 earthquakes,
that were located in the region,
by the University of Utah Seismograph Stations
and they're responsible for the operation
and maintenance of the Yellowstone Seismic Network.
Now, in addition to the swarm between Norris and Mammoth,
we had a small swarm of about a dozen quakes or so,
north of West Yellowstone
and then a couple dozen earthquakes,
in the area north of Old Faithful,
otherwise seismicity distributed throughout the region.
The largest earthquake of the month,
was a magnitude 2.9 that was located as part
of this long-lived swarm between Norris and Mammoth.
In terms of ground deformation,
we haven't seen many changes over the past month.
This is vertical deformation at the White Lake GPS site.
Each one of these blue dots is one day's worth of data.
This is vertical deformation over the past two years,
where downward trends indicates subsidence
and upward trends indicate uplift.
Now, every summer since 2015,
when the current subsidence began,
we see an interruption in that overall subsidence,
a pause in the subsidence or even slight uplift
and that's as water from snow melt,
percolates into the ground
and causes the ground to puff up a little bit.
So we see that every summer,
there it is in the summer of 2021,
then back to subsidence,
here it is in the summer of 2022
and it looked like it was starting to turn around,
back to subsidence in September,
but so far that hasn't fully taken hold.
So not a whole lot of deformation over the last month.
And this is on the east side of Yellowstone Caldera.
On the west side of Yellowstone Caldera,
the Mallard Lake Resurgent Dome near Old Faithful,
we see the same overall trend,
subsidence of a couple of centimeters,
a few inches per year, transitioning
perhaps to a little bit of uplift in the summertime,
back to subsidence and then uplift
and there hasn't been much of a change,
since the onset of that summertime uplift here.
So we might expect to see that transition,
sometime in the coming month.
At Norris Geyser Basin,
there's been very little net deformation,
over the last two years.
This deviation here in December of 2021,
was due to a winter storm that covered the antenna in snow.
Now here's that summertime uplift
and it's basically stayed more
or less constant over the last few months.
So no real changes at Norris.
And finally, turning to Steamboat Geyser,
everybody's favorite geyser, tallest geyser in the world.
We started out the month with no minor activity at all.
These fluctuations are just daily temperature variations.
And then starting in mid-October,
we started to see lots of little activity.
All of this sort of jagged activity,
here in this temperature graph,
is due to minor eruptive activity
and that's putting out small amounts of hot water,
that are detected by our temperature monitoring station
that's in the outflow channel for Steamboat.
And that continued through the end of the month.
So we might expect
that we would see a major eruption,
sometime during the month of November,
since major eruptions tend to be preceded
by this now prolonged minor activity.
So no major eruptions during the month of October,
but hopefully we'll see one in November.
So far in 2022 there have been nine major water eruptions,
of Steamboat Geyser.
Well that does it for the November 1st update.
Now remember, if you have any questions at all,
please feel free to email us any time,
at yvowebteam, all one word @usgs.gov.
Stay safe, stay healthy.
We'll see you next month.
Bye-bye.
(cheerful instrumental music)