Volcanic ash in Kansas.
It's true there's thick deposits of this stuff there.
But where are the source volcanoes?
Geologists began puzzling over this in the late 1800s, when
these deposits were first recognized.
We're coming to you today from the Rock Chemistry Laboratory
at the Cascades Volcano Observatory of the US Geological Survey.
And it's in places like this that geological mysteries like
that of the Kansas ash get solved.
Now, initially, it was thought that the ash came from
northern New Mexico.
That's the direction of the prevailing winds.
And of course, there are lots of volcanoes in northern
New Mexico.
But the chemistry of the ash didn't match the chemistry
of the rocks.
There wasn't a good match with the rocks in Long
Valley Caldera, another big explosive volcanic system located in eastern
California.
But Yellowstone, spot on match, not only in terms of
the rock chemistry, but also in the timing.
These ash beds in Kansas and throughout the Great Plains
matched up with the big caldera forming eruptions from 2.1
million years ago, 1.3 million years ago and 631,000 years
ago.
And these deposits have been found throughout the West, in
fact even offshore of Northern California in marine sediment drill
cores.
And it's not just these most recent three eruptions that
have deposited ash across the landscape.
Past Yellowstone system eruptions have done that as well.
The asphalt fossil beds in Nebraska are made-up of ash
from a 12 million year old volcanic eruption when the
Yellowstone hotspot was in southern Idaho.
We can learn an awful lot about the Yellowstone System
by looking at ash that covers the western United States.
All right, well, that's the story from Kansas.
Now let's head back to Yellowstone and talk about ground
deformation, seismicity, and geyser activity that occurred during the month
of February.
February continued to see background levels of seismicity in the
Yellowstone region.
The University of Utah located 125 earthquakes in the area
during the month.
The largest was a magnitude 2.6 event that occurred on
February 23rd just to the north of Yellowstone Lake.
There were also two swarms during the month.
One included 49 events in the vicinity of Norris Geyser
Basin and the other included 15 events just to the
north of West Yellowstone Mt.
Those both occurred in this area where we see a
lot of the seismicity in the Yellowstone region between Hebden
Lake and the North Central part of Yellowstone National Park.
Turning now to ground deformation.
This is vertical deformation at the White Lake GPS station
on the east side of the caldera.
It spans 2 years.
Each one of these blue dots is one day worth
of data.
Downward trends indicate subsidence, the ground sinking and upward trends
indicate uplift or rising of the ground.
And the trends we're seeing over this two year.
Are the same things we've seen since 2015.
At the ground subsides at a few centimeters an inch
or two per year and it's interrupted in the summertime
by a little bit of uplift or at least a
pause as groundwater is recharged from snowmelt and spring runoff.
Now since about September or so of last year, we've
seen about 2 1/2 centimeters, a little over an inch
of substance.
So we're really just continuing the trends that have been
going on now for nine years.
Finally looking at the tallest geyser in the world, Steamboat
Geyser.
This is the temperature measured in the runoff channel of
the geyser.
All of this little spiky activity are minor eruptions.
And then we had our first major eruption of the
year in the early morning hours of February 26th and
then it dropped back down to background temperatures.
So Steamboat remains active.
One eruption so far in 2024.
Well, that's the YVO update from March 1st, 2024.
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any questions at all, either leave us a comment or
drop us a line.
Our e-mail address is yvoweb.team@usgs.gov.
Stay safe, stay healthy, and we will see you next
month.
Bye bye.
No place like home.