A few weeks back as part of our collaboration with Hopa
Mountain I led 27 high school students from around the region through a one and
a half hour geology walk around the dynamic Mammoth Hot Springs and as always,
I was astonished by how much change had occurred since my last saunter along
the Terraces. The title of the
presentation I shared with these wide eyed students was the same as the one I
led every week for five years for the Park Service as a ranger naturalist, “Yellowstone Is Not A Place, But A Process.”
I always posed the question to visitors from all over the
globe, how in the middle of the Northern Rockies do we have more thermal features
than anywhere else on earth? The majority
of visitors and certainly many of the youth from around Yellowstone Country on
a brilliant winter day just two weeks ago know the answer. Yellowstone is sitting on a hot spot. A hot spot is a plume of magma very close to
the earth’s surface. In our case the
magma plume is approximately 3-7 miles beneath the earth’s surface and the magma
chamber’s heavy breathing and pulsing sends upwards of 2,000 earthquakes—or
what we like to call small tremors—to Yellowstone’s surface each year.
Yellowstone’s approximately 2,000 quakes per year makes us
second only to California in the number of seismic episodes we experience each
year. Recently we have been experiencing
a swarm of quakes across the Yellowstone ecosystem. The University of Utah’s Seismograph Stations
which monitor seismic activity in and around Yellowstone National Park have
registered two quakes of magnitude 3.0 and 3.1 occurring last night, the
evening of January 24th.
Though there has not been a supervolcanic eruption in the
Yellowstone ecosystem for approximately 640,000 years, two of the earth’s
largest eruptions have occurred here over the course of the last 2.1 million
years including the infamous Huckleberry Ridge eruption. The Huckleberry Ridge eruption occurred 2.1
million years ago and is considered by geologists to be the single largest
volcanic eruption in history of the earth.
While it is unlikely we will experience a Yellowstone eruption in our
lifetime, the current seismic activity certainly gives us all something to
ponder and clearly demonstrates Yellowstone’s wild nature.
According to a recent press release distributed by the
Yellowstone National Park, the events of the last few days are most likely being
caused by plate tectonic slips and not magma movement. To read more about the current seismic episode
in Yellowstone National Park visit Yellowstone’s official website.
Series of Minor Earthquakes Continue in Yellowstone
Even during the doldrums of winter, there is always
something exciting of epic proportions in Yellowstone Country! Yellowstone indeed, is not a place, but a
process…
~Michael Leach, Director