1859_Nov_Dec_2017_final

what i’m working on
Anais Ferot
Exploding Targets
Thomas Giachetti’s research
may help the Pacific
Northwest avoid a major
volcanic catastrophe
interview by Vanessa Salvia
FOR UNIVERSITY OF OREGON
volcanologist Thomas Giachetti,
studying volcanoes is his dream job—a
dream he’s held since he was 12 years
old and watched a documentary on
volcanologists in his native France.
While he doesn’t get to perch on the
edge of active volcanoes as much as
his predecessors from decades ago, he
gets close enough to realize how cool an
eruption can be, and how much there is
still to learn—especially in our volatile
Pacific Northwest.
Thomas Giachetti, with his colleague Tom Shea, does research at an old lava flow in Hawaii in December 2014.
You’re studying magma degassing
during volcanic eruptions. What
does that mean?
A volcano is similar to a soda bottle.
You can’t see any gas bubbles in the
soda bottle until you open it, which
releases the pressure. If the pressure
release is relatively slow the eruption
may be gentle enough that you could
get close to it and be fine.
If the pressure releases too fast, the
magma could explode in a Mount St.
Helens-type eruption, for example.
I’m currently looking at both the last
eruption of Newberry Volcano in
Oregon and that of Medicine Lake
Volcano in California because they
are very similar. Both experienced a
transition from explosive to effusive
eruption, and I’m trying to figure out
how you can tell what type of eruption
you’re going to get from the deposits
they produced.
How does your work intersect with
the Pacific Northwest’s increased
risk for seismic activity?
Because the Juan de Fuca Plate is
going under the North American
Plate, that creates a lot of seismic and
volcanic activity. You better know if
an eruption will be gentle enough that
you can watch it with your cameras or
if it will it be big enough to shut down
all aviation.
How do you get your data?
I first read what my colleagues have
published. Then I take my shovels,
pickaxe, hammer, GPS and camera to
the field. I collect pounds and pounds
of pumice and obsidian rock that I
bring back to the laboratory. What
most people don’t realize is that most
of the time pumice and obsidian are
exactly the same type of rock, except
one erupted really explosively and
the other one erupted effusively, like
a lava flow.
Are there any truly predictive events
prior to an eruption?
Not really. You might be able to say a
few weeks or a few months in advance
that something was going on. Most
of the time you wouldn’t actually
see anything, but the monitoring
instruments would detect something.
What’s next for volcanology?
At the University of Oregon, Gwen and
Chuck Lillis have committed $10 million
to create the volcanic cluster, meaning
we will hire more volcanologists and
Eugene will be the place to be in the
U.S. to study volcanoes. That is a game
changer and is really exciting.
72 1859 OREGON’S MAGAZINE NOVEMBER | DECEMBER 2017