(Describer) Title: USGS – Science for a changing world.
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(Describer) Quick scenes show work at laboratories and footage of giant plumes of ash rising from a volcano.
(Describer) Waves and colors are reviewed on many computer screens. Title: Volcano Web Shorts Number 1 – Photogrammetry.
I'm Angie Diefenbach.
I'm a geologist with
the U.S. Geological Survey
Cascades Volcano Observatory.
(Describer) The building is shown from the outside.
Photogrammetry is
a technique by which
you can make measurents
from photographs.
Why use photogrammetry
to study volcanic eruptions?
We use equipment like this--
a standard digital camera.
(Describer) She sets it down.
Flying in an airplane
or a helicopter,
we take snapshots like this
from around the volcano.
We put these
into a software program
and add points to represent
the surface of the dome.
Those points tie together
to make a digital model
that looks like this
of the volcano.
(Describer) In archival footage, a small plane takes off.
With traditional
photogrammetry,
we had to contract
an aerial flight service,
send the negatives to be
high-resolution scanned.
Then a different lab would make
our digital elevation models.
Now with a standard
digital camera,
we can produce the same
results within hours.
(Describer) Different photos form one model.
During the 2009 eruption
of Redoubt Volcano in Alaska,
we would fly out there
with a fixed-wing airplane
or a helicopter and,
equipped with a digital camera,
take snapshots of the lava dome
as we fly around it.
Then I would put the images
into a software program
and build a digital elevation
model of the lava dome.
We found, over
a three-month period,
that the lava dome grew
to 72 million cubic meters.
On average, the growth rate
was equivalent to...
(Describer) Photos are shown in quick succession.
Photogrammetry provides
the fundamental metrics
of an eruption--the size
and how fast its growing.
Combined with other data,
like seismicity, gas emissions,
and thermal output,
we can better understand
the volcano as a whole.
That helps us provide
better forecasts
for what may happen next.
That also gets tied
into potential hazards
that may occur.
(Describer) Titles: A production of USGS Volcano Hazards Program, USGS Office of Communications and Publishing.
Funding to purchase and make this educational program accessible was provided by the U.S. Department of Education. Contact the Department of Education by telephone at 1-800-USA-LEARN, or online at www.ed.gov.
Funding to purchase and make
this educational production
accessible was provided by the
U.S. Department of Education:
PH: 1-800-USA-LEARN (V)
or WEB: www.ed.gov.
♪
