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complete will
full color photos.
Witness
a Volcanic Eruption
Earthquakes, Steam, and Small Ash Plumes
from Lava Dome Rock Fall Continue
The ongoing
eruption of Mount St. Helens has amazed volcano watchers
both in terms of its longevity (2 ½ years) and
the largely non-explosive extrusion of seven massive
“new” lava spines into the crater. As rising
lava pushes up through the crater floor, the growing
lava dome shoves glacial ice east and west against the
crater walls, effectively splitting the glacier in two.
The east and west arms of the Crater Glacier flow north
and surround the “old” lava dome that formed
between 1980 and 1986 (see photo at left).
As you visit the monument, listen for the sound of
a helicopter transporting USGS scientists or one of
the
remote “spider” instrument packages in or
out of the crater. The “spiders” are part
of a network of instruments that continuously monitor
earthquakes and ground motion at the volcano. Real-time
data are combined with field observations to assess
potential hazards and forecast future activity. As we
watch the ongoing eruption, scientists and volcano enthusiasts
eagerly await the next dramatic development in the unfolding
story of Mount St. Helens’ dynamic history.
Current
Eruption Facts
October,
2004 – Mount St. Helens erupts after
18 years of quiet. Lava extrudes from the crater floor
at a rate of 1 dump truck load per second and builds
a new lava dome.
March, 2005 – Dome growth continues
(½ dump truck load per second), small steam and
ash eruptions lightly dust nearby areas.
October, 2006 – Seven massive
lava spines have been extruded (114 million cubic yards);
enough to fill Portland’s Rose Garden Arena 150
times. At 1300 feet, the top of the “new”
lava dome is taller than the Empire State Building.
May, 2007 - Lava extrusion decreases
(a small pickup truck load every 2 seconds). No explosive
eruptions in a year. Dome rock falls produce some
small ash plumes.
Howdy and a Big Volcano Welcome!
Join
us for another exciting year at Mount St Helens. We
invite you to explore our erupting volcano, engage with
our friendly volunteers
and staff, and leave with an enhanced appreciation
of this special place.
With the help of our partners, the Mount
St. Helens Institute and the Northwest
Interpretive Association we will strive to make
your visit memorable and enjoyable.
By staying on paved walkways and
developed hiking trails, you will help us protect fragile
features and the result of 28 years of nature’s
handiwork.
Tom Mulder
Monument Manager
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Visitors view Mount St. Helens over low clouds from the Johnston Ridge Observatory - August, 2007
About
Volcano Review
Volcano
Review is available online as a set of Adobe
PDF file format downloads. We reproduced the
contents of the Volcano Review as a mini-web site,
as well as provide those same download
files for you.
The
hard-copy Volcano Review is distributed at the
Monument and in the surrounding communities.
You may use the links to
your left to find your way around, and/or begin
your exploration using the map below. Move your
mouse over the map to locate items of interest
(and the links that go with them). Here's a hint
-- look for the items marked in red on the map! |
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