The Cascades Volcano Observatory, operated by the USGS, in Vancouver,
Washington, reports the growth of a 300-foot spire projecting out from
near the top of the new dome. Called a "fin" by the USGS, this rock projection
has been growing as much as five to six feet a day since last November.
Similar spires and fins have grown from the new dome, only to eventually
collapse. This is a normal occurrence in dome-building.
With the annual reopening of the Johnston Ridge Observatory, the media
is again paying attention to Mount St. Helens, especially since the USGS
report was issued earlier in the week. We are receiving numerous emails
from VolcanoCam viewers asking if it is possible to the new fin using
The answer is yes!! Well, at least until is collapses.
Below are a series of digitally enhanced images created from the above
"master" image. We removed some of the image clutter caused
by the fine ash on the VolcanoCam's lens window, as well the dust in
the air. While
the enhanced images should help you to locate the fin in the "live" image,
there is nothing quite like a visit to the Johnston Ridge Observatory
to see it for yourself!
|Enhanced Image #1 - General View
In the above false color digitally enhanced image,
we digitally removed quite a bit of the dust in the air between the volcano
and the camera, as well as the dust on the camera window.
Fine volcanic ash is a regular occurrence here. In early winter before
the snows cover the surrounding area, winds swirl the dust over, under,
and into everything, including the VolcanoCam. While we endeavour to
visit the VolcanoCam during the winter to perform some equipment checks
and do a bit of cleaning, winter weather often prevents this from taking
place. We only managed two visits to the VolcanoCam during the 2005-2006
winter, one in December and the second one a month later. Hence, the
considerable amount of fine volcanic ash partially obscuring the view.
|Enhanced Image #2 - Old Dome Outline
|The above digitally enhanced image outlines the
top of the old dome. This dome grew during a six year period (1980-1986)
immediately following the 1980 eruption of Mount St. Helens.
|Enhanced Image #3 - New Dome Outline
The above digitally enhanced image outlines the
top of the new dome. This dome began with the October 2004 eruption sequence,
which is still in progress. The new dome is above and behind the old dome
and the south crater wall.
According to the USGS: "The new dome’s summit altitude currently
is about 7,550 feet, towering about 400 feet above the 1980s dome as
seen from the U.S. Forest Service’s Coldwater visitor center. But
that’s still below the 7,770-foot altitude reached last July, before
collapse of a previous spine, and well below the crater rim, which is
mostly above 8,100 feet except at Shoestring Notch or northward where
the crater opens outward toward the roadheads. [March 2, 2006, Daily
|Enhanced Image #4 - Current Fin Outline
The above digitally enhanced image outlines
the current "fin" or spire projecting upward from the new dome. The USGS
fin started growing in November 2005, with a growth rate of five to six
It is only a matter of time before the brittle nature of the fin gives
way and collapses, as all the other fins and spires that have emerged
during this current dome building growth. While there is no way to predict
when this will occur, we can only hope it will happen during daylight
hours with good, clear weather so the VolcanoCam is able to capture the
|Enhanced Image #5
You may notice the near vertical fuzzy line
just above the volcano rim in the upper right-hand quadrant of the image.
We've had guesses ranging from an ash plume, a smudge on the camera lens,
and a tornado, to that errant Mutant Fly with an extra leg. During
our visit to the VolcanoCam in January 2006, we discovered a fine scratch
in the glass window of the VolcanoCam case. The scratch is not on the camera lens.
What caused it? That fine volcanic ash can be as sharp as a surgical
knife. When blown about by the winds, it is relatively easy for a larger
sharp piece to scratch the glass.
Winter weather this past winter
was especially fierce, complete with long periods of clouds obscuring
any views of the volcano so the scratch was not always visible. Now
that the weather is much clearer, it is also much easier to see the scratch.
We plan to replace the glass.