Most of our destinations are beautiful sites, but today’s
outing focused on an event and its implications: the volcanic eruption of Mount Saint Helens on May 18, 1980. Here is what the mountain looks like today.
Okay now here is what we want you to do. Enlarge the picture. (You can do that by clicking on the
picture.) Then hold your left index
finger in line with the left side of the mountain and your right index finger
in line with the right side of the mountain, with your fingers touching at the
top. Well that is what the mountain used to look like. It looked similar to Mt Fuji – fairly pointy.
Not anymore – now it is a massive horseshoe-shaped crater.
We went to the Johnston Ridge Observatory where we heard an
interesting ranger-led program. We also watched their excellent video, with
computer graphics simulating the different stages of the eruption. At the end
of the video, the screen rose dramatically to reveal the mountain.
The 1980 eruption released 24 megatons of energy or 1600 Hiroshima atomic bombs. The
area around the mountain was evacuated, but the eruption was ten times larger
than expected and 57 people were killed.
The north side of the mountain blew out, sending a landslide and
scorching air sideways, creating the deadly lateral blast. Trees within 8 miles
were incinerated, trees up to 19 miles were blown down, and trees shielded from
the blast by topography or distance were seared and left standing. This picture
shows all three.
Chunks of the mountain were hurled miles and are called
hummocks, the light rocks in this picture.
Bill hiked to Harry’s Ridge, which gave views of Spirit Lake.
The eruption raised the lake level 200’ and filled it with dead trees. After 34
years, many trees sunk, but others are still floating.
Bill summarizes his hike by rock, sun/wind, desolation, and
life. Rock – rock is everywhere, gray dacite, white pumice, black basalt, all
deposited by various eruptions, without much soil. Sun/wind – the area has almost
no trees, the old trees are weathered stumps or trunks and few new trees have
started, so there is no shield from the sun or wind. Desolation – large swaths
of land are still barren and feel eerie and moonlike. Life – in this
barrenness, life is creeping back, scrub bushes, coarse grass, and wildflowers
are gaining a foothold. This picture tries to capture this juxtaposition of
desolation and life – weathered stumps of incinerated trees surrounded by
wildflowers in the foreground and barren swaths with some green areas in the
background.
