Geomorphology

After a long (unpredictable! windy! beautiful!) road trip from Upper Michigan, I arrived at the Andrews Experimental Forest in the Willamette National Forest late Friday afternoon —- just in time to check in, and catch part of a talk by researcher Fred Swanson, who was addressing an inaugural gathering of geomorphologists, who are calling themselves the Bretz Club, in honor of J. Harlen Bretz.

Fred Swanson gave me a whirlwind tour of the Andrews admin building, and we walked out to a “gravel bar” site in Lookout Creek, where geologist Gordon Grant was speaking to the assembled geomorphologists. From there, we drove out into the forest a bit, so he could show me a log decomposition study site, one of the “Reflection Sites” that the writers are asked to respond to.  Since I’m new to this pacific-northwest-cool-wet-old-growth-rainforest environment, every detail of the forest scene is new, and staggering. I’m sure I’m missing 90% of it, looking everywhere at once, unfocused.

Evidence of experiments (flagged markers, white plastic buckets and funnels) are scattered like a bit of seaside flotsam, hardly noticeable amid the grand old trees.  A few plastic buckets jut out of downed logs in various stages of decomposition, everything lichenous and moss-cushioned from ground to canopy.

Andrews Forest: LTER - Log DecompAndrews Forest: LTER - Log Decomp

I was given a topo map of Andrews, and marked directions to several other study sites including a clear-cut plot and the “Blue River face timber sale” (which is another reflection site).  My plan for today (Sunday) will be to explore the Andrews further.

Yesterday (Saturday) was my “establishing context” day:  a crash course in the surrounding GEOMORPHOLOGY.

After a serene night sleeping under great trees, with the sound of Lookout Creek sluicing over rocks below, I joined the Bretz Club gathering on their all-day Field Trip to see various hydrological, geological and vulcanological sites in the surrounding McKenzie River system, just above/outside the Andrews system.   We hiked in to a secretive “lost” spring  (large, cold, pristine) nicknamed “hobbit-land” and then up to the Collier Cone lava flow, hiking onto it and beyond, to see dry stream channels (complete with stream-rounded cobbles amid the broken landscape of the larger flow) and the absolutely stellar “Proxy Falls” — a waterfall which cascades down from a high ridge drainage area, forms a large clear pool, and disappears!  It is like an inverted spring, flowing down *into* the ground, where it escapes under the lava flow.

During our hike we frequently stopped to hear the fluvial geology comments of Gorden Grant, as well as current research findings (with lots of fascinating and as-yet-unanswered questions!) about the lava flows by researchers Natalia Deligne and Sarah Lewis and comments from world-renowned vulcanologist and professor Kathy Cashman. Often the group hiked with (or started by consulting) large LIDAR images, which are revolutionizing landscape research/scientific mapping, or we passed around small xeroxed copies showing the locations of numerous lava flows of various ages.  Some flows are hidden by moss and old growth forest, while other flows are young and easily visible, lying black and broken atop the terrain…  new research is showing, among other things, there are far more flows of distinct ages/events than previously understood.

We stopped at Olallie Creek (high Cascades spring-fed stream) for lunch, then on to see the Carmen Reservoir (and dry channel) of the upper McKenzie River, much of which is siphoned off through a surreal tunnel in the mountain, bypassing the water to an entirely different canyon, allowing Oregon Power to harvest hydrological power from the river, before it rejoins the original McKenzie downstream.

Geomorphology Field Trip: McKenzie River

Geomorphology Field Trip

We hiked along the upper McKenzie as it roars in full whitewater form over logs and through rock gorges and over several drop-dead waterfalls, where the geologists debated erosion theories while the poet sketched and eavesdropped.  As a sign at the NFS trailhead put it:  “Centuries of visitors have stood in awe of this place.  You can almost see their spirits lingering still.”

Geomorphology Field Trip

Finally, we visited Clear Lake where we commandeered a fleet of rental row boats and observed downed (and still-standing) trees along the bottom of the lake.  The water is tropically blue-cerulean, ice-cold, and crystal clear.  The lake bottom is marbled white with diatomaceous material, reminding me of snorkeling over the white coral reef floor along Cozumel (minus the tropical-fruit colored fish).  We put ashore on the far side, and hiked around to see the “Great Spring” which is the source, or headwater, of the McKenzie.  Crystalline, teal-sky-blue, the water pours forth with such force that we could not row into the spring’s inlet, which enters the adjacent lake like a whitewater stream.  The Great Spring is surrounded with huge trees (including a great Douglas Fir that has fallen down into it on one side, and older bleached trunks visble, deeper down). As with the other hydrological sites we visited, there was a great rubbly lava flow just uphill from the Great Spring.

Repeatedly, the inter-connection was made between the lava flows and the activity of groundwater, and the interplay between river-courses and obstacles such as the lava flows.  It was fascinating to hear researchers discussing the underlying seismic activity of the area, including past eruptions and inevitable future volcanic events.  How do we plan for catastrophes?  How will these groundwater systems be affected by large change (volcanic) or subtle changes (climate shifts could affect groundwater volumes, seasonal precipitation, etc.)  The McKenzie provides a key drinking water source for cities like Portland Eugene… begging such questions as how will flooding or ashfalls or earthquakes continue to change this critical high Cascades landscape of complex systems?  And how to respond, poetically…

“Ideas without precedent are generally looked upon with disfavor and men are shocked if their conceptions of an orderly world are challenged.”

- J. Harlen Bretz, 1928

Geomorphology Field Trip: Clear LakeGeomorphology Field Trip: Clear Lake
Geomorphology Field Trip: Great SpringsHow big are the woodpeckers out here?
Geomorphology Field Trip: Riparian SpringsGeomorphology Field Trip: Koosah Falls
Geomorphology Field TripGeomorphology Field Trip
Geomorphology Field TripAndrews' Debris Flow Flume
Geomorphology Field TripGeomorphology Field Trip



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