J Harlen Bretz concerned himself with a rather more geographically discrete puzzle than
did Alfred Lothar Wegener. Rather than fitting all the continents together, Bretz confronted
overwhelming evidence over the eastern half of Washington State that one or more
horrendous, catastrophic floods or cataclysms had savagely torn away the soils that should
have built up as they had elsewhere in the Pacific Northwest.
37
Let’s look more closely at the Bretz dilemma. What was Bretz looking at? Here, an
overview in Google Earth, of the eastern Washington channeled scablands. For reference,
Portland OR in lower left on the lower Columbia, Seattle WA, due north of Portland, and
Spokane near the eastern edge of the channeled scablands. Note the vertical arrow near the
top centre of this image. That’s Dry Falls, part of the Grand Coulee system we shall next
look at more closely.
38
This is a surface view of Dry Falls Lake, a mere remnant spot of “wetness” in the enormous
plunge basin into which an almost unimaginably deep sheet of water tumbled during one or
more of what used to be called the Bretz or Spokane floods.
39
Right below Dry Falls is an area of flood-swept basalt with this remnant of ridge rising from
the old channel of the Columbia River drainage: Note the notch in this ridge.
40
The large impoundment just upstream of Dry Falls, with Coulee City at the right (eastern)
end of the dam.
41
This artist’s rendition represents water flowing over Dry Falls on an ordinary day in the late
Pleistocene, 15-18,000 years ago. Just upstream is one of the terminal moraines to an
extension of the Cordilleran continental ice sheet. Dry Falls was many times larger, more
extensive, than Niagara Falls.
But this image does not reflect the enormity of Dry Falls at peak flood. There were an
estimated 100 m of water cascading over the 120-m high lip of the falls along a front of 40
km, and crossing that plunge at speeds of up to 100 kmh. In reality, 15-18,000 years ago,
this torrent of water would have been brownish, laden with debris, and flowing so fast that
the lip of the falls would have formed a minor crease where the water surface inclined to a
slightly sharper angle of descent. For getting your bearings in the next image, note the
notched ridge, pointing to the northeast, like an arrow here, at the concave crescent of Dry
Falls.
42
This is more representative how one of Bretz’s inferred peak cataclysms at Dry Falls would
have appeared. The notched ridge in the background is a reference for depth and orientation
of the water flow during this near-maximum flood stage.
43
J Harlen Bretz spent his early career (1910s-20s) focused on the channeled scablands of
eastern Washington. He patiently amassed solid information that persuaded him of the
enormity of prehistoric flooding. Catastrophic flooding accounted for the stripping away of
soil from bedrock, over-sized river channels, waterfalls that dwarfed any modern waterfalls,
glacial erratic boulders. But he could not identify a credible source for the enormous
amounts of water that had to have been involved. Joseph Pardee of the USGS made a
career out of identifying the dimensions of one big proglacial lake. He knew that this lake
contained a lot of water, but as of 1927 he had not yet discovered any field evidence that it
emptied catastrophically when Bretz was so savagely held up to public critique by scientific
colleagues.
44
Today, we think nothing of peering down at the earth’s surface from space, or using Google
Earth to do that for us. J Harlen Bretz (1882-1981) was publicly skewered in 1927 for his
unsupported hypotheses of catastrophic flooding through the Channeled Scablands. In
1940-42 Joseph Pardee in Montana returned to his earlier (1910) study of the dimensions
of Glacial Lake Missoula, and discovered that within the lower reaches of this
impoundment, where the lake itself must have been as much as 650 m (2,000 feet) deep
when the ice dam broke through, there were giant ripple marks of the same sort and
dimensions described by Bretz years earlier from the channeled scablands of the Columbia
Plateau. Pardee reported his discovery that there had to have been enough water released by
Lake Missoula’s sudden emptying to account for Bretz’s floods. Pardee’s discoveries did not
arouse immediate interest during the years of WW II. Belatedly, in 1962, the American
Geological Society conferred one of its highest distinctions on J for nothing Harlen Bretz.
Most of his critics and detractors were already deceased, but he at least lived another 19
years to savor his triumph.
What is so easy for us to see today using satellites, telescopes, and other forms of remote
sensing devices was too close underfoot for most observers to appreciate. So the Darwins,
the Wegeners, the Bretzes and the Pardees pioneered in an era that pre-dated much of the
remote sensing that we take for granted today.
45
Bretz and other investigators in the early 20th century dealt with clues that they largely had
to perceive and interpret strictly from ground level. Gulch-filling gravel bars and giant
ripple marks were indicators of the depth and velocity of inferred cataclysmic flooding.
46
J Harlen Bretz (1882-1981) ca. 1930, and about 40 years later. Took a merciless scientific
beating in 1927 for his work on what he termed the “Channeled Scablands” of eastern
Washington State. As a faculty member in Geology at several institutions, he amassed field
evidence for one or more enormous, catastrophic floods that swept through the valleys of
the upper Columbia River. Mainly on foot, sometimes supported by automobile on primitive
roads in arid Washington, J Harlen Bretz documented the enormous energy and mindboggling volumes of soil that must have been removed from basaltic bedrock. He worked
on several sorts of surficial geologic evidence. 1. giant erratic boulders littering the bottoms
of bodies of water that had to have contained enormous volumes of water and ice
(dropstones); 2. perched bars; 3. kolk lakes; 4. giant ripple marks; 5. oversized river
channels and giant abandoned waterfalls, with plunge basins that had to have been gouged
out by unimaginable volumes of water that reached velocities of at least 100 kmh (60 mph)
or about 10 times the velocity of currents in the Tanana and Yukon Rivers.
Popular mythology has it that both Alfred Wegener (1880-1930) and J Harlen Bretz
(1882-1981) were treated savagely by their colleagues because they lacked a mechanism for
their respective hypotheses. Wegener could find or account for neither the energy required,
nor the malleability in geologic materials, which would allow his continents to drift around
on the surface of the planet. Bretz similarly was plagued by failure to find a big enough
source of water to match the dimensions of his cataclysms.
47
Back to the wild geological features of Alaska: On the 9th of July 1958, a large (8.2
Magnitude) earthquake struck near Yakutat, Alaska. That earthquake did little damage to
human infrastructure. It took the lives of 2 fishermen and 3 berry pickers caught in gravity
waves following slumps. Neil Davis was fortunate to get to see some of the results of this
large earthquake, as he relates in his book, Head, Tail and Guts Included (2012, AlaskaYukon Press).
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