Ice Age Floods Around the World
(03 December 2023) The last ice age of Earth involved immense floods with peak flows comparable to those of ocean currents. About 40 examples are now known from Asia, Europe, North America, South America, and Iceland. These mega-floods generated major landscape changes and huge fluxes of freshwater to the world oceans, resulting in global climatic change. The profound consequences of this flooding for Earth’s inhabitants may have even inspired many oral traditions of world-wide inundation. Vic Baker’s interest in the ice-age flood landscapes began in the 1950s when he was living in Bothell, Washington. His Ph.D. research on the scablands, completed in 1971, partly advised by J Harlen Bretz. A former President of The Geological Society of America, his publications include 20 books and more than 450 geology articles. He has appeared internationally in more than a dozen television documentaries dealing with ancient mega flooding on Earth and Mars.
Recording of Erratics’ October 10 program, “Reading the Okanogan Lobe Glacial Landscape”
Because of problems with the Zoom broadcast of the Erratics’ October 10th program, Ralph Dawes graciously recorded for us his talk, “Glaciated landscapes that formed beneath the Okanogan Lobe of the Cordilleran Ice Sheet,” so that we could all enjoy it. Or re-enjoy it. He talks through the slide show, with all the illustrations showing up clear and supportive. The video software lets you view the slides full size, or the slides plus a table of contents at the side, if you click in the right places.You can watch at 1.5x speed by clicking on the gear icon lower right, if you want to hurry along to topics of interest (that appear in the side bar). You can also pause the video to study individual figures. The recording is hosted on a server Wenatchee Valley College provides for faculty to store teaching videos that are retained for the foreseeable future. The video is set to be open to anybody, no password needed. https://wvc.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=5105f23e-e869-4909-b7b8-b0b10002f143 Here is also a link to the YouTube version: https://youtu.be/1A2hkmxTDdo
Lyle Cherry Orchard Interpretive Panels Installed
Last week, Friends of the Columbia Gorge completed installation on their first-ever interpretive trail signs at the Lyle Cherry Orchard Preserve! They’ll be sharing MUCH more on this story in spring 2024 (including guided outings!), but if you’re intrepid enough to hike this trail during the winter, check out the brand new signage with QR-code links to learn more about the preserve and the Gorge. Stay tuned for more in the coming months. And check out the Ice Age Floods geology recording.
Wenatchee Valley Erratics Leadership Changes Are Coming
Major changes are looming for the Wenatchee Valley Erratics Chapter. The chapter president (Brent Cunderla), treasurer (Dan Smith) and publicity person (Susan Freiberg) are all planning to step down in June, 2024. These critical positions don’t involve a lot of time or work, but they are essential.to the health of the chapter. All three are willing to help guide replacements, so if you are interested to learn more about the positions please email the chapter at Wenatchee@iafi.org.
An Old Timer (Jeff Silkwood) IAFI Story
In the early days, the IAFI and National Geologic Trail were mainly good intentions and lacking in ways to communicate how enormous and special this landscape was. Jim Shelden, then Regional Geologist for Region One of the US Forest Service in Montana and now president of the Missoula chapter of IAFI, realized a good map was necessary to galvanize action on the project and legitimize the new group Jim Shelden had just hired Jeff Silkwood in an open-ended position as a Stay in School Cartographer and Database person in 1995. Jeff had just returned from military service and was enrolled in classes at U Montana. Jeff was assigned to digitizing maps of the Beartooth Mountains and other mapping projects in the states of the Northern Rockies. But he was particularly interested in Glacial Lake Missoula and the Ice Age Floods. And he knew he had the computer skills to use existing data to put a map together. As the maps grew larger, more complex and included features like hill shaded relief and multi 1-degree by 1-degree tiles fitted together that no one else could do, it slowly dawned on Jim that this guy was really something. The only limitations were equipment – no Dept of Ag computer could handle it nor could any plotter manage the print task. In those early days this involved overcoming computer limitations on the size of files. Combining digital elevation models for multiple tiles and maps resulted in gigantic files for the times and processor’s abilities. Jeff wrote 2500 lines of code linking multiple computers, writing new code to handle the plotter problems to complete this project over about a two year time span, working on this while completing other jobs which had more firm deadlines. The basic data came from the USGS digital version of topographic maps supplemented with data from NASA satellite images. Google was working with some of the same data for use in its own maps, and there was some back and forth communication with them on how to solve similar mapping problems. Mapping issues that came up for this project included drawing a boundary for the west coast at a time when the ocean level was much lower – which had to be done by hand. And decisions about the extent of the lake and the extent of the continental ice sheet and glaciers – maximum levels and multiple contributors as to extent were used. Initial drafts were printed on a pen plotter, then the imagery was upgraded to an ink jet printer, which was subject to fading. The final map with photo images was turned into print plates by the Forest Service special Publications group in Washington. Approval for even printing the map was complicated. – it was (and still is) the only map ever printed by USFS which was more than a travel map and identified by author. An initial printing of 2000 copies was authorized – and sold out in 3 days. Another printing of 2500 was done. The USGS ordered a third printing they sold from their Denver and Spokane Libraries. It is no longer available, supplanted by on-line maps, and subsequent versions with different detail (such as highways) done by Eastern Washington University and others. A few copies of the original map still exist, and Jeff is still working on cartography for a private firm in Missoula. The importance of the original map to give IAFI credibility and as a tool to tell the story and sell the need for a special designation has never been officially recognized…until now. Thank you Jeff for your personal commitment to this project, and thank you Jim for your support in making it happen.
Let Your Feet, and Your Imagination Roam at Rowena Crest and Tom McCall Preserve
Scenic Rowena Crest and the Tom McCall Preserve area provide an incredibly scenic place to let your feet, and your imagination wander as you look out on a major chokepoint along the Ice Age Floods path. The wildflower displays are amazing during the Spring, but several compelling flood-related features are visible from the vantage of the Rowena Crest Viewpoint any time of year. Rowena Crest lies nearly 700 feet above the Columbia River at the upstream end of the Rowena Plateau, a miles-long plateau that the river flows along. Just upriver from the plateau is the narrow section of the Gorge known as the Rowena Gap The drive to the viewpoint on old Hwy 30 from either east or west is a spectacular ride through a wonderous section of the Columbia River Gorge. A roundabout parking area at the viewpoint, with a safety wall above a sheer cliff, provides a great observation point eastward toward Rowena Gap. At Rowena Crest it’s easy to imagine what it might have been like to witness the approach of those massive floods. There is not yet scientific evidence that humans were in the area to bear witness to the Ice Age Floods, but there is solid evidence of humans in the Americas by that time. And there is growing concensus that if they came in during a glacial maximum, they would have come in by a coastal route that offered plentiful food and shelter for their journey. The mouth of the Columbia River would have been the first major waterway path inland that might have led them to settle in the area of the Floods. Your village might have been situated across the Columbia at the mouth of the Klickitat River where the town of Lyle now sits. If you were foraging, or just relaxing, atop Rowena Crest on a late summer day, you might have felt the ground begin to temble as if there were a small earthquake, but the trembling would have slowly increased for a few hours. Eventually you would have heard a low roaring sound that also grew over an hour or more before you could see turbulent brown muddy water begin flooding across the broad basin to the east. Then the roaring flood of water, only a few feet deep at first, would have entered the narrows, now called Rowena Gap, and sped on, crashing against the promontory you’re standing on and being diverted toward your village which was quickly washed away by the muddy torrent. But the muddy flood waters would have kept rising, unlike the Spring floods you’re used to on the Columbia, becoming a hundred feet deep, then two hundred as the levels just kept rising. Soon a huge whirlpool formed in the flood waters near the base of the promontory and a giant eddy formed where your village had been as flood waters flowed backward up the Klickitat River even as the bulk of the water continued downstream on the main stem of the Columbia. As the flood waters reached 400 and 500 feet deep and kept coming, suddenly to your right and left, huge blocks of the promontory broke off and slumped down into the rampaging flood waters. Now, even more fearful, you would have begun running south toward higher ground, climbing higher and higher as the still rising flood waters poured across the plateau and plunged into the small creek valley to the west, tearing away at the valley walls and massively widening that little valley. Eventually the flood waters stopped chasing you upward as you climbed higher, 200 then 300 feet above the now submerged promontory. Now, as you turned and looked out across that expanse of muddy water you could see massive white blocks of ice being carried along on the flood waters, similar but inconceivably larger than the ice blocks carried on the river during the Spring floods. But the flood waters didn’t begin to recede that day, nor the next, as they might in the Spring floods. In fact it was almost half a lunar cycle before they began to slowly recede, exposing a mud coated Columbia River valley that was now noticeably wider, with layers of shear vertical rock walls extending over 1000 feet above the normal river level below. As you began the recovery from the floods devastation, your family returned from from their hunting and gathering in the high mountain meadows, and you have an incredible story to pass along to them and your ancestors. This story is easy to imagine as you look out to the east from Rowena Crest. The onrushing Ice Age Floods waters easily flowed over the low relief of the broad Dalles Basin to the east, but the major Rowena Gap created a chokepoint in the path of the floods as they made their way through the Columbia River Gorge. This “hydraulic dam” forced the flood waters to build to over 1000 feet deep in this area, flowing hundreds of feet deep over Rowena Crest while forming a temporary lake in The Dalles basin. It is estimated that many of the 40-100 Ice Age Floods may have taken up to a month to completely flush through the system to the Pacific Ocean, but the duration of the flood waters at any point along the path probably lasted less than a couple of weeks. But this was more than enough to create several major floods features visible from this vantage point. At Columbia River level below and east of the promontory is a round Kolk pond that was created by giant whirlpools in the flood waters as they were deflected around the Rowena Crest promontory. Other similar Kolk features can also be seen on the Dallesport area to the east, and along the hiking path atop Rowena Crest where they are marked by surrounding groves of oak trees. Across the Columbia, the floods deposited a huge eddy gravel bar that the entire town of Lyle, Washington is built upon. The Klickitat River was backed
Ice Age Floods throughout the Quaternary – Don’t forget the older ones!
(12 October 2023) Most of the time when we discuss the Ice Age Floods, we are talking about the Missoula Floods which happened from 18,000-15,000 calendar years ago. Our research shows that there are many sites of much older flood deposits (they have calcite horizons in them) that show that megafloods happened throughout the Quaternary. In my book, I call them Ancient Cataclysmic Floods because we do not know where the water came from. Scott Burns is a professor emeritus of geology at Portland State University where he is starting his 34th year. He has been teaching actually for 54 years with previous positions in Switzerland, Colorado, Washington, Louisiana, and New Zealand before returning to his hometown of Portland in 1990. His specialties in geology are: Quaternary Geology (Missoula Floods). engineering geology and geomorphology (landslides), environmental geology (radon, heavy metals in soils) and soils (terroir of wine). He has been a member of the Ice Age Flood Institute since it started.
Tualatin: Crossroads of the Ice Age Floods
Tualatin, Oregon, lies in its own valley near the head of the Willamette Valley. In the time of the Ice Age floods, about 18,000 years ago, the area was a rich wetland. The gift those floods left behind was a hearty silt containing loess that was picked up from lands in Eastern Washington in the rush of the flood waters. The depositied loess supported abundant plant life that supported the megafauna animals that benefitted from this rich land, including Columbian Mammoths, Mastodons, Giant Sloths, Grey Wolves, the first Horses, Bison and others in the Pleistocene Age. In today’s world, fossil hunting for these extinct animals is a fruitful treasure hunt and celebrated in the Tualatin area. Tualatin has helped lead the way in displaying Ice Age fossils at various family friendly sites in the City: Tualatin Public Library: Enter, and the first thing you see is the Mastodon skeleton displayed high behind the checkout desk framed in an etched glass panel depicting the grassland and the Mastodon’s body. This fossil skeleton was discovered nearby during a site excavation for a large retail store. Further on into the Library are a group of lighted display cabinets for fossils arranged on shelves. The cabinets are arranged side by side in a gentle arc for easy family viewing. 18878 SW Martinazzi, Tualatin, 97062. Tualatin Greenway: To the right and behind the Library/City Building is the entrance to the Tualatin Greenway, a trail system along the Tualatin River. It is complete with signage concerning Ice Age Floods. The primary trail is a long winding concrete path with a blue meandering mosaic center strip representing Tualatin’s part of the National Ice Age Trail. It’s a favorite for joggers, cyclists and those who love to walk. Cabela’s Shopping Center: Return from the Greenway to the front of the shopping center building. See the full-size juvenile Mastodon sculpture being admired by a farm boy holding a spade with which to find a fossil skeleton. At his farm, a molar tooth is a barn doorstop. Read the story on the plaque. Brian Keith is the sculptor. Inside Cabela’s store, see the Cave at the back which shows Ice Age fossils displayed in context. Tualatin Heritage Center: Here, Columbian Mammoth and Mastodon tusks are featured among other Ice Age fossils. Of special interest are the large granite boulder erratics on display outside, all with explanatory plaques. 8700 SW Sweek Dr., Tualatin, Oregon 97062 In addition, the Lower Columbia Chapter of the Ice Age Floods Institute offers regular presentations about various Ice Age Floods topics by renowned experts, as well as newsletters and other events of interest. Visit the Ice Age Floods Institute website (IAFI.org) for much more information.
Mima/Desert/Biscuit Mounds – An (Possible) Explanation
If you’ve visited the Rowena Crest Viewpoint at Tom McCall Preserve, west of The Dalles in the Columbia River Gorge, you may have noticed the many dome-shaped earthen mounds that cover the Rowena Plateau. These mounds are broadly circular and are surrounded by collections of basalt rock fragments. If you’ve visited the spring wildflower mecca of Catherine Creek on the Washington side of the Gorge, you may have also wondered at what caused the stripes of black rock extending down the slopes above the area. Tens of thousands of similar soil mounds cover large areas of the high desert lands of north-central Oregon, often in swarms that number in the hundreds. These mounds can be round or elongated, can range from a dozen feet to more than 60 feet in diameter atop the rocky Columbia River Basalt bedrock, and are typically surrounded and separated from each other by rings or stripes of basalt rock fragments. The mounds also appear similar to those at Mima Mounds Natural Area Preserve near Olympia, WA. There have been many suggested causes for the creation of these mounds, from burial mounds, to Pleistocene pocket gophers, to plants or glacial sun cups trapping wind-blown sediment, to sorting by earthquake vibrations, to turbulence at the base of ice-age floods flowing over the landscape. Research by two Oregon graduate students, Clark Nelson of Oregon State University and John Baine Pyrch of Portland State University, independently came up with what may be the most likely explanation for the origins of these enigmatic features. Their theses suggest desert mounds and their rock rings formed through a process of natural sorting, where fine soil material is pushed up into mounds and associated rocks are pushed out to the edges to form rings through countless cycles of wetting/drying and freeze/thaw during the wetter and colder period of the late Pleistocene. Clark Nelson cut a trench through a mound that exposed layers of soil and volcanic ash whose lack of mixing discounts the pocket gopher theory. Nelson also found that slope angle less than or greater than 10 degrees determined whether the features would form rounded mounds vs. elongated stripes. Pyrch showed the strips to be distinct from common talus slopes, because no obvious source of rock exists at the head of the talus stripe. He also observed that rocks within these stripes are sorted, unlike talus slopes, suggesting the same ice age freeze-thaw origins as soil mounds and rock rings. You can read more detailed articles about these enigmatic features in these articles: Mystery of the Desert Mounds Great Pyramids of the Gophers: Mima Mound Mystery Solved Similar processes are also thought to be responsible for the “patterned ground” found in periglacial environs. However these various types of features may have formed, we can be certain how the few mounds in the center of the parking circle at Rowena Crest Viewpoint came to be. They were man-made during the construction of the viewpoint and made to look like the mounds that cover the Rowena Plateau. At least one origin has a definitive answer.
Must See Floods Features in Northern Idaho
SOME LOCAL NORTHERN IDAHO ICE AGE FLOODS and GLACIAL FEATURES Purcell Trench – This structurally formed valley became the passageway for the Purcell Ice Lobe that divided into five glacial sub-lobes. The east moving sub-lobe blocked the Clark Fork River forming Glacial Lake Missoula, the source of the Ice Age Flood waters. Other sub-lobes modified and deepened the basin now occupied by Lake Pend Oreille or helped define several important N-S transportation routes. The Purcell Trench is visible from City Beach in Sandpoint and Schweitzer Mountain Rd. Hwy 95 follows the Purcell Trench from Sandpoint to beyond Bonners Ferry. Cabinet Gorge – Contact of Pleistocene Ice and Glacial Lake Missoula Water – Although the contact of the Pleistocene Ice and the lapping waters of Glacial Lake Missoula was in flux as the glacier advanced and retreated, the Cabinet Gorge is considered by many to be a likely location of the terminus of the Clark Fork sub-lobe that blocked the drainage of the Clark Fork River. Evidence of glacial erosion and till deposits indicate glaciation; however, flood deposits on the south side of the river attest to Ice Age flooding. Cores taken during the construction of the Cabinet Gorge Dam suggest multiple stages and events of ice damming. An AVISTA maintained viewpoint at the Cabinet Gorge Dam with Ice Age Floods signage provides an excellent location to ponder the formation and disintegration of the ice plug blocking the Clark Fork River. Glacial Striations – Striations can be viewed along Hwy 200 east of Hope and on the south side of Castle Rock east of Clark Fork. Glacial/Flood Related Erratics – Large and small erratics cover the glacial and flood modified landscape. Large erratics can be seen along Hwy 200 east of Clark Fork, in Sandpoint’s City Beach and in Farragut State Park. A large pile of erratics excavated from flood deposits are visible on the west-side of Hwy 95 south of the Hoodoo Channel. A giant ice-rafted flood related erratic weighing over 1,600 tons is located on the east-side of Hwy 41 near Twin Lakes. Lake Pend Oreille – Cross-section morphology, depth, and sediments – This is where it all started! Lake Pend Oreille is the largest lake in Idaho and the deepest lake in the Pacific Northwest and the 5th deepest in the US. The lake level is 2062 ft above sea level with depths over 1,000 feet and an additional layer of over 1,500 feet of glacial-fluvial deposits going to bedrock, with the surrounding terrain as high as 6002 ft. The glacially modified U-shaped bedrock valley, cut to approximately 600 feet below sea level, was formed by the Pend Oreille glacial sub-lobe. This glacial sub-lobe was up to 4,000+ ft. thick and 30+ miles wide. It was the ice plug responsible for blocking the Clark Fork River. It collapsed catastrophically as often as about every 10-60 years, releasing 40-100 Ice Age Floods. The location of the lake is probably related to an old river valley controlled by faults. The Lake Pend Oreille basin was carved by the repeated advances of Pleistocene ice and scoured by ice age floods. With the waning of ice age flood waters, the basin was, and continues to be, filled with glacial outwash and flood deposits. The lake is dammed at the south end by thick glacial and flood deposits the mark the beginning of the “Outburst Deposits”. There is a pullout on Hwy 200 approximately one mile west of Hope with signage already established that provides a great view looking south across Lake Pend Oreille to the Green Monarch Mts. Another view of the former ice plug location along Hwy 200 is the mouth of the Clark Fork River at the Clark Fork Drift Yard. Giant Current Dunes or MegaRipple Marks – One of Bretz’ most important pieces of evidence for catastrophic flooding was the “giant current dunes.” These large-scale bedforms appeared as patterns of parallel ridges and swales on many aerial photographs in the flood channels in the scabland of Washington, but had escaped recognition from the ground because of their size. Giant Current Dunes are visible west of Clark Fork near Castle Rock; however, the most prominent and visible Giant Current Dunes are located several miles east of Spirit Lake along Hwy 54 where the highway cuts through the dunes showing their undulating profile. The location of many of the telephone poles on the crest of these dunes accentuates these landforms. The dunes form transverse to the current direction, and form cusps that are convex upstream, with arms that point downstream. Furthermore, the size of the cusps appears to decrease in the direction of lower velocity. Internally, the dunes consist of gravel and pebble foresets. Giant current dunes exhibit an asymmetrical profile with the downstream (lee) slope steeper than the upstream slope. Crests range from 20 to 200m apart and heights range from 1 to 15m (Baker and Nummedal, 1978) and are among the largest measured throughout the Floods area. The Spirit Lake current dunes can also be easily recognized from the air by their characteristic pattern, accentuated by vegetation. This dune field is immediately in the path of the breakout from Lake Pend Oreille, and experienced some of the highest energy flows. Rhythmites – Rhythmites are glaciolacustrine sediments associated with flood events and are useful in attempting to determine the number of Ice Age Floods. A 112-foot cross-section of rhythmites is located at the junction of East Fork Creek and Lightning Creek approximately 6.5 miles northeast of Clark Fork along Lightning Creek Road (NF-419). Proglacial Deposits – This type of deposit is found associated with most of the drainages on the south side of the Clark Fork Valley and extend from the mouth of the Clark Fork River to nearly Thompson Falls in Montana. These sediments are glacio-fluvial deposits deposited in contact with the ice and therefore provide evidence of glaciation in the Clark Fork River drainage. The associated geomorphic features formed by these deposits are referred to as “kame deltas”. The gravel pit associated with Dry Creek (approximately 8 miles west of Clark Fork