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    Northwest Geology Field Trips, by Dave Tucker, is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 United States License. You can use what you find here, repost it with attribution to the author, "remix" it for your own purposes, but may not use it with the intent of making money off of it.

    EDUCATORS: Please feel free to use anything you find here that is useful to your mission educating people about Earth science. E-mail me if it would help to have a larger or higher-resolution version of any of the images. tuckerd at geol dot wwu dot edu

Snohomish and Tacoma Geology Underfoot Book talks

A reminder that I will be in Snohomish this Saturday, Feb. 20, and in Tacoma next Thursday, Feb. 25, to talk about Geology Underfoot in Western Washington.

SNOHOMISH Saturday February 20th, 2 PM, Sno-Isle Public Library, 311 Maple Ave., Snohomish, WA

TACOMA Thursday February 25 Kings Book Store, 218 St Helens Ave Tacoma, WA. 7 PM http://www.kingsbookstore.com/event/2016-02

 

Geology Underfoot in Western Washington Book Launch a big success!

A very belated but very hearty thanks to all who came to the standing-room-only Grand Book Launch event May 12 at the Whatcom Museum, sponsored by Village Books, North Cascades Institute, and the Museum. It was a great pleasure to share Geology Underfoot in Western Washington with the huge crowd, sign copies, and tell you a bit about my background, how the book came about and how I put it together. Village Books sold out their entire advance shipment. The rest of the print run is on its way across the Pacific and will be available for bookstores at the end of May. NOW IS THE TIME TO ORDER A COPY FROM YOUR FAVORITE BOOKSTORE! The store will obtain copies via their distributors. Some sources tell me that advance sales are pretty brisk. The initial print run is 5000 copies. Mountain Press Publishing and I think the first printing will go fast, so don’t delay.

I am available for presentations at bookstores and your organizations throughout western Washington and down to Portland. Contact your bookstore, and drop me an email.

Best regards,

Dave Tucker

Here is a link to an article about me and the book by Dean Kahn that appeared in the May 18 Bellingham Herald:

http://www.bellinghamherald.com/2015/05/18/4296226_bellingham-geologist-writes-western.html?rh=1

Geology Underfoot in Western Washington- order copies from your bookstore.

Dear friends,

Geology Underfoot in Western Washington should be available in late April or early May. Order copies from your favorite bookstore now. You have the title; the ISBN is 978-0-87842-640-9. It is being published by Mountain Press Publishing. The store won’t have heard of it yet. Get the word to the store now and they will place their orders with the publisher or with their distributors.

Cover art by Eric Knight

Cover art by Eric Knight

Two presentations are scheduled:

May 12th, 7 PM, Whatcom Museum in Bellingham, sponsored by Village Books and the Museum.

May 13th, University Bookstore [Seattle’s U-District] at 7.

I will be signing copies at each of these talks.

Feel free to ask a bookstore or group to sponsor a presentation. They can contact me via my email:

email address to send reports and photos. I'll credit you.

email address.

Cover art for Geology Underfoot in Western Washington

GUWW cover. Painting by Eric Knight.

Geology Underfoot in Western Washington cover art. Painting by Eric Knight. Click for full size image file.

Geology Underfoot in Western Washington has gone to the printers, and should be on store shelves the end of April or early May. Start bugging you local bookstore to get orders in now. Here’s the book’s cover. It is an oblique view of Mount Rainier during a moderate eruption, made by Eric Knight, and is modeled in part on the 500-year-old Electron lahar. Eric painted the bird’s-eye-view in an arc looking from the north  to the southeast, from the Tacoma Tideflats around to the erupting volcano. There is a lot of detail. Look closely and you will see lahars descending the northwest and western flanks into the Mowich and Puyallup River valleys. The boiling cloud of a pyroclastic flow is on the right, covering the Tahoma Glacier. The lahars coalesce and inundate the Puyallup valley. That’s Lake Kapowsin at lower right. A short distance downstream from the lake, the lahar passes through the center of Orting, which appears seriously damaged and on toward Puyallup and Tacoma. The lahar would likely have a much reduced sediment load by this point, and be more of a hyperconcentrated flow- predominantly extremely muddy water rather than a dense slug of mud. The muddy flow enters Puget Sound at Commencement Bay, having sloshed mud and water all over the Tacoma tideflats industrial area. Suspended sediment has discolored Puget Sound most of the way to Elliot Bay at Seattle. There’s not enough detail in this image to tell, but I-5 appears intact where it crosses the Puyallup. In this hypothetical eruption, no lahar has entered the White River valley so the Auburn-Kent-Duwamish area has been spared.

ERic Knight's art showing a glacier-filled Yosemite Valley on the cover of Geology Underfoot in Yosemite National Park by Allen Glazner and Greg Stock.

ERic Knight’s art showing a glacier-filled Yosemite Valley on the cover of Geology Underfoot in Yosemite National Park by Allen Glazner and Greg Stock.

Erik also did the cover art for Geology Underfoot in Yosemite National Park. He makes wonderful panoramic maps. Visit his website to see a fine panoramic painting of the Salish Sea. It is interactive, so you can zoom in, pan very different perspectives. The tool bar at the bottom includes a ‘help’ button for instructions.

Nooksack River landslide near Deming- Update #2

Red line marks scarp of Feb 21 landslide. A later, undated slide is outlined in green. The second slide send brown soil over the top of the earlier clayey slide.

Red line marks scarp of Feb 21 landslide. A later, undated slide is outlined in green. The second slide sent brown soil over the top of the earlier clayey slide. Click to enlarge any image.

Thursday I visited the toe of the February 21 Clay Banks landslide on the Nooksack River, in company with Scott Linneman (landslide geomorphologist at WWU Geology) and John Thompson, a geologist with Whatcom County Natural Resources. If you haven’t been following this story, please visit Dan McShane’s blog post for the background to the story including some fine maps and photos, and my original post from February 22, the day after the landslide. Dan has also posted a great set of old maps and LiDAR showing changes at the Clay Banks as the river changes position. The landslide occurred just at midnight Friday February 21; you can see the sudden radical, short-lived drop in the river discharge graph below (recorded at the river gage a mile downstream at Cedarville). Click link to annotated You Tube video.

The Nooksack River gage at Cedarville (Nugents Corner) recorded a brief but sharp drop in discharge while the landslide dammed the river.

The Nooksack River gage at Cedarville (Nugents Corner) recorded a very brief but sharp drop in discharge (from ~2500 to 400 cfs) while the landslide dammed the river. Click to enlarge.

Annotated Google Earth image, with corrected location of 2-21 landslide and new river channel at the toe. Click o enlarge any image.

Annotated Google Earth image, with corrected location of 2-21 landslide and new river channel at the toe. Click to enlarge any image.

The Clay Banks are a steep bluff of Pleistocene glacial clay around 100 feet high on the south side of the river about 1.8 river miles upstream of the Nugents Corner bridge. The landslide bit deeply into only the upper half of the bluff, leaving a prominent bench hanging above the river. There is landslide debris on the bench, but most of it appears to have flowed over the bench, down the bottom of the bluff and into the river.

Shaky split log spans a side channel.

Shaky split log spans a side channel.

We crossed a shaky foot log across a narrow side channel to get to the big gravel bar on the north side of the river, and then walked 350 yards to the river side directly opposite the landslide toe. The landslide began in a layer of glacial clay a few meters above a prominent alluvial bed called the Deming Sand. If there is a stratigraphic layer at this level in the Clay Banks that contributed to this landslide it was not apparent using a high power spotting scope.

The toe of the landslide consists of large blocks of clay.

The toe of the landslide consists of large blocks of clay.

The river is still ponded against the landslide toe which protrudes into the river for 200 feet or so from the south bank. The river has cut through the outermost edge of the landslide toe. The river drains the partial impoundment by racing through a 60-foot-wide (19 m, measured with a laser range finder) gap. We couldn’t measure the river depth, but know it was 5 feet right up against the bank we were standing on, and 10 feet or more may be a reasonable guess. The landslide toe consists of car-sized, or maybe even garage-sized, clay blocks, and rests on the surface of a gravel bar; the bar gravel is exposed beneath the debris. At the time of the landslide, the river was closely beneath the high bluff, and the gravel bar we now see beneath the toe was part of the one we were on. The river then cut a new channel around the outer edge of the deposit, isolating the bar gravel beneath the toe from the gravel bar on the north side of the new channel. We found a single, angular clay block lying on the north side side of the channel, and a number of rounded ones. We figure the angular one (see photo below) was tossed laterally out of the landslide toe. It hadn’t been rounded by river flow, so is almost certainly right where it landed at around 12AM Friday 2-21-2014. You can see the same block in Dan McShane’s post, though when he visited the river bank was a few feet furthe away. This block is direct evidence that the river is continuing to cut outward and remove the bar on the north shore. This block will probably tumble into the river in the next few days.

Angular clay block marks extreme outer margin of the landslide toe. River has cut a new channel between this block and the rest of the landslide.

Angular clay block marks extreme outer margin of the landslide toe. River has cut a new channel between this block and the rest of the landslide.

The surface of the landslide toe is covered with large clay blocks. These sit on topo of a pre-landslide gravel bar.

The surface of the landslide toe is covered with large clay blocks. These sit on topo of a pre-landslide gravel bar.

The river makes an end run around the toe, and then cuts sharply south and runs directly into  the base of the bluff below the landslide. This is certainly undercutting the base of the Clay Bank, setting the stage for another collapse, perhaps involving the entire bluff height rather than the upper half.

Among our observations is that there has been a second, much smaller landslide in the same place. We don’t know when this occurred, but it sent darker material over the bank and down onto the southern margin of the Feb 21 toe. Compare the photo taken by Dan McShane on the morning of Feb 22 with the one I took today (Feb 27). The center of the 12-hour old scarp in his photos is now deeper where the 2-?? landslide collapsed. Also in the photos, note the toppled trees that rode the slide over bank.

The Clay Banks extend another 1/4 mile or so upriver and 1/2 mile downriver from the 2-21 landslide. Earth movements have been happening here at various scales for decades, and are likely to continue long into the future.

ACCESS NOTE: All access is over private land, so you are dependent on reports from authorized visitors. Sorry. Don’t even try to get there yourself. It is difficult to see the Clay Banks scarp from anywhere on the north side of the river. You may get a glimpse from the Deming Road somewhere in the first half mile after it branches off Mount Baker Highway a bit east of Nugents Corner. However, you will be 7/10 of a mile away, and for sure can’t see the river or the landslide toe.

Geology Underfoot: BOOK SENT TO PUBLISHER!

DT and the Geology Underfoot in Western Washington files. You will get to read it on paper, soemthing I've yet to see.

DT and the Geology Underfoot in Western Washington files- all on one flimsy bit of plastic. You will get to read it on paper, something I’ve yet to see. Chico stands guard my monitor. Photo by Kim Brown.

I finally completed the manuscript of Geology Underfoot in Western Washington. The sum of the last three years of my life was copied onto a DVD and sent off to the publisher today – 423 files including chapter text, photos, diagrams, and maps. There are (at this point) 22 self-guiding field trips, plus a lengthy Introduction that is a primer on plate tectonics, a capsule history of the geologic history of western Washington, a bit about petrology, and how to date a rock (“You need to be a little boulder” says Kim.) Groan. I promise I do not use that pun in the book, but there may be a few other gneiss ones. (Sorry). OK, now my editor James Lainsbury at Mountain Press Publishers gets to hack away. He’ll send it back to me for what I’m sure will be shortening, revisions to some of the figures I made, and who knows what else. The book will be on bookshelves in 2014 unless James says ‘This sucks. Start over.’ Thanks to all the people, geologists and ‘civilians’ alike, who read and field checked the chapters.

You can read a sample chapter (pre-editing) and learn more about the book here on my website.

So, time for a beer. Well, maybe a nap first.

Dave