CWU's Nick Zentner learns from UW's Kathy Troost near the Tacoma Narrows Bridge in Puget Sound, Washington. Double Bluff till (Marine Isotope Stage 6) is featured. Trailhead parking: maps.app.goo.gl/Umb3Yo6M3Prmp...
I wonder if it is because there is a significant tradition of (scientific) disagreement/critique which results in absolute wonder and constant re-evaluation. I work in Computer Science, and it is really bitchy! :)
This is one of the best videos. Thanks for bringing Kathy on board she is a good teacher with all her enthusiasm. She’s got a way of making explanations understandable.
Dang it Nick! You keep coming up with fascinating guest geologist that are great. Her work has helped fill in the work of the old guys and pushed our knowledge of ice ages and North American landscapes forward. Thank you Kathy. Your so fun, cool, and smart!!!!
Wow! Kathy is an amazing educator, able to really convey the complexities of these multiple glaciations in a way that we can really relate to. Well done! I feel like I have a much better grasp in what was going on in the last ice age over on the coast, as well as how modern geologists figure it all out. And how amazing was Bretz to have figured out so much over 100 years ago without the benefit of all our modern technology developments? It is easier to see now why Bretz was so fixated on the Eastern Washington flooding having a northern origin. I would still like to see a paper on origins of erratics along the upper Columbia LOL, especially around Wenatchee. I do not think it is out of the question that we have erratics from the Cascades. Thanks Nick for another amazing video.
This episode, IMHO, has been the most interesting of the glaciation deposits series. Kathy is walking encyclopedia in her field. I was throughly impressed by her demeanor, personality, & her knowledge. I agree with you Nick, "Job well done!" 👍👍👍
Glacial tectonics? What a joy to observe Cathy Troost in full teacher mode. Learning new stuff right through this video . Clearing up old misconceptions and naming in an area that has been long examined. Great!! 🐻
The Port Washington Narrows is a tidal strait located in Bremerton, Littlerock is 11 miles southwest of Olympia. This was so fascinating. When I was a kid and I saw the bluffs on Whidbey (we went to Mukilteo beach a lot) and the bluffs on Hat (Gedney) Islands, I knew they were due to glaciation but I never knew any of this. So fascinating, Nick. Thanks to both of you for a fascinating field trip.
That was just a master class of information Nick & Kathy! I can see more clearly the amazing construct of the glaciation periods and where the BC interconnection is. I remember growing up and seeing some of the Pink / Reddish granite-like rocks further up north along the coast and inland in Whatcom, Skagit counties hills and mountains. Again, a stellar job.
Really enjoyed the knowledge Kathy is able to share here. She is well-spoken and breaks down descriptions as a skilled educator should. And…I’m really, really, really jealous of her 1951 entrenching tool (shovel)!
What a treat, she is fantastic! I have to say, growing up in Seattle with just a popular view of its underlying geology, I always felt a bit inferior living where somebody just backed up a giant dump truck, with only the occasional tusk or hunk of smashed wood poking out for interest, but she can read our layers like the Grand Canyon.
Oh man Nick..trying to digest this one. Right in my backyard so to speak. Thankyou for your ongoing quest for quality geological documentation and your incredible tool box of colleagues willing to contribute their knowledge. What a treasure.
I have taken my kayak down under the Narrows Bridge and by Point Evans a number of times, chasing fish. I now have a much greater appreciation of the beautiful exposure she calls Double Bluff! I have also hauled home several kayak loads of cool rocks washed out of the tills onto the very spot they sat looking at the old till...
Hey Nick, your videos are amazing and have encouraged me to read more geology. Now everywhere I go I look for geologic remains and then search the internet to confirm. Thanks for introducing this field to me.
Thank you Nick and Kathy. My mind is also blown. So happy you came to my neck of Washington. I always thought that the clay banks over in Point Defiance park was formed from a pooling of Gracial Waters.
An analogy of Puget Glaciation and Eastern Washington glaciation is too much to wish for, Nike. It's a thought experiment to find similarities, but there are so many variables unique to each glacial region that anything more specific than generalities could be made. That there is debate about subglacial water behavior is fascinating. What would ocean levels globally during periods of glaciation have on the Puget sound area?
As a consulting geotechnical engineer with a background (bachelors) in geology, I greatly appreciate this series of lectures and field visits! Keep up the great work!
That's for giving credit to those experts that enhance your teaching experiences to us lesser mortals that want to learn about geology. I have three degrees (two technical AS degrees and one BS Education degree) and not one is related to earth sciences. So, at 65 years old I'm willing to learn something new. PS. I love geology. Your RU-vid videos as well those from other experts in geology, to include volcanoes and earthquakes, is fascinating for a retiree from modern technology (Electronics, Avionics, Radars, and Electronic Warfare). My first introduction to Washington State Earth Sciences was in 2007 during a PBS program (while I was visiting Seattle) on the theories and evidence behind the 1700 Cascadia Mega quake. Since that program I've been fascinated by the geology in the Northwest US.
I used to walk along there in 1966, stationed at McCord, but living close to the bridge, and wondered about all the different stuff making up the banks. Now I know a little more, but am in East Texas and can't walk it again. Thanks for the fun.
I lived for a time back in the early 70's at Salmon Beach on Point Defiance. It was/is a community(and site of an old First Persons village) built on pilings at the foot of the described deposits. I used to climb the loose nearly sheer bluffs on both sides of the Narrows Bridge(old one) with nose to all the different deposit layers and was left with many questions as to what they represented... Thanks for this post Nick & Cathy as 50-year old questions are now mostly answered.
Gig Harbor is my hometown and I have friends who live near the trail you took to get down to the beach. I lived on the other side of the Gig Harbor peninsula by Horsehead Bay. I love learning about how this region formed. Keep up the good work.
Nick, being this is a place I have walked from time to time over the years, now I will pay more attention to these details whenever I see one of these exposed areas. Thanks for another great presentation! Hugh in Puyallup
Now, I finally know where the pink granites are from! Growing up in Skyway (South Seattle) I would find that stuff in the neighborhood, but was never able to find a pink granite cliff. Not the kind of thing that bothers me now, but it was a real head scratcher for me when I was about 10, and already passionate about rocks.
...great stuff Nick...I was first fascinated with your Liberty lectures back when I was retailing gold prospecting equipment...last year I was lucky enough to holiday from Australia to the U.S. west coast.I spent nearly 4 weeks walking this beach from the Narrows up to Tides Tavern and you guys have answered A LOT of questions! Love Ya Work..👍
Wow who knew. there was so much to see and wonder about in Tacoma! that was great. What a nice day, to just even imagine the amount of ice long ago on top of the lady and in that quanity what happens when it melts. and that rocks could be transplanted all the way from canada, What a terrific episode. will probably watch it again.
It never ceases to amaze me the all-around legend Bailey Willis was. From glaciers to coal(although not as much 😂) to Mt. Rainier. Great video as always Should have someone come out to Black Diamond.. We've got some weird spots between known glacial deposits and the 10,000 feet of sandstone..
😊 This is truly amazing. My mind is well blown. As the first video, after deciding to branch out in expanding my glaciation locations, this is a perfect start. It also expands on my Tacoma Narrows life experiences. It's also my introduction to western Washington glaciation knowledge. As a teenager in Seattle, I knew there had been glaciers. I knew that city had cut down the size of some of the hills. Otherwise, I really didn't care. I was busy growing up from 62 to 67 when I went away to college in E'burg (Ellensburg to most people). Yes, a major part of my life has centered around CWU. I was a sophomore when it changed from CWSC to CWU. The consistent thing through my has been and continues to be learning. I found this video today really fascinating. Thank you to Nick and Kathy Troost.
Great video with Kathy Troost. There are rarely visible deposits like this in Pt. Defiance Park. Glacially contorted and folded and thrust faulted silt. However, nearly all of the time landslides cover these deposits.
Thank you-I’d never considered that surface is unaltered as in this location and with Skye Cooley and Bruce Bjornstad! Continued astonishing professional geology!
We came here from the southwest region and so fascinated with ALL of this. First stumble on Nick from a UW lecture about cascade megathrust fault. And I'm not even into this stuff 😮. This is my 4th video binging 😂👍 and I love it 💪 Thank you both
Enjoying this series, and huzzah, I can help! Port Washington Narrows is where Sinclair Inlet passes to become Dyes Inlet, dividing Bremerton & Manette & spanned by the Manette bridge. I live right next to it! 😆. Also curious about exposed bluffs further south on Harstine Island!
6:40 " You've got a mistake down here..." (( " I love it ! " )) . . . But ... Imma gonna get even with you for correcting me on cam by titling this video "Older Glaciations..." with a picture of me pointing at you ! Haaa . . . sorry, I kid, but I was a bit struck by that "thumbnail" ... Thanks, as ever, Nick Z. for inviting us along and what a treat to hear from Kathy T. as well! B-)
Boy, oh boy! This is like being in a candy shop. Everywhere you look there's more goodies to find! And when you think you know what you see, there's Kathy to point out some new mind boggling details! Thank you Nick and Kathy!
Excellent Q & A's! And to see the visual from your podcast (fast turnaround 👌🏼). Just fascinating, educational, and fun! (The interglacial periods are certainly important...including volcanic, etc. clasts) Plus, the processes that carve deep troughs! Just wow. What a great picture you and Kathy have given us. And questions. Always questions.
I often get confused by the difference between till and outwash. After finding this entry on Wikidiff, I think I understand. "...the difference between outwash and till is that outwash is the sediment (mostly sand and gravel) deposited by water flowing from a melting glacier while till is a cash register."
Glacier till fills previous low areas much like lava flows in Columbia Basin where they filled river valleys and are cliffs we see today. These till fills become the cliffs along lower, current waterways. Timeline discussions were very instructional.
Thanks for these vids! I live and work all over Puget sound and am fascinated by all the geological things here. I've discovered some cool places to visit from your videos too!
Years ago I saw similar at Port Townsend and Oak Harbor. I wondered what on earth had caused it. At the time I imagined some horrendous disaster. 20 years later I finally understand :-) Well Done!
Wow, I fish and boat along that beach all the time. Just missed each other. I look at the stratigraphy on that bluff every time I go by. A lot of cross-beds. Nice to see this. Listening to Kathy talk about the "clay banks" is fantastic because I have always wondered which layer was glacial and inter-glacial. The glacial-tectonic feature is interesting. At the clay banks of Pt. Defiance, just around the corner from you, there are small faults the cut across the huge clay deposits there. I wonder now if this is from the weight of the ice above?
I have access to a private beach in the northern portion of Puget Sound near Hood Canal with extremely weathered granites that may be a locality that Bretz visited and is talking about. I have collected a lot of those pink phaneritic clasts that came from the till. The sea-side cliff exposures have so many interglacial and glacial layers available, and I'd love to send some pictures of the bluffs I've taken over the last year to someone that may be able to interpret them better.
Thank you so much for this field trip. Video imagery is so helpful for myself in helping to identify deposits around the Sechelt Penninsula. There appears to be a history of a large flood or a glacial lake ice dam failure where I live.
I agree, what a treat! I grew up along the beach in the Minter Creek to Glen Cove area. Saw so much of this in the layers of the local beach cliffs. Curiosity about these deposits started a lifetime interest in the geology of this area, the PNW, and beyond. Thank you so much for this video Nick, and thank you Kathy for your studies of these deposits. So many questions from my younger days are answered here!
