The Geologic Oddity in Washington; The World's Longest Andesite Lava Flow

Lava flows generally do not travel very far from a volcano. On rare occasions, a basaltic lava flow like those seen in Hawaii might stretch for 10 or 15 miles from an erupting vent. However, these vast distances are typically not obtained by more silica rich lava flows which have a viscosity similar to Molasses. Yet, in the recent geologic history of Washington State, two lava flows from the Goat Rocks wilderness area broke this rule. One of these lava flows was 46 miles or 74 kilometers long, representing the world's longest viscous lava flow. What I am referring to are the Tieton Andesite Flows.

Google Earth imagery used in this video: ©Google

0:00 Laki Fissure Eruption
0:37 Speed of a Lava Flow
1:14 Tieton Andesite Flows
1:50 Goat Rocks Geology
2:56 1st Andesite Flow
4:01 2nd Andesite Flow

Citations:

[GeologyHub]

The Tieton andesite flows are confirmed as the longest viscous lava flows in the world! The exact reason why they were so long is complex, but heavily is related to its unusually high eruptive output (peaking at ~800 m^3/second). Another area of the world with unusually long lava flows is the Garibaldi and Garibaldi Lake volcanic complexes in Canada. There, a series of three unusually long dacite lava flows formed in the last 15, 000 years, the longest of which is 20 km in length.

[pamelapilling]

I have long been listening to the Youtube lectures, presentations and field seminars of Prof. Nick Zentner of CWU, Ellensburg WA. If I have found one thing outside Washington State, heck Northern California, Oregon, British Columbia, to Alaska, are all weird and unique. Lots to explore not just volcanic sites.

[robnorris]

It’s amazing how much detail you can get from reading the rocks. Sometimes I expect him to say something like “1.39 Million years ago, on a rainy Tuesday in February, ...”

[dl]

Andesite lava and polygon columns; two phrases I just never thought would occur together. Fascinating...Thanks, and cheers.

[spenceisthebest]

You can always tell when someone isn’t from the PNW the way he pronounced Yakima and a few other places mentioned lol. Anyways I’ve been watching your videos for a couple years now and love the videos. Thank you for covering all the stuff here in the Northwest.

[kcvail]

Washington has so many oddities you could do a whole series just on that area.

[blitzmann]

My geology professor visits this place very often, he has videos on his YouTube channel talking about it. Nick Zentner

[StuffandThings_]

I've read about the Tieton volcano and those fantastic columns in an old roadside geology book on Washington. Mt Baker also has some really nice columnar andesite too. I never really thought about how unusual it was to have such a long andesite flow in the state.

[augustolobo]

Nick Zentner mentioned this in one of his lectures I think it was about the columbia flood basalts, but he didn't go very deep on the topic. I got very interested about it since, so having you explaining in detail is awesome. Thanks for this video!

[kwgm]

Thank you. Washington State has some of the most varied and fascinating geology in the world, from the accretion of the West Coast Terranes, to the Cascade active subductive volcanoes and back arc extinct hidden volcanoes, to the fantastic coolies that run through the Central state, and the volcanics in the East -- and that is just an overview. You could easily spend weeks covering all of these cataclysmic events.

[KS-hjxn]

On your ride over White Pass on HWY 12 many locations reveal the massive lava flows. Stop at the Oak Creek Ranger Station to admire the massive columns across the Tieton River. Many people even climb the columns in warmer weather.

[BrilliantDesignOnline]

I used to live there: Yack-im-Ma and Cow-witch-ee and Nat-Cheese; gotta work on your native american names :-). 3:50 I can see my good friend's house. Again, I learned something-I had no idea that that even WAS a lava flow, much less the longest one. A suggestion for another local feature is Yakima canyon, which runs about 35 mile from north of Selah (see-LAA)(north side of Yakima) up to Ellensberg, WA. One of the more beautiful rugged drives you can take and REALLY fun on a motorcycle.

[marciakeilee]

Wow! So interesting! Thank you so much!

[larkmacgregor]

Love the geology in this part of the world - there's always something unexpected! Thanks for such an informative vid! Btw - it's YAK-em-uh, not ya-KEY-ma 🙂.

[StuffandThings_]

The Grande Ronde basalt flows would be another really interesting ancient volcano in the PNW to cover. Supposedly it was a singular volcanic feature which contributed a significant amount to the Columbia Flood Basalts, which is quite impressive to think about. Must've been a lot like an ancient Laki in the PNW.

[carportchronicles]

Thanks for the great description of our local geology! I won't give you too much grief about mispronouncing Yakima, Naches and Cowiche.

[xwiick]

Thanks for all the hard work on these videos!

[AstonMartin]

Hey GeologyHub, great channel by the way! Love your videos! Can you do a video on the formation of Cape Cod and the Islands in Massachusetts? Thanks!

[OuterGalaxyLounge]

I have to admit, sometimes I just click on this guy's videos for his comforting voice, and to get away from the craziness of the rest of the world and social media.

[MA]

Been asking for this for years and now I find out you've already done it. Thank you