Dettifoss, Iceland's Largest and Most Powerful Waterfall: Learn Its Geology

[@shawnwillsey]

Please be sure to LIKE and SUBSCRIBE. You can support my educational videos by clicking on the "Thanks" button just above (right of Like button) or by going here: www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8 Or: www.buymeacoffee.com/shawnwillsey

[@LurkingInTheGrey]

Thank you Shawn! My deceased husband migrated to the U.S from Keflavik Is. He described where he came from but we never had the means to travel there. Because of your videos I can now put a picture to his words.

[@vicki90272]

My mother was also from Keflavik and I have a lot of family there! Small world!

[@AxelÞór]

The largest jökulhlaup in this river has been estimated to have a peak discharge rate of 900,000 m³/s. If you want to visualise that then you have to combine more than 40 of the largest rivers on the planet, or "just" 4-5 Amazon rivers. Next time you come here you should take a look at Ásbyrgi further downstream for evidence of these floods.

[@shawnwillsey]

I did check this out. Very cool n

[@luisantos1996]

Dettifoss was the place used in one of the scenes of Prometheus- Alien, the engineer sacrifice, opening scene of the movie.

[@Steinninn]

Also in Oblivion with Tom Cruise

[@pootthatbak2578]

Yes..that was some legendary film photography!!

[@gayleschultz8383]

Very interesting but it makes me nervous when you get sooooo close to the edge!

[@marymachunis3778]

Good morning! The falls are beautiful and the landscape is amazing.

[@vicki90272]

Thanks for this video. It never occurred to me that waterfalls move over time as they erode the rocks beneath the water, but it makes complete sense. I like your 66N hat!

[@shawnwillsey]

Glad it helped!

[@Dragrath1]

Yep waterfalls eat through rocks and retreat over time so the stronger the rocks are against erosion in an area the slower a waterfalls retreat is. In VA where I live Great falls is an example of this with the waterfall along the Potomac currently held upstream by the metamorphic rock units of the Piedmont, which is basically a Triassic aged horst of uplifted metamorphic igneous and metaigneous rocks but once reaches the far weaker sedimentary (and ultramafic volcanic) units of the Triassic basin, the adjacent graben which like its neighboring horst is a left over failed rift from the extensional rifting that opened up the Atlantic ocean, the falls will rapidly retreat upstream towards the blue ridge mountains.

[@adelaferreira4575]

Thank you Shawn for this beautiful experience,there’s no doubt Iceland is a magical land ,fire erupting on one end and this glacier and waterfall on the other ,much appreciated video !

[@pleegjepleegje]

What a landscape! Gorgeous!

[@marlenemitchelson6405]

It's absolutely stunning. Looking at waterfalls of this magnitude, one realises the power of water. The gorge/canyon is unbelievably amazing. Thank you Professor for taking us on this road trip in Iceland. It's such a beautiful country.

[@maryt2887]

Amazing waterfalls and surrounding terrain! Thanks for the lesson on the geological history of this area.

[@kateclover874]

WOW!! Impressive waterfall. Very cool to see the gorge and the outwash with all the boulders too. The power of water never ceases to amaze me. Thanks for documenting your tour.

[@susiesue3141]

Wow! What a great video and the photo footage is awesome! Beautiful waterfall! Thanks so much for sharing! 😊

[@joannekellam191]

So beautiful! And my hat’s off to you for scrambling over those wet mossy rocks without slip-sliding!

[@tthappyrock368]

As you showed us the formations around the waterfall, it reminded me of Dry Falls and the channeled scab lands in Washington. The falls there must have eroded in a similar manner when the area wasn't inundated. What a pretty area this is in Iceland!

[@66kbm]

Its just like the Lower Grand Coulee in central Washington but on a smaller scale. Nice video, thanks.

[@MyMemphisable]

Thanks!

[@billmurray4895]

I too have seen those worl holes in the Niagara escarpment along the lower Niagara river in Canada, totally awesome!

[@timpointing]

Rather fittingly, after this video played, I got a KZbin ad for a cruise up the Rhine River 🙂 I was shocked to hear of the outwash flood events in Iceland... perhaps I am just ignorant of the country's [geological/glacial] history! Thanks for the lesson, Prof Willsey 😀

[@christinedaly2694]

What lovely country thank you for the information

[@GRosa]

Impressive waterfalls and landscape in general. 👌🏻

[@jahl5130]

Thanks for the view of Dettifoss. I was there last year. You had better weather then me. We walked on slush, ice, and snow. They were building a new path that looked like it would be easier to use. I enjoy your videos.

[@lozunicorn]

I'm not sure if anyone else has said this, but the basalt columns (around 4 minutes in) are incredibly reminiscent of Fingals Cave on the Scottish island of Staffa and Giants' Causeway in the west of Ireland. Great video as always, thanks Shawn 💜🌋🦄

[@shelleyszulinszky9732]

Wow....just want to close my eyes and see it, hear it, feel it. Just wow Shawn, great vid ❤️✌️👍

[@brucedymock6635]

Great little video thanks getting a great look at Iceland and geology thanks again

[@HH.......]

Thank you Shawn 😊 Wow beautiful waterfall ❤ great content information 👏 😊

[@marumiyuhime]

I figured this one out it used to flow along the surface then over 1000s of years it formed a channel concentrating flow and creating a feedback. more channeling more erosion less water flowing over surface. just shows you things want to be in lower energy states. so cool TY

[@heatherw9996]

Great to watch your video of Dettifoss and explanations of the landscape - we were fortunate top get a short stop there on 10 June - the day the road reopened after snow and gales, but a difficult walk through snow making it difficult to observe all that you show in your video. Thanks Shawn.

[@shawnwillsey]

Glad you enjoyed it

[@sandrine.t]

Shawn, what's the word you used to describe the "thing" that migrates upstream? (I hear "nickpoint" but it doesn't make sense in French... 🤔) I love Iceland! I love these fantastic bare black and white landscapes, these impressive waterfalls, you took me back 10 years, when I visited... Thanks for taking the time to make this video and explain the geology of Sellfoss and Dettifoss to us 🤗

[@calluna5030]

In geomorphology, a knickpoint or nickpoint is part of a river or channel where there is a sharp change in channel bed slope, such as a waterfall or lake. Knickpoints reflect different conditions and processes on the river, often caused by previous erosion due to glaciation or variance in lithology.

[@debrawest4859]

Wow that is beautiful Shawn, thanks for sharing!

[@steveegbert7429]

Wow! Just looking at that icy water made me want to turn on the heat, and it's 78° in the house with the ac on! Thanks Shawn.

[@thomasrobinson3111]

We were there last September- a truly impressive place.

[@williamwood9948]

Great fun thinking of the 250m.yrs. of landscaping work that was done in my back yard! (I can see a lush and comfortable dwelling located adjacent to those vortecie in the near Geological future!) Ty

[@clydecessna737]

Always interesting.

[@bennyp7]

I went to the other side of the falls and found it more impressive from that view. You get much closer to the falls. Only drawback is the road that leads to the opposite is very rough/unpaved.

[@Vergos001]

A long drive to get there but totally worth it!

[@anitapaulsen3282]

What a fantastic waterfall!

[@paulproctor5555]

Thanks Shawn ❤

[@sasqetshenkley1190]

I'd be curious to compare the surface characteristics of the those boulders side by side with the watermelon gravel here in our Snake River Canyon to compare the effects of their respective environments since deposition. 🔬 *Example:* The dry heat & desert varnish in Idaho vs the cool moisture & lichens in Iceland.🤔

[@lornaperryman489]

Gorgeous!

[@DianeSmith-h3t]

That was amazing. Must go and see that. Di..Cumbria

[@loisrossi841]

Thank you.

[@muzikhed]

Wow, .....Awesome.

[@gladysdecelles9951]

Amazing ❤

[@NesconProductions]

Quite a contrast in the erosion process of the waterfalls that has occurred over millions of years (beautiful scenery shown here..) and ongoing volcanic eruptions that have occurred recently. Need to acknowledge the efforts of the Icelandic government / people in a battle against nature. Bulldozers & firetrucks literally fighting against the Earths mantle. An incredibly tough proposition .. 😮‍💨 Thank you Professor Willsey for your education / efforts ! PS - Wonder if P. Willsey ever crossed paths with my former Geology professor Mike Hozik 🤔(Stockton U. of NJ)?

[@Frying_Owl]

I have been there in june 2023 on the other side of the canyon, at selfoss exactly where you stand was a loooong wall of water falling down expandng about 100 meters from the first fall part down the river

[@alpineflauge909]

wow thank you

[@davidk7324]

Sellfoss is reminiscent of what Box Canyon might have looked like under flooding in my mind's eye.

[@Icelandlover]

OMG! I can't beleive how sooo much smaller the "wideness" of Selfoss is from less than 2 years ago. The reach of the falls were so much wider. It seems that Iceland's waterfall are drying up. I see this on my vdieos on my channel. Another evidence of this and the effect of global warming is in the Westfjords. I will be doing my 8th annual trip on July fifth, and as much as I am looking forward for my visit, i am dreading the " dryness"of the landscapes.

[@jsel6576]

How many hundreds of thousands of gallons of water would you guess are going down that waterfall? Very beautiful, as is the smaller one. Thanks for sharing this.

[@karllove57]

Hi I can´t remember the exact number but no other waterfall in Europe has a larger volume of water per/sec. Greetings from Iceland.

[@Anne_Umphrey]

Interesting. I see that Selfoss is more or less perpendicular to the flow of the water. Dettifoss flows down at an angle to the direction of the flow of water, making a diagonal cut into the cliff. That seems to be unusual. Can you explain this?

[@CintamaniCrawford]

how long does it take for those potholes take to form? hours/days/years?? does it depend of the size of the flood?

[@clintonturner5545]

Reminds me of the beginning of Prometheus.

[@VanessaThompson-mw4ud]

So this looks a lot like Giants Causeway. Do you think they were connected pre continental divide or just the same flood situation? Thx so much!

[@phillee2814]

The Giant's Causeway is in and below a coastal cliff, not in a river which floods, so no connection, and from a different volcanic event (although of the same type). Basalt forms those columns wherever it cools very slowly from the molten state, so is visible in that structure wherever that has happened, although you only see large exposures like this on cliffs or other places where there is a lack of topsoil or vegetation and a steep slope. There is an interesting linguistic connection with the British Isles though. In Northern parts of the Isles that spent some time under Viking rule, the name for waterfalls is a "Force" - a clear Anglicisation of Foss, the Nordic name. It survives mostly in the old Northwestern English counties of Cumberland and Westmorland, where some of England's finest waterfalls can be found.

[@ChrisBMobiusman]

What’s going on with Mt St Helen’s??

[@DrewNorthup]

Potholes: There's a couple places in NH with "high aspect ratio" potholes; EG 0.7m×2.5m. Pretty damn cool.

[@ingibjorningason2014]

could it be that the river flowed there and gratually broke away collums and moving the water wall higher in the land?

[@lhaaa1059]

Beautiful but I was holding my breath a couple times as you edged forward.

[@notvanpron4115]

Dry falls doesn't look so dry right now. 😂. Thanks for this video, all I could think about was how the PNW looked like this as the last ice ages melted.

[@GRosa]

How old is Iceland, I mean when did it form, and how old are its oldest rocks? 🤔

[@spvdh93]

500m/2000years=25cm per year. That is a lot 😲

[@3xHermes]

[@jeeperp3926]

Beautiful. From the video Dettifoss does not look at large or as powerful as Gullfoss. Video is deceiving…

[@z0n4l1]

has a larger volume of water per/sec not wider or taller

[@jeeperp3926]

@@z0n4l1 interesting. Thanks for the clarification!

[@zexisak4085]

@@z0n4l1 Dettifoss is indeed taller.

[@amandagreen3270]

Oh gosh Shawn don't go so near the edge next time, it made me quite nervous watching you

[@pootthatbak2578]

If you dont stay away from these cliff edges, im gonna unsubscribe. Why are you always standing over a 200 foot high ledge?...youre creeping me out😮 YES THERE IS SLIPPERY MOSS

[@pleegjepleegje]

You even have a rainbow for Pride Month at the end of your video🌈

[@JohnMcNamer]

Thanks!

[@JohnMcNamer]

Very well done Shawn