Large volume landslides have occurred at many island shield volcanoes such as in the Canary Islands and Hawaiian Islands. However, incredibly large volume volcanic landslides are incredibly rare.
Whenever you cover Hawaii geology I always think about the Honolulu volcanic complex and their tuff cones which you have already covered. Could you cover the Menan Buttes in Idaho?
Before Waianae was what we now call Ka'ena volcano, currently deep underwater towards the direction of the older island Kauai. So Ko'olau is the third volcano making up the O'ahu system. At the time of the Nu'uanu slide, Ko'olau was likely as high as today's Mauna Kea, so that also helps to visualize why the slump is so far offshore. The caldera is usually regarded as being south of Kaneohe Bay near to Maunawili, but of course it was thousands of feet higher in the air so we cannot be certain where the center was. You don't have to look far to find a more recent slump off the north shore of Molokai.
Excellent! Was waiting for GeologyHub to publish this episode, being raised in HI and learning about the Nu‛uanu Landslide in the '80s. Just the sheer scale of the collapse must've been terrifying -- esp to life on the Eastern side of the Ring of Fire... can you imagine a 50-story-high wave after all the water drains out of your little idyllic bay home, 1Ma ago? 🤯 Small note on pronunciation of Hawaiian names: the Western O‛ahu mountain range is the Ko‛olau range, pronounced 'KOH-[/ʔ/ glottal stop]-oh-lau (all open vowels, as in the word 'loud'). Only use a glottal stop when the *‛okina* or rotated apostrophe's present and you'll be fine (regular apostrophe's fine for most non-academic publications imo). What many publications not sensitive to proper presentation of Hawaiian names tend to do, is omit the apostrophe altogether (like Google unfortunately) which spell it Koolau -- doesn't help those new and well-meaning to Hawaiian / Polynesian names. Thanks and keep publishing and growing the channel! It's a must watch for this GenX Maui boy geology fan 🙂👍👍
Think of it as (KO-OOOOO-L-AU) and say LAU like wow but with an L. You almost had Waianae but you over pronounced the seconded A. Pronounce it kinda like this (Why-a-N-I) Hope it kinda helps haha
I was wondering about the timeline as it related to human history, but nothing we've got shows humanity reaching the Pacific Ocean on its way east any earlier than 30,000 years ago. So while it happened within the timeline of human prehistory on the planet, unless evidence comes up to the contrary it doesn't look like there was anyone around to see it.
@@DeborahRosen99 granted -- but the part about 'draining out of your bay home', meant the bay was your home, meaning animals living in the bay ecosystem, not humans on shore. Aloha! 🌺
I learned of this slide back in the early nineties. Sure does change one's perspective. I am so glad you covered this event, We little creatures need to understand the geology beneath, and all around us.
I think that Molokai experienced a flank collapse like Oahu. The offshore seafloor topography north of Molokai is very similar to what we see NE of Oahu only in the case of Molokai, the blocks are parallel to the north shore of the island. Even more interesting is that we are witnessing the formation of another major flank collapse on the southeast side of Hawaii. Note the steepness of the undersea terrain dropping 15,000 feet in 15 miles. I believe the fissure that opened in the Leilani Estates in 2018 was a result of the south flank of the island experiencing extensional forces due to the instability of the south flank.
There's been flank collapses and slides all over the entire island chain. There are a few good topography maps that you can scroll around on that shows them.
As you probably know there are many many of these massive landslides among pretty much all the Hawaiian islands. Can you do a video on this phenomenon as a whole and all the places around the world where volcanic islands show this occurrence all over the ocean floor. It’s fascinating.
I live on Molokai. I know the north side fell but have heard people say Molokai, Lanai and Maui were part of one volcano. I can't picture how that could be. Any truth to it?
@@kiska5947 Not one volcano, but one landmass. Similar to how the big island is made up of five volcanoes currently. The volcanoes subside over time due to the combined effect of their weight on the sea floor and the fact that they're being carried into deeper water to the northwest. On top of that they get weathered and eroded from the top. So eventually one large combined landmass breaks down and separates into several smaller ones.
Mahalo nui loa for this! I asked for it a while back, and you delivered! Such excellent timing, too! My brother, who lives in Lʻaie, is coming to visit in 2 weeks! I can’t wait to show this to him, to get to watch it together! Aloha! 🤙🏼
THANK YOU!!! Also a cool tidbit, when it rains heavily enough ( which is often esp during winter like now ) we get plenty little waterfalls known as tears from Koolau
@@thehilife92 lucky you I only saw them when we traveled on the H2? 3? To go clean houses windward side but absolutely breathtaking nonetheless and I miss them too
Great information! And for future reference, the proper pronunciation of the upper east mountain range on the Windward side of the island is pronounced Ko'olau (Ko•oh•laow). The 'okina in our language is read as a glottal stop and is technically its own letter in our alphabet. How you pronounced Waianae was perfect though!
I wondering these insane slides or edifice collapse events happen mostly over a long time span or kinda like the way falts constantly creep for years a few mm a day or even less. I'm surprised you didn't mention the big island of Hawaii southern segment that is currently sliding now, just a few mm a year as of now. But to have blocks the size of Manhattan transported over 20 miles means an enormous event took place suddenly. Really fascinating stuff.
There is evidence of tsunami several hundred feet high up & down the Oregon coast - I wonder how many of those were caused by landslides like that & islands like (but bigger than) Krakatoa exploding.
The slide is far longer than the vertical drop of the collapse indicating a Long Run Out Land Slide. A long run out slide creates so much friction heat and sonic vibration that the sliding mass begins riding atop a cushion of sorts and can travel a very long way.
I've always wondered whether this massive landslide would have also triggered any small scale eruptions. We know that some Hawaiian volcanoes, notably Oahu's, enter a rejuvenated stage after going extinct for the first time, and such a large slide might have potentially released a large amount of pressure on any remaining magma chambers below the island, or even fully exposed them. Any thoughts on how possible this is?
Yes! Many “secondary” eruptions feature in the landscape of o’ahu. Even the ko’olau mountains themselves are thought to be volcanic dykes of secondary eruptions where the newer lava squeezed between the rocks of the primary eruption, forming more resilient rocks which have resisted erosion. The primary eruptions forming Oahu have been thought to mostly have eroded away. This cataclysmic event of the Nu’uanu slide would have been a huge boon to the erosional events and given way to the secondary (and tertiary…?) eruptions such as what formed features like rabbit island, koko head and the other, newer craters of o’ahu like diamond head and punch bowl crater.
The beautiful hanauma bay is thought to be formed by five smaller, “secondary” eruptions! Koko head is the result of the koko crater eruption of which the volcanic debris was blown to the southwest of the crater, much the way that diamond head/Leahi had its volcanic debris blown to the southwest which gives it it’s characteristic shape that we see today. These secondary eruptions have evidence of being submarine eruptive events as these tuff cones show coral layers far above sea level in their hillsides today! The island of O’ahu as we know it, is much like the bones and remnants of a formerly very large volcanic land mass. It’s a bit sad to see people now fighting and hurting each other over this reduced piece of rock and dirt. Peace and Love, everyone!!
Caveat: I'm a complete amateur, only happen to have read a book on the geology of another Hawaiian island recently. If I understood and remembered right what I read, I think the large landslides and the rejuvenation stage happen at two different times of a Hawaiian volcano's development. The landslides are associated with the initial shield building stage. The rejuvenation stage happens much later usually after a gap of half a million years or more.
Interesting vid! For anyone who cares, Ko‘olau is pronounced "koh-oh-lau" where "lau" is pronounced like "loud" without the d. Not exactly correct, but close enough.
My parents live right on the coast near kaneohe bay and it is so cool to know when I visit I will have been swimming in an ancient caldera/historic landslide.
I was lucky enough to be stationed at MCAS Kaneohe on two separate occasions. Absolutely stunning view. I was able to see the elevated view daily as I drove through the tunnel on H3. The view from base was equally impressive. It’s tempting to keep your eyes off the road for too long when driving in that area. 👍👍👍
Thank you for talking about this. I live on Oahu, and when I drive on that side of the island and observe the overall geology, I came to my own conclusion that that side if the island did, in fact, have a HUGE collapse into the ocean. I had not yet been aware that this was the official scientific conclusion, but it' really is obvious. The formation of those mountains and cliffs would have been impossible without the existence of a very large volcano that obviously isn't there anymore. But, I believe strongly that the same thing can, and likely will, occur again on the Big Island's south side. To Mr Geology Hub, if you haven't yet been to the Hawaiian islands, I strongly suggest you plan a trip here. You absolutely need to see the crater inside Haleakala, and the active lava on Mauna Kea, and explore Volcano National Park. Spend several days here and get to see the islands and how they were all formed by lava and ash. Wait for springtime of course. Weather is a bit nasty and cold at this time.
I lived there for 2 years and it's my favorite place on the planet. It's now known that Kilauea is also sliding. It slides through earthquakes like what happened with the 2018 Puna eruption but it also slides with a newly discovered phenomenon that's a slow quake. It occurs over a week. Usually 2 to 3 days. So instead of a massive slide and tsunami. I am going to propose that the Oahu slide might have been similar in that it slowly slid into the sea. Anyway, something to consider.
What is happening with Kilauea is pretty much exactly what he was describing for the early slow phase of the slide and indeed its likely that some point in the distant future a critical threshold will likely be met due to the relative center of mass offset which triggers the big slide . A similar process occurs at many eroding shield volcanoes on both Earth and of course Mars where the relative lack of fast erosional processes means that the remains of slides can be seen across the planet from both recognizable and unrecognizable shield volcanoes. Like on Earth it appears that how recent the volcano has been active is critical in determining whether the shield volcano looks recognizable Tharsis (site of Olympus Mons) and Elysium Planitia have been active far more recently (i.e. in the last 250 to 2 million years) than many other hence they have more recognizable edifices that have yet to fully collapse.
Glad I found this video. I knew Oahu had a big slide, but I thought it somehow involved the west half and the east half of the island. This clears it up.
I am finding it very difficult to visualize a landslide traveling 140 miles over a slope depth of only, what, 3-4 miles? Wow! Sheer mass combined with extremely low coefficient of friction.
I was either 10 or 11 when I first saw the Nuuanu Pali Lookout. Even then (1964-66), I was blown away by the sheer cliffs and the stark contrast with the gentle slopes of the leeward side. I only recently heard about the Nuuanu slide in relation to another similar geological disaster a'building, I think Monteserrat? I always enjoyed our opportunities to visit that site. Thanks for the memories!
I’m glad that you enjoyed this video. It is truly an impressive site to behold. Other iceland based shield volcanoes have similar albeit less voluminous flank collapses such as El Hierro in the Canary Islands (it’s flank collapses leg scars visible from satellite and occurred long ago, >10,000 years ago). Also, thank you for your support!
Wow, I had no idea when I visited there in 2017. I did a bus tour around the south half of the island and have video and pics that I'll need to look at again. Thank you, Oahu is such a beautiful place now. That side of the volcano is luckily not commercialised like Honalu. I wish I knew this before but thats a good excuse to go back again. :)
It's amazing to think this happened historically in numerous spots amidst the islands. I wonder if the Helena Slump will ultimately succumb to a catastrophic collapse, or a relatively incremental subsidence into the sea? Lō ihi : "give me time, I'm not even touching air yet".
I just posted about this on Reddit last week. This is a very common occurrence along the entire Hawaiian island chain, going all the way towards Siberia.
I would like to know how the volcanoes on Oahu formed. I would specifically want to know about the mount Diamond head, Koko crater, and the punchbowl domes since they are the most visible ones. I really love your content and learned a lot from it so thank you so much for making these videos.
Mt Leahi- otherwise known as diamond head…. Think bubble ….of hot ash magma and gas. And it’s explodes with the hot ash and rock settling back down solidifying into a near perfect circle. If you ever happen to go to diamond head that is why some of the rock looks powdery white, and some looks like typical black basalt.
Wow! Big fan of your channel here. Thank you so much for this! I requested this topic but the comment was buried somewhere so I didn't think you'd get to it - very, very much appreciated! If you ever get the chance - GO to Pali Lookout. Be respectful, it is a sacred place and a historic monument as well as a geological wonder even though they've made it almost tourist-proof. Google Maps cannot do the view justice, and images on a computer screen cannot give weight to the sheer scale of what must have happened that day on the island that would be known as Oahu. The Waianae volcano also had a similar slide (the Waianae Slump), as did the north shore of Molokai. It makes me somewhat concerned for the active rift zones slowly opening across the Big Island on Mauna Loa and Kilauea...
I really like your cataclysmic videos. Where there’s been an impact or super eruption or an incredible landslide. Thank you very much for offering these well thought out produced videos.
there is evidence of large volume landslides occurring in Hawaii such with lanai and Kohala where you can tell parts of the volcano has been cut in half
@@GeologyHub we'd love to see a video on that, and examining why Hawaii's volcanos seem to tend to cause these massive landslides as it seems to happen only to these two islands from what I can tell. It would also be cool to explore what happens to these islands where they inevitably get subducted under the Kamchatka peninsula. I mean, we know they get destroyed, but it would be nice to see your interpretation of what exactly happens, if there's multiple or very large magma chambers under the peninsula, your interpretation on how long the islands have been subducting under the peninsula, etc. I guess I'd just like to see a video on all of that if you don't have one already. If you do, what's it called so I can search for it? Thanks. 🙂
@@GeologyHub the same thing is eventually going to happen on The Big Island as well. It's only a matter of time. Hopefully not anytime soon though. 😁. I do miss living there though.
When I saw the movie Donovan's Reef, I wondered why they went to the Grand Canyon for one of the scenes (the movie was shot on the BIG island of Hawaii). About ten years ago, I found out that this canyon is on the big island. During an eruption 6 or 7 years ago I feared that the east side of the island was going to break off, like it did with Oahu. In any case it will happen, it's just a matter of time.
Kamaʻāina kāne here. I live on Hawai'i Island aka: The Big Island. Donovan's Reef was mostly shot on Kaua'i. That's Waimea Canyon you're seeing on that island. The great crack here is nowhere near that large, being only 60ft wide by 60ft deep. The Hilina Slump would be the danger; I live pretty near it's north eastern edge; but because of a number of seamounts there is very little to no movement on most of the slump.
I was born, raised and still live on O'ahu. Mahalo (thanks) for your great video filled with wonderful and informative information. Keep up the great work!
Magma chamber question. Rather than a large open area(cavern), I am guessing it is more like a sponge. Lots of interconnected voids, supported by the magma. when the magma drains or vents the structure cannot support itself and you get a collapse. Am I close or way wrong. And thank you.
a similar volcanoe of hawaaii is teneriffe (canary island near la palma who errupted 2y ago), there s more than 20 reccord of mega slide overthere, the teide is above 3000meteres and the floor of the ocean is 4000m...that make a nice slide too of hundred of km3. they dont know every reason, you can have steam explosion like they warn about lapalma 2years ago, or a caldera forming after a big erruption then a flank collapse, or a caldera forming on the flank underwater etc.. there also icesheet during glaciation that can add some extraweight.
Very cool. I loved stopping at the Pali overlook cliff when I was a kid. I wonder if the fact that this was the wet side of the island had anything to do with the slippage. Maybe a river carving away at the island, like Waimea Canyon on Kauai. And I’m sure others have mentioned it, but its pronounced Koh-oh-lau.
Extremely interesting. Two questions remain for me: Are there any signs of this catastrophic landslide in the coastal parts of any continent, especially North America? Which hot spot shield volcano in the world has the highest risk of such a massive landslide nowadays? (Of course there will be no landslide in our lifetime, I'm sure.) Have a nice day 🖐👴
The highest risk of this now could be in one of two spots. Kilauea on the Big Island will most likely have a similar fate, and an island in the Canary Islands in the Atlantic off Africa, forgot which one
Yes a smaller landslide exactly like Oahu’s occurred that took the north half of Molokai and sent it into the sea, you can actually see the two debris fields overlap in this video.
Didn't the same thing happen on Molokai, only in a more spectacular fashion? The sheer cliffs there are about 3000 feet above sea level, and remnant blocks can also be found up to several (150?) miles away on the sea floor.
Does anyone know how a portion of the remains of the slide came to be named the Tuscaloosa seamount? I learned about it in a geology class at Hawaii Pacific University back in the 90's but have never been able to find out how it acquired a name from Alabama.
Please do an examination of the Hilina Slump. All the more relevant after watching this. Also, it appears the Waianae mountains show signs of the Flank collapse of a shield volcano rather than formation via a curved rift zone, as you described. Mahalo!!
Pretty unlikely. These are pretty solid blocks, which show signs of sliding. A volcanic eruption powerful enough to destroy half the island wouldn't have left large landslide blocks.
The current Pali was NOT formed by the Nuuanu slide. Mount Olomana and the 3 mile long ridges in the Kailua area wouldn’t be there if it were. The present Pali cliffs were formed by the stream piracy erosional process. The Nuuanu slide occurred over a mile off the present coastline.
My thinking is that these landslides happened millions of years after the respective volcanoes went extinct. Relative to the islands, their respective slumps and landslides are relatively in the same location as the islands themselves. With the Pacific Plate moving at about 10 cm per year, the Big Island was already formed and experienced its own slumps and landslides. One of the factors not mentioned was that there was a tremendous amount of iron that came with the lava to form the volcanoes and mountains. That iron, combined with the directions of the winds bringing air highly saturated with water caused iron oxide to be formed in the mountains making them more brittle and likely to collapse under their own weight. All around each island there are slumps and landslides that happened millions of years ago and are likely to continue to happen with the newer islands. I'm not sure, but I think the current islands (except the Big Island) have already dumped most of their slumps and landslides.
Isn't the southeastern portion of Kilauea also slowly sliding south? Is there a chance that flank could fail catastrophically in a similar fashion to the Nu'uanu slide?
it could, but most likely not. The reason is because it creeps. it moves. It meets an equilibrium. This doesn't allow for the slope to over steepening to a critical mass. If it stops moving but the volcano continues to expand, grow and erupt, then perhaps in a couple thousand years, it may collapse. The thing is at the same time, Kamaehuokanaloa (formerly Loʻihi), is growing and may buttress Kilauea's southern slope before there is a collapse.
@@ervinmalalis7150 Well... I get all that about oversteepening, but my assumption is that prior to the Nu'uanu slide that slope was rather gentle as well. Curious what actually triggered the Nu'uanu slide.
I’ve long been interested in the Cumbre Vieja volcano (en.wikipedia.org/wiki/Cumbre_Vieja_tsunami_hazard) for a similar reason, though I understand it’s less likely to collapse suddenly than the Hawaiian one. The crack running along the mountain is impressive! Do you have any interesting info?
SciShow covered that not too long ago. It was a rift zone, similar to the East African Rift Zone, that failed to open into an ocean basin. Here is the link. th-cam.com/video/HO1FplJGsgY/w-d-xo.html
@@eriklerougeuh5772 Well, I did a bit of reading up and discovered that yes, it has slid and generated tsunamis a few times which have done some considerable damage on Pacific islands, but nothing mentioned about NA coastline damage, although it’s quite possible that is has contributed to some coastal effects. Doubt is cast on whether that would be truly damaging.
Read up on the eventual slide that will happen with The Big Island. Some of the damage estimates make the Oahu and Molokai slides look like an ant hill.
@@DethOnHigh I’ve read a synopsis of the risks, which are said to be minimal due to the stabilizing effect of sea floor features that prevent major and potentially catastrophic landslides. I’d take some of the doom-mongering with a healthy grain of sodium.
@@johncampbell9216 it's still a huge amount of mass though which translates a huge amount of energy getting transferred to the ocean. I guess it all depends on how much of it actually gives way in a single event. Fortunately, it's very, very unlikely to happen anytime soon.
I am amazed that a landslide has enough energy to distribute debris more than 100 miles horizontally under water. I get that there was a lot of material, and that the ocean is very deep (so a lot of potential energy) but the water would surely have provided a lot of resistance to the horizontal momentum. Was there not some explosive energy component involved?
It would at first, but once that initial 'shock wave' of water gets pushed, everything behind that water will get pulled behind it, giving it even more momentum. Similar to when you get some friends into a circular pool, and all go along the edge as fast as possible in one direction, and after several revolutions you can stop and just float with the artificial current you made that can last for several minutes or more.
For your information the New York Times did an article on the Koolau Range cataclysm dated December 8, 1991 entitled Sea Floor Holds Story of Hawaiian Isles' Doom.
Ok. What makes some obsidian that beautiful purple color rather than the nearly black color in different layers of the same piece of rock? I know it's probably different chemical compositions. But how does that happen?
A number of commentators, including both professionals and non-professionals, express skepticism that a collapse at an oceanic shield volcano such as those that have occurred in Hawaii could displace water in a manner that propagates an oceanwide mega tsunami. The hypothesis of a mega tsunami from a hypothetical collapse at La Palma gets derided a lot, in particular. However, I think these detractions miss something. In the 1975 earthquake at Hawaii, the Hilina Slump slid some meters downwards, basically, and caused a tall tsunami on the island but also a displacement of the water that was detectable at stations on multiple Pacific coasts. This comparatively small event lends credibility to the theory that these events indeed may have the ability to cause long-distance disturbances. But, importantly, whether it would cause mega tsunami heights at great distance is an important discussion but not the only important aspect of the potential hazard. Tsunamis that are a mere meter high or shorter can cause life-threatening damage due to their force and immensity. So, even if a great deal of energy was lost, as long as the event can propagate as far as the historic small events have suggested, it remains hazardous on a wide scale. Any significant height of a tsunami makes a collapse like this one which occurred long ago on Oahu a potential hazard to the coastlines of the ocean basin in which it occurred.
Half of this is kinda common knowledge if you grew up in Hawaiʻi (cuz they go over this a lot in school) but I didn't realize the majority of the original volcano had slid into the ocean with remnants still visible on satellite imagery. I knew the Koʻolau side was created from erosion & landslides but never imagined at that caliber Also, I died every time they said "Koʻolau" (ko-o-lau) it's a phonetic language so you say every sound, no silent letters, no compound sounds. We use all the vowel sounds like English: A like in fAther, E like the beginning of Elephant, I sounds like swEEt, O like in dOOr, and U like in spOOn. That little apostrophe looking thing in between Koʻolau is called an ʻokina, indicating a glottal stop like the space between "uh-oh"
Nice video. Here's a question nobody I know knows. If ko'olau volcano reached a height 10k feet (I remember learning) and the Molokai channel is 650 feet at its shallowest, was there ever a land bridge between O'ahu and Maui nui?
@@howzt ~1.5MYA when all four islands/volcanoes, Maui, Molokai, Lanai, Kahoolawe were connected above water, they formed one giant island twice the size of Hawaii island. Geologists call that island Maui Nui. Cool, huh?
Supposedly O'ahu was connected to Moloka'i for a time via the Penguin Bank. This connection didn't get above 800ish ft and was shortlived. I think it separated long before the other islands making up Maui Nui formed. I think that paper is 20 years old now; don't know if new evidence corroborates or refutes that theory.
This doesn't make sense to me as the the outline you shared in the video didn't include all the debris on the ocean floor. Also, that debris is also scattered in an arc. Beyond that arc there appears to be markings still left on the ocean floor as you would see from a super powerful blast on land. Looking at both the field of debris and these arcs, none of it looks like it originated from the island of Moloka'i. Instead, they all point towards a central point approximately the Southeast point of Oahu perhaps just offshore of the city of Kailua. If this was a landslide, how do you explain the rest of the debris on the ocean floor, the arcs and everything pointing back towards a single location like a super massive explosion?
You must mean 1:00. I always wondered the same thing! Those lines are incredibly straight and peculiar across the sea floor for hundreds of miles. When I first saw them I assumed they were just an artifact of the mapping software, but they exist on all maps of the sea floor. Whatever the explanation is, it must be mind blowing!!
Oh also don’t forget Molokai had a very similar landslide off it’s entire north face, the debris field overlapping the Nu’uanu Slide. His red outline does not include the Molokai debris.
What would sea levels have been at the time? It would seem like that much material would go farther if sea levels were lower, but that’s just wild speculation on my part.
The size of Manhattan.. of you look at it with the East pointing up, it also has roughly the shape of Manhattan. How does an eruption move a black that size over some 100 kilometers? What's the force that keeps it going rather than just come to a stop as soon as it reaches level ground?
An eruption likely didn't cause this, not an explosive one at least. And the force that keeps it going is inertia. Once you get a 9000 foot tall mountain moving 100mph it's going to take a lot of friction to stop it.
According to a ResearchGate paper in the 3rd reference at the bottom of the Wikipedia fo Nu’uanu Slide........about 27 minutes from start to finish!!! Omfg! 👀
Has any time in human history a weak point in the earths crust that never had a volcano, formed one? I noticed lots of spots in the USA that has hot springs because of weak spots in crust that let water go down and come up to boil..but has any resulted in a volcano this way?
In New Mexico the Rio Grande rift was pulling the state in half beginning about 30 million years ago. This created weakness in the crust along the edges of the rift. The weak points resulted in a series of mostly fissure volcanoes to erupt. The Albuquerque volcanoes are one such example dated to 185,000 years ago. This chain of cinder cones lies in a north south line west of that city. The tallest is only about a 100 feet 30 m high. Because the rift opened up a large blocks of crust called grabens miles thick and 100 miles 160 km long to drop into the rift and this forced up mountains on either side of the rift that were not volcanic in origin.
Catastrophic. This is so cool. By the way, I have difficulty communicating because I had a stroke in Broca’s area, the part of the brain that controls speech. 2/8/2021 but I lived again. (My wife helped me compose this.)
Large volume landslides have occurred at many island shield volcanoes such as in the Canary Islands and Hawaiian Islands. However, incredibly large volume volcanic landslides are incredibly rare.
There’s a lot of concern over the potential damage that such a collapse at Cumbre Vieja could cause
500 feet tsunami ? is that possible . how much big it can be a tsunami ? it can grow limitless with power ?
@Sam Howell in recorded history? It’s the one that ripped mount saint helens apart in 1980
@@hk8450 The largest mega tsunami was around 1700 feet high and was from a landslide
Whenever you cover Hawaii geology I always think about the Honolulu volcanic complex and their tuff cones which you have already covered. Could you cover the Menan Buttes in Idaho?
Before Waianae was what we now call Ka'ena volcano, currently deep underwater towards the direction of the older island Kauai. So Ko'olau is the third volcano making up the O'ahu system. At the time of the Nu'uanu slide, Ko'olau was likely as high as today's Mauna Kea, so that also helps to visualize why the slump is so far offshore. The caldera is usually regarded as being south of Kaneohe Bay near to Maunawili, but of course it was thousands of feet higher in the air so we cannot be certain where the center was. You don't have to look far to find a more recent slump off the north shore of Molokai.
Excellent! Was waiting for GeologyHub to publish this episode, being raised in HI and learning about the Nu‛uanu Landslide in the '80s. Just the sheer scale of the collapse must've been terrifying -- esp to life on the Eastern side of the Ring of Fire... can you imagine a 50-story-high wave after all the water drains out of your little idyllic bay home, 1Ma ago? 🤯
Small note on pronunciation of Hawaiian names: the Western O‛ahu mountain range is the Ko‛olau range, pronounced 'KOH-[/ʔ/ glottal stop]-oh-lau (all open vowels, as in the word 'loud'). Only use a glottal stop when the *‛okina* or rotated apostrophe's present and you'll be fine (regular apostrophe's fine for most non-academic publications imo). What many publications not sensitive to proper presentation of Hawaiian names tend to do, is omit the apostrophe altogether (like Google unfortunately) which spell it Koolau -- doesn't help those new and well-meaning to Hawaiian / Polynesian names. Thanks and keep publishing and growing the channel! It's a must watch for this GenX Maui boy geology fan 🙂👍👍
Think of it as (KO-OOOOO-L-AU) and say LAU like wow but with an L. You almost had Waianae but you over pronounced the seconded A. Pronounce it kinda like this (Why-a-N-I) Hope it kinda helps haha
🤙808 Kapolei here but Waianae girl at ♥
I was wondering about the timeline as it related to human history, but nothing we've got shows humanity reaching the Pacific Ocean on its way east any earlier than 30,000 years ago. So while it happened within the timeline of human prehistory on the planet, unless evidence comes up to the contrary it doesn't look like there was anyone around to see it.
@@DeborahRosen99 granted -- but the part about 'draining out of your bay home', meant the bay was your home, meaning animals living in the bay ecosystem, not humans on shore. Aloha! 🌺
Thats not how it would work. All shores of Oahu would be hit by a nearly equal sized wave/
I learned of this slide back in the early nineties. Sure does change one's perspective. I am so glad you covered this event, We little creatures need to understand the geology beneath, and all around us.
I think that Molokai experienced a flank collapse like Oahu. The offshore seafloor topography north of Molokai is very similar to what we see NE of Oahu only in the case of Molokai, the blocks are parallel to the north shore of the island.
Even more interesting is that we are witnessing the formation of another major flank collapse on the southeast side of Hawaii. Note the steepness of the undersea terrain dropping 15,000 feet in 15 miles. I believe the fissure that opened in the Leilani Estates in 2018 was a result of the south flank of the island experiencing extensional forces due to the instability of the south flank.
There's been flank collapses and slides all over the entire island chain. There are a few good topography maps that you can scroll around on that shows them.
Leilani estates isn't on the south flank of Kilauea. It's on the northeast rift zone. The 2018 eruption was a typical rift zone eruption.
@@BlueCyann I said the south flank of the island, not Kilauea.
That would be correct
As you probably know there are many many of these massive landslides among pretty much all the Hawaiian islands. Can you do a video on this phenomenon as a whole and all the places around the world where volcanic islands show this occurrence all over the ocean floor. It’s fascinating.
I would love to see a video about this to
Yeah, I am wondering too
I live on Molokai. I know the north side fell but have heard people say Molokai, Lanai and Maui were part of one volcano. I can't picture how that could be. Any truth to it?
@@kiska5947 Not one volcano, but one landmass. Similar to how the big island is made up of five volcanoes currently.
The volcanoes subside over time due to the combined effect of their weight on the sea floor and the fact that they're being carried into deeper water to the northwest. On top of that they get weathered and eroded from the top. So eventually one large combined landmass breaks down and separates into several smaller ones.
Mahalo nui loa for this! I asked for it a while back, and you delivered!
Such excellent timing, too! My brother, who lives in Lʻaie, is coming to visit in 2 weeks! I can’t wait to show this to him, to get to watch it together! Aloha! 🤙🏼
THANK YOU!!! Also a cool tidbit, when it rains heavily enough ( which is often esp during winter like now ) we get plenty little waterfalls known as tears from Koolau
Lived at HPU Kaneohe and I miss seeing those waterfalls right after the rain passed. Absolutely stunning
@@thehilife92 lucky you I only saw them when we traveled on the H2? 3? To go clean houses windward side but absolutely breathtaking nonetheless and I miss them too
Imagine witnessing such an event (and living to tell about it)
I can not…
Literally impossible, place is uninhabited even after Constantinople fell to the Turks
Great information! And for future reference, the proper pronunciation of the upper east mountain range on the Windward side of the island is pronounced Ko'olau (Ko•oh•laow). The 'okina in our language is read as a glottal stop and is technically its own letter in our alphabet. How you pronounced Waianae was perfect though!
I wondering these insane slides or edifice collapse events happen mostly over a long time span or kinda like the way falts constantly creep for years a few mm a day or even less. I'm surprised you didn't mention the big island of Hawaii southern segment that is currently sliding now, just a few mm a year as of now. But to have blocks the size of Manhattan transported over 20 miles means an enormous event took place suddenly. Really fascinating stuff.
There is evidence of tsunami several hundred feet high up & down the Oregon coast - I wonder how many of those were caused by landslides like that & islands like (but bigger than) Krakatoa exploding.
The slide is far longer than the vertical drop of the collapse indicating a Long Run Out Land Slide. A long run out slide creates so much friction heat and sonic vibration that the sliding mass begins riding atop a cushion of sorts and can travel a very long way.
L.E.R.Z. is too active to shelf collapse on a mass scale..
Much further than 20 miles!!
I've always wondered whether this massive landslide would have also triggered any small scale eruptions. We know that some Hawaiian volcanoes, notably Oahu's, enter a rejuvenated stage after going extinct for the first time, and such a large slide might have potentially released a large amount of pressure on any remaining magma chambers below the island, or even fully exposed them. Any thoughts on how possible this is?
Great question I'm hoping we get an answer!
Same
Yes! Many “secondary” eruptions feature in the landscape of o’ahu. Even the ko’olau mountains themselves are thought to be volcanic dykes of secondary eruptions where the newer lava squeezed between the rocks of the primary eruption, forming more resilient rocks which have resisted erosion.
The primary eruptions forming Oahu have been thought to mostly have eroded away.
This cataclysmic event of the Nu’uanu slide would have been a huge boon to the erosional events and given way to the secondary (and tertiary…?) eruptions such as what formed features like rabbit island, koko head and the other, newer craters of o’ahu like diamond head and punch bowl crater.
The beautiful hanauma bay is thought to be formed by five smaller, “secondary” eruptions!
Koko head is the result of the koko crater eruption of which the volcanic debris was blown to the southwest of the crater, much the way that diamond head/Leahi had its volcanic debris blown to the southwest which gives it it’s characteristic shape that we see today.
These secondary eruptions have evidence of being submarine eruptive events as these tuff cones show coral layers far above sea level in their hillsides today!
The island of O’ahu as we know it, is much like the bones and remnants of a formerly very large volcanic land mass.
It’s a bit sad to see people now fighting and hurting each other over this reduced piece of rock and dirt.
Peace and Love, everyone!!
Caveat: I'm a complete amateur, only happen to have read a book on the geology of another Hawaiian island recently.
If I understood and remembered right what I read, I think the large landslides and the rejuvenation stage happen at two different times of a Hawaiian volcano's development. The landslides are associated with the initial shield building stage. The rejuvenation stage happens much later usually after a gap of half a million years or more.
Interesting vid!
For anyone who cares, Ko‘olau is pronounced "koh-oh-lau" where "lau" is pronounced like "loud" without the d. Not exactly correct, but close enough.
My parents live right on the coast near kaneohe bay and it is so cool to know when I visit I will have been swimming in an ancient caldera/historic landslide.
I was lucky enough to be stationed at MCAS Kaneohe on two separate occasions. Absolutely stunning view. I was able to see the elevated view daily as I drove through the tunnel on H3. The view from base was equally impressive. It’s tempting to keep your eyes off the road for too long when driving in that area. 👍👍👍
I got stationed at Schofield Barracks the same year H3 opened. I've regretted moving back to the Mainland ever since.
@@DethOnHigh , things have changed there since then. Still beautiful, although I prefer the tranquility of the other islands. Kauai is my favorite.
Blow my mind every single time I watch one of your videos!!!! Dang!!!! 🤙🏼
Thank you for talking about this. I live on Oahu, and when I drive on that side of the island and observe the overall geology, I came to my own conclusion that that side if the island did, in fact, have a HUGE collapse into the ocean. I had not yet been aware that this was the official scientific conclusion, but it' really is obvious. The formation of those mountains and cliffs would have been impossible without the existence of a very large volcano that obviously isn't there anymore. But, I believe strongly that the same thing can, and likely will, occur again on the Big Island's south side. To Mr Geology Hub, if you haven't yet been to the Hawaiian islands, I strongly suggest you plan a trip here. You absolutely need to see the crater inside Haleakala, and the active lava on Mauna Kea, and explore Volcano National Park. Spend several days here and get to see the islands and how they were all formed by lava and ash. Wait for springtime of course. Weather is a bit nasty and cold at this time.
I lived there for 2 years and it's my favorite place on the planet. It's now known that Kilauea is also sliding. It slides through earthquakes like what happened with the 2018 Puna eruption but it also slides with a newly discovered phenomenon that's a slow quake. It occurs over a week. Usually 2 to 3 days. So instead of a massive slide and tsunami. I am going to propose that the Oahu slide might have been similar in that it slowly slid into the sea. Anyway, something to consider.
Is the tsunami proven? Because if it is it might have been a fast collapse. Good thinking though! It's definitely possible.
I regret moving back to the Mainland too. We're you military?
What is happening with Kilauea is pretty much exactly what he was describing for the early slow phase of the slide and indeed its likely that some point in the distant future a critical threshold will likely be met due to the relative center of mass offset which triggers the big slide . A similar process occurs at many eroding shield volcanoes on both Earth and of course Mars where the relative lack of fast erosional processes means that the remains of slides can be seen across the planet from both recognizable and unrecognizable shield volcanoes. Like on Earth it appears that how recent the volcano has been active is critical in determining whether the shield volcano looks recognizable Tharsis (site of Olympus Mons) and Elysium Planitia have been active far more recently (i.e. in the last 250 to 2 million years) than many other hence they have more recognizable edifices that have yet to fully collapse.
@@DethOnHigh Yes I was. If I had a choice I would die there. I loved Hawaii.
@@Dragrath1 excellent reply.
Mind Blowing! I love thinking about these huge destructive events in our history! Great Video! 👌
Glad I found this video. I knew Oahu had a big slide, but I thought it somehow involved the west half and the east half of the island. This clears it up.
I am finding it very difficult to visualize a landslide traveling 140 miles over a slope depth of only, what, 3-4 miles? Wow! Sheer mass combined with extremely low coefficient of friction.
I love this kind of video. Imagine the tsunami after that landslide
I was either 10 or 11 when I first saw the Nuuanu Pali Lookout. Even then (1964-66), I was blown away by the sheer cliffs and the stark contrast with the gentle slopes of the leeward side. I only recently heard about the Nuuanu slide in relation to another similar geological disaster a'building, I think Monteserrat? I always enjoyed our opportunities to visit that site. Thanks for the memories!
I’m glad that you enjoyed this video. It is truly an impressive site to behold. Other iceland based shield volcanoes have similar albeit less voluminous flank collapses such as El Hierro in the Canary Islands (it’s flank collapses leg scars visible from satellite and occurred long ago, >10,000 years ago).
Also, thank you for your support!
Thank you for doing this one, I recall suggesting it a few months ago.
Wow, I had no idea when I visited there in 2017. I did a bus tour around the south half of the island and have video and pics that I'll need to look at again. Thank you, Oahu is such a beautiful place now. That side of the volcano is luckily not commercialised like Honalu. I wish I knew this before but thats a good excuse to go back again. :)
It's amazing to think this happened historically in numerous spots amidst the islands. I wonder if the Helena Slump will ultimately succumb to a catastrophic collapse, or a relatively incremental subsidence into the sea?
Lō ihi : "give me time, I'm not even touching air yet".
I just posted about this on Reddit last week. This is a very common occurrence along the entire Hawaiian island chain, going all the way towards Siberia.
I would like to know how the volcanoes on Oahu formed. I would specifically want to know about the mount Diamond head, Koko crater, and the punchbowl domes since they
are the most visible ones. I really love your content and learned a lot from it so thank you so much for making these videos.
Mt Leahi- otherwise known as diamond head….
Think bubble ….of hot ash magma and gas. And it’s explodes with the hot ash and rock settling back down solidifying into a near perfect circle.
If you ever happen to go to diamond head that is why some of the rock looks powdery white, and some looks like typical black basalt.
Super interesting, what a huge event!
Wow! Big fan of your channel here. Thank you so much for this! I requested this topic but the comment was buried somewhere so I didn't think you'd get to it - very, very much appreciated! If you ever get the chance - GO to Pali Lookout. Be respectful, it is a sacred place and a historic monument as well as a geological wonder even though they've made it almost tourist-proof. Google Maps cannot do the view justice, and images on a computer screen cannot give weight to the sheer scale of what must have happened that day on the island that would be known as Oahu.
The Waianae volcano also had a similar slide (the Waianae Slump), as did the north shore of Molokai. It makes me somewhat concerned for the active rift zones slowly opening across the Big Island on Mauna Loa and Kilauea...
I really like your cataclysmic videos. Where there’s been an impact or super eruption or an incredible landslide.
Thank you very much for offering these well thought out produced videos.
Didn’t a similar slide also happen on Molokai’s north side?
Yes, Molokai's north side also produced an ancient large volume landslide.
@@GeologyHub , never knew this fact. 👍👍👍
there is evidence of large volume landslides occurring in Hawaii such with lanai and Kohala where you can tell parts of the volcano has been cut in half
@@GeologyHub we'd love to see a video on that, and examining why Hawaii's volcanos seem to tend to cause these massive landslides as it seems to happen only to these two islands from what I can tell. It would also be cool to explore what happens to these islands where they inevitably get subducted under the Kamchatka peninsula. I mean, we know they get destroyed, but it would be nice to see your interpretation of what exactly happens, if there's multiple or very large magma chambers under the peninsula, your interpretation on how long the islands have been subducting under the peninsula, etc. I guess I'd just like to see a video on all of that if you don't have one already. If you do, what's it called so I can search for it? Thanks. 🙂
@@GeologyHub the same thing is eventually going to happen on The Big Island as well. It's only a matter of time. Hopefully not anytime soon though. 😁. I do miss living there though.
When I saw the movie Donovan's Reef, I wondered why they went to the Grand Canyon for one of the scenes (the movie was shot on the BIG island of Hawaii). About ten years ago, I found out that this canyon is on the big island. During an eruption 6 or 7 years ago I feared that the east side of the island was going to break off, like it did with Oahu. In any case it will happen, it's just a matter of time.
Kamaʻāina kāne here. I live on Hawai'i Island aka: The Big Island. Donovan's Reef was mostly shot on Kaua'i. That's Waimea Canyon you're seeing on that island. The great crack here is nowhere near that large, being only 60ft wide by 60ft deep. The Hilina Slump would be the danger; I live pretty near it's north eastern edge; but because of a number of seamounts there is very little to no movement on most of the slump.
What a quality video; thank you for the work. Mahalo.
Can you do a video on Waianae and the Waianae Slump? It appears it had its own collapse.
I was born, raised and still live on O'ahu. Mahalo (thanks) for your great video filled with wonderful and informative information. Keep up the great work!
I'm from the Canary Islands and I love and enjoy your watching your content.
Would love to hear about the Hilina Slump! And the potential tsunami threat to the westcoast.
That would be s good one! ✌️😎🍀
Wouldn't be very good for Hawaii either.
Magma chamber question. Rather than a large open area(cavern), I am guessing it is more like a sponge. Lots of interconnected voids, supported by the magma. when the magma drains or vents the structure cannot support itself and you get a collapse. Am I close or way wrong. And thank you.
a similar volcanoe of hawaaii is teneriffe (canary island near la palma who errupted 2y ago), there s more than 20 reccord of mega slide overthere, the teide is above 3000meteres and the floor of the ocean is 4000m...that make a nice slide too of hundred of km3.
they dont know every reason, you can have steam explosion like they warn about lapalma 2years ago, or a caldera forming after a big erruption then a flank collapse, or a caldera forming on the flank underwater etc.. there also icesheet during glaciation that can add some extraweight.
Great video. I would have liked to have seen (or separate video in the future) an exploration of the effects of the tsunami around the world.
Very cool. I loved stopping at the Pali overlook cliff when I was a kid. I wonder if the fact that this was the wet side of the island had anything to do with the slippage. Maybe a river carving away at the island, like Waimea Canyon on Kauai. And I’m sure others have mentioned it, but its pronounced Koh-oh-lau.
What about the Geologic oddity in Wyoming known as "Heart Mountain" & it's related components?
Extremely interesting. Two questions remain for me:
Are there any signs of this catastrophic landslide in the coastal parts of any continent, especially North America?
Which hot spot shield volcano in the world has the highest risk of such a massive landslide nowadays? (Of course there will be no landslide in our lifetime, I'm sure.)
Have a nice day 🖐👴
The highest risk of this now could be in one of two spots. Kilauea on the Big Island will most likely have a similar fate, and an island in the Canary Islands in the Atlantic off Africa, forgot which one
I think I remember a similar story from somewhere else that the island of Molokai having a landslide believed to have caused a crazy large tsunami.
Yes a smaller landslide exactly like Oahu’s occurred that took the north half of Molokai and sent it into the sea, you can actually see the two debris fields overlap in this video.
Looking at the sea floor, and the island also, am I right in assuming that the same thing happened on the north side of Moloka'i?
Yes, and pretty much all of the Hawaiian islands.
Really good video. Wish you had gone into the subject a little deeper. Good job!
I feel the exact same, I could watch a 2 hour documentary on the Nu’uanu Slide
Always found this fascinating and always stare at the Ko’olau range imagining what the volcano would have looked like.
Didn't the same thing happen on Molokai, only in a more spectacular fashion? The sheer cliffs there are about 3000 feet above sea level, and remnant blocks can also be found up to several (150?) miles away on the sea floor.
It did, but not as catastrophic. All of the islands have experienced slides and you can see a lot of these on topography maps of the area. Wild stuff!
Yes, but the collapse was not as voluminous as on Oahu in prehistoric times.
I’ve lived here for over 20 years and never knew this. Very interesting!!
Does anyone know how a portion of the remains of the slide came to be named the Tuscaloosa seamount? I learned about it in a geology class at Hawaii Pacific University back in the 90's but have never been able to find out how it acquired a name from Alabama.
Please do an examination of the Hilina Slump. All the more relevant after watching this.
Also, it appears the Waianae mountains show signs of the Flank collapse of a shield volcano rather than formation via a curved rift zone, as you described.
Mahalo!!
Could you do an episode on Vulcano Island in the Aeolian Islands? Apparently, activity has been picking up there in recent months.
Nice with the drawing of the island in the past!
The nuuanu slide could also be debris from a massive phreatic eruption that exploded to the Northeast
Pretty unlikely.
These are pretty solid blocks, which show signs of sliding. A volcanic eruption powerful enough to destroy half the island wouldn't have left large landslide blocks.
@@johnperic6860 of course it could. A Caldera collapsed combined with the phreatic nature of being an island volcano
@@BlackCeII
It definitely couldn't.
An explosive release of energy would destroy landslide blocks.
The current Pali was NOT formed by the Nuuanu slide. Mount Olomana and the 3 mile long ridges in the Kailua area wouldn’t be there if it were. The present Pali cliffs were formed by the stream piracy erosional process. The Nuuanu slide occurred over a mile off the present coastline.
When this massive slide occured, was the island of Oahu closer to the hot spot? Perhaps where Maui sits today?
My thinking is that these landslides happened millions of years after the respective volcanoes went extinct. Relative to the islands, their respective slumps and landslides are relatively in the same location as the islands themselves. With the Pacific Plate moving at about 10 cm per year, the Big Island was already formed and experienced its own slumps and landslides. One of the factors not mentioned was that there was a tremendous amount of iron that came with the lava to form the volcanoes and mountains. That iron, combined with the directions of the winds bringing air highly saturated with water caused iron oxide to be formed in the mountains making them more brittle and likely to collapse under their own weight. All around each island there are slumps and landslides that happened millions of years ago and are likely to continue to happen with the newer islands. I'm not sure, but I think the current islands (except the Big Island) have already dumped most of their slumps and landslides.
This was super interesting!
Isn't the southeastern portion of Kilauea also slowly sliding south? Is there a chance that flank could fail catastrophically in a similar fashion to the Nu'uanu slide?
it could, but most likely not. The reason is because it creeps. it moves. It meets an equilibrium. This doesn't allow for the slope to over steepening to a critical mass. If it stops moving but the volcano continues to expand, grow and erupt, then perhaps in a couple thousand years, it may collapse. The thing is at the same time, Kamaehuokanaloa (formerly Loʻihi), is growing and may buttress Kilauea's southern slope before there is a collapse.
@@ervinmalalis7150 Well... I get all that about oversteepening, but my assumption is that prior to the Nu'uanu slide that slope was rather gentle as well. Curious what actually triggered the Nu'uanu slide.
@@unclelou8636 Possibly a catastrophic eruption like what happened at Tonga last year.
Phenomenal! I wonder how big the tsunami was for that incident?
I just read a research paper that says some odd coral gravel found on Hawaii 1000ft above sea level is possibly from the tsunami!!!!
@@Syclone0044 so cool! Thanks for sharing.
It does look like slumps and tsunamis are popular in the comments. Undersea geology is fascinating, perhaps because much of it is recently revealed.
So the other side of Oahu kinda looks like it only has half a caldera as well. Was that another landslide, or did that caldera just erode in half?
It's surreal. The physics seem upscaled. Like it's not normally something that would happen, because it never gets big enough.
This slide would be kinda like the future La Palma slide that's been theorized will happen, right?
It was around six times larger than La Palma's largest known slide.
I’ve long been interested in the Cumbre Vieja volcano (en.wikipedia.org/wiki/Cumbre_Vieja_tsunami_hazard) for a similar reason, though I understand it’s less likely to collapse suddenly than the Hawaiian one. The crack running along the mountain is impressive! Do you have any interesting info?
Topic request. I recently learned that Basalt rocks can be found in lake superior. What is the vulcanic history of the great lakes.
SciShow covered that not too long ago. It was a rift zone, similar to the East African Rift Zone, that failed to open into an ocean basin. Here is the link. th-cam.com/video/HO1FplJGsgY/w-d-xo.html
@@owenkjartanson7476 thank you.
Would love to hear about molokais slump too.
I wonder if the same kind of event would be possible at Mauna Loa? If directed at the North American coastline, it could be absolutely devastating.
it already happened many times, look about "hilinia alika and south kona avalanche/slump",
@@eriklerougeuh5772 Well, I did a bit of reading up and discovered that yes, it has slid and generated tsunamis a few times which have done some considerable damage on Pacific islands, but nothing mentioned about NA coastline damage, although it’s quite possible that is has contributed to some coastal effects. Doubt is cast on whether that would be truly damaging.
Read up on the eventual slide that will happen with The Big Island. Some of the damage estimates make the Oahu and Molokai slides look like an ant hill.
@@DethOnHigh I’ve read a synopsis of the risks, which are said to be minimal due to the stabilizing effect of sea floor features that prevent major and potentially catastrophic landslides. I’d take some of the doom-mongering with a healthy grain of sodium.
@@johncampbell9216 it's still a huge amount of mass though which translates a huge amount of energy getting transferred to the ocean. I guess it all depends on how much of it actually gives way in a single event. Fortunately, it's very, very unlikely to happen anytime soon.
Wow! Very Cool and Thank YOU!!!! Best Regards and Best Wishes for 2023!
@GeologyHub a video on possible large landslides in the future would be interesting to see
Learned something new today about Hawaii thanks from a Hawaiian
That is fuckin insanely mind blowing
I am amazed that a landslide has enough energy to distribute debris more than 100 miles horizontally under water. I get that there was a lot of material, and that the ocean is very deep (so a lot of potential energy) but the water would surely have provided a lot of resistance to the horizontal momentum. Was there not some explosive energy component involved?
It would at first, but once that initial 'shock wave' of water gets pushed, everything behind that water will get pulled behind it, giving it even more momentum. Similar to when you get some friends into a circular pool, and all go along the edge as fast as possible in one direction, and after several revolutions you can stop and just float with the artificial current you made that can last for several minutes or more.
For your information the New York Times did an article on the Koolau Range cataclysm dated December 8, 1991 entitled Sea Floor Holds Story of Hawaiian Isles' Doom.
Ok. What makes some obsidian that beautiful purple color rather than the nearly black color in different layers of the same piece of rock? I know it's probably different chemical compositions. But how does that happen?
Another fantastic video! Would love to hear about the last British volcanoes
Topic suggestion/request.
Were Maui county islands ever one island mass?
That's it! I like this channel. I'm subscribing and leaving a comment beLOWWW.
😂 👏🏼 Reminds me of how his videos used to always end in a line about “PAY-Tree-Onn”
A number of commentators, including both professionals and non-professionals, express skepticism that a collapse at an oceanic shield volcano such as those that have occurred in Hawaii could displace water in a manner that propagates an oceanwide mega tsunami. The hypothesis of a mega tsunami from a hypothetical collapse at La Palma gets derided a lot, in particular. However, I think these detractions miss something. In the 1975 earthquake at Hawaii, the Hilina Slump slid some meters downwards, basically, and caused a tall tsunami on the island but also a displacement of the water that was detectable at stations on multiple Pacific coasts. This comparatively small event lends credibility to the theory that these events indeed may have the ability to cause long-distance disturbances.
But, importantly, whether it would cause mega tsunami heights at great distance is an important discussion but not the only important aspect of the potential hazard. Tsunamis that are a mere meter high or shorter can cause life-threatening damage due to their force and immensity. So, even if a great deal of energy was lost, as long as the event can propagate as far as the historic small events have suggested, it remains hazardous on a wide scale. Any significant height of a tsunami makes a collapse like this one which occurred long ago on Oahu a potential hazard to the coastlines of the ocean basin in which it occurred.
Great video!
Half of this is kinda common knowledge if you grew up in Hawaiʻi (cuz they go over this a lot in school) but I didn't realize the majority of the original volcano had slid into the ocean with remnants still visible on satellite imagery. I knew the Koʻolau side was created from erosion & landslides but never imagined at that caliber
Also, I died every time they said "Koʻolau" (ko-o-lau) it's a phonetic language so you say every sound, no silent letters, no compound sounds. We use all the vowel sounds like English: A like in fAther, E like the beginning of Elephant, I sounds like swEEt, O like in dOOr, and U like in spOOn. That little apostrophe looking thing in between Koʻolau is called an ʻokina, indicating a glottal stop like the space between "uh-oh"
It's very impressive we can learn so much about the past from what we can see now.
Nice video. Here's a question nobody I know knows. If ko'olau volcano reached a height 10k feet (I remember learning) and the Molokai channel is 650 feet at its shallowest, was there ever a land bridge between O'ahu and Maui nui?
Just curious, why are you using the word "nui" after Maui?
@@howzt ~1.5MYA when all four islands/volcanoes, Maui, Molokai, Lanai, Kahoolawe were connected above water, they formed one giant island twice the size of Hawaii island. Geologists call that island Maui Nui.
Cool, huh?
@@KimoPollock sweet, totally learned something new. Mahalo my friend 🤙🤙
Supposedly O'ahu was connected to Moloka'i for a time via the Penguin Bank. This connection didn't get above 800ish ft and was shortlived. I think it separated long before the other islands making up Maui Nui formed. I think that paper is 20 years old now; don't know if new evidence corroborates or refutes that theory.
This doesn't make sense to me as the the outline you shared in the video didn't include all the debris on the ocean floor. Also, that debris is also scattered in an arc. Beyond that arc there appears to be markings still left on the ocean floor as you would see from a super powerful blast on land. Looking at both the field of debris and these arcs, none of it looks like it originated from the island of Moloka'i. Instead, they all point towards a central point approximately the Southeast point of Oahu perhaps just offshore of the city of Kailua. If this was a landslide, how do you explain the rest of the debris on the ocean floor, the arcs and everything pointing back towards a single location like a super massive explosion?
You must mean 1:00. I always wondered the same thing! Those lines are incredibly straight and peculiar across the sea floor for hundreds of miles. When I first saw them I assumed they were just an artifact of the mapping software, but they exist on all maps of the sea floor. Whatever the explanation is, it must be mind blowing!!
Oh also don’t forget Molokai had a very similar landslide off it’s entire north face, the debris field overlapping the Nu’uanu Slide. His red outline does not include the Molokai debris.
Would you please do a video on the largest known tsunami. Thanks.
A similar event happened on Molokai as well.
Didn’t this also happen on the slimmer island next to Oahu as well?
On Molokai, yes. Also on pretty much every Hawaiian island in the chain. There are some topography maps that show them.
I read that there's evidence of a third volcano that helped form O'ahu that is off Kaena Point, next to the Waianae volcano
What would sea levels have been at the time? It would seem like that much material would go farther if sea levels were lower, but that’s just wild speculation on my part.
That depends precisely when it occurred, but given a range of 800,000-1,200,000 years it would likely be around 50 meters lower.
The size of Manhattan.. of you look at it with the East pointing up, it also has roughly the shape of Manhattan.
How does an eruption move a black that size over some 100 kilometers? What's the force that keeps it going rather than just come to a stop as soon as it reaches level ground?
An eruption likely didn't cause this, not an explosive one at least.
And the force that keeps it going is inertia. Once you get a 9000 foot tall mountain moving 100mph it's going to take a lot of friction to stop it.
Would it have all gone at once or could it have collapsed in sections? Days apart? Year apart? Centuries apart?
According to a ResearchGate paper in the 3rd reference at the bottom of the Wikipedia fo Nu’uanu Slide........about 27 minutes from start to finish!!! Omfg! 👀
What could have been the elevation of Oahu before the landslide?
And this all makes for beautiful island mountains!
Has any time in human history a weak point in the earths crust that never had a volcano, formed one? I noticed lots of spots in the USA that has hot springs because of weak spots in crust that let water go down and come up to boil..but has any resulted in a volcano this way?
In New Mexico the Rio Grande rift was pulling the state in half beginning about 30 million years ago. This created weakness in the crust along the edges of the rift. The weak points resulted in a series of mostly fissure volcanoes to erupt. The Albuquerque volcanoes are one such example dated to 185,000 years ago. This chain of cinder cones lies in a north south line west of that city. The tallest is only about a 100 feet 30 m high.
Because the rift opened up a large blocks of crust called grabens miles thick and 100 miles 160 km long to drop into the rift and this forced up mountains on either side of the rift that were not volcanic in origin.
@@michaeldeierhoi4096 That is fascinating information about NM! Thank you for sharing. ✌️😎🍀
Similarly story to the Kohala volcano on the big island which iv is the oldest volcano on the island, I’d love to see a video on that one too
Catastrophic. This is so cool. By the way, I have difficulty communicating because I had a stroke in Broca’s area, the part of the brain that controls speech. 2/8/2021 but I lived again. (My wife helped me compose this.)
Looks like the island directly east of there did the same thing at some point…almost looks to be the same shape after as well…
Formally submitting a request for you to cover Tres Vírgenes in Baja California (if you haven't already).
Would this be at the time that Oahu was a part of the massive Maui Nui conglomeration?