What's the Biggest Canyon on Earth?

in the united states there is only ever one canyon that people seem to talk about the grand canyon if you live here you've at least heard of it and i'm willing to bet even most of my viewers from outside the us are familiar as well with annual visitations rising to over 6 million in recent years along with making it so far as to be considered an official natural wonder of the world i don't think it's a stretch to say this very well may be the most popular canyon on earth naturally i assumed this popularity carried over into meaning it was also the world's biggest after all it is called the grand canyon right and just like you i never needed to know for sure what the biggest canyon was because well that's something that just doesn't matter all that much that is of course unless you're making an intro to aerography video like this one and at some point in that video need to compare a canyon on earth to the great valley's marineris of mars if you haven't seen that video the long story short is that even the biggest canyon on earth would be dwarfed by this martian feature but therein lies the problem what is the biggest canyon on earth first off no matter how you look at it the grand canyon is a big canyon there's no argument here but what exactly does big even mean in this context i mean after all canyons are three dimensional features meaning they can be measured in not one or two but three basic ways running 446 kilometers long 1857 meters deep and 29 kilometers wide the grand canyon gives us a sizable baseline to judge all other canyons against that being said depending on what you're looking for this isn't even the biggest canyon in the americas with both the kolka and kotahuasi canyons in the peruvian andes extending down over 3000 meters or nearly twice as deep as ours in arizona despite not running for very long and coming off fairly minor rivers what gives these canyons their great depth is the fact that they are nestled within the andes mountains the second highest mountain range on the planet okay well if that's the case then shouldn't we be looking at the first highest mountain range on the planet well i'm glad you asked the himalayas naturally feature a number of astoundingly deep canyons the kaligon donkey is yes another exceedingly deep canyon and heck on the wikipedia page it even claims to be in fact what we're looking for wedged between annapurna the 10th tallest mountain on earth and dologiri the seventh tallest mountain on earth the canyon reaches down 5500 meters between these two peaks making this claim awfully tempting to believe but if you got tired of me drawing out this answer and have just decided to look things up on your own you've probably found this canyon along the yarlong sangpo river so yeah good job you beat me to the punch or whatever literally called the yarlung sengpo grand canyon what's so grand about this canyon is that not only does it run for over 500 kilometers but this part here between the mountains of namcha barwa and gyala perry reaches all the way down to a purported 6 000 meters deep a greater depth than any other canyon on earth making the yarlung a grand canyon a full 60 kilometers longer and over three times deeper than the colorado grand canyon that's why most sites on the internet will tell you this is in fact the biggest on earth but if you're like me and spent one month of your life making a video about what would happen if we melted all the ice off greenland then you'd remember learning about a recently discovered mega canyon entirely hidden beneath miles of ice looking at just the bedrock of the island we'll find an ancient canyon making its way 750 kilometers across the bottom of the landmass making it yes the longest canyon on earth as a result this canyon has also been named the grand canyon parentheses greenland but okay i get it it's still pretty unsatisfying to say the biggest canyon on earth is hidden never to be seen under miles of ice so it was at this point that i had to ask myself what about the ocean or what horrors lie in the ocean as it turns out a continental shelf meeting oceanic crust creates a huge potential for more dense water to move down against these dense water currents can come in the form of sediment laden river water or can even be caused by sharp temperature or salinity gradients generating flow in the water column no matter how they form though over time these underwater currents can carve out canyon after canyon after canyon against any land mass while these submarine canyons are shockingly extensive across the ocean floor only a few of them reach beyond the narrow shelf boundary to become anything extraordinary a perfect example of this can be seen off the coast of congo already the deepest river in the world the congo canyon begins even before the river reaches the ocean here sediment-rich waters coming from the river have caught a clear path down through the sea floor all the way across the shelf unfortunately africa's continental shelf doesn't last too long here making the congo canyon a distinct but rather short-lived feature overall looking for a longer example i was brought actually not too far away from where i live in new york where the hudson river ends up carving a 1.2 kilometer deep canyon along its way to the atlantic this journey ends up taking 640 kilometers from just outside the new york harbor all the way to the hudson fan a structure that signifies where the sediment finally empties and settles onto the surface at this length the hudson qualifies as the longest canyon i could find not entirely covered by ice meanwhile this stretch of coast off the eastern united states features some of the most developed submarine canyon systems anywhere in the world i highly suggest you take a look if you're into this sort of thing but okay so we've established the deepest and the longest canyons exposed or otherwise leaving us with one last criteria to search for and i saved width for last because well this is sort of where the very definition of a canyon starts to fall apart not too far from the hudson canyon we'll find the bahamas by far one of the most confusing features on the planet to look at but hopefully this will help make some sense out of it all what you're really looking at here is a large but flat land mass essentially one big hill that for the most part sits just below sea level the plateau's shallowness allows the sunlight penetrating the water to reach its bright carbonate sands which is what you're seeing here only the tallest banks break over the ocean to become the scattered islands and atolls of the bahamas during the ice age however the buildup of polar ice caused sea levels to drop by as much as 130 meters lower than modern sea levels this would have been enough to expose much more of the bahaman plateau adding a whole new island cluster to the atlantic ocean even during times like these however the landmass was still bisected by this distinct darkened trail cutting through the otherwise shallow bank this is the great bahama canyon not only reaching as deep as 4 000 meters but at its widest spanning 50 kilometers between the greater and lesser bahama banks however not too far away from the bahamas and actually even closer to the hudson canyon will find a path cut out of the shelf by glaciers leading all the way up to the saint lawrence river while technically called the laurentian channel this long eroded trail starts to blur the line between canyon and other simple grooves on the surface like channels gaps straights fjords you know all those words this channel is twice the width of the bahama canyon making it definitely noteworthy but whether or not that makes it a true canyon is really up to you so are either the bahama or laurentian canyons the widest on earth well as it turns out length depth and width are all the dimensions needed to come up with area and volume which means we actually have two additional ways to define canyons by which is why at last my search for an answer to what i thought was a simple question has led me all the way to the bering sea so buckle up i think i'll spare us all a little time by skipping the naverin canyon but you should just know that this canyon is second overall both in terms of area and volume area being a two-dimensional characteristic however is determined only by length and width what this means is that a canyon doesn't need to be very deep at all to still potentially have a very big area that's what we can see happening with the 495 kilometer long bearing canyon given a width of 65 kilometers at parts the canyon covers a total area of over 30 000 square kilometers or roughly the size of belgium earning the title of the canyon with the greatest surface area a look at the bering canyons cross section however compared to let's say the nearby navarin reveals the shortcomings of this metric but like i said naverin is the second largest by area and volume which means even this isn't the end reaching deeper than any of the other bearing shelf canyons and wider than any other canyon yet to be discovered is the mighty zhemchug canyon with depths reaching nearly 3 000 kilometers down and a span of approximately 100 kilometers zhemchug features the greatest cross-sectional area of any canyon on earth this means it also earns the title of the most voluminous canyon in the world although the ocean doesn't seem to be having any problems filling it and so i was finally at the end of my search for the best canyon to compare against mariner valley of mars well actually no all i knew was the longest deepest widest etc canyons and the choice was still mine as to which one to use but i'll be honest i still don't know which of these would be best for a comparison in all regards mariner valley is five times longer than the earth's longest canyon a full kilometer deeper than our deepest and over twice as wide but perhaps the most impressive comparison comes by measuring volumes where zhemchug's 5800 cubic kilometers represents less than 1 800th of mariner valley's incredible 4.9 million cubic kilometers of space but i don't know comparing the biggest canyon system in our solar system to just some random big hole in the ocean doesn't carry as much weight to me as comparing it to something i've known about my whole life and actually you know have seen myself sure the yarlung senpo grand canyon is deeper the greenland grand canyon is longer and the bering canyons are bigger but at the end of the day it didn't matter what i used as an example so long as the people watching understood what i was saying hey everyone thanks for watching this is really one of those topics where the more you look the more you'll find so if you enjoyed this definitely get on google earth and do some exploring of your own if you guys think i should do the same type of exploration for other features of the earth let me know in the comments what you'd like to see and of course if you want to continue seeing videos like this you can head over to my patreon to help support what i do here [Music] thanks

Channel: Atlas Pro

Views: 522,912

Keywords: education, geography, science, atlaspro, canyon, grand, yarlung, gorge, united, states, world, deepest, longest, hudson, greenland, valles, marineris, mars, earth, bahamas, bering, congo, fjord, himalayas, andes, submarine, underwater, geology, Mariana, Trench, Valley, Erosion

Id: Ohb2JgT_SRc

Length: 11min 45sec (705 seconds)

Published: Thu Oct 01 2020