50 WONERS! 50 WONERS! Hi!
I brought this fun shirt. Sorry. My uncle gave this to me.
It's pretty fun. It's got Fisher on it. like ocean, ocean-related, and flatfish too.
Thunders. Much like in the ocean. Okay, we've been talking about marine provinces.
Yes, I know I fumbled that in the last video. Marine provinces, there's three of them. We talked about continental margins. And the last one in this video, we're going to talk about deep ocean bases.
As I mentioned previously, deep ocean basins are anywhere not underlined and italicized. Anywhere not continental margin or mid-ocean ridge, right? So most of the ocean is deep ocean basin. This includes abyssal plains, there's a lot of these, right?
Abyssal plains are the big areas of the seafloor that are flat, sediment covered. This includes ocean trenches, the deepest parts of the ocean, they're found at convergent boundaries, we talked about that. Well, we talked about active margins, right?
Active continental margins. So right there. The trenches, basically, are the edge of those.
And deep ocean basins also include volcanic peaks and arcs. There's lots of these, too. They're mostly old and inactive, but things like seamounts, table mounts, geodes, those are all things you would find in deep ocean basins.
Most of the deep ocean basins are abyssal plains. So we have here an image of the east coast of the US, the Atlantic Ocean. We have the mid-Atlantic ridge right here. And then you can see that there's a lot of little bumps and there's a few sea mounts. and stuff.
But this is all this stuff right here is abyssal plain, right? And this is kind of an ocean ridge area. So most of the deep oceans is abyssal plains.
It says abyssal plains... which are generally located between a continental margin and a mid-ocean ridge, are large, flat, and deep sea floor regions with occasional volcanic peaks that protrude above the sediment. How many volcanic peaks are there, you ask? I tell you, you're looking at me weird.
I tell you, most sea potions are abyssal plates, but don't forget there's a lot of sea mounts. So volcanic peaks are sea mounts, guillots, things like that. There are, this is a map of, with crosses for each one.
showing you predicted locations from satellite imagery of us satellites altimetry of seamounts that are greater than 1500 meters off the seafloor so 1500 meters is more than a mile so these are large large features right and so we think sea amounts larger than 1500 meters that there are about 6,000 of those on the seafloor and if you go for just like the little hills that are above 100 meters is over 200,000 that's like that's like a top but even if you go with more than a thousand meters so more than a kilometer above the seafloor there's about 15,000 of them right so so then don't forget there's a lot of abyssal plates most of it is abyssal plates which is kind of you know low-grade flat seafloor covered by sediment, but popping up pretty regularly into that environment is these seamounts which would manifest as essentially rocky outcrops in the middle of the ocean, seemingly in the middle of nowhere. Deep ocean basins, again, also home to ocean trenches. The deepest parts of the ocean, they occur only at seduction zones, convergent boundaries. So we don't have ocean trenches. in the Atlantic Ocean because the mid-Atlantic ridge is in the middle of the Atlantic Ocean.
We don't really have them in the Indian Ocean either because that ridge is also in the middle of the ocean. There's the Java Trench. And I should say, in the Atlantic Ocean, there is the Puerto Rico Trench, and the South Sandwich Trench is right down there.
But these are smaller features compared to the Ring of Fire, right? which encircles the Pacific Ocean on both sides. The reason for this is because we have the East Pacific rise creating new seafloor.
Basically here, that seafloor spreads across the entire Pacific Ocean. But it almost immediately bumps into North and South America. And it's subducted underneath those. And so where it's being subducted, you have those trenches.
And then on the other side of the ocean, after it moves all the way across the ocean, it meets these... younger, less dense pieces of sea flora. These are different plates, and the Pacific plates and ducts underneath those plates are, in the case of this, the Asian continental plate.
And so you have trenches all around here. Right, so most occur in the Pacific, but at least one in all oceans except the Arctic. Do remember, this is where we have the most intense earthquakes, right?
And so it's important to understand how these work. These are... It says, no, nearly absent continental margin along conver...
Ah, yeah. Sorry. I had to read this for a second. I feel like I asked what I wanted to say.
So this is showing you a convergence active margin, continental margin that's active. And so in this case... you have the seafloor subducting underneath the continent, right, you get this huge trench where you get it's deep in this case this is an actual one so we have the Peru-Chile trench goes down to a little over 8,000 meters of depth that's quite deep and that when you have an active margin like this the The length of the continental shelf is very short.
It's almost absinthe. So it's getting deep pretty quickly. So if you were ever...
raise your hand, two 51ers, how many of you have been to the west coast of the US, to a beach, or the west coast of South America or any of these other areas where you might see a trench? It's a bunch of you. You notice, right, that you can't walk out really far on those beaches before the water gets deep. It's because the slope is a lot greater, so the water gets deep pretty fast. If you were to actually go out on a boat and, you know, look at it, the depth of the sea floor as you're going, or take a submarine out right along the sea floor, it gets deep real fast, in particular up in California.
And so these are, again, the features of the deep ocean basin, which is a marine province, are abyssal plains, trenches, and these seamounts and volcanic edifices. Thank you. That's it. This is a quick one. So in the final video in the series, we are going to talk about mid-ocean ridges.
So be good people, and I will see you in the next video. Last time, I think I went off this way. I'm going to go off this way this time.
So I'm going to take this slow roll, walk away, and I will see you in the next video. I'm going to... I'll still give you some napalm death as I'm walking out.
Just put it on the shirt, the rhino shirt. Because we should definitely have... I'll see you next video.