Why is the Marianas Trench the deepest place on Planet Earth? A look beneath the ocean

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The Challenger Deep of the Marianas Trench is the deepest point in any of Earth's oceans at 35,876 feet below sea level. Specific details of plate tectonic interactions create this impressive depth. This video uses Google Earth and simple diagrams and illustrations to explain the interacting forces and processes that form the deep Marianas Trench and impact other aspects of the Earth, like global climate. The video refers to some publicly available geologic studies that describe the evolution of the area and shed light on just what happens deep inside the Earth that controls what happens at its surface.

[scottygdaman]

lived on Guam for a while right next to the shore.
go snorkling and you would end up looking down and see this edge that just kept going down .
very creepy.
sometimes at night when it was very quiet you might hear distant thunder actually it was giant boulders falling down the edge of this endless cliff.

[mrblock]

What's odd to think is that what used to be life is possibly 400 km deep into the Earth by now.

[Nojaru]

It wasn't enough that you had sand models, Google Earth tours and Paint Diagrams. No, you had to go represent the Earth's mantle with green. Now I have to like this channel even more. ;)

[Cheka__]

If Guam tips over, those people are in some seriously deep water.

[Trendyflute]

I remember seeing a tech demo several years of a home-made plate tectonics computer model. He said the trick to making it work was "old oceanic crust must die". And with that implemented, it did seem to produce rather plausible plate tectonics! Also I guess this is a good place to state my little 15 seconds of fame moment, I worked as a calibration tech at a company that manufactured physical oceanography sensors and I pre- and post-calibrated a few sensors that James Cameron took with him to the bottom of Challenger Deep in 2013.

[DevinDTV]

Anyone else confused why he said the mantle would be green if cool, I looked it up and the mantle is largely composed of olivine which is a green mineral .

[eliinthewolverinestate]

Litke Deep is closer to the earth's core than Challenger deep by 9.2 miles. It's because of the oblate spheroid shape of the planet Earth, which is flatter at poles and thicker at the equator. However, by depth below sea level, Litke Deep is not the deepest point in the Arctic Ocean.

[EricBandholz]

[Draws volcano]

"Nothing too bad. They got everyone out of there in time." - Philip Prince, 2024.

This is the best explanation I've seen on YT regarding the Marianna Trench. Thanks alot!

[ataricom]

I'm guessing that you've presented this before, right? Your ability to convey the immense size of our planet in MS Paint, in real time, is a god-teir skill that I wish I had.

[vhhawk]

It never occurred to me that the lithosphere stops sinking. I thought it went down and just blended into the mantle... wow. Love it when my mental model gets corrected.
Edit: So, is the mantle just "paved" with all these relics of lithosphere that has subducted?

[garysloan]

You had me duped with the beginning of your Paint model but damn it sure turned out phenomenal, you are a great visual talent in addition to your science expertise! Looking forward to more

[blades]

It's definitely past my bed time, I was hungry so I heated up a few slices of pizza and grabbed a beer and clicked on a random tube before I called it a night. I am riveted. This is so cool, thanks for making this information accessible and easily digestible for us lay people. This does not help my fear of open water, but it does help my understanding of how the world works!

[brucebradburyIII]

I’d say the most surprised I was was when I learned that rock in the mantle is literally greener… that’s crazy. Thank you so much for making this video. I feel like the YouTube algorithm is bringing old YouTube back, more educational content . This was a stellar piece.

[cameronknoechel]

As I'm sitting in my living room watching this on my phone you remind me of high school science class. I absolutely hated school but I loved science, you remind me of one of those cool teachers that really cared and taught things in a way to make it interesting and make you want to learn more. Thank you, I love learning about geography and the history of things. 👍👍

[BowzKnows]

The Pacific Ocean is crazy to think about, almost like space on Earth.

[earthexpanded]

Excellent presentation. There are some rather significant issues with the traditional interpretation of the Pacific Plate in the region of Marianas Trench, however. In general, it is simply described as the Pacific plate forming at a ridge and moving under other plates such as in this region. However, this is based off the models of oceanic crustal age such as by Muller et al. that are largely based off of isochron lines. There have been studies of East Mariana Basin where drill samples are anomalously low in age in the region.

One such example is "East Mariana Basin tholeiites: Cretaceous intraplate basalts or rift basalts related to the Ontong Java plume?" by Castillo et al. where they conclude the East Mariana Basin basalts to be distinct from the Jurassic basalts of Pigafetta Basin to the north, but to have a similar isotopic signature to the basalts of Ontong Java and Manihiki Plateaus and also indistinguishable from the basalts found at Nauru Basin dated to ~111Ma (the region east of the Mariana Trench is generally claimed to be significantly older).

There are no studies (to the best of my knowledge--I certainly could not find any) that found Jurassic basement rock below the anomalous Cretaceous crust of the East Mariana Basin--all samples from the region show purely Cretaceous layers.

The magnetic anomaly patterns would predict the igneous basement of these regions to be Jurassic, which is the basis by which the interpretation of the formation of Marianas Trench is formulated. As a result, this data appears inadequately explained by present descriptions of the formation of the Marianas Trench due to its relationship to East Mariana Basin by physical proximity and by the claimed process for the formation of the Marianas Trench.

[tippyc]

That's one of the best diagrams of subduction I've ever seen, and you just freehanded it in MS paint while we watched.

[gmxkey]

Interesting. Not a geologist but a former resident of Saipan who was always curious about the Trench and the Deep. The big piece for me was the age of the sinking plate. FYI, I was in Saipan when the had their last 7.x earthquake and it was a real long minute. Anatahan which hadn't errupted in 20, 000 yrs also happened while I was there. The vog turned the morning to night in about a hour. Interesting section of the world geologically.

[garyb]

This was really well done. I've been looking at that trench and pondering about it for many years.