<p>Oceanic trenches are formed by the subduction of an oceanic plate underneath usually a continental plate. So the depth of how deep a trench can be depends on the thickness of the plate that is not being subducted. However, as mentioned in the link, the depth of the MAriannen Trench is also the theortic maximum depth:</p>
<p><a href="https://earthscience.stackexchange.com/questions/71/how-deep-could-the-surface-of-the-earths-crust-get">How deep could the surface of the Earth&#39;s crust get?</a></p>

CC BY-SA 4.0
2022-08-01T14:03:40.777Z
2022-08-01T14:03:40.777Z
Weiss
<p>I was listening to a creepypasta story on YouTube about extremely deep places in the ocean deeper than the Marianas' Trench, and that makes me wonder.</p>
<p>On Earth specifically, how deep could an ocean trench theoretically be? Would it be much deeper than Challenger Deep? I'm sure there is a limit to it, just as there's a limit to how tall a mountain can be, but I'm very curious to know what the limit may be.</p>

CC BY-SA 4.0
2022-08-01T12:55:01.333Z
Related: https://earthscience.stackexchange.com/q/9745/18081
Jean-Marie Prival
<geology><oceanography><geography><geodynamics>
How deep could an ocean trench be on Earth theoretically?
Luke
# How deep could an ocean trench be on Earth theoretically?

(Asked by: username_0 on 2022-08-01)

I was listening to a creepypasta story on YouTube about extremely deep places in the ocean deeper than the Marianas' Trench, and that makes me wonder.

On Earth specifically, how deep could an ocean trench theoretically be? Would it be much deeper than Challenger Deep? I'm sure there is a limit to it, just as there's a limit to how tall a mountain can be, but I'm very curious to know what the limit may be.

**Tags:** geology, oceanography, geography, geodynamics

> **Comments:**
> **username_1**: Related: https://earthscience.stackexchange.com/q/9745/18081  

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## 1 answers

### Answer by username_2 on 2022-08-01. Score: 0

Oceanic trenches are formed by the subduction of an oceanic plate underneath usually a continental plate. So the depth of how deep a trench can be depends on the thickness of the plate that is not being subducted. However, as mentioned in the link, the depth of the MAriannen Trench is also the theortic maximum depth:

[How deep could the surface of the Earth's crust get?](https://earthscience.stackexchange.com/questions/71/how-deep-could-the-surface-of-the-earths-crust-get)


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