<p>The carvings are submarine canyons, a part of the continental slope leading from the continental shelf to the continental rise and ultimately the Abyssal plains. They are a product of :</p>

<ul>
<li>erosion through currents and </li>
<li>slumping of the continental shelf</li>
</ul>

<p>Like other erosive or slumping effects, they can be self-reinforcing, leading to canyon-like structures. The highlighted canyon here is the Gollum Channel system, seen <a href="https://en.wikipedia.org/wiki/Submarine_canyon#/media/File:Porcupine_Biscay_canyons.png" rel="noreferrer">here</a>.</p>

CC BY-SA 4.0
2020-03-26T14:38:12.810Z
2020-03-26T14:38:12.810Z
R.K.
<p>Browsing around Google Maps, I came across this off the south-west coast of Ireland</p>

<p><a href="https://i.sstatic.net/F9fWl.png" rel="noreferrer"><img src="https://i.sstatic.net/F9fWl.png" alt="Continental shelf southwest of Ireland"></a></p>

<p>It looks very consistent with the shape rivers and their tributaries might make, but it has me puzzled since it's all underwater!</p>

<p>The main, most "river-like" one is in the middle-left of the picture but there are more (which look more like fjords) at the bottom.</p>

<p>What caused this feature?</p>

CC BY-SA 4.0
2020-03-23T12:41:53.790Z
So you discovered the Gollum channel system, nice (it really is called so). Have an extensive read at wikipedia on [submarine canyons](https://en.wikipedia.org/wiki/Submarine_canyon), then return with further questions.
Erik
<oceanography><rivers><satellite-oddities>
What are these river/canyon-like carvings in the ocean?
komodosp
# What are these river/canyon-like carvings in the ocean?

(Asked by: username_0 on 2020-03-23)

Browsing around Google Maps, I came across this off the south-west coast of Ireland

[![Continental shelf southwest of Ireland](https://i.sstatic.net/F9fWl.png)](https://i.sstatic.net/F9fWl.png)

It looks very consistent with the shape rivers and their tributaries might make, but it has me puzzled since it's all underwater!

The main, most "river-like" one is in the middle-left of the picture but there are more (which look more like fjords) at the bottom.

What caused this feature?

**Tags:** oceanography, rivers, satellite-oddities

> **Comments:**
> **username_1**: So you discovered the Gollum channel system, nice (it really is called so). Have an extensive read at wikipedia on [submarine canyons](https://en.wikipedia.org/wiki/Submarine_canyon), then return with further questions.  

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## 1 answers

### Answer by username_2 on 2020-03-26. Score: 7 | Accepted answer

The carvings are submarine canyons, a part of the continental slope leading from the continental shelf to the continental rise and ultimately the Abyssal plains. They are a product of :

* erosion through currents and
* slumping of the continental shelf

Like other erosive or slumping effects, they can be self-reinforcing, leading to canyon-like structures. The highlighted canyon here is the Gollum Channel system, seen [here](https://en.wikipedia.org/wiki/Submarine_canyon#/media/File:Porcupine_Biscay_canyons.png).


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