<p>Below are two cropped screenshots from the super-cool video <a href="https://youtu.be/-uOwv_Krqk8" rel="noreferrer">Draining Earth's oceans, revealing the two-thirds of Earth's surface we don't get to see</a> with the oceans "drained" to 4000 and 5000 meters below sea level.</p>

<p>We've all read about the magnetic field reversals leaving alternating lines of residual magnetic field trapped in the crust that go in the north-south direction, but I was surprised to see these topographic ripples that extend in the east-west direction.</p>

<p>What caused these to form?</p>

<p>I've added some annotation to indicate the direction of the ripples I think I'm seeing.</p>

<p><a href="https://i.sstatic.net/O5Rar.png" rel="noreferrer"><img src="https://i.sstatic.net/O5Rar.png" alt="cropped screen shots from Draining Earth&#39;s oceans, revealing the two-thirds of Earth&#39;s surface we don&#39;t get to see"></a></p>

CC BY-SA 4.0
2020-02-04T05:54:25.850Z
["An oceanic core complex, or megamullion, is a seabed geologic feature that forms a long ridge perpendicular to a mid-ocean ridge. It contains smooth domes that are lined with transverse ridges like a corrugated roof. They can vary in size from 10 to 150 km in length, 5 to 15 km in width, and 500 to 1500 m in height."](https://en.wikipedia.org/wiki/Oceanic_core_complex) [Role of melt supply in oceanic detachment faulting and formation of megamullions](https://pdfs.semanticscholar.org/73dc/11f7a8c2d8a0e177af5e2dab38b811b5920a.pdf?_ga=2.108718274.1341586451.1580794274-721078197.1580506373)
Keith McClary
CC BY-SA 4.0
2020-02-05T11:47:59.193Z
@KeithMcClary searching for "megamillions" finds this http://rjes.wdcb.ru/v06/tje04146/fig01.htm which contains https://i.sstatic.net/5wMN7.gif Any chance you're interested in writing this up as a short answer?
uhoh
CC BY-SA 4.0
2020-02-07T01:33:36.007Z
1 hour 2015 lecture: ["The Life and Death of Oceanic Core Complexes and the Largest Normal Faults in the World."](https://www.youtube.com/watch?v=sGDqbasw19I) about how this is more complicated than previously thought.
Keith McClary
CC BY-SA 4.0
2020-02-07T01:40:30.303Z
@KeithMcClary cool! *I love stuff* that turns out to be "...more complicated than previously thought!"
uhoh
<topography><ocean-ridge>
What causes the "ripples" that extend east-west along the mid-atlantic ridge?
uhoh
# What causes the "ripples" that extend east-west along the mid-atlantic ridge?

(Asked by: username_0 on 2020-02-03)

Below are two cropped screenshots from the super-cool video [Draining Earth's oceans, revealing the two-thirds of Earth's surface we don't get to see](https://youtu.be/-uOwv_Krqk8) with the oceans "drained" to 4000 and 5000 meters below sea level.

We've all read about the magnetic field reversals leaving alternating lines of residual magnetic field trapped in the crust that go in the north-south direction, but I was surprised to see these topographic ripples that extend in the east-west direction.

What caused these to form?

I've added some annotation to indicate the direction of the ripples I think I'm seeing.

[![cropped screen shots from Draining Earth's oceans, revealing the two-thirds of Earth's surface we don't get to see](https://i.sstatic.net/O5Rar.png)](https://i.sstatic.net/O5Rar.png)

**Tags:** topography, ocean-ridge

> **Comments:**
> **username_1**: ["An oceanic core complex, or megamullion, is a seabed geologic feature that forms a long ridge perpendicular to a mid-ocean ridge. It contains smooth domes that are lined with transverse ridges like a corrugated roof. They can vary in size from 10 to 150 km in length, 5 to 15 km in width, and 500 to 1500 m in height."](https://en.wikipedia.org/wiki/Oceanic_core_complex) [Role of melt supply in oceanic detachment faulting and formation of megamullions](https://pdfs.semanticscholar.org/73dc/11f7a8c2d8a0e177af5e2dab38b811b5920a.pdf?_ga=2.108718274.1341586451.1580794274-721078197.1580506373)  
> **username_0**: @username_1 searching for "megamillions" finds this http://rjes.wdcb.ru/v06/tje04146/fig01.htm which contains https://i.sstatic.net/5wMN7.gif Any chance you're interested in writing this up as a short answer?  
> **username_1**: 1 hour 2015 lecture: ["The Life and Death of Oceanic Core Complexes and the Largest Normal Faults in the World."](https://www.youtube.com/watch?v=sGDqbasw19I) about how this is more complicated than previously thought.  
> **username_0**: @username_1 cool! *I love stuff* that turns out to be "...more complicated than previously thought!"  

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## 0 answers

