<p>Let me propose that if an anoxia event were a cause of the P-T marine extinction; then it wouldn't be Pangaea that would slow recovery, but Panthalassa; the global ocean counterpart to Pangaea. </p>

<p>Here is a map of the oceanic conveyor:</p>

<p><a href="https://i.sstatic.net/XQJkU.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/XQJkU.jpg" alt="enter image description here"></a></p>

<p>Its complex structure is driven by the location of the continents. Without continents spread around the world, the ocean circulation would look more like the Pacific ocean, with three separate gyres (probably four if Antarctica was not there, as in the Permian) and much smaller areas of upwelling water:</p>

<p><a href="https://i.sstatic.net/M5t0W.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/M5t0W.png" alt="enter image description here"></a> </p>

<p>Reduced complexity of ocean circulation could reduce the ability of the ocean recover oxygen levels. Deep water anoxia especially would take far longer to correct with reduced upwelling currents.</p>

CC BY-SA 3.0
2016-11-20T14:01:46.267Z
2016-11-20T14:01:46.267Z
kingledion
<p>252 million years ago, Earth underwent its worst, most violent chapter in the form of the Permian-Triassic extinction event, or "The Great Dying".  70% of the terrestrial species and 95% of the marine species became extinct.</p>

<p>There was one thing that I had noticed in Permian and Triassic landmasses--both periods had Pangaea, all the world's continents clumped together into one singular landmass.  And recent evidence has found that it took life ten million years to recover from the Great Dying.</p>

<p>So why did it take so long?  Was the damage of the Great Dying that extensive?  Or did Pangaea play a part in delaying the recovery process?</p>

CC BY-SA 3.0
2016-07-12T08:09:46.017Z
Relevant: http://earthscience.stackexchange.com/q/7731/87
plannapus
CC BY-SA 3.0
2016-07-12T13:49:46.423Z
Nice question to pose for a few years of PhD research.
Gordon Stanger
CC BY-SA 3.0
2016-07-12T14:33:38.757Z
@plannapus  That doesn't really answer the question as to whether Pangaea played a part in delaying the recovery process or if the damage from the Great Dying was that extensive.
JohnWDailey
CC BY-SA 3.0
2016-07-12T14:48:36.707Z
@JohnWDailey which is why i said it was "relevant" and not "duplicate". It does not answer whether or not Pangaea played a part but it does explain some basics about recovery from a mass extinction, and about possible reasons behind the length of said recovery. In this case, I think (but I m not that up-to-date on the PT boundary event, so don't quote me on this) that the long recovery is merely a result of primary producers being directly affected by the event.
plannapus
CC BY-SA 3.0
2016-07-12T15:08:04.260Z
I'll check on the literature and get back to you on that when i'll have time. I do have an additional question though: when you ask if Pangaea had a role in delaying the recovery process, do you have a specific mechanism in mind?
plannapus
CC BY-SA 3.0
2016-07-12T16:32:54.510Z
Well, just the observation that Pangaea was so vast that the interior was pretty much waterless, even if we don't have flood basalt eruptions and melted methane ice saturating the atmosphere with greenhouse gases.
JohnWDailey
<paleontology><mass-extinction>
Recovery From the Great Dying
JohnWDailey
# Recovery From the Great Dying

(Asked by: username_0 on 2016-07-12)

252 million years ago, Earth underwent its worst, most violent chapter in the form of the Permian-Triassic extinction event, or "The Great Dying". 70% of the terrestrial species and 95% of the marine species became extinct.

There was one thing that I had noticed in Permian and Triassic landmasses--both periods had Pangaea, all the world's continents clumped together into one singular landmass. And recent evidence has found that it took life ten million years to recover from the Great Dying.

So why did it take so long? Was the damage of the Great Dying that extensive? Or did Pangaea play a part in delaying the recovery process?

**Tags:** paleontology, mass-extinction

> **Comments:**
> **username_1**: Relevant: http://earthscience.stackexchange.com/q/7731/87  
> **username_2**: Nice question to pose for a few years of PhD research.  
> **username_0**: @username_1  That doesn't really answer the question as to whether Pangaea played a part in delaying the recovery process or if the damage from the Great Dying was that extensive.  
> **username_1**: @username_0 which is why i said it was "relevant" and not "duplicate". It does not answer whether or not Pangaea played a part but it does explain some basics about recovery from a mass extinction, and about possible reasons behind the length of said recovery. In this case, I think (but I m not that up-to-date on the PT boundary event, so don't quote me on this) that the long recovery is merely a result of primary producers being directly affected by the event.  
> **username_1**: I'll check on the literature and get back to you on that when i'll have time. I do have an additional question though: when you ask if Pangaea had a role in delaying the recovery process, do you have a specific mechanism in mind?  
> **username_0**: Well, just the observation that Pangaea was so vast that the interior was pretty much waterless, even if we don't have flood basalt eruptions and melted methane ice saturating the atmosphere with greenhouse gases.  

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## 1 answers

### Answer by username_3 on 2016-11-20. Score: 1

Let me propose that if an anoxia event were a cause of the P-T marine extinction; then it wouldn't be Pangaea that would slow recovery, but Panthalassa; the global ocean counterpart to Pangaea.

Here is a map of the oceanic conveyor:

[![enter image description here](https://i.sstatic.net/XQJkU.jpg)](https://i.sstatic.net/XQJkU.jpg)

Its complex structure is driven by the location of the continents. Without continents spread around the world, the ocean circulation would look more like the Pacific ocean, with three separate gyres (probably four if Antarctica was not there, as in the Permian) and much smaller areas of upwelling water:

[![enter image description here](https://i.sstatic.net/M5t0W.png)](https://i.sstatic.net/M5t0W.png)

Reduced complexity of ocean circulation could reduce the ability of the ocean recover oxygen levels. Deep water anoxia especially would take far longer to correct with reduced upwelling currents.


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