Earth 96339 - An Alternate Earth

[WoodytheClimateGuy]

Hello everyone!

For a while, I've started up and still working on an Earth (now given the name Earth-96639), which included geographical changes while Pangea broke up and evolved.

Some of these changes may have been there but have changed to the point of not being there in the modern day, while some are almost brand new. However, I will try to make this as realistic as possible. But before I start with the changes, I just want to thank AML Official on Discord, and Thursasprengir#8580 especially, for approving of the changes, and making it as realistic as possible, therefore, they helped me with this project and want to thank them for that. In addition, also thanks to the Worldnbuilding Pasta for their tutorials.

https://worldbuildingpasta.blogspot....ch-part-v.html

Now, I will list the outline of changes, expect that Pangea base/outline soon.

[WoodytheClimateGuy]

Point of Divergence 1: Australia and Antarctica Don’t Separate.

Time: 100-95 Ma

Causes:
The Indian Rift that originally split Australis into Antarctica and Australia ends up failing, and thus, allowed Sahul to stay together.
In addition, a new rift ends up happening between Antarctica and South America, sending Shaul upwards.
Effects:
Despite the Indian Rift failing in terms of Australia and Antarctica, a new rift forms in its place at around 85-80 Ma. A rift that splits East Sahul, which is more where Zealandia would be, from Sahul.
Zealandia ends up emerging as two separate plates/parts, the Northern Zealandian Plate and the Southern Zealandian Plate. But as they rift, their eastern parts end up building up, while erosion happens in the West.
However, after a short while, they both end up rotating and moving up alongside Sahul, building up mountains and crust.
A small island arc of Zealandia ends up splitting from the two islands, and with the Pacific Oceanic Plate, there ends up being a chain of oceanic plateaus, island arcs, and igneous rock on the Pacific Plate’s borders with the Sahulian and the Zealandian plates.
Broken Ridge and Kerguelen don’t end up separating and end up as one singular oceanic plateau, and after a series of buildups, the united Kerguelen ends up mostly being above water.
New Guinea ends up connected with Sahul, just barely though.
A new shield can be seen in Sahul, stretching across the continent.
What’s left of the Sahulian side of Zealandian rift is lowland terrain with some islands, like Marie Byrd island and Tasmania, although they may be modified.
As a result of the rift of Antarctica-America, Sahul ends up moving north to where Papua New Guinea is about where it is today, maybe a little higher.


Point of Divergence 2: A new rift appears in North America, splitting Laramidia from Laurentia.

Time: 110-105 Ma

Causes:
The brief split of North America ends up becoming permanent, due to a rift between Laramidia and Laurentia, splitting the two continents away from each other.
Effects:
Thanks to the Mid Atlantic Rift not yet affecting the North Atlantic, Laurentia ends up briefly reconnecting with most of Europe. This ends up uplifting most of the mountains and land, which this event was known as the Grenville Rebirth.
But eventually, the Mid Atlantic Rift caught up to them, thus splitting Laurentia from Europe. However, the uplift caused by the collision allowed Northern Europe, East Laurentia, and Western Europe to end up rising more out of the ocean. Here are some examples:
Britain: Both Britain and Ireland end up being connected.
A new island chain from Iceland ends up in between Britain and Scandinivia.
Greenland, Britain, Scandinavia, and Ireland end up more elevated.
The Greenland and Quebec mountains end up more elevated.
As for Laramidia, the moving of the Western part of the North American plate, now known as the Laramidian plate, ends up accelerating towards Eurasian plate even more. Allowing places like Beringia, Eastern Siberia, and Kamchatka to rise more out of the ocean. Laramidia itself ends up further west in OTL’s West Coast.
The North America Rift ends up affecting South America too, but it doesn’t actually split, but it does end up creating the Amazon Sea, an inland sea in South America that splits the North andes from it, while also taking lowlands from the Amazon region.
This rift attempt across the Americas will be known as the Great American Rift.


Point of Divergence 3: The East African Rift ends up happening a lot earlier.

Time: 90-80 Ma

Causes:
As a byproduct from the rift of India, East Africa ends up splitting as well. However, it doesn’t entirely split off.
Effects:
This partial split ends up making the way for a new Gulf in Eastern Africa near Mozambique and Tanzania, which ends up providing for new rivers, lakes, and moisture.
Madagascar ends up moving further east, by not too much. However, the sunken islands near it end up being risen.


Other Geographical Changes:

The Balkan Oceanic Crust, which today has the Balkans and Italy, ends up rifting and connecting with Africa instead of being caught between it and Europe. After that, a new rift splits off the Balkan Microcontinent from Africa, and towards Europe. Forming a much bigger Alpine orogeny, and leaving some of its Southern parts to be more built up, even a part of Northern Tunisia and Algeria becomes an island between the Balkans and Northern Africa.
Africa and Arabia end up not colliding with Asia as much, leaving the middle east to be more of an archipelago.
Arabia never ended up rising out of Africa, leaving it to be with the continent, and the Tethys Sea to survive.
There are numerous lakes across North Africa and Arabia, such examples include Lake Chad, Lake Congo, the Maghreb Sea, and Lake Fazzan, splitting what would be the Sahara, into smaller pits of desert.
The biggest gain of all, is a new inland sea that sticks out into modern Nigeria that stuck around.

[WoodytheClimateGuy]

Hello everyone! I made yet another update to the project! I've decided to make concept landmasses. Although they are mostly freeform and traced, I try to make some modifications. This is again a prototype and is subject to change. But you can provide criticism since this is one of my first attempts of making maps like this. I'm using Christopher Scotese's map of Continental Drift as the reference for this and the project.

"Scotese, C.R., 2019. Plate Tectonics, Paleogeography, and Ice Ages, YouTube video: https://youtu.be/UevnAq1MTVA."

https://www.earthbyte.org/paleomap-p...s-for-gplates/

https://www.youtube.com/watch?v=fxaUWL9RSxc

https://www.youtube.com/watch?v=2WDZ313vdXc

https://www.youtube.com/watch?v=IlnwyAbczog

Thanks to him for the references! Check out his content!

Anyways, here is the reference image:

Zealandian Comcept Base.png

And here is the sketch:

v3Artboard 1.png


Hope you like this and expect for more!

[Tiluchi]

This is a very cool project! I'd actually considered doing something similar with my world as it would have more or less fit with the concept I'm working with, but ultimately I ended up building a new world from scratch. One thing you might consider is that you can download sample data for GPlates that goes back 400Mya or so, meaning that with a bit of work you could simulate your alternate earth quite nicely. It would require fiddling around a fair amount with their .rot files but the nice thing is that you'd have lots of data ready to go rather than having to start from scratch. Either way, excited to see how this progresses!

[WoodytheClimateGuy]

Finally, some feedback! Thanks, Tiluchi! I saw some of the GPlates data, I that would have probably been easier, but I aready got a lot of progress done with the method I'm using, so I'm sticking with it. Although for a while, I've mostly been tracing from Scotese's Continental Drift, and in order to spend less time, I decided to do it more roughly, and the specific changes can be added when I do the map, like how you did. Thanks for the feedback and the inspiration!

[WoodytheClimateGuy]

Welp, after all of this time, I finally created the tectonic evolution of this version's Pangea; well part of it anyway, and it's still subject to change. But for right now, here is a GIF (that was a pain of an ass to put together), of the animation.

image_109.00Ma_4.gif

[Harrg]

Looks amazing!

[Rubikia]

That GIF is mesmerising! Really incredible work and it is super interesting to see your detailed divergences occur in the animation. I found it quite fun to watch it through and then read the lists to notice a couple more things! These changes must alter the course of evolution and history quite significantly

[Tiluchi]

Looks like a great start! Will be super interested to see where the tectonic plates go from there.

[WoodytheClimateGuy]

Hello! New update people! This time, we have the GIF for Earth-96639 from the year, 200 Ma, to now, 60Ma.

image_60_1.gif

And because the GIF was compressed like hell, here is a 60Ma image of the world.

image_60.00Ma.png

And as from the image here, you can see the number of changes which are seen on the map.

The split of North America allowed Laramidia to continue on as it would if it was attached to North America, and for Laurentia to collide with Eurasia. And with Laramidia technically collided to Eurasia, and with India eventually colliding to Eurasia, it will end up expanding the glorious supercontinent of Nova Laurasia! Also, Yucatan Island.

Africa's movement ended up changing and slowing its plate movement so much that India ended up as close to Eurasia as Northern Arabia is.

Antarctica seems to be going with Australia and its movement.
Zealandia's northern and southern parts end up splitting apart more like a continental piece, with the micro-oceanic plate of Java splitting from both.

Seems like Adriata seems to finally break off from Africa, specifically at 90Ma, and with slightly more land, and that might even change too!

There might be a break-up of South America and East Africa based on the line, but who knows?

Stay tuned for more updates!