1

Physiology & Medicine / Re: Can primates with longer necks and hips and shorter torsos take many roles?

« on: 11/08/2022 19:45:24 »

What about on non-flying primates?  Would those three features work?

2

Physiology & Medicine / Can primates with longer necks and hips and shorter torsos take many roles?

« on: 11/08/2022 06:29:45 »

In this image by jerica128, they created a hypothetical kind of winged humanoid called a "legnarian", and it was portrayed as having the following features to justify flight capability:

•     Longer necks, said to ease stress on the vertebrae and muscles when flying
•     Shorter torsos for larger core muscle stabilization
•        Longer hips for the same reason as #2

Impressive feats to have for a flying primate, but what about arboreal primates? In a fictional alternate Earth, would having those make them better climbers than they already are? And would they also be useful in primates with less conventional forms, niches or guilds, preferably comparable to those of carnivorans, pigs and even elephants?

3

Plant Sciences, Zoology & Evolution / When did the parrots, kingfishers and woodpeckers come from?

« on: 30/06/2020 04:59:55 »

Have there been molecular (not fossil) evidence of when the following bird orders debuted?

Coraciiformes (bee-eaters, rollers, kingfishers, todies and motmots)
Piciformes (woodpeckers, toucans, jacamars, puffbirds and barbets)
Psittaciformes (parrots)

I ask this because of two reasons.  One, because the first two orders are featured in the Speculative Dinosaur Project, a speculative evolution scenario which detailed on how life might've looked had the dinosaur empire not fallen 66 million years ago.  This would have suggested that both clades were in our timeline around long enough to witness the Chicxulub extinction event, but is this true? 

Two, the Wikipedia article on "Parrot" states that the order debuted 50 million years ago in the Eocene, yet the molecular evidence suggests that Psittaciformes is a much older order than that:

   

Molecular studies suggest that parrots evolved approximately 59 million years ago (Mya) (range 66–51 Mya) in Gondwana. The three major clades of Neotropical parrots originated about 50 Mya (range 57–41 Mya).[6]

But the article on "New Zealand parrot" says this:

   

The superfamily diverged from the other parrots around 82 million years ago when New Zealand broke off from Gondwana, while the ancestors of the genera Nestor and Strigops diverged from each other between 60 and 80 million years ago.

Which article is more accurate?

4

Plant Sciences, Zoology & Evolution / What are the consequences of a longer Paleocene-Eocene Thermal Maximum?

« on: 21/06/2020 17:59:26 »

The following questions are crucial for a worldbuilding project of mine.


Sometime between the Paleocene and Eocene epochs, there was a mysterious, sudden, dramatic rise in global temperature. This moment in time was known as the "Paleocene-Eocene Thermal Maximum", shortened into "PETM". In just 20 to 50 millennia, the temperature rose by five to eight degrees Celsius, and this heatweave persisted for another 200 millennia (that's just the mean estimate.)


While its impact on terrestrial plant and animal life is well-known, the focus of the question is on how the PETM impacted the marine ecosystems. The warmer the water's temperature, the less oxygen it can hold, resulting in ocean anoxia. And since water has a low albedo, it absorbs carbon dioxide rather than reflects it. And in an episode as CO2-rich as the PETM, the oceans absorbed so much of the greenhouse gas that they had become acidifed. That, in turn, depleted the supply of carbonates, which many animals relied on to build shells and other structures. Indeed, fossil remains of coral reefs dating from the PETM to several million years afterwards were rare, and anywhere between one-third and half of all the deep-sea species of foraminifera (tiny, planktonic lifeforms) went extinct. Finally, the warmer waters also affected the arrangement of a particular layer called the lysocline:

The lysocline marks the depth at which carbonate starts to dissolve (above the lysocline, carbonate is oversaturated): today, this is at about 4 km, comparable to the median depth of the oceans. This depth depends on (among other things) temperature and the amount of CO2 dissolved in the ocean. Adding CO2 initially raises the lysocline, resulting in the dissolution of deep water carbonates. This deep-water acidification can be observed in ocean cores, which show (where bioturbation has not destroyed the signal) an abrupt change from grey carbonate ooze to red clays (followed by a gradual grading back to grey). It is far more pronounced in north Atlantic cores than elsewhere, suggesting that acidification was more concentrated here, related to a greater rise in the level of the lysocline. In parts of the southeast Atlantic, the lysocline rose by 2 km in just a few thousand years.

The point of departure is this--The Paleocene-Eocene Thermal Maximum did happen at the same time as OTL and at the same speed, but it lasted three to four times longer. With that in mind, questions follow:

• Would a longer PETM lift the lysocline closer to the surface?
• Based on our knowledge of shark and ray species that were around to witness the PETM, would any of them survive the longer period of warmer, more acidic oceans? And were there any freshwater species at the time?
• Would a longer PETM destroy the coral reefs (as is my primary target), and if yes, how would that affect the other invertebrates and the fish that relied on the reefs for food, shelter and breeding?
• Would life in brackish and fresh water fare better than in seawater?
• Could pelagic (open-ocean) species have a chance of surviving a longer PETM? And if they colonized the shallow water ecosystems, could they evolve to grow smaller?

5

Geology, Palaeontology & Archaeology / How can a population of massive Basilosaurus fit in a mangrove swamp?

« on: 15/01/2020 13:26:23 »

• Since Walking with Beasts, is the "love-hook" idea of the smaller back legs still a valid explanation?  Or have others been brought up over the years?
• How on Earth can you fit a population of 65-foot-long, multiton predators like Basilosaurus in habitat as dense, shallow and unstable as a mangrove swamp?

6

Just Chat! / How Different Should a Perissodactylian Whale look from an Artiodactylian Whale?

« on: 28/12/2019 04:46:53 »

Perissodactyla is an order of mammals consisting currently of the seventeen species of horses, rhinoceroses and tapirs. Usually, any clade is connected by a coupling of genetics and physical morphology.

The ancestors of all perissodactyls, even the extinct brontos and indriks, were the rodent-like hyopsodontids.  They were likely swift and nimble, living in burrows and perhaps hunting with echolocation like some species of moles still do today. The hyopsodontid family did not last long--living from the early Paleocene to the Eocene. But what if they held on a little bit longer, long enough to assume a larger, more otter-like form and taking on an evolutionary path similar to the archaeocetes, the earliest of the true whales?

Back home, whales are confirmed to be artiodactyls, with their closest living relations being hippopotamuses. But in this alternate Earth, a clade parallel to whales--let's call them "illhveli", for discussion's sake--are perissodactyls. Using modern perissodactyls as reference, what sorts of anatomical, skeletal or other kinds of morphological differences should I watch out for in an odd-toed cetacean ("illhveli") in comparison to our even-toed cetacean ("whale", "dolphin", "porpoise")?

7

The Environment / Did the Azolla Event 49 Million Years Ago Create an Extinction Event?

« on: 14/03/2019 15:15:07 »

55 million years ago, the world was literally a jungle. With such high temperatures, rainfall and humidity, life could proliferate. But 49 million years ago, something drastic happened: The Azolla Event, where ice was forming at the poles. The culprit? A kind of plant called Azolla. Within 800,000 years, photosynthesis and carbon sequestration from those plants reduced the atmospheric quantity of carbon dioxide from 3500 parts per million to 650.


But the real question here is--did the cooling caused by the Azolla Event create a major extinction event of plant and animal species?

8

Just Chat! / Re: Avian Crocodylomorph

« on: 31/10/2018 23:42:57 »

one might propose that a modern flying creature of a non terrestrial ancestry might primarily live in the water; but have the ability to rise and fly; unlike today's sea birds who do not "live" in the water, but simply float on it.

the creature would have such unique attributes as teeth adapted to catching underwater prey.

I said "crocodylomorph", not "crocodilian", which came later.

9

Just Chat! / Avian Crocodylomorph

« on: 30/10/2018 03:10:15 »

Today, dinosaurs, alligators, crocodiles, gharials and caimen are all that remains of a special group of reptiles called the archosaurs. Recently, it has been accepted by the public that birds did not evolve from dinosaurs but are themselves dinosaurs.

But what if birds evolved from a different group of archosaurs?

Unsurprisingly, as far as reptiles go, Crocodilia is as bird-like in anatomy and even behavior as we're going to get. In the distant past, there were crocodylomorphs of a great slew of varieties imaginable, so it would make sense, in an alternate Earth where pterosaurs definitely never existed and dinosaurs might not exist, for a crocodylomorph to become Aves, the traditional name for the avian dinosaurs, known vernacularly as "birds".

But giving benefit to the presumption that all crocodylomorphs shared at least one anatomical attribute that separated them from dinosaurs, would an avian crocodylomorph have certain and noticeable anatomical differences from avian dinosaurs that I should watch out for? Or would an avian crocodylomorph look exactly like an avian dinosaur?

10

Just Chat! / Re: How Will the Geographic Differences Between Earth and AE111 Affect AE111?

« on: 30/10/2018 03:02:52 »

That's quite a post... it's going to take me some time to get through this!

Have you come up with the answers yet?

11

The Environment / Re: Which Animals Thrive in Low-to-No-Oxygen Environments?

« on: 07/10/2018 05:48:26 »

Some loriciferans can live their entire lives in anoxic conditions: https://www.nature.com/news/2010/100406/full/464825b.html

The crucian carp can survive anoxic conditions for at least 140 days: https://en.wikipedia.org/wiki/Crucian_carp#Physiology

Could the phyla from either species be around in periods of Earth's history when the oxygen levels in the water really were lower than today?

12

The Environment / Which Animals Thrive in Low-to-No-Oxygen Environments?

« on: 07/10/2018 00:32:48 »

As far as I know, Porifera (sponges) and Cnidaria (jellyfish, corals and hydroids) can thrive in conditions where oxygen contents are low.  Jellyfish, in particular, thrive better in warmer, oxygen-lower water than cooler, oxygen-higher water.  And sponges were around when oxygen contents really were lower than they are today.  But is that everyone?  What other animal phyla, if any, can thrive in water that have low if not no oxygen content at all?

13

Just Chat! / Re: In Search of Climate Modeling Forums

« on: 06/10/2018 21:42:37 »

I note you have not posted your ideas on this forum, why not??

I did.  But because of its fictional nature, it's on the "Just Chat" forum.

14

Just Chat! / In Search of Climate Modeling Forums

« on: 05/10/2018 06:13:00 »

Does anyone in this forum know where I can find online forums specifically on climate modeling that will accept hypothetical what-if questions and models?

15

Just Chat! / How Will the Geographic Differences Between Earth and AE111 Affect AE111?

« on: 24/09/2018 21:07:27 »

Dark brown=mountains.  Light brown=uplifts.  Black=Igneous provinces still visible today at their original extent with no consideration of erosion.

Let us say that, in the future, some scientists have created satellites capable of something that seems science fiction for now — punching the walls of the universe to study an alternate reality. By that scenario, some hundreds of “alternate Earths” from hundreds of alternate universes would already have been discovered and meticulously studied. As much as half of them would still be ruled by humans, unfolded by events that turned out differently. One universe, for example, had an Earth where 9/11 never happened, or where the outcome of the Revolutionary and Civil Wars ended up differently.

One of the most interesting to note was a planet that scientists call “Alternate Earth 111”, known to the public as “Great Lakes Earth”.

Why?

Because at first glance, it seemed that almost every continent is dominated by lakes, even those larger than the Great Lakes that we have in North America.

The Americas

The Appalachian Range used to exist, but all that remains nowadays are their metamorphic bedrocks. Since then, the Atlantic Coast is a labyrinth of islands, straits, channels and sounds, making New England the eastern equivalent of the Inside Passage, caused by five million years of being repeatedly scraped and bulldozed by ice.  The terrain is not quite dramatic, the tallest above sea level being only 122.2 feet (37.25 meters.)

While our Rockies stand no taller than 14,440 feet above sea level, the tallest peak in a Great Lakes Rockies is measured to be 20,310 feet. Back home, our Rockies formed between 80 and 55 million years ago through the Laramide Orogeny, the subduction of the North American and Pacific plates at a shallow angle. Their Rockies first formed 55 million years ago as the result of a collision between eastern and western North America. They stopped becoming active as recently as nine million years ago.  Since then, a series of faulting had shed off the mountains’ sedimentary skin and exposed the tougher granite-and-gneiss core.  No wonder, then, that transdimensional explorer Mark Greene called the Great Lakes Earth Rockies “a single, continuous spine of breathtaking Tetons.”  West of the Rockies stands an uplift varying in elevation above sea level between 2,000 and 13,000 feet (between 610 and 3962 meters.)

Minor differences in geological history could create major differences in geographical shape.  Without the Cascades or the Alaska Range, the distinctively whiplike Alaskan Peninsula simply does not exist.  The area we’d recognize as San Andreas (Baja Peninsula and southwestern California) is fused into what we’d call southeastern Alaska.  Evidence in the rocks beneath the soil shows that San Andreas did indeed collide with Alaska only 24 million years ago, but the mountain-building period did not last long, and the peaks were reduced into quarter-mile-tall hills.

The Black Hills of South Dakota don’t exist on Great Lakes Earth. The Ozarks, larger in area and elevation than back home, are the closest analogy.  The tallest stands 7242 feet (2207 meters) above sea level.  They started life as a dome of granite that, over millions of years, had been replenished with fresh supplies of magma.  This allowed the crystals that made the granite dramatically larger, making the rock itself a lot harder.  After 2.2 billion years under the surface, the dome popped above sea level only as recently as 20 million years ago.  Even though rain and river played a part in carving the dome into numerous spires, pillars and gorges, the real player in shaping the Ozarks is lower air pressure, exfoliating the surface into pieces like layers of onions.

True to the spirit of the planet’s name, North America is full of large lakes. The largest of which is Agassiz. In fact, it is the cornerstone of all of Great Lakes Earth’s great lakes — enormous depressions, tectonic rifts or volcanic calderas reshaped and filled in by ice, rain and river. To have an idea on the shape, size and scope of Agassiz, we must look at the familiar faces of the Great Lakes — Superior, Michigan, Huron, Erie and Ontario — and then flood off the entire basin. This is Lake Agassiz, 95,000 square miles and 5500 feet at its deepest. Agassiz started out as a series of rifts and faults that failed to split the continent. The valley wouldn’t become a lake until the ice bulldozed the depressions during the Pleistocene glaciations.

West of the Rockies, there are even more lakes—Bonneville, Carson, Olympia, Hamilton and Red Deer.  All of them formed separately late during the Cenozoic as tectonic weaknesses sank the land, sometimes to the point below sea level.  Further shaping the lakes were the last five million years of ice ages strengthening and weakening the freeze-thaw cycles.  As a result, not only do they have their distinctive shapes, they are also deep.  Bonneville, the deepest, is currently over a thousand feet deep.

What we’d presume to be the Brooks Range in northern Alaska actually isn’t.  The Murchison Mountains, as we call them, are actually volcanic peaks standing 14,411 feet (4392 meters) above sea level at the tallest.  They stand at one of the points where the Arctic Plate sinks beneath the Laurasian Plate.

The Yellowstone mantle plume is still present. Except that instead of Wyoming’s northwestern corner, it can be found in northeastern California. The upland itself covers an area of 5,000 square miles and stands almost like an island between the surrounding lakes and lowlands.

Five million years ago, the oceanic Panamanian Plate had been invaded on both fronts—by the Caribbean Plate in the northeast and the Pacific Plate in the southwest.  This uplifted the basaltic slab to above sea level and had volcanoes guarding the plateau.  The Twins, as they are called, are still active. One twin is currently 6,684 feet above sea level, the other 9,698 feet.  Curiously, the Twins make up the coastline of Central America on Great Lakes Earth, which makes sense considering their young age.  What doesn’t make sense is how they could be so tall in so short a time.  The same problem is said of the Andes, which also make up South America’s entire western coastline.  But if we look at a bathymetrical map, we start to understand why—from Argentina to Guatemala, the Pacific Plate is paralleled by the younger, narrower Nazca Plate.  It first formed only ten million years ago and uplifted the Andean coastline for five million years before reaching the Panamanian Plate.  This double-subduction may explain why the Andes, 25,122 feet above sea level and still rising, as they have been for the last 45 million years, had such devastating eruptions in the last 10,000 years, with an average of one eruption measuring eight on the VEI every thousand years.

Andean uplift notwithstanding, there is a transition between northern and southern South America—a transition separated by 2,891 feet of elevation. That is because from 250 to 200 million years ago, South America’s southern half was part of an uplifted plateau much like Tibet back home. The more recent uplift of the Andes nearly attempted to resurface that past.

Questions follow:

    Are these changes enough to spare northeastern Nebraska from the onslaught of Tornado Alley without sacrificing the Midwest’s prairie fertility in the process?
    Will all these lakes and rivers (not pictured) turn the Wild West into a greener Eden?
    How much of the Amazon Basin will be contained within South America?
    What kind of landscapes should I expect to see in Argentina and Brazil?

Eurasia

Physically absent in the supercontinent are Turkey, Iran, and the Low Countries (Belgium, Netherlands, Luxemburg and Denmark). Back home, Scandinavia is one of Earth’s recognizable peninsulas. On Great Lakes Earth, the body we’d recognize as the Baltic Sea is actually known as the Baltic Plain.  It is all that’s left of a mountain-building process from 250 to 200 million years ago that connected Scandinavia to the rest of Europe.

Long ago, the British Isles used to be an extension of mainland Europe before splitting off 100 million years ago. Proof — the very shape of the sea that we back home would call the Low Countries.

The dominating feature of Asia is a large region of basaltic rock, the Siberian Traps. It formed as a series of eruptions spewed out lava 60 to 43 million years ago.  Since most of northern Asia was a receding series of shallow seas at the time, the eruptions resulted in all four compositions of lava—low on both gas and viscosity, high on gas but low on viscosity, low on gas but high on viscosity and high on both gas and viscosity.  However, 96% of those eruptions happened underwater, so they wouldn't react exactly like they would on land.  Each eruption could last anywhere between 10,000 and 60,000 years, with breaks varying between 30,000 and 80,000 years.  When the last eruption had finished, seven million square miles of Eurasia were buried under four million cubic miles of lava.

Eurasia is subject to Great Lakes Earth’s largest sea, one that we used to have back home — the Tethys. Back home, the Mediterranean has an average depth of 1500 meters and a maximum of 5267. The Tethys’ depth is 1205 meters on average and 7,000 maximum. Even so, the ratio between deep and shallow water is remarkably similar to that of the Mediterranean — more or less than 45% of the sea is no deeper than 200 meters (the required maximum depth for a sea to be “shallow”). It’s also connected to two oceans with two different personalities — the Indian to the east and the Atlantic to the west.  What we’d recognize as the Arabian Peninsula is, on Great Lakes Earth, an extension of northeastern Africa, erasing both the Red Sea and the Gulf of Aden out of existence. This further widens the passage from the Indian Ocean to the Tethys.

The island of Newfoundland is the southeastern extension of Iceland. It stands at a point where a stationary mantle plume, loaded with silicon, stands at a crossroads between the Mid-Atlantic Ridge and the edge of the Arctic Plate.  Unlike our Iceland, in which the Ridge has split it in east-west, the Iceland of Great Lakes Earth is split in a north-south division.

In Asia, what looks to us like Borneo is a big extension of eastern India, erasing the Bay of Bengal from the map. Sumatra is an extension of India’s western coast. The rest of Indonesia, as well as the island chain of the Philippines and the Malay Peninsula, don’t exist.

Back home, the Himalayan range in Asia is impressive enough. On Great Lakes Earth, they are even more so. The highest peak, Kailash, stands 33,500 feet (10,210.8 meters) above sea level and still rising. If the base of Mauna Kea in Hawaii were above sea level, this would have been its equal. Their Himalayas are older than ours, if the differences in height suggest anything. Ours first formed 50 million years ago. Theirs rose from the plains between 65 and 70 million years ago.

65 million years ago, sub-Himalayan Asia was subject to a series of lava eruptions lasting a total of 30,000 years.  When it was all over, the lava covered a thickness exceeding one mile, an area of one-and-a-half million square miles and a volume greater than one million cubic miles.

The islands of Japan on Great Lakes Earth are the result of multiple faults and subductive hot spots, stationary mantle plumes standing in the intersections of colliding plates. Japan, consisting of six large hotspots, stands three miles southeast of the Laurasian Plate and five northwest of the Pacific Plate.  The fact that the mountains make up the coastlines suggest that Japan on Great Lakes Earth formed very recently—no longer, it’s been surmised, than 11 million years.  Like the Andes, Japan was subject to massive, earth-destroying eruptions.

The Alps remain tall, as they are back home.  However, they are formed as the result of a piece of Africa, known to us as Balk, colliding with southeastern Europe 40 million years ago.  Currently, the range’s highest peak, Olympus, stands 22,838 feet (6961 meters) above sea level and is still rising. Behind the Alps is a plateau that covers lands we’d recognize as Romania, Moldova, Slovenia, Austria, Slovakia and Hungary. Also, Balk’s terrain on Great Lakes Earth consists of plains and hills rather than mountain ranges like back home.

The Scandes, stretching the length of the northern Scandinavian coast, are the results of ocean/continent collisions — volcanoes. They are also taller than they are back home — 18,510 feet (5642 meters) above sea level and still rising.

The Ural, Caucasus, Pyrenees and Apennine mountain chains used to exist on Great Lakes Earth, but not anymore.

Questions follow:

    With open connections to both the Indian and the Atlantic, what would the Tethys’s personality be?
    Will a higher Himalayas — which means a higher Tibetan Plateau — pose any noticeable differences on India’s climate and precipitation?
    Would adding Borneo and Sumatra pose any difference to the climate and landscape of the Indian subcontinent?
    With the rest of Indonesia, the Philippines and the Malay Peninsula out of existence, how would this absence affect ocean currents?
    How would all this added water affect the Mediterranean Basin as well as the Indian monsoon?
    Concerning the Siberian Traps, 40 million years of erosion would mean an altogether different Russian landscape, no doubt, but to what extent? Would we still see vast, singular bands of boreal forests and steppes, or would we expect to see Russia hosting a wider variety of habitats?
    Would a larger Deccan Traps pose any difference to the 65 million years of erosion?
    How would the changes in mountain building and coastlining affect the climate and landscape of the rest of Europe?

Africa

Like some of the other continents, Africa has its share of great lakes — Chad, Congo and Makgadikgadi.  Lake Makgadikgadi, the southernmost, is also the youngest—100 feet (30 meters) at the deepest and formed as water flowing from the Aden Bahçesi inundated a series of fault lines only three million years ago.

The Atlas Mountains used to exist on Great Lakes Earth, but not anymore.

The defining mountain range of Africa is the Aden Bahçesi, which first formed 45 million years ago as the Indian Plate sank beneath the African Plate.  Currently, the tallest peak stands 21,810 feet (6647.7 meters) above sea level and still rising.

Lakes Chad and Congo had a shared history.  They originated less than 200 million years ago as a series of horsts and grabens that would quickly be inundated aftewards.  It wasn’t until 80 million years ago, when the seafloor slowed down and sea levels began to recede, that perhaps the deepest points on Great Lakes Earth during the Cretaceous period became surrounded by dry land.  In time, freshwater diluted the lakes, pushing the salinity deeper and deeper.  Today, Lake Congo to the south averages 221 meters deep, with a maximum of 2001 meters, the bottommost 15 feet being brine.  Lake Chad to the north has an average depth of 337.5 meters with a maximum of 3791 meters, with the Pharaoh’s Brine taking up the bottom 20 meters.

Questions follow:

    Are any of these changes enough to turn North and South Africa from desert to more verdant habitat, like savanna?
    Would having a tropical megalake be enough to make a noticeable difference to the equatorial climate of the Congo rainforest?

Australia

First and foremost, it’s not called “Australia” in Great Lakes Earth, but rather “Sahul”. The first major difference is the presence of Lake Eyre, a body of fresh water over 460,000 square miles in area and 49 meters at the deepest.

The northern and eastern coasts of Sahul are worth noticing. To the northwest, it looks as though the two main islands of New Zealand are glued into the mainland. It’d also look as though someone were shoving the island of New Guinea down the throat of mainland Australia, known geographically as the Gulf of Carpentaria. The northern and eastern extremes of Sahul are defined by volcanic mountains, the tallest standing 18,500 feet above sea level.

The final difference is that Sahul is much further south than Australia. So much so, in fact, that by comparison, the distance between it and Antarctica is cut by half.

Questions follow:

    Will the Outback still be desert?
    In the same scenario, Indonesia and the Philippines don’t exist. What kind of ocean current(s) would one expect to see influencing Sahul?
    What kind of climatic and ecological influences would we expect Lake Eyre and the continent’s closer proximity to Antarctica to create?

Pole to Pole

Compared to our oceans, the Arctic Ocean of Great Lakes Earth seems to have a little elbow room. The reason — the Atlantic on Great Lakes Earth is wider than ours by over 1350 miles. Africa, Eurasia and Sahul have, compared to our Old World, moved that far eastward, creating a landbridge that connects Asia to North America, erasing the Bering Strait off the map and shrinking the Bering Sea. To that extent, it would be like turning the Russian urban locality of Egvekinot (66.3205 degrees North and 179.1184 degrees West) into the next-door neighbor of Teller, Alaska.  But that is in our eyes only.  On Great Lakes Earth, North America has always been a part of Laurasia for 250 million years.

The island of Greenland looks, to us, rearranged to the extent that Mont Forel, the island’s highest peak, is located in 90 degrees North — the North Geographic Pole.

There is another difference, one that applies also to the Southern Ocean surrounding Antarctica. Back home, the Arctic’s average depth is only 1205 meters, whereas its deepest point is 5,625 meters. The Southern Ocean averages 4,000 meters deep and has a maximum depth of 7,235. On Great Lakes Earth, the Arctic averages 663 meters deep with a maximum of 7235 meters, whereas the Southern Ocean averages 2212 meters deep with a maximum depth of 5625 meters.

Then, of course, there is the Arctic Plate, something that doesn’t exist back home. Horizontally cutting Iceland in half, we can find the border straddling the coasts of Baffin Island, Alaska, and Scandinavia, creating the Scandes and the Murchison mountains.

Questions follow:

    How would these differences affect ocean currents and polar landscapes?
    Could any of these changes have influenced the global average temperature and precipitation? If so, to what extent?

Ocean Deep

Back home, the Pacific Ocean, the largest of the five, has an average depth of 4028 meters and a maximum of 10,924 meters.  On Great Lakes Earth, the Pacific’s depth averages 2025 meters  and the maximum is now 8486 meters.

Back home, the Indian Ocean averages around 3963 meters deep with a maximum depth of 7258.  On Great Lakes Earth, the Indian Ocean averages around 1467 meters deep and has a maximum depth of 7906 meters.

The Atlantic Ocean back home has an average depth of 3926 meters and a maximum of 8605 meters.  On Great Lakes Earth, its average depth is now 1725 meters, and the maximum is now 10,911 meters, the same as the Pacific.

Questions follow:

    How would the changes in depth affect ocean currents, therefore the global climate?
 

16

Just Chat! / Are Speculative Scenarios Allowed in This Forum?

« on: 24/09/2018 05:20:10 »

Hello, my name is AutumnBison, and I had taken Earth Science classes at the University of South Dakota in Vermillion. At that time, what I had learned in those classes had inspired me to create an alternate Earth, with geographic and geological features different from Earth's but still inspired by them. The problem I have is that I know only the Cause--i.e. the changing of the geography--and not the Effect (how the changes in geography influence landscape, climate and weather). Before I continue on with this, I have to ask--are speculative, what-if scenarios allowed in this forum?