The Paratethys Sea was the largest lake in Earth’s history | Hacker News Reader

The Paratethys Sea was the largest lake in Earth’s history

bigthink.com

50 pointsPetiver35 comments

> the physical parameters or our world — continents and oceans, mountains and lakes — appear fixed only because our own lives are so infinitesimally short, measured against geological eras.

And the geological eras are over in a nanosecond in comparison to the lifetime of the universe. It makes me wonder if the lifetime of the universe is over in a nanosecond in comparison to whatever the universe is embedded within (this is assuming the multi-universe theory is correct).

Given the infinite dimensions of the universe, I’d say your assumption is just as valid as any other argument.

High on mushrooms as a teenager I used to flick my lighter and imagine a whole universe spinning up, stars and planets forming, life evolving and lives being lives, decline and eventual heat death, all in that quick spark.

Reminded me of https://en.wikipedia.org/wiki/The_World_Inside_a_Pillow

There's a science fiction story wherein our protagonist's experiment goes awry and he starts shrinking without end. After disappearing from our world, he soon reappears in the sky over one of the Great Lakes, and lands in it, only to continue shrinking.

bit of quibble, but a geological era, as a technical term, describes a duration on the order of 100MYA, which is nearly 1/100th of the age of the universe, making 'nanosecond' a bit of an exaggeration. even if we consider periods on the order of 10MYA (how long ago the titular lake disappeared), that's still on the order of 100000x a human lifespan, versus 1/1000th the age of the universe.

anyway, i bring this up mostly because, while it's widely appreciated that spatially speaking earth exists an a scale utterly insignificant compared to astronomical distances, from a temporal perspective the age of the earth (and the duration of life on earth) are actually quite comparable to that of the universe

A microsecond of 1e8 or 1e9 year nanoseconds, is... a night sky without galaxies (observable universe is a coalesced Local Group)? A millisecond, a sky of stellar remnants? A second... black holes and ejected remnants?

The heat death of the universe is in 10, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000 years. 100,000,000 years is not 1/100th of the lifetime of the universe.

I might be misunderstanding, but could OP mean ‘age’ and you mean ‘portion of lifespan’?

I don't think that "lifetime of the universe" is well-defined. The universe would still exist after the heat death.

The headline claims that a lake estimated to be 34 million years old was the largest ever on a planet billions of years old. Seems a little presumptuous.

I don't think it's entirely unreasonable.

It's the largest we have any evidence of ever existing, and it's also stupendously large- where and how could a larger lake have existed?

Just because we don't know everything doesn't mean we can't be pretty certain of anything.

I mean, the article says it formed as Africa and Europe came together, and that's not the only time continents collided to form larger landmasses. Certainly we've had larger supercontinents that could've accommodated larger lakes.

> where and how could a larger lake have existed?

It exists somewhere in the gap of your logic. The undeying complaint is against the superlativ, and not against "largest" but "in Earth's history", which equates to everrr.

It's clearly click-bait.

I’m from Crimea and found a seashell inland once. Someone told me “of course, this was all covered with water long time ago!”. I guess the seashell had nothing to do with the lake, but it’s still amazing how the Earth isn’t static at all.

Deep geological time is hard to get your head around. 34M years ago is basically an eyeblink in deep time.

https://nautil.us/the-greatest-animal-war-235067/ has a neat graphic in it.

> Deep Time: If the timeline of Earth were mapped onto the human arm, it would begin around the shoulder where the earth formed about 4.6 billion years ago. Animals originated within the palm, but the myriad forms alive today exploded onto the scene around the first knuckle, in the Cambrian period. Blocks along the fingers represent the periods that followed, such as the Jurassic (dinosaurs!) and the Cenozoic (in which humans evolved, a microscopic sliver at the tip of a fingernail)..

I was doing student summer job for a month in Crimea sometime in 70s. We were building dwellings for locals. The walls were made of stone that was billions of shells cemented together. It was very soft and we were all covered in dust. In combination with the summer heat it was awful.

> I guess the seashell had nothing to do with the lake...

Maybe it could have?

I found a rock with a shell in it near Tipple Divide Peak in Montana. 1000 km inland and 2200 meters above sea level.

It's just amazing.

If you ever have the opportunity, head north a bit to Yoho National Park in Canada.

A picture of the quarry of the most famous early fossils - https://upload.wikimedia.org/wikipedia/commons/f/f7/WalcottQ... - the Burgess Shale ( https://en.wikipedia.org/wiki/Burgess_Shale )

The "that's a long time" for me occurred when I learned about the Mississippian Period (named after Mississippi in the United States) - part of the Carboniferous period, and only really useful within the US because the rock beds within that period are different than the adjacent Pennsylvanian period rocks.

In this period, you've got crinoids - related to starfish (and still around - https://youtu.be/ror_fFswejM ). The classic ones had "stems"...

https://www.wired.com/2008/03/friday-field-foto-46-crinoid-f...

Look at all those circular things in that fossil that are scattered about - those are parts of stems that aren't intact.

The Mississippian layer is up to 460 feet (140 meters) thick with these fossils.

The crinoid fossils are so common you can buy them cheaply in bulk - by the pound. https://www.dinosaursrocksuperstore.com/collections/bulk-fos...

I'd stumbled across the fact a few years ago that the oldest ocean crust on Earth is near this region: the Mediterranean, dating back roughly 340 million years.

Most sea floor is (geologically) quite young, as oceans are constantly recycled and re-formed. The Med though is the remnant of a much larger sea, dubbed the Tethys, shrinking as the African, European, and Asian land-masses converge, and ironically it's one of the smallest seafloors (and as others in this thread have noted, occasionally largely dry), that is also the oldest.

"This 340-Million-Year-Old Ocean Crust Could Date Back to Pangaea"

<https://www.smithsonianmag.com/smart-news/oldest-bit-seafloo...>

<https://en.wikipedia.org/wiki/Tethys_Ocean>

The other fact that stands out is that the oil-rich regions of Baku and Romainia (both important objectives during WWII) probably owe their existence to the Paratethys / Tethys seas.

<https://en.wikipedia.org/wiki/Petroleum_industry_in_Azerbaij...>

<https://en.wikipedia.org/wiki/Ploie%C8%99ti>

<https://en.wikipedia.org/wiki/Oil_campaign_of_World_War_II#P...>

I know, that at one time, the Mediterranean Sea was just a gigantic (dry) below-sea-level valley.

Then the Straight of Gibraltar popped a cork, and there was the world's most awesome waterfall, for a long time.

> world's most awesome waterfall, for a long time

Apparently it was more of a big ramp and rapids. And it was maybe as short as only one (wildly incredible) year.

> This flood would have descended a relatively gentle ramp into the Mediterranean basin, not as a giant waterfall

> later estimates of the size of the Strait of Gibraltar channel implied that it would have taken much less, potentially less than a year until reconnection

https://en.m.wikipedia.org/wiki/Zanclean_flood

Anyone interested in this should also read the most ambitious XKCD ever, "Time", which is about 3,000 panels long: http://geekwagon.net/projects/xkcd1190/

The https://en.wikipedia.org/wiki/Missoula_floods would have been epic to watch

> 2.7 million m³/s, 13 times that of the Amazon River

But it was only yesterday, relatively.

It's worth a trip to get to Gibraltar (duty-free booze!) and walk to the south end and check out Africa.

Used to live in Tangier.

We would go to Gibraltar on the weekend.

I remember the monkeys, and a weird slanted train.

There must have been some very surprised cetaceans caught up in the torrent.

Could someone explain the semantic difference between "lake" and "sea" here?

Why is this called a "lake" (or even "megalake") even though it was far larger than many of today's seas? (or indeed some of today's seas are fragments of the ancient lake)

Edit: I guess it has more to do with salinity and whether or not the body of water is connected to the ocean?

Seas are connected to the ocean. Lakes are land locked.

Ah, that makes sense. Thanks!

Like the Caspian Sea?

I think the OP was onto something about salinity.

Seems like it was a proper sea and then got cut off, was a massive lake for a bit and evaporated.

Reply on news.ycombinator.com