The flood that filled the Mediterranean Sea - in one year | Hacker News Reader

The flood that filled the Mediterranean Sea - in one year

everythingisamazing.substack.com

209 pointsbandibus59 comments

I assume it looked very similar to this apocalyptic 1993 video from a landslide in Malaysia (which formed a new cove nearly 1 km wide) except many times wider (the Gibraltar strait is around 14 km wide) and higher:

https://www.youtube.com/watch?v=H6Ma0SVjMHA

Starting at around 1:00 you can see the entire pacific ocean looming behind this thin and crumbling earth wall. And then the water comes.

Here is the cove it created: https://www.google.com/maps/@4.402039,100.5917748,1546m/data...

That inflow was on the order of a few thousand cfm. The Gibraltar event was ~ 5 orders of magnitude more flow. So imagine 10,000 of those side by side.

I think there are two possibilities: either the strait of Gibraltar was suddenly lowered by an earthquake and the atlantic immediately started to flow into the mediterranean over the entire 13 km (which would have look very different than the video), or the land barrier slowly eroded at some small location until a tipping point, and the water than quickly widened the hole in a few hours/days. In the latter case, I think it is reasonable to assume that it first looked somehow like in the video.

But I still agree that is near to impossible to imagine the scale of the peak inflow.

Exactly. It's not like a dam breach where you have a constant and steep incline into deep water. You've got a taper up on one side and down on the other. So your initial breach is going to only have a small cross section. You get something like river rapids as a result. And then erosion quickly does its thing, but much less quickly than it does when water goes over the top of a dam because the much shallower grade means that the amount of material that needs to be moved to get a deeper breach increase more quickly than in the case of a dam.

The video from Malaysia is water flowing into what was formerly a mine pit so (like a dam) the wall is going to be about as steep as the geology can support. Natural geology tends to create much more mild slopes.

Earthquakes don't suddenly lower terrain by much. (Unless the 'quake triggers a landslide...)

My two guesses:

- The natural barrier was quite low (due to some combination of things). Then waves from either an exceptional storm, or an tsunami, swept over the top - eroding it enough to start the run-away erosion/flooding process.

- Setup similar to my first guess, but the soil/rock/bedrock of the natural barrier aren't able to withstand the groundwater pressure and flows. (Think of a slowly-failing dam, with water seeping through it faster & faster.)

Wikipedia's best guess:

> The most widely accepted hypothesis is that a stream flowing into the Mediterranean eroded through the Strait of Gibraltar until it captured the Atlantic Ocean...

(Which is more-specific version of your second idea.)

That's the Malacca strait, thousands of km from the Pacific ocean. Pretty amazing video though!

Once things get in motion it can go very quickly. It must have looked like this: https://www.youtube.com/watch?v=eDmoXkF-g9I

Starting very small and then growing exponentially.

When I was a child we also did something like in the video. The initial channel was very narrow and we could have easily stopped it by putting back some sand, but 15 minutes later through the game of erosion the stream was so intense that it became impossible to even cross it.

Remove that annoying sticky header with this js snippet pasted in your url bar:

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Do you have a tool that computes this for you?

Or unstick it with a uBlock Origin filter:

  substack.com##.main-menu-content:style(position: relative !important)

it's a neat story but i find this style of writing unreadably grating

Sorry to hear - but thanks for reading it anyway!

I loved your style. Different strokes for different folks, I guess.

Thank you!

Me too, I enjoyed the style. Bill Bryson esque

Are you really English? I didn't know they were allowed to be this positive.

Here's more of a textbook style of the account if that's your style. https://en.wikipedia.org/wiki/Zanclean_flood .Or here is a creative way of describing the account (which I happen to like) https://everythingisamazing.substack.com/p/in-search-of-a-fl...

fwiw I agree with you too. It read like a kitchen recipe article that has the whole history of apples and grandma's cooking before the recipe steps.

the author's regular readers might be interested in this though. to me, a reader sources from HN I wanted to get to the factual history of the event, than the author's background as well

Before the flood I wonder what life was like in the basin? In particular steeper areas of the outer edges must have been fascinating. During the summer the warm but relatively cool air at sea level I assume could sink down into the basin. With the basin a mile or so deeper the temperature of the sinking air would have increased drastically as the pressure increased. I’ve not done the calculations but my intuition is the temperature would make hot days in Death Valley look cool.

I read somewhere that adiabatic heating would result in temperatures of around 170 degF at the deepest.

The flood that took place in the Mediterranean was what inspired the plot of the biggest XKCD ever, a time-lapse slideshow that took place over 123 days and 3,102 panels: https://en.wikipedia.org/wiki/Time_(xkcd) .

Here's a site that lets you step through it one panel at a time: http://geekwagon.net/projects/xkcd1190/ . Well worth a read.

Yes! Still one of the best things on the internet, just incredible.

It also inspired the Saga of the Exiles book series by Julian May. (It's presented as an act of terrorism by time travellers, to repel alien invaders.)

Ah, I see that you mention this at the bottom :P

So glad you mention the Julian May book. It was the first thing I thought of when I started reading your (excellent, highly readable) post!

Reminds me of https://yearofslurm.com/ a year-long connected art piece.

I am still, after nine years reminded that it started on my birthday. It was a beautiful present by chance.

I should watch it again. It was lovely.

There are quite a few videos of it on YouTube [0].

[0]: https://youtu.be/VoV-jzwaw_Q

I suggest:

https://explainxkcd.com/wiki/index.php/1190:_Time

If there was some way across, the Dead Sea valley would become an ocean. I have always wondered that no river or channel naturally was able to overcome te relatively thin mountain range in between.

Talking about overcoming unsurmountable obstacles, I find the story of the Brahmaputra river an intriguing (and inspiring if used as a metaphor) opposite. The river predates the Himalayas that came up and blocked its path. Nevertheless it wore it down to find its way into the sea on the other side.

There's a few of those :)

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

Thanks for teaching me the name

Sounds like a high school class graduation project. Bring your own shovel.

If a 2KM bed of salt became liberated and released into the med, and IIRC both the bosphorus and the pillars of hercules are subject to tides...

How long would it take to reach "homeostasis"?

there's already semi-stable thermohaline layers between the med and the atlantic. differential current flows depending on depth.

Good (& lengthy) Earth-Science Reviews article (Feb 2020) on Zanclean here:

[https://www.sciencedirect.com/science/article/pii/S001282521...]

I like Manly Wade Wellman’s speculation in his Hok the Mighty stories that Atlantis was located in the giant valley.

Built by who? There were no humans back then.

Aliens of course

Yes, everybody have been knowing that from more than 40 years. And there were humans back then. They time travelled from not so many years in our future.

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

Don't worry, the Time Patrol, which has an site near Gibraltar Falls, will be there. https://www.baen.com/Chapters/9781476780528/9781476780528___... (a Poul Anderson short story).

Fair enough

It's commonly believed that the myth of Atlantis may have been inspired by the destruction of the Minoan city Akrotiri by a volcanic eruption and ensuing tsunami.

[*] https://forbes5.pitt.edu/article/eruption-thera

Holy crap, so the Po river was ridiculously long

apparently, a Twitter thread led to the writing of the linked article, which publicizes careful modelling done by science teams years earlier. The "gonzo enthusiastic" voice of the author strongly contrasts to the science museum core of the subject. Perfect? nah, but modern and .. now people can see it. "publicity" you might call it.. not bad, definitely worth ten minutes to see one of the great geological events of pre-history.

It did. I know this, because I'm the author of that Twitter thread. :) And yes, I'm not a science writer (ex-archaeologist turned travel writer). But the enthusiasm, which is real, is what seemed to make it go viral on Twitter. I hope I stayed on the side of being engaging rather than shamelessly clickbaiting, but - yeah, slippery slope. Nevertheless, the whole research project is incredible, and I was lucky enough to have the lead scientist weigh in, in the comments. (The comments were spectacular and I'm very grateful for that.)

Efforts like that to 'sell' science - by dumbing it down, using 'gonzo' presentation, etc. - signals that the author believes there is little intrinsic value in the science, little of actual interest. Like a bad tasting medicine, it must be consumed with sugar.

There is an enormous amount of intrinsic value and highly engaging content in science. Scientists need to have the courage of their convictions, and express what they find so interesting and beautiful about it.

I'm very interested, but when I anticipate such presentations I run: I expect they will displace the interesting stuff with the presentation, and/or it will distract from or obscure it, sometimes unbearably. I don't want to eat delicious food with spoons full of sugar.

Not true in this case! I'm the author, and I believe the exact opposite about science - that there's astonishing value in learning about the work being done right now, that it's easy to miss so much of it simply because of the amount of information we all consume, and that the scientific process has a lot to teach the world about putting aside ideas of "right" and "wrong" in favour of keeping an open mind and holding our opinions lightly. But also: I'm happy if I can just point anyone towards those doing the actual scientific work, because I'm just a middleman here. If someone thinks I'm an idiot but clicks through to the research itself - that's a win too.

Thank you for responding! To be clear, I was talking about the parent comment's suggestion, not your essay.

All I know is my personal experience: I struggled through years of science journalism, popular scientific coverage, etc. It was almost all as I described: like bad-tasting medicine coated with sugar or cherry flavor or whatever. Ugh.

Then on a lark one day, I subscribed to Nature (for others, that's considered one of the world's two leading science journals, along with Science). The front of Nature is not research papers but coverage of research and other issues - no sugar or cherry flavor or strained analogies - just coverage of what is valuable. I loved it! It was, and is, incredible. And I learned in an hour far more than I learned from reading 10x the 'science journalism'.

I'm an audience of one, so maybe it doesn't apply, but I don't see science journalism having great success in the general public. Most people roll their eyes if I try to talk about anything, and are deeply unaware. As a recent example, someone I know - with a graduate degree, who is generally well-informed - thought the International Space Station was somewhere beyond Mars. Think of all the knowledge you need to be missing in order to believe that (in what orbit? why? how do we get crew there and back?, etc.), and it's a belief about something relatively commonly in the news.

Ah, apologies. Got it. Thank you!

Yes, I agree with you there about some science journalism, and in particular the tabloid variety. When you read quality writing like you'd find at Nature, Aeon/Psyche etc, which values the ideas for themselves rather than for what outrageously speculative headline can be squeezed out of them for "the man on the street", you can see a huge difference in the way it's being communicated. And you're right - it's not as successful, because the good stuff isn't negative-emotionally triggering (unless the worst kinds of tabloids get their hands on it).

Negativity bias deranks science stories that are all about careful, quiet optimism and cautious hopefulness. That's a huge, huge problem - especially as our curiosity seems to grow out of positive rather than negative emotional responses to information. (Anhedonia, strongly correlated with depression, is the inability to feel pleasure, and it includes the inability to take pleasure in learning something new - ie. it kills your curiosity).

Anyway, I'm rambling. Thank you for this thoughtful clarification!

> When you read quality writing like you'd find at Nature, Aeon/Psyche etc, which values the ideas for themselves rather than for what outrageously speculative headline can be squeezed out of them for "the man on the street", you can see a huge difference in the way it's being communicated. And you're right - it's not as successful, because the good stuff isn't negative-emotionally triggering (unless the worst kinds of tabloids get their hands on it).

To be clear, to anyone reading, I guess that the approach used in Nature, which values ideas for themselves, would be more successful with the general public; it's just not used.

> guess that the approach used in Nature, which values ideas for themselves, would be more successful with the general public; it's just not used.

I sadly have to disagree. As much as I'd rather not. After university I worked as a junior editor for an online site with > 10 million uniques per month. Shortly after joining I was handed over the "science" section (double, triple, quadruple the quotes). I tried to make it more about current scientific ideas, the big findings of the past and less about 'Hitler living on the dark side of the moon', 'Aliens visiting earth', 'This dietary idea will make you loose weight fast' and all the other bullshit one reads in tabloid.

No clicks. Advertising revenue down the drain. The audience had no interest in scientific ideas and great findings. They wanted entertainment.

Maybe I just wasn't able to deliver modern scientific research with enough entertainment value. At least not compared to described topics above.

I know. This is just anecdata from a random guy on the internet. YMMV.

> This is just anecdata from a random guy on the internet.

You actually have some experience. Thank you.

I wonder what Isaac Asimov, a great science communicator, would think of contemporary science journalism.

> Efforts like that to 'sell' science - by dumbing it down, using 'gonzo' presentation, etc. - signals that the author believes there is little intrinsic value in the science, little of actual interest. Like a bad tasting medicine, it must be consumed with sugar.

You know, I've read some history that was written to read well, and I've read some that was unbelievably dry but that I slogged through anyway because I was interested in the topic.

There's plenty of room for writing that isn't unpleasant to read.

I agree, but it's not a trade-off; it's not one or the other. You can have excellent, engaging writing that values the topic deeply. I would say that the dumbed-down presentation I describe makes for worse reading; that's what I had a hard time reading. What I read in Nature, in my example, is much more enjoyable to read.

I remember well-written history much better than the dryly written.

> There is an enormous amount of intrinsic value and highly engaging content in science.

Some find this kind of articles highly engaging. What you're calling for is rigorous, and I do not believe that pop-sci needs to be rigorous and matter-of-fact to have value. Quite the opposite, in fact.

i always thought a giant asteroid hit the atlantic and moved Americas further away from EU/Africa and spit lot of water/sand on north Africa, wich covered the Sahara forest with sand and killed ancient Egypt civilization and the whole South America civilization

That makes no sense.

Any asteroid big enough to move a continent would effectively destroy the world's biosphere.

We know what asteroid impacts look like. None would do what you say.

Only about a quarter of the Sahara is covered in sand. Why weren't the other parts covered in sand?

What does "killed ancient Egypt civilization" mean? The Assyrian conquest ca. 663 BCE? And which South America civilizations? The Chavín? Wikipedia says the Jarabarriu period ended until ca. 250 BCE. That's a 400 year difference.

The Assyrian came when the ancient egyptian civilization was already long gone

I refer to the flooding theories dating from 4000+ BCE from all over the world

Including https://en.wikipedia.org/wiki/Outburst_flood#Glacial_floods_...

I should note that it's just fantasized thoughts, i'm just dreaming

What "ancient egyptian civilization" do you refer to?

4000+ BCE predates the Early Dynastic Period, so for that postulated event to have occurred you must be referring to something earlier, during the prehistory of Egypt.

The better reference is https://en.wikipedia.org/wiki/Flood_myth#Historicity .

When expressing a dream you understand to be non-realistic, please don't start "i always thought ...". Perhaps "I always fantasized ..."

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