Slashdot Mirror
Mediterranean Might Have Filled In Months
An anonymous reader writes "A new model suggests that the Mediterranean Sea was filled in a gigantic flood some 5.3 million years ago. According to Daniel Garcia-Castellanos' paper in Nature, the sill at the Straight of Gibraltar gave way rather suddenly, with 40 cm of rock eroding and the water level rising by 10 m per day at its peak. They imagine a shallow, fast-moving stream of water (around 100 km/hr) several kilometers wide pouring into the basin with a flow greater than a thousand Amazon rivers — that's about 100,000,000 cubic meters per second." The flood would have dropped worldwide sea levels by 9.5 meters, probably triggering climate changes. In this model the Mediterranean filled in anywhere from a few months to two years at the outside.
just had an orgasm.
Are you sure that flood didn't happen 5 thousand years ago?
It has been done, it can be undone: http://en.wikipedia.org/wiki/Atlantropa
Whatever the arguments against it, I suppose it is within reason that it could be done. But should it be done?
This research has inspired me to save the planet.
Consider, what are the 3 big problems with AGW?
1. The climate gets warmer than we'd like.
2. The sea levels rise.
3. Mass famine as the farmland goes dry.
4. The extra CO2 acidifies the oceans screwing with the fishies and shellfish.
So now I give you the perfect geo-engineering solution to all these problems!
Step 1: Set off a bunch of Nukes in a desert somewhere, excavating giant holes in the ground.
Step 2: Dig a little path to the ocean and have it fill in the holes.
Benefits: First the ocean levels go down to their regular levels, yay! Second the resulting Nuclear winter offsets global warming, another yay!
Third the desert is now ocean front property and not as deserty, maybe more farm land (do this in Africa for bonus famine offsetting points).
And lastly to handle the acidy oceans... the fallout from the Nukes mutates the fishies and shellfish to adapt to the carbonic acid oceans!
Now can I have my Nobel Peace now? Other than some minor side-effects this should be a pretty effective solution.
I stole this Sig
Julian May already wrote about it in The Golden Torc back in the '80s and her story is way more interesting than this one :-)
This story would be much cooler with a video clip.
Jesus was all right but his disciples were thick and ordinary. -John Lennon
Well, before that, it was a lake. Where do you think the aliens stole all the water from?! It was freshwater then, of course. Sadly the Sahara Forest never recovered.
Don't think of it as a flame---it's more like an argument that does 3d6 fire damage
Normally I consider news like this "well nice to know, but it doesn't really affect me".
This case is different, living in a country which is already mostly under sealevel, these 9.5 meters would have made a huge difference.
For example see the map at http://www.rivm.nl/vtv/object_map/o1213n39037.html. If it hadn't happened, we would now have had the island "De Veluwe" :-)
bash$
This one happened almost 5 million years before modern man first arrived. There are several better floods, if you want to explain the presence of so many flood stories in ancient cultures. Really, there are several candidates that could explain all of those stories about the entire (known) world getting flooded, and Noah isn't the only ancient story about the world being flooded. Frankly, such things being passed down in oral history is only reasonable. If anyone had seen this flood, you can bet that every generation for a very long time would have heard the story!
It's like all those myths about dragons, which are spread through many different cultures. Of course they never really existed, but they have a basis in reality: people probably found dinosaur fossils and the legends grew. Just because things have been legendized doesn't mean they have no basis in fact.
The crucial difference is whether scientists do understand the shaky foundation or they foolishly insist on objectivity of their research.
All hope abandon ye who enter here.
Ok, just once, giving you the benefit of doubt concerning trolling:
The mediterrean doesnt have that many rivers flowing into it, but is in a relatively hot climate.
This means that much more water evaporates than it recieves.
Several times in history, the connection of the mediterrean with the other oceans (i.e. the atlantic) was closed by the way of plate tectonics,ice age, etc (plate of africa going north and forming the alps...)).
During these times, the entire sea evaporated away. IIRC, it was once MUCH deeper, but at the ground there are a few km of salt and sediments from those times.
But such things cannot last. Thousands (if an ice age) or millions of years later there was a breach somewhere to let water enter (be it by way of an earthquake, rising water level of the outside oceans, etc). And after that, erosion had its way.
It must have been an unimagineable awesome display ...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Noah shit??
99% of me agrees with you wholeheartedly. It's rather useless.
Yet there is 1% of me which also knows that it is an integral part of science to make up some silly theories and models about stuff which we would never know for sure. After all, pretty much everything in the today's science started some long time ago from a silly theory. It was silly and unknowable in the past - while now it is treated as an fact.
All hope abandon ye who enter here.
Probably the best small-scale example of how violent this event would have been is given by the flooding of an open-air mine in Malaysia. The rocks separating the mine from the sea became unstable and collapsed, filling the whole thing in minute or so: video!
karma police: arrest this man, he talks in maths; he buzzes like a fridge, he's like a detuned radio. [radiohead]
Please correct me if I'm wrong, but it looks like the science is even shakier than that.
The Mediterranean could easily have formed over tens of thousands of years (it says so in the article), but they're puzzled that there's a U-shaped sediment deposit instead of a the V-shape made by slow water erosion.
Glacial valleys are also U-shaped. Glaciers have covered that area many times over the last 5 million years.
Tectonic movement could also smooth out the normal V-shape of slower water erosion. All patches of earth are constantly rising, sinking, and/or moving horizontally. The middle of the V rising could explain the U. The sides of the V sinking or moving away from the center could also explain the U. Notice the mountainous areas around Spain and NW Africa. There is a tectonic plate boundary next it. There's been plenty of movement in that area over the last 5 million years.
Multiple rivers could also have broken into the Mediterranean and eventually carried off the bits of land in between, also explaining a U-shape, but over a longer period of time than the "2-year max" their simulation shows.
Here are 3 less exciting, but (as far as I can tell) plausible explanations. It could also be a mixture of these and/or other factors we haven't considered.
It looks like they simply chose one hypothesis that sounded impressive and made a computer simulation of it.
The Mediterranean flood hypothesis is not new - these authors have just done more work on the geology. They lean against the giant waterfall idea ("We do not envisage a waterfall..."), which is a shame - I always liked the idea of a supersonic waterfall.
"The flood would have dropped worldwide sea levels by 9.5 meters, probably triggering climate changes."
OMG, something MUST be done to revert the planet to it's pre-Mediterranean-Sea-filling pristine state, or you will all rot in Al Gore's climate Purgatory!
If Valdrax thought you were a creationist he would hardly have accused you of trolling creationists, would he?
That the earth is 5000 years old, or 6000 years old. In fact, the bible doesn't give a date for any of its events at all. It's really only certain protestant faiths that have the bible as being completely inerrant and the earth as 6000 years old. The rest of us Christians are in it for some good food on Dec 25th and maybe to bomb some muzzies when they get out of line.
This is my sig.
Huge salt desert in Australia which used to be an inland sea. It's about 15m below sea level
Dig 2 canals. boom. you have an inland sea again. Australia stops being a huge desert.
You'd need 2 canals at opposite ends to pump the salt out.
Deleted
And you just know there are cave drawings somewhere showing jackasses trying to body surf in it.
Computer models of chaotic systems may not reflect the exact performance of what they are modeling, but they can demonstrate the range of possible and likely results.
And the model is not just based on mountain streams; it is also based on some much larger and more recent events, such as the creation of the Snake River Gorge (300 meters deep in a matter of weeks) and the flooding of the English Channel. Water has enormous power to carve up rock, and the conclusion of the study is not in any way extraordinary; it's what anyone who has ever stood at the bottom of the Snake River Gorge would even find rather obvious.
The problem is that throughout the colonial era it was widely assumed by learned men that the Earth is a stable place where a comfortable equilibrium reigns. What we have found in the last 40 years or so is that the Earth is actually an extraordinarily violent and often inhospitable place, and the relative stability of the last few centuries is an exception, not the rule. If we hang around here long enough we will have to deal with violent changes, and efforts to engineer such a complex and sensitive system might make things worse. The problem is that we are engineering it by pumping carbon into the atmosphere, and a sensible person might conclude knowing what the system is capable of that kicking it might not be such a good idea.
Brackets contain world's first nanosig, highly magnified:[.]
I've heard it said before that the only reason so many scientists get those dates is that they base them on assumptions. Assuming the earth is so many billion years old will get you a date that confirms your theories. Like, if you assume that a variable in an equation is a certain number, and depending on the number you assume you'll get a totally different answer than if you assumed a much larger or smaller number. Could someone confirm or deny (with evidence if possible) whether or not this is true for me? I'm very curious about this.
Read something like The Age of the Earth.
The 4.54 billion year age of the Earth is not an assumption. It is the conclusion reached over the last few hundred years of effort from geologists and scientists in related fields, built upon the naturalists that came before them.
According to Daniel Garcia-Castellanos' paper in Nature, the sill at the Straight of Gibraltar gave way rather suddenly, with 40 cm of rock eroding and the water level rising by 10 m per day at its peak.
I'm relieved to know the Strait of Gibraltar is not gay; I was convinced he was hitting on me the other day.
Don't confuse this with actual observation. It's far from it.
This "research" is little more than a computer game where the programmer puts in the physics of a closed environment, and plays with some numbers with a big incentive to get an impressive result in order to get published.
Did you RTFA?
Because if you did, you obviously didn't understand shit.
Instead of trying to explain it for you, go back and read the two paragraphs with "Strait of Dover" in them and the paragraph in between.
The short version is that someone was digging for a tunnel and the new information caused scientists to change their opinion of Gibralter's geologic past.
[Fuck Beta]
o0t!
I always thought it would be cool to cut a canal from the ocean to Death Valley. With the heat there you would get a lot of evaporation and could sustain a current that you could use for power generation. Plus you could cool the air and get some rainfall. We can make our own little Med.
I love Jesus, except for his foreign policy.
but it is indeed based on assumptions, and the actual parent post is in the scientific spirit, while replies such as yours are in the "prestigious people said so, thus it must be true" category. If you delve to the root of the generally accepted age of the earth, you will find statement such as "The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238".
in other words, most of solar system considered to have about the same age (an assumption with some evidence suggesting it likely is true), and the decay of isotopes used to date not being affected by any outside source during that time (another assumption with good evidence, but perhaps unknown forces in Universe modified decay rates at certain times?)
Alright, lets do some back of the envelope calculations here:
The Eyre basin is some 171000 cubic kilometers, assuming an average of 15 below sea level.
The entire ocean has some 1347000000 cubi kilometers.
This makes the Eyre Basin approximately 0.000126948775 of the entire oceans in the world, and since the average depth of the ocean is about 3,796 meters, that comes to a roughly 48cm drop, which according to wikipedia should offset the effects of global warming for a century or so.
Current sea level rise has occurred at a mean rate of 1.8 mm per year for the past century,[1][2] and more recently at rates estimated near 2.8 ± 0.4[3] to 3.1 ± 0.7[4] mm per year (1993-2003). Current sea level rise is due significantly to global warming,[5] which will increase sea level over the coming century and longer periods.[6][7] Increasing temperatures result in sea level rise by the thermal expansion of water and through the addition of water to the oceans from the melting of continental ice sheets. Thermal expansion, which is well-quantified, is currently the primary contributor to sea level rise and is expected to be the primary contributor over the course of the next century. Glacial contributions to sea-level rise are less important,[8] and are more difficult to predict and quantify.[8] Values for predicted sea level rise over the course of the next century typically range from 90 to 880 mm, with a central value of 480 mm.
Haha, that was way too much fun.
What he can't kill, he has sex on. Trent.
I'm a geology grad student doing a thesis on tectonic geomorphology. I read this article with great interest; my research is on mountain rivers/streams so I know a bit about this kind of thing.
Your alternate theories don't really work, for a variety of reasons. I'm not an expert on all these topics, but I'll explain as best I can and hopefully anyone that might know better will correct me :)
The glacier theory doesn't work because glaciation did not, in fact, reach that far south. The area has stayed at a relatively stable latitude for the past 250 million years at the least (check out a plate reconstruction for 30 Ma compared to the present - the site has earlier reconstructions as well). Even during ice ages, glaciation never got that close to the equator. This is beside the fact that you can actually distinguish between a glacial valley and the kind of thing they're saying this is - based on the shape, type of sediments, and so on.
Tectonic movement doesn't operate on the same time scale as erosional and stream processes. Tectonics has a major influence on the way rivers operate - in fact that's what my research is about - but not in the way you're speculating. You might be surprised how well preserved rock formations are compared to when they originally formed - it sounds like this one is more or less the same as when it was deposited, which is common in most areas. Tectonics is constantly shifting the crust, yes, but not as much or as fast as you're supposing, and even then this is a relatively inactive area.
Now, your final theory is actually about right, but if you change it to follow how river erosion actually works, then you're basically saying what the researchers here are saying. Their description is a bit misleading, depending on how long you think this took to occur (and I would lean more towards it taking longer - two years as they say, or even a little more, but I don't know the specifics of where they came up with that figure).
The valley shape and sediment type suggest a braided river system, with multiple small, fast streams covering a broad area, constantly shifting left and right. As they drop sediment and fill in depressions, the areas where water is not flowing become the new depressions, so the streams shift back and forth, filling the area with sediment evenly. The coarse of meandering rivers (which are more mature and have slower flow rates) can change on sub-decade time scales, and braided rivers are constantly shifting. Now, the important thing is that these braided streams don't carve v-shaped valleys - they spread themselves out broadly, eroding laterally.
Thus, the initial break would have carved a v-shape valley, but it would quickly erode laterally. Most of the initial deluge would not be recorded - it simply wiped everything away. What's left is the wide valley that got flushed out, and the coarse deposits that filled the valley from the braided streams that existed near the end of the deluge, when flow rate was still high but not enough to wipe away absolutely everything.
One of the most interesting things about this research is that it supports the idea that these things can happen catastrophically. In the 1800's, during the early days of geology, there was a huge debate surrounding whether geology happened catastrophically or gradually. Now, the theories those guys were pushing were ridiculous (although a lot of fun), but the question of time scales is still relevant. It became clear by the early 1900's that gradualism is more realistic, and all of geology is essentially based on that - almost anything can happen if you give it enough time. It's the same conceptual leap that you need to understand biology and evolution, but with geology there is even more time to play with, and physics can easily explain how rocks are affected by forces over long time periods.
This led eventuall