Ancient Crash, Epic Wave (Megatsunamis) - NYT

[MattSh]

From article. - Check out the graphic too.

At the southern end of Madagascar lie four enormous wedge-shaped sediment deposits, called chevrons, that are composed of material from the ocean floor. Each covers twice the area of Manhattan with sediment as deep as the Chrysler Building is high.

On close inspection, the chevron deposits contain deep ocean microfossils that are fused with a medley of metals typically formed by cosmic impacts. And all of them point in the same direction — toward the middle of the Indian Ocean where a newly discovered crater, 18 miles in diameter, lies 12,500 feet below the surface.

The explanation is obvious to some scientists. A large asteroid or comet, the kind that could kill a quarter of the world’s population, smashed into the Indian Ocean 4,800 years ago, producing a tsunami at least 600 feet high, about 13 times as big as the one that inundated Indonesia nearly two years ago. The wave carried the huge deposits of sediment to land.

...

Scientists in the working group say the evidence for such impacts during the last 10,000 years, known as the Holocene epoch, is strong enough to overturn current estimates of how often the Earth suffers a violent impact on the order of a 10-megaton explosion. Instead of once in 500,000 to one million years, as astronomers now calculate, catastrophic impacts could happen every few thousand years.

http://www.nytimes.com/2006/11/14/science/14WAVE.html

:wow: :wow: :wow:

[aquart]

1. Ah. Like Velikovsky said happened?

My, my, my, my, my, my, my.

[MonkeyFunk]

2. Not really, no....

Velikovsky didn't write about comets and asteroids. He believed such catastrophes were caused by a radical difference in the orbits of the planets, within human memory. For intance, Earth was a satellite of a "proto-Saturn", which went into a "nova state" which led to the Biblical flood.

His beliefs are recognized as even more silly today than they were in his time. His work on myth and history, though, is very interesting. But his astronomy and physics were lacking.

[aquart]

3. You've read him?

Because I recall quite a few sentences about comets. Beginning with "The Origin of the Comets" in Chapter 1 of Worlds in Collision.

[MonkeyFunk]

10. many years ago

but surely you're not saying that he believed the Biblical flood was caused by a comet or asteroid?

You're leaving out 99% of his (now debunked) theories.

[aquart]

13. Really? Which ones were debunked?

[MonkeyFunk]

17. Really?

You believe it's plausible that Earth and Saturn were near-neighbors within the last 4,000 years? That Venus was a comet ejected from Jupiter?

Not a single bit of astronomical research supports that.

[Xithras]

4. Oh wow. This is cool...evidence for the Biblical Noah myth.

Nope, this isn't a fundie post, it's a historical one.

Any reasonable analysis of the two stories makes it clear that the Biblical story of Noah's Ark was copied from the much older Epic of Gilgamesh in Babylonia. Lots of people here already know that, so it isn't news. What many people may not know is that the flood story in Gilgamesh was copied from the far older Ziusudra, the epic creation story of the Sumerians. According to the Sumerians, the gods helped the first people create the five great cities, and the kingship of humanity rotated between them. When the fifth city, Shuruppak, ruled the world, the gods became angry for some reason and flooded the world, destroying the human cities. After the floodwaters receded, the king of Shurupaak, a man named Etana who had survived the floods, founded the city of Kish, creating the first Sumerian dynasty and founding the Sumerian empire (which gave rise to all kinds of interesting things, like irrigation and writing).

It would be interesting to look at this as just another religious creation myth, but we know today that it wasn't a myth. About a century ago archaeologists FOUND Shuruppak and Kish. Shurupaak is in modern day southern Iraq, and Kish is about 50 miles south of Baghdad in central Iraq. When they began excavating Shurupaak, they discovered that it really WAS destroyed in a massive inundating flood. Even more interesting, the ruins discovered from the other pre-flood cities were also wiped out by a massive flood at the same time. Lots of speculation has occurred over what exactly caused the flood, but sedimentary analysis makes one thing clear...Kish was founded at the point where the water stopped. ALL of southern Iraq was under water at one point, and the reality is that Sumeria, one of the first great human civilizations, was probably started by refugees and survivors who fled north out of the flood zone.

Current estimates put the floods date at 2,900-2,750 BCE. According to this article, the asteroid struck in May of 2807 B.C. Fascinating fit.

[AIJ Alom]

5. Dr. Jackson, is that you ? Sorry couldn't resist. you sound so

much like my favorite sci-fi character. And yes I was thinking the same thing. This is the event described in the early human written history as the great flood. The Gods sent down a "thunderbolt" from above that generated a great massive flood.

[Xithras]

11. Bah, Jackson is a beginner.

His knowledge of the Ancients is impressive, but I think I could take him in a post-Indus trivia shootout :)

I once wanted to become a history teacher, and even today love reading the latest research on new discoveries in ancient and classical history. I had to look the dates and the kings name up for that original post, but the rest is pretty much off the top of my head :)

Yeah, I'm a nerd. Proud of it too!

[AIJ Alom]

20. Here's something to think about, could the Inca or the Maya, I forget

which, already have calculated the chances of such impacts and thus the Maya/Inca myth exists that the world will end in 2012 ?

[Xithras]

21. About as likely as the Rapture, I'd say. (a scientific explanation of the Maya calendar here)

I had to look this one up a bit!

Two points: 1) Belief in the Mesoamerican end-times mythology requires you to believe that large impacts or astronomical events happen at regularly scheduled intervals. Anyone with even the most passing understanding of astronomy knows that the universe is inherently random.

2) More importantly, you need to remember that the Mesoamerican mythologies don't actually claim that the world will end in 2012. Nope, not one. There hasn't been one bit of myth found ANYWHERE that indicates any sort of religious importance to the date whatsoever.

What has actually happened is that MODERN people have combined two separate bits of Mayan fact. There is indeed an ancient Mesoamerican belief and myth which claims that the world has been "renewed" and started again four times, and that it will happen again. We are in the fourth age today, according to the Mayans, but they gave no hint about when it was supposed to end.

Independently of that, the Mayans developed a calendar which ended in 2012. Why 2012? Well, that would take a bit of math to explain. There are theories that the Mayan's may have been tracking celestial precession, that it may have coincided with one of their religious beliefs, or even that it may have simply been a nice round number in their calendrical system. It appears to most people that the last guess is the correct one. Unlike our mathematical system which is in Base-10 (cycles every 10th number), the Mayan used an interesting Base-20 counting system and apparently gave some religious signifigance to the number 20 (if you aren't a computer programmer or skilled at math, you probably don't know what a non-10 base looks like...and sadly there isn't room to explain it here). For reasons we don't completely understand, they also attached some signifigance to the number 13. The calendar, therefore, is broken into cycles of 13 and 20. A Katun is one complete "decade" cycle of the Mayan calendar. Because they use a base-20 system, a "decade" took 20 actual years. Continuing on with the base-20, twenty "decades" were required for a Mayan "century", or a Baktun...which means that a Mayan "century" actually lasted about 400 years. Where things get interesting is their definition of a "millenia". Instead of continuing their system on and making a "millenia" equal twenty Baktuns, they instead used the other religiously signifigant number of 13. One "millenia" to the Mayans was 13 Baktuns, or about 5200 years. The current "millenia" ends on December 20, 2012 on our calendar. As conjectured above, it looks like they ended the calendar there simply because it was a nice round number for them.

We ALSO know that the Mayans themselves never connected that date with the end of the world, it was simplythe end of this "millenium". In fact, the Mayans never gave ANY date for the end of the world. What we have is simply a supposition that this age will be the same length as the last age. And there is one MASSIVE problem with that.

Summarizing from wiki here:

The most common reason for people thinking that 2012 is the end of the world is the notion that the last age ended when the long count reached 13.0.0.0.0, and 2012 represents the next occurrence of 13.0.0.0.0. What most people fail to realize is that the 13.0.0.0.0 long count is ABBREVIATED. The actual full long count from Mayan mythology put the ending date of the last age at 13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.0.0.0.0. The end of the calendar in 2012, by contrast, will only represent 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.13.0.0.0.0. Even if you buy into the assumption that the Mayans could predict the future, and if you agree with the unsubstantiated belief that the ages are all of the same length, you're still faced with the fundamental problem that the dates don't match! It's funny how the nutcases trying to sell end-times books fail to mention that fact.

Every indication is that the Mayans looked at 2012 the same way we looked at the Year 2000. It's an important date on the calendar, perhaps even something to be celebrated, but nothing more. Why did they end their drawn calendars at that point? Let's use a little common sense. The Mayans developed a calendar which correctly and accurately measured time over a several thousand year period. Without an infinitely large stone, however, they had to stop SOMEWHERE. So they ended it at the termination of their current "millenium". They probably made the (incorrect) assumption that their descendants would be around to create updated calendars for the next one.

[aquart]

6. Cool. I think I remember something about that.

But it was disputed until the tsunami. We tend not to believe things that not even our grandparents have seen.

[Xithras]

12. The cause of the flood is still widely disputed.

All sorts of theories have been floated regarding the floods causes, but none really sufficed. Once in a thousand year flood events, unusually high tides connected to the flood events, earthquake generated tidal surges, temporary blockages of the outlets to the rivers in the valley or the Strait of Hormuz, you name it. Tsunamis were never really considered a possibility because of the Persian Gulf's geography. The Gulf itself is shallow and flat bottomed, so there are no large blocks of earth to slide in an earthquake. There are also no major active faultlines under the floor of the Gulf to explain a local water displacement. Any major tsunamis would have been generated in the Arabian Sea or Indian Ocean. That, in turn, wouldn't work because the Strait of Hormuz and Oman provide a "break". Any incoming tsunamis would be de-energized as they snaked their way through the straits S-turn, keeping the Gulf relatively protected from that sort of thing.

In order for a tsunami to cause the inundation seen in southern Iraq, it would need to be massive enough to completely overwhelm the strait and widen the seaway. A depth of hundreds of feet would have been required, so archaeologists wrote it off as an impossibility. I sometimes think that "impossible" is just a codeword for "we don't have evidence for that yet".

Interestingly, the Strait of Hormuz would also introduce another factor to support the creation flood myth found in the middle-eastern religions. Once the initial tsunami lost power, the water would have settled and would have had to exit back through the Strait of Hormuz (without the impact energy behind it, the water couldn't flow uphill over land). That bottleneck would have slowed the draining of water from the flooded lands and led to an extended period of inundation for much of the middle east. 40 days and 40 nights anyone?

An impact like the one described would have also vaporized a LOT of water. This is only speculation, but the Northern Equitorial Current could have also drawn much of that water vapor over the middle east, causing the torrential rainfall described in the myths.

It all fits so well.

[xchrom]

9. very real possibility.

we know the flood happened in modern iraq -- we know a lot details - but pin pointing it's exact cause remains a mystery.

i think your explanation is very, very reasonable.

[Strelnikov_]

15. I Could Imagine The Pressure Wave Running Up The Persian Gulf

And from what I remember, the sea floor falls away gradually, perfect for wave runup.

[AIJ Alom]

7. Amazing isn't it ? They're looking for Chevrons using the power

of the google !

[xchrom]

8. it's possible that ''rare events'' happen more frequently than we think.

they might still be ''rare'' -- but that's the catch isn't it?

[Strelnikov_]

14. We Have No Concept Of The Frequency Of Major Events Like This

The fact that there was an oral tradition among some indigenous people to run when the sea goes out tells me that tsunami's of the magnitude of the Indian Ocean event are a hell of a lot more frequent than modern industrialized society would like.

If that tsunami would have happened 200 years ago, what record would there have been?

I run across this in flood control work. Tell someone they are good for the 100 year flood, doesn't sound so bad, until you tell them they have a 1/100 chance of being wiped out any given year.

Lets say a major tsunami is a 500 yr. event, or a 1/500 chance any given year. Wonder if modern Hong Kong or Tokyo likes those odds.

[Selatius]

16. Would this suggest we are due for an impact? Or did Tunguska fulfill our quota?

Or was Tunguska a pea shot compared to what happened in the Indian Ocean?

[Xithras]

19. Not a pea shot.

Tunguska was a massive hit, but it was probably cometary which is why there was no ground crater. Still, it was tiny in comparison to the impacts described here.

[bidiboom]

18. Very interesting

The tsunami created by this impact would most certainly reach the ancient Iraq and it happened around the time of the Noah's flood.

[muriel_volestrangler]

22. Also waiting in the wings: 50 metre high tsunami for US east coast from collapse of island

What scientists are predicting is that the collapse is likely to happen any time within the next few thousand years. Scientists also know that a collapse will not happen without any warning. They will be able to alert people to possible danger several weeks in advance.
...
The western flank of the Cumbre Vieja volcano would slide down westwards into the Atlantic ocean. There would be very strong earthquakes across La Palma while the flank was sliding. As the flank slid into the sea, it would create a very large wave called a mega-tsunami. This wave would move rapidly westwards.

Most of the energy of the wave would head straight out across the Atlantic towards the United States, Bahamas and the Caribbean, but a smaller wave or waves would head in other directions too. All these waves would get smaller as they cross the Atlantic. However scientists believe that they could still be as much as 50 metres high, for example, when they reach the east coast of the United States.
...
Most of these islands have not been studied in as much detail as La Palma, but one exception is the big island of Hawaii in the Pacific Ocean. Here too there are some signs that it might collapse in the next few thousand years.

http://www.bbc.co.uk/science/horizon/2000/mega_tsunami_qanda.shtml