Monday, December 04, 2006

The next theory
I love this sort of news. It fills in some more details of Earth history and human prehistory and shows how there is always something new to discover.
A massive tsunami smashed Mediterranean shores some 8,000 years ago when a giant chunk of volcano fell into the sea, researchers say.

Waves up to 165 feet (50 meters) high swept the eastern Mediterranean, triggered by a landslide on Mount Etna on the island of Sicily, according to the new study.

The research team says the natural disaster likely destroyed ancient communities, with a series of killer waves hitting the eastern Mediterranean coastline from Italy to Egypt.


The researchers also speculate that a Neolithic village just off the coast of present-day Israel was hit by the tsunami.

The well-preserved Atlit-Yam settlement, which due to altered sea levels today lies submerged, "shows evidence of a sudden abandonment" 7,000 to 8,000 years ago, the researchers write.

Mt. Etna is one of the best studied volcanoes in the world. Since at least the time of the Classical Greeks, curious men have been climbing into Etna to measure, and test, and just see what's going on. It's not much of an exaggeration to say that the science of geology was born in Etna.

Mt. Etna is a pretty typical cinder cone* type of volcano. In a cinder cone, lava and ash pile up around the volcanic vent forming a fairly symmetrical cone shaped mountain. This is the cartoon volcano that most kindergarteners learn to draw. Cinder cones become most dangerous when they become tall without becoming very wide; their slopes become too steep to be stable. Because a cinder cone is essentially a pile of rubble, it's very easy for an enormous chunk of it to slide off.

Eruptions are the most dangerous time. One point seven cubic miles of Mt. Saint Helens slid off during the 1980 eruption when the rising magma chamber caused that side of the mountain to bulge outward. Other volcanoes give way when they become saturated with water, as happens in frequently in Central America and the Andes during the rainy seasons. In 1998, Hurricane Mitch caused the side of Casita Volcano in Nicaragua to collapse, creating a landslide that wiped out two villages and killed over 2,000 people.

When such landslides happen on the shore or underwater, they cause some of the biggest tsunami known to science. In the event called the Nuuanu landslide, 3000 cubic kilometers of the Hawaiian island of Oahu broke off and slid northeast. The slide would have caused a 70 meter (215 foot) tsunami in southern California. Fortunately, this was about 1.5 million years ago and only mastodons were there to see it.

Back to Mt. Etna. This story is interesting enough in its own right, but my first thought was to wonder which fringe researchers will be encouraged in what direction by it. Sudden gigantic tsunami smashes around the Eastern Mediterranean wiping out costal communities just before the dawn of history--that has possibilities. I'm sure someone can work this into a theory of Atlantis or the Biblical flood.

In their 1998 book, Noah's Flood, William Ryan and Walter Pitman described a massive flood through the Bosporus into the Black Sea about 7600 years ago. At the time, they believe the Black Sea was a landlocked glacial lake about five hundred feet lower than the present sea. As the oceans and seas rose at the end of the last ice age, the Mediterranean eventually became deep enough to flood over the narrow ridge separating its Sea of Marmora arm from this lake. The lake filled to it's present level in less than a year. Any people present on the shores of the old lake would have had to flee as everything they knew disappeared beneath the expanding sea.

Ryan and Pitman's geology was quite good and, although some geologists question their interpretation of the evidence, many were convinced. Unfortunately, Ryan and Pitman chose to push their narrative beyond their area of expertise. They speculated than the primitive farmers who escaped from the rising waters were responsible for the spread of agriculture, the spread of the Indo-European and Semitic languages, and the origin of the Biblical flood myth. This speculation was a nice hook on which to base their popular book, but was nowhere near as well supported by the evidence as was their straight geological narrative. Scientists in a half-dozen fields cringed at what they saw as naive and sensationalist nonsense. Worse, hundreds of catastrophist theorists claimed that Ryan and Pitman, who are real scientists, supported their preferred theories of the past, whether Noah, Atlantis, or rogue planets.

The Mt. Etna landslide and tsunami is not only liable to get the same treatment down the line, it could even be made to fit into the Black Sea narrative. The timelines are compatible. Suppose it was the Etna tsunami that first sloshed the water in the Sea of Marmora over the ridge separating it from Black Lake and started carving the Bosporus channel? Most Atlantis theorists like to work a volcano into their story (even though Plato doesn't mention one). By combining the Etna landslide and the Black Sea flood we get more than enough tectonic drama to keep the Atlantis fans happy. There is even a school of thought that thinks the Bosporus and Dardanelles were the Pillars of Hercules and not the Straits of Gibraltar.

When the inevitable catastrophist book on the Mt. Etna landslide and tsunami comes out, remember that you read it here first.

* I've simplified a bit. Many geologists distinguish between different types of cones depending on the type of material that has piled up. I've lumped them all together.

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