A Place to Stand

I wrote previously of the largest meteor strikes in history the biggest of which is the Burckle Crater in the Indian Ocean. I mentioned this on Pournelle's blog & on Sunday somebody mentioned this New York Times article on the subject

But Madagascar provides the smoking gun for geologically recent impacts. In August, Dr. Abbott, Dr. Bryant and Slava Gusiakov, from the Novosibirsk Tsunami Laboratory in Russia, visited the four huge chevrons (characteristic shape of debris formed by the high point of a meteor caused tsunami) to scoop up samples...

About 900 miles southeast from the Madagascar chevrons, in deep ocean, is Burckle crater, which Dr. Abbott discovered last year. Although its sediments have not been directly sampled, cores from the area contain high levels of nickel and magnetic components associated with impact ejecta.

Burckle crater has not been dated, but Dr. Abbott estimates that it is 4,500 to 5,000 years old.

less certain is this

Bruce Masse, an environmental archaeologist at the Los Alamos National Laboratory in New Mexico. He thinks he can say precisely when the comet fell: on the morning of May 10, 2807 B.C.

Dr. Masse analyzed 175 flood myths from around the world, and tried to relate them to known and accurately dated natural events like solar eclipses and volcanic eruptions. Among other evidence, he said, 14 flood myths specifically mention a full solar eclipse, which could have been the one that occurred in May 2807 B.C.

Half the myths talk of a torrential downpour, Dr. Masse said. A third talk of a tsunami. Worldwide they describe hurricane force winds and darkness during the storm. All of these could come from a mega-tsunami.

Of course, extraordinary claims require extraordinary proof, Dr. Masse said, “and we’re not there yet.”

Indeed we aren't there yet. Nonetheless the size of the Chevrons & their position do show how high the water came in that area & can give an assessment of how high it should be elsewhere. This was an era when clay tablets were the height of literary communication so it is hardly surprising that no record of scientific measurements or explain it without reference exists. Anybody who has seen records of battles as late as the Middle Ages will know that records rarely accurately assessed how many men were in the armies, & that is something that kings & their scribes must have known & have had a deep personal interest in so a lack of decisive records is no surprise. The dating of 2,807 BC seems enthusiastic but a similar mention of an eclipse when Odysseus returned home has been used to date the Odyssey. We are at the stage regarding this crater that we were when the Dinosaur Killer meteor was first hypothesised by Dr Alvarez on the basis of finding a geological layer of iridium. We will see how it goes.

Still fairly isolated. As a species we have been lucky. Here is a rather elderly article that estimates a 1-6,000 risk to us all.

Labels: Science/technology