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Black Sea '01 Expedition
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THE 2001
EXPEDITION
The latest attempt
to unlock the secrets
of the Black Sea
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In August 2001, the Institute for Exploration launched another expedition to the Black Sea, this time off the western coast, working with the Institute of Oceanology at the Bulgarian Academy of Sciences. The investigation would be similar to the wildy successful one done off Turkey in 2000, except this time the team would be working hundreds of miles to the west. Also, unlike the 2000 season, there would be no ROVs tagging along, so the expedition could concentrate on pinging a much larger area of the seafloor for sonar targets. (Ships are forced to travel much slower when operating ROVs off the stern -- crawling at only a knot or so -- than when just towing a sonar device.)
By working in an entirely new region of the Black Sea for the first time, this expedition was a crucial geographical complement to previous expeditions, and it served to extend our knowledge of the mysterious conditions for submerged archaeology in the area. The sonic and geological roadmap drawn in 2001 will very explicitly guide ROV and submersible expeditions in this Western Black Sea over the next few years.
SURVEY AREA
There are a few reasons why the IFE chose the western side of the Black Sea for this season. For one thing, discoveries (or non-discoveries) here would fill in more gaps in the underwater archaeology panorama of the Black Sea, since most of our data and finds were restricted to the Turkish coast. Another advantage to working in the western Black Sea is the flatter continental shelf. The shelf (indicated by light blue on this map) is the region of seafloor adjacent to the coastline, and in the Black Sea this used to all be land (when the Black Sea was the Black Lake, 7600 years ago). As you can see, the western Black Sea boasts a wide and very flat continental shelf (compared to the steep features in the south). This is significant because the steeper your shelf, the more sediment will cascade down the slope from above with the potential of burying any ancient archaeology forever. (To put it another way, a hut on the side of a Himalayan mountain might be tough to spot after 7,000 years of avalanche and snowdrift.) With a flatter shelf, the Bulgarian-Romanian side of the Sea has a much lower sedimentation, and seafloor archaeology should (in theory) be more readily discernible on a sonar image.
CREW & DATA
Ten American scientists (and students) joined 7 Bulgarian scientists (and students) along with about 20 crew on the research vessel Akademik in the second week of August, 2001. Embarking from the port of Varna (a nice resort town on the Black Sea), the R/V Akademik spent over two weeks scanning the coasts of Bulgaria and Romania, out to 100 miles offshore, running sonar tracklines, pulling up gravity cores of the seafloors and taking oceanographic samples.
Two different types of data were collected: 1) Sonar images (which a researcher's eye constantly scanned for habitation and wreck candidates) and 2) Geologic and oceanographic samples, which will increase our knowledge of the flood and the anoxic zone.
The main tool used on the expedition was the IFE's homemade sonar towsled, ECHO. This device and 1500lbs of lead ballast, the Clump, were towed behind the R/V Akademik along specific tracklines, navigated by GPS. ECHO was used in tangent with other research equipment on the Akademik, collecting data by these methods:
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Open a gallery of bicycles, mannequins, handguns and shipwrecks imaged with sidescan sonar
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TECHNIQUES
Side-scan Sonar
Right on ECHO's udder is a device that emits pulses of sound waves in a cone below the towsled, like an acoustic flashlight. (Click here to open an IFE page with a diagram showing how ECHO scans the seafloor.) These sonar waves propage to the seafloor, bounce off it, and head back towards the towsled. When ECHO receives the sonic reply, the lag and intensity of the reflection is processed by hardware and software, and a computer screen paints an acoustic image of the seafloor below the ship, along with any objects that might be resting on it. The side-scan sonar (SSS) was our primary tool in looking for shipwrecks and habitations.
Sub-bottom Profiling
Similar to the side-scan, the sub-bottom profiler (SBP) emits a lower frequency sound wave which will actually penetrate the seafloor, and return images of the stratigraphy below the bottom of the sea (as if you were looking from the side). The main reason we had the SBP was to trace ancient river channels to their old mouths -- where they used to empty into the Black Lake (locations that are now submerged). The shores of these river channels would've been nice places for people to live before the flood, so these are good spots to look for habitations (see more about the Danube River Canyon below).
Also, if a strong target is found on the side-scan, the sub-bottom profiler might be able to give you the stratigraphy of the submerged archaeology. (David Mindell at MIT is using this principle to pioneer an amazing SBP that will allow archaeologists to "virtually excavate" a shipwreck, to see what's inside without touching it.)
Gravity Coring
The seafloor contains an enormous amount of data on the geological history of the Black Sea (and pre-flood Lake), in the form of sediment layers and mollusc shells. One of the central tenets of geology is the principle of superposition, which states that material is piled higher and higher over time, so peeling back layers means going back in time. By taking a cylindrical piece of the seafloor (which will fit in a PVC pipe), gravity coring gives us a vertical timeline of history.
The features and events recorded in the seafloor are interpreted through analysis of the mud and deposits in the core. You can also date seashells left in different layers in the core (although shell dating is not a very reliable technique yet -- see discussion below). In short, lengthy analysis of these cores will give us a better understanding and trauma date for Ryan & Pitman's flood.
Bathymetry
Throughout the voyage, we used SIMRAD depth sounders to collect data on how deep the sea was. Obtaining more detail than is available on conventional seacharts of the Black Sea, we traced the bathymetry to find ancient river channels and the coastline of the old Black Lake.
CTD
An octopus-like device is lowered into the sea from the foredeck (the open ship at the bow), which has this charming ability to take water samples at various depths and bring them up to us. It is a neat oceanographic game of fetch. Back on the ship, chemical analysis of the samples allows you to compile Conductivity and Temperature data at different Depths (hence the acronym). This technique is very useful for studying the anoxic zone.
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Download the official IFE summary of the 2001 expedition (26K Microsoft Word file)
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FINISH LINE: The 2001 Results
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SUMMARY
The data collected in 2001 are still being analyzed by Dwight Coleman and the IFE, and more will be known by mid 2002. It is possible that the ultimate analysis of the data here will provide the strongest evidence yet for or against the Ryan & Pitman flood. But here's a review of things we've already learned from the expedition:
The R/V Akademik scoured over 700 miles of sonar tracklines in five survey areas. Over 100 targets were located on the seafloor by side-scan sonar, each target having the possibility of being man-made (either in the form of a shipwreck or a submerged habitation). Particularly interesting targets were often surveyed again with a higher frequency (and thus higher resolution) sidescan sonar -- but only direct analysis with an ROV or submersible in the future will be able determine if we actually found anything of archeological significance. So this story does not have an ending written yet.
TARGET 32
Even without face-to-robotic-face ROV analysis, several targets caught the eyes of the researchers (and the crew), particularly the so-called "circle target." This was the 32nd target located in Romanian waters, southeast of the Danube Canyon. It is a peculiar circular outcropping of high return on the side-scan sonar, about 65 feet by 42 feet in dimension, parked only a dozen feet above the ancient shoreline of the lake. While "Capitan" (the Akademik's captain) joked that we had found our "first village," we really don't know what Target 32 is. It could be a settlement, a merchant wreck, an unusually goofy pile of rocks -- anything. It remains to be seen if Target 32 will soon be known as Site 32.
But that first visual investigation of Target 32 sometime in the next few years will certainly be a suspenseful moment, with visions of Target 82 from 2000 dancing in the researcher's heads. The National Geographic video of this future expedition will surely have very dramatic music playing in that scene.
THE DANUBE RIVER CANYON
Several ancient river channels were traced on the seafloor,
the most dramatic being that of the Danube. The Danube River currently runs over 1700 miles from Germany all the way to the Black Sea. But 7600 years ago the Black Sea was a lake and significantly smaller, so the shoreline was much "further out" than it is now. The pre-flood mouth of the Danube (where it emptied into the Black Lake) now lies 600 feet under the Black Sea.
We spent a significant amount of time over the Danube River Canyon (covered in our survey Areas III and IV), studying the former mouth of that river as it now appears on the seafloor (see contour map above). The canyon is located on the Romanian coast over 60 miles southeast of the Danube's current mouth, and happens to contain the deepest waters we traversed during the expedition. There are some features near the old mouth that seem to reflect
calm, protected bays before the flood; these would've been nice places to live back in the day (7600 years ago).
Dwight has grafted the sonar images from Area III into a mosaic depicting the Danube River Canyon. Compare this image (at right) with the contour map (above).
GRAVITY CORES
The gravity cores provide intriguing visual evidence of an abrupt change in the Black Sea during the Holicene era (meaning sometime in the last 10,000 years). It doesn't take a geologist to see a dramatic geological event recorded in the the layering of lake and marine deposits (see photo on the left). But it does take a geologist to locate plant roots and sandstorm remnants inside the cores, evidence that these submerged locales were once above water. But perhaps the most intriguing material of the cores are the shells.
Saltwater and freshwater molluscs live in different kinds of shells. At a certain date in the cores (if you treat the core like a timeline), the shells of freshwater (lake) molluscs go away, and seashells suddenly appear. While it usually takes a specialist to distinguish between lake and marine shells, the difference is sometimes as dramatic as a color change from white to purple. This substitution seems to indicate a flood of saltwater killing all the freshwater molluscs in the lake,
along with carrying saltwater molluscs from the Mediterranean into the newly-saline Black Lake. Continuing radiocarbon analysis of these shells have given us approximate flood date, and though the technique has given birth to much supporting evidence for Ryan and Pitman's Flood Theory, we have to view these dates "with a grain of salt". Unfortunately, shell dating has not been shown to be very accurate yet, because of a quirk with molluscs (beyond the inherent ambiguity of radiocarbon dating). (You can go on to a further discussion of radiocarbon dating and the trouble with shellfish.) This statistical setback is being attacked by simply obtaining a larger sample size of shells, which should slowly pierce through the error bars and converge on a better flood date.
COMING ANALYSIS
Notwithstanding the challenge of dating shells, the analysis of gravity cores and bathymetric data taken in 2001 does have the potential of giving us the best answer to date of how accurate Ryan & Pitman's flood story is. The cores will go under the microscope in the spring of 2002, and many scientists and enthusiasts are waiting anxiously for the results.
Another extremely important result of the expedition is the strong relationship forged between American and Bulgarians researchers. As this is the first joint expedition between the IFE and the IO-BAS, the working collaboration and friendships made at sea will be of enormous importance in the physical investigation of the 2001 targets, and the locating of hopefully many more.
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FUTURE EXPEDITIONS
In the summer of 2002, researchers at the IO-BAS will use their submersible to investigate some of the shallower targets logged during 2001. The IFE plans to return with its loyal army of robots soon after, sending Little Hercules (or its big brother, Big Herc, presently under construction) to study more targets up-close, in particular the candidates in the anoxic zone, too deep for the submersible to reach.
It remains to be seen if the targets we found on the bottom of the Black Sea will prove to be more flooded habitations and naturally preserved shipwrecks. But when you consider the profound discoveries that were made just inside the tiny search area of the 2000 season, you can't help but think there are scores of archaeological treasures on the silent seafloor, waiting patiently for the day when they will be seen by men again.
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This is the end of the overview section. The remainder of the site is devoted to a more personal account of the 2001 Black Sea expedition.
Please feel free to email me (at chadparmet@comcast.net) if you have any questions or comments. Have a good one! Chad
From here you can check out:
TEAM
:: A colorful group of scientists and seamen worked aboard the R/V Akademik.
JOURNAL
:: There were a lot of interesting experiences on this cruise, along with one scary moment.
PHOTOS
:: The digital camera was a wonderful invention.
RESOURCES
:: Download papers, bounce to other websites, read some books.
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Site by Chad Parmet: chadparmet@comcast.net | home.comcast.net/~chadparmet
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