Cornell University has a world-famous dendrochronology lab. Well, world-famous to people who keep tabs on things like dendrochronology labs. My advisor, Prof. Sturt Manning, is the director of the lab and after I took his dendro course at Cornell, I spent a semester working in the lab for some extra money. One of these days I’m sure I’ll write a post about all of the very cool things that you can do with dendro. Because they are VERY cool. But this post is going to be about dendro samples. Specifically the samples from a site known to the Cornell dendro lab as YNK, or Yenikapi.
The problem with being a grunt in the dendro lab is that you get to work on the material that no one else wants to. When I worked in the lab the post-docs and full-time researchers all had their own personal projects, and the students in the dendro course were given some choice in what kind of material to work on for their final projects. This left for the techs the samples that were hard to work with, boring (there are only so many cedar cores you can read from Cyprus before you want to gouge your eyes out), or… the wood from Yenikapi.
For the past three years the lab at Cornell has been flooded with samples from Yenikapi. The lab techs don’t get told too much about the samples that they are working on. Its just another piece of wood that has to be prepped appropriately, stuck underneath a microscope, and have each of its rings read and recorded in the computer to the precision of 1/100,000th of a meter. That’s 100ths of a millimeter. But even when we didn’t know what Yenikapi meant, me knew what having to work on Yenikapi meant.
See, there are four main kinds of wood that come into a dendro lab. First are your samples from living or recently deceased trees. Theses are cores or slices, usually in really good condition, that just need to be mounted and then sanded to a beautiful mirror finish before they can be read. Second are cores or slices taken from older decease trees… these might come from the wood used in a historical building or from an artifact like a piece of furniture, a coffin, or even the wood panel backing to a Rembrandt. Likewise these must be mounted and sanded, but often the wood isn’t in as good condition and the samples can be smaller and more fragile. The third and fourth categories of samples are the types found in archaeological or paleontological contexts, as they are ancient wood that has been somehow preserved. The third category is burnt wood, or charcoal, as once the wood has been reduced to carbon it usually doesn’t decay any further, unless it is damaged by water or impact (microscopic flakes of burnt wood can’t have the rings read!). The charcoal is wrapped with cotton string and masking tape to stabilize it, and then a clean surface is prepared for reading with a razor blade. The fourth and final category of sample is wet wood. Yenikapi is wet wood.
When wood or other organic material is submersed in water it doesn’t decay the same way it would on land, as there is no oxygen present. However, wood usually isn’t submersed in perfectly clear distilled water, and the salt, other chemicals, and biological agents found in the water have a definite effect. This is why sunken ships and old piers last so long, even for thousands of years, but not forever. The wood becomes dark and discolored, the structure of the wood becomes completely saturated and spongy, and finally it does eventually disintegrate. It can also be pretty gross. To get a smooth surface that allows the rings to be read, the sharpest razor blades must be used, and even they can often only make two or three cuts before they become too dull, and instead of shaving the surface of the delicate sample, you smoosh it into unrecognizable goo or fluff it into a cashmere sweater. The frustration of prepping wet wood must be experienced to be truly appreciated, and takes a remarkable amount of patience, which I really didn’t possess. There was lots of swearing involved. Thank god they put that lab in the basement and the prep room behind its own heavy door.
Additionally, wet wood samples aren’t sent into the lab submersed in water as they were found, as it simply isn’t practical. Instead the wood sample is tagged, and while still dripping wet its sealed in a Zip-Lock baggie. Now ideally, the air is removed from the bag, but its nearly impossible to get it all out, and sometimes the air removal step is skipped entirely. So, take organic material, and stick it in a moist environment in the presence of oxygen, and what do you get? Mold! Mildew! Fungi! Louis Pasteur would be horrified. Not to mention all the weird little insects from the water and the wood which just keep on merrily reproducing! I have seen wet wood under a microscope that looked like the surface of some alien planet, covered in a dense forest of bizzare trees and giant toadstools. It even has its own unique lifeforms, as bright orange and silver and even translucent insects scurry through the spongy remains of the wood.
But really, its the smell that gets to you. Because the wood from Yenikapi is oak that was submerged in the filthy stinking harbour of Istanbul back when it was still Constantinople. Some of it came from the hulls of sunken ships and some from the pilings of the Byzantine piers, but eventually this part of the harbour was filled in, most likely with garbage and household refuse and lord knows what else (the same way Manhattan was expanded in the 18th and 19th centuries), and after sitting down there, muddy and foul for over a thousand years, the whole area gets ripped up during the construction of a new subway system, and the archaeologists swarm in to do their thing.
And several hundred pieces of wood with the consistency of an overcooked souffle and a scent that falls somewhere between a high school linebacker’s jock strap and a rodent that’s been dead for a week, with notes of decaying seaweed, sewage, and the acrid tang of seawater, end up half a world away in the Cornell dendro lab.
The archaeological work on the site has steadily increased since the site’s discovery in 2004, as the Turkish government really wants to move forward with construction, and as a result more and more Yenikapi samples have flooded the lab each year. There was so much of it this year, that I heard its all the students or the lab techs get to work on. For once, I am thankful for my thesis.
CNN article about the construction at Yenikapi
Cornell Tree-Ring Laboratory
excellent Saudia Aramco World article about the archaeology