Exploring Ancient Deep Sea Shipwrecks with Dana Yoerger, Senior Scientist at the Woods Hole Oceanographic Institution


Jennifer Berglund, Dana Yoerger


Jennifer Berglund 00:04


Welcome to HMSC Connects, where we go behind the scenes of four Harvard museums to explore the connections between us, our big, beautiful world, and even what lies beyond. My name is Jennifer Berglund, part of the exhibits team here at the Harvard Museums of Science and Culture. And I'll be your host. Today I'm speaking with Dana Yoerger, a senior scientist at the Woods Hole Oceanographic Institution who works in the Deep Submergence Laboratory. For his very cool job, he designs builds and operates new kinds of underwater robots for use in the deep ocean. Back in the 90s, Dana was part of the research team that first explored the Tanit, a deep sea Iron Age shipwreck off the coast of Israel containing a cargo of hundreds of amphora clay vessels used to transport goods throughout the ancient world. In our new exhibit at the Harvard Museums of the Ancient Near East, we're featuring a few of the amphora recovered from the depths. I wanted to ask Dana, about that experience, and the ways in which the tools for deep sea archaeology and exploration have changed in the decades since. Here he is. Dana Yoerger, welcome to the show.


Dana Yoerger 01:34

Nice to be here.


Jennifer Berglund 01:42

How did you start doing this? This is a very interesting to many people, obscure field. How did you get into it?


Dana Yoerger 01:50

I did my PhD at MIT. And we were working on robots, particularly robots that cooperated with people. My adviser was Dr. Thomas Sheridan, who is a pioneer in how humans and computerized things did or didn't get along. He worked on the Apollo Project, for example, in his PhD thesis. And also they were trying to figure out how you could operate robots distantly where there were large time delays, right. So they started working on those problems and thinking about how the people and the computerized systems. And he had won a research grant with the Office of Naval Research to start thinking about that in the context of underwater robots. So that's what I was working on when I was a PhD student. But it was all fairly abstract. It wasn't operational in any sense. But then it turns out one day, he called me up and he said, I have a visitor coming in my office. ONR, Office of Naval Research, set him up to see us, I think you might like to meet him. Oh, that was Robert Ballard. So I remember sitting in my advisors office. with Bob, I remember looking at the clock, I think it was like 12 minutes into his presentation. And I thought, wow, this is what I want to do. Ballard was very much part of establishing the Alvin submersible as the premier scientific tool that it is. But after it matured, there sort of wasn't a place for his kind of creative force anymore. As someone explained to me, once it was run by a committee, Bob had to go find something else to do, because someone explained, and I mean, this affectionately, if you have a committee with Bob on it, it's not really a committee anymore. I mean, Bob is bigger than life. He's, as we say, large and in charge. So Bob said, okay, I need to find something else to do, because I succeeded. And now I don't have a job anymore. I mean, remember, his expertise was actually in geology. And so he was still very much on the cutting edge of the deep ocean seafloor geology and all that, but his technological aspirations, he didn't have a submarine anymore. But he looked into his crystal ball. And he said, the future is not in human occupied vehicles. The future is in remotely operated vehicles. So not autonomous, but vehicles that operate on tethers. So they have power and communications to the surface, but that's going to be the next generation of scientific assets. And he said, okay, so I'm going to build a new generation of those. And that was just starting up when I met him. Bob Ballard is my mentor, close personal friend, he hired me here at Woods Hole. But, of course, what he's most famous for, is discovering the Titanic, and I was lucky enough to be on that expedition back in 1985. But that's a very narrow view of Bob's accomplishments. So over time, what he did was, as I mentioned before, he brought along the US capability for scientific deep submergence, making those vehicles work, like Alvin, for example, making them effective for science, getting them funded, most importantly, getting them upgraded technologically to the point where they were useful. And then he used those tools to discover fabulous things about how the Earth works. In particular, he was a graduate student when the theory of plate tectonics was verified. And that whole part of Earth Science got literally turned on its head. He rode that wave scientifically, he collaborated with some of the best scientists in the world, from the United States, from France, from all over the world, that he was part of a group that really figured out how that seafloor spreading and all of that basic geological understanding of basically how our planet works, was being formulated. So he was very impactful in a basic Earth Science discovery.


Jennifer Berglund 05:34

I want to talk a bit about this cruise that happened in 1999. Yeah, that you did with Bob Ballard. Basically, it was to explore this Iron Age shipwreck, two shipwrecks, really, but the one I really want to talk about is the Tanit. And it's of interest because you were able to recover some objects that we actually have on display. Yeah, one of our I know, I know. I'll keep you posted on that. But tell me how this expedition happened in the first place. What led you there...


Dana Yoerger 06:07

These things all sprung from Ballard's desire to prove to the world that the sea floor is the world's greatest museum of ancient history? So I guess the first question, why are shipwrecks important? Well, they're obviously they're exciting, right? I mean, when I was a kid, I was fascinated by shipwrecks. I mean, everybody was. The Titanic, Viking ships, and Roman, everything. They're important for a lot of reasons. First of all, they teach you about ancient trade. Because most trade... travel on land in ancient times was very dangerous. You think about the Silk Road connecting East and West, that was a perilous journey. Ships were a much better way to move stuff around, and the ancients moved lots of stuff, the Romans would build a harbor in the Middle East, and they would bring all the concrete from Italy. The amount of trade that went across the ocean was tremendous. And some fraction of those ships were lost due to storms or accidents or whatever. So that they're all there on the bottom of the ocean, some of them, some of them are buried somewhere covered up some of our there to be found. There's the ships, but there's also the stuff the ships were carrying, and what do they teach us, the ancient shipwrecks are the remnants of the ancient economy- who was trading with whom, what were they trading- and the ability of archaeological science to understand that stuff, if you get your hands on it, is unbelievable. For example, if you bring up a clay jar an amphora, which by the way you don't do casually, there's a lot of things that you do before you touch anything. There's the design of the jar itself, that tells them a lot, there's the material. They can take a chemical sample of the clay that that jar is made of, and they can tell you what clay pit in Lebanon or wherever that amphora came from. And they do that with isotopes with very exotic chemical analysis.


Jennifer Berglund 07:54

And all this tells you more about where trade was happening, what kind of trade..


Dana Yoerger 07:58

They can tell you how old it was, they can tell you where it came from. And you know something about the route it was on. So you can speculate about maybe where it was going. And here's the most outrageous thing, one of my friends, Brendan Foley, who's at Lund University in Sweden, he and his collaborators, they've extracted DNA from inside the amphoras. And they'll tell you what they were carrying. Sometimes there's chemical recipes even more straightforward. There's stuff like pollen in there, you know, you recover a jar that used to carry some cargo, and, maybe there's fish bones in there, because it was carrying fish sauce. So if you know where it came from, you know how old it was. And you can speculate something about where it was going. That's tremendously valuable for archaeologists and historians to understand ancient trade.


Jennifer Berglund 08:42

Talking about the Tanit, how was it initially discovered,


Dana Yoerger 08:46

I think the Navy found it, and they tipped us off, that they'd see these things. And then we used those, really, one of the things that we did was, even though the ship had already been discovered, we used it as a kind of training target. So we brought all our search sonars out, this thing called the DSL-120, and we mapped it from all different directions. So we could learn what those kinds of shipwrecks looked like to support future explorations. Because you know, sonars are great. They cover wide swaths of the sea floor, but they don't show you a picture of what's there. You get this kind of blobby, blippy thing. So you can extract some knowledge about what it is from the sonar returns, but it's not like, it's rare, occasionally, you get a picture of the ship, with the mast standing and whatever and you go 'Whoa, that's an ancient ship', but that's actually rare. Normally, it's just some anomaly on the sea floor and there's a lot of anomalies on the seafloor, there's natural seeps, there's piles of garbage. There's modern ships, there's geological formations, there's all kinds of things. So one of the objectives of that expedition was to get better at recognizing shipwrecks. So we went to known shipwrecks and we pretended we didn't know they were there. And we tried to get better at recognizing them. That was one step. Then of course, we went there, and we surveyed it visually with our remotely operated vehicle, Jason, and we mapped it with sonar with very close up sonar. So we're actually kind of making a sort of fine-scale map of the wreck. And we made photomosaics. You know,


Jennifer Berglund 10:12

Photomosaics are basically images composed of lots of different images.



Yeah, it's like panorama mode on your cell phone. But on a much larger scale, and it puts all those pictures together. But it's really interesting to see how that technology has evolved. Because what we did was what we call old school photomosaicing, which actually used to be done in dark rooms with kind of a fancy kind of enlarger, they would, or what we used to be done with scissors and glue. You'd get all the pictures and you'd cut them out, stick them together. Then there's kind of more of a darkroom way of doing that. And the darkroom way was good, because you could like tilt the enlarger so you could undo some of the distortions optically. And then my colleagues, John Howland, Ken Stuart, Marty Mara at Woods Hole, they figured out how to do that digitally. But it was still that kind of computational version of cutting and pasting the pictures together. Now, those methods have been completely obsoleted by full 3D photo. The goal of a photomosaic is to make a kind of 1,000-foot aerial view of the scene. A 3D reconstruction is really building the entire 3D shape of something that's not flat. For example, you can take a drone, an aerial drone, and you can fly it around a complicated structure now like a building or a bridge, and the software will assemble a full, pretty accurate and beautiful 3D model of that complicated thing. So it's not this flat, photomosaic 1,000-foot view looking down planar view, it's the full 3D model of the real shape of the thing. But if you think about your drone, that you're flying around, let's say it's flying around the building that I'm in right now, but it's smart enough is not gonna hit the trees and all that, it has GPS on it, so it knows pretty much where it is. And it's got a compass, it's actually more than a compass, but it knows exactly which way it's pointed. And so that really helps the software, build that 3D image. Underwater, that's a lot harder, because you don't have GPS, you can have a good compass, if you will. So the underwater problem is more difficult. Now back when we did it, we would have a very precise acoustic navigation system that would locate the vehicle to within like an inch. It was difficult to use, it was extremely effective. But it was kind of temperamental, and I think there were fewer than half a dozen of us who could actually make sense of the thing. But now, because the software is so much better, they can do those 3D reconstructions, without that kind of aiding. We have another trick too, Doppler sonar that measures the relative movement of the vehicle over the seafloor. So it doesn't know exactly where it is, but it knows how it's moving. And obviously, if you're trying to reconstruct a scene, that's super valuable information, we would put all that together. But now the software is so much better, that as long as you make a fairly organized survey of it, the software can figure out how to connect all the pictures together. It's amazing. Those techniques have evolved tremendously.


Jennifer Berglund 13:13

So in the 1999, expedition, that was kind of the first thing you did, you sort of mapped the wreck, you did a photomosaic. And basically, you just sort of documented everything, as-is without touching anything. And then once you were done with that, what did you do next?


Dana Yoerger 13:31

Then the archaeologists said, you know, was able to study the maps and the images and say, okay, we have this many different kinds of amphoras, for example, so we need two of these and one of those. And here's the one that if you pick it up, you won't disturb the others. So the archaeologist then made a strategy.


Jennifer Berglund 13:49

Because there's basically like, if you look at the image, and I believe we have an image of it in the exhibit, there are just piles of these amphora, I mean


Dana Yoerger 13:58

And the ship was full of these, and it sank, and then now the ship's pretty much gone. And you're left with the cargo hold, basically. And so they were all stacked in there. So there,


Jennifer Berglund 14:08

I mean, there were at least hundreds of them, just so so many. So, when you're going in and you're actually trying to recover one, you have to think about, well, how am I going to impact its environment if I remove this one? Which one is removable?


Dana Yoerger 14:23

You have to think about all those things. We had to make that whole strategy. And then what was really cool, this was a fun thing. Now normally you if you want to pick something up on the seafloor with a remotely operated vehicle, you land on the seafloor and you reach out and you get yourself nice and stable. And then you lift it up with some specialized gripper, maybe, or whatever. Well, of course, the archaeologists wanted all the ones that were like in the middle of the pile or whatever. So we actually had the vehicle hovering under its computer control and reaching down and that was kind of fun.


Jennifer Berglund 14:51

And how in the world, do you stabilize a vehicle when it's floating, when you can't?


Dana Yoerger 14:57

Well, it's got thrusters, it's got a compass. And then it has those two different ways of knowing exactly where it is. It has the acoustic beacons that are sort of the GPS, and then there's the Doppler sonar, which gives you its relative motion. And so you fuse all that together, that's in a classic feedback loop so that it's going to stay where you tell it, and then you can make the lift without touching the wreck without stabilizing yourself mechanically, and disturbing the wreck.


Jennifer Berglund 15:23

That's such a complex process.


Dana Yoerger 15:26

It was a lot of moving parts. But people can do that much simpler now. For example, you don't need the high frequency acoustics. Doppler sonars are great, they're fantastic. And they don't need any external reference, they actually bounce sound off the seafloor, and they determine your relative motion based on that. So it's kind of like the odometer in your car, but it works in three dimensions. So the vehicle's slowly drifting sideways, it's measuring that. It's creeping forward, it's measuring that. So it's giving you your relative motion over the seafloor with tremendous precision. It's a remarkable thing. That's the primary information you need to stabilize the vehicle. If you're trying to stabilize it, you don't care where it is, you want to know, how's it moving. And that's exactly what the Doppler sonar gets you. So most modern ROVs now have an auto hold button to where you want, the Doppler sonar data is good, you push the button.


Jennifer Berglund 16:20

So you had to pick up the amphora. So how did you do that?



Well we have some specialized, big tongs that would cradle them, and then we could bring them directly to the surface, but more often, we would put them in a device, which we call an elevator, which is a bit of a tongue-in-cheek description of it, but it's basically a basket that has weights on the bottom and buoyancy on the top. And so you'd carry the amphoras over to the elevator, there were bins in the elevator. So you put it in this soft net bin, you close the lid, and you get another one, put it in there, close the lid, latch it. And then when the elevator was loaded up, you'd pull up the pin that was holding the weight on the bottom, and the buoyancy would bring it back to the surface. And then they'd go over with the vessel, and they pick it up and bring it on deck. So the ROV didn't have to carry these big, ungainly things to the surface. In this elevator where they were really cradled and really kept like a baby in a bassinet. Yeah, it's just like, treated very gently. And then the other thing is you want to find objects that aren't the cargo you want to find like everyday objects from the crew, and maybe things related to the operation of the ship, which can tell you important things, again, about who these people were and where they were coming from, and maybe even something about where they were going. So, if you find their lunch pail or something, that's very exciting. You find a lamp, you'd love it if you found a navigational instrument. Some, so right. I remember, on a different shipwreck, we found, we called it a cooking pot. But once the conservators started cleaning it up, they found that it wasn't a cooking pot, because then the first thing that conservator, she was a character, she looked at me and goes, "I think theyr're dinner's still in here", right? She's cleaning it out and she goes, "No, I don't think it was their dinner. It was tar". And you can imagine if you've got a leaky old wooden ship, you might always have a pot of tar ready to heat up and melt so that you could waterproof parts of the ship. Yeah. So it was there. It was part of their ship maintenance. And then, as they were dissolving, they went through the tar, and they found a coin. Somebody had dropped the equivalent of a penny in the...Which of course, you know, helped date the wreck. It had to be older than that, right? Yeah, I'd be newer than that. When you find a coin, it says 1900 on it. The ship wreck couldn't have been from before then. And of course, the coins, they have tremendous knowledge of the chronology of those and everything. They can date them by looking at them. Yeah. But again, just to make it clear, you'd love to find everyday objects from the crew, from the ship operation from even something personal. Obviously, it's emotional. But it's also, because, you know, that the thing about this is, we never forgot, certainly on the Titanic, we never forgot. And all the other shipwrecks certainly all the people on that vessel died. Yeah, they're graves, it's very unlikely that any of them survived out in the middle of the ocean in a storm. So you know, that never leaves you, even though it was 2,500 years ago, even more. And then I remember when we were searching in the Med, there would be places where you'd find amphora, amphora, amphora, and Ballard really learned to study this, and then there'd be the ship. And his interpretation of that was the ship was sinking. And so they were throwing cargo, trying to lighten the ship trying to save themselves. Yeah. And then there's the ship. And then sometimes we'd find a line of amphora. And there wouldn't be a ship at the end. They would say they made it. They made it. You know, they made it they save themselves.


Jennifer Berglund 19:46

Yeah, it's just so interesting how you, sort of, the many different ways you decipher that story, that sort of moment in history. And the catastrophes that were or weren't. So if you had to do that same expedition today, how would the technology, this is something you've talked about a little bit, but how would you do it now?


Dana Yoerger 20:13

We would be searching, rather than towing a sonar through the water from the ship, we would certainly have multiple AUVs that would fan out, each with the perfect sonar for that kind of search job. And we would be, rather than towing that one sonar along, our job would be to be servicing those vehicles. So watching them, recovering them, recharging them, putting them back in, and getting this whole kind of three-ring circus up and running, and then processing the data. Then you got options for the next step. So then you end up with all this list of candidate targets. You could use a remotely operated vehicle, or you can actually use AUVs to revisit them and get close-up data. The analog there is when they were searching for the airplane Air France jet that was flying from Brazil to France that was lost over the Atlantic and they couldn't find it. It was found with autonomous vehicles. And that's exactly what they did. They had three vehicles, all three were in the water most of the time, and they were systematically executing a search strategy. And then when they found it, they programmed the vehicle to fly down lower. They found something that looked good on sonar. So then they programmed the vehicle to fly over that much lower with the cameras running and they verified that they had. So you could do something like that. Or you could use a remotely operated vehicle, depending on your resources and what the capabilities of the vehicle were. The ultimate thing would be to have your vehicle smart enough that it would survey the area, and then it would pick the end best targets and go back before you even recovered it. They would say, look what I found. We're not quite to that point, but the Navy is developing capabilities like that, for example, mine countermeasures. And there's a lot of really interesting research about what the best strategies are to do that. Do you check something out whenever you see something that might be something? Do wait till the end, and then go back and look at the most likely things? Or... It's a complicated, there's a lot of issues there. But the obvious thing of every time you see something that might be interesting stop and looking at it, you may burn all your time looking at things that ultimately aren't very interesting.


Jennifer Berglund 22:12

Case in point, you had an incident like that on this expedition, right? Where you thought you saw a stack of amphora and what happened?


Dana Yoerger 22:21

It's hilarious. Yeah, I had drawn the four to eight watch, which, you know, normally when you're on the ship, we're operating a remotely operated vehicle at the time, Jason. And so normally we have three shifts, and whe're there four hours, then we get eight hours off in four hours on eight hours off. So and I do the four to eight. And I always do badly on that, because I never seem to get my sleep schedule. So kind of in a state of exhaustion all the time. We were checking out these targets, we had found them on the sonar, and then we logged in them. And now we're visiting and the anticipation as you're coming up on the target. With a remotely operated vehicle and a long cable things move very slowly, right, so there's anticipation, and you know, the targets way ahead, then you can kind of see the target on the forward-looking sonar, and you're getting closer to it. And then finally, you get the first glimpse of it with the cameras. And I distinctly remember, we came up on this target, it really looked like a good one on the sonar. And my first impression from the cameras was I literally saw a pile of amphoras. My mind, if I could take a photograph of what was in my mind, it was a pile of amphoras. And three seconds later, I realized it was a pile of garbage. Modern garbage. But my mind wanted to see amphoras so badly. I was so exhausted that, I like to say, if the screen had gone blank after that first glimpse that I had, I would have raised my right hand and sworn it was an amphora pile. I could only laugh at myself after that. Wishful thinking is powerful force.


Jennifer Berglund 23:47

It is it is. What about the recovery of the import? Like how would the technology be different today?


Dana Yoerger 23:54

So finding it has gotten much more systematic, because the autonomous vehicles are so much more effective, and we can operate many of them at a time. It's like painting the wall with four or five painters instead of one painter, you're going to be done a lot quicker. You got to manage four or five painters. It's a little, you know, there's some other problems there, but you're just covering the wall. Right? Yeah. And then to the extent that they're smart enough that they can go back and confirm what's interesting and what isn't, that's cool. The ROV technology has gotten more polished, but not in a breakthrough way. You'd probably pretty much still be doing it. The ROVs are bigger and more powerful, so they could bring more stuff up without using an elevator for example, that's a bit of a convenience, but you probably want the ROV to stay down so the elevator paradigm would probably still be enforced. You'd want to put the vehicle down shuttle the stuff that you recovered to the elevator and then have the elevator go up and down have the vehicle continued to work the wreck. You could have multiple elevators you know, it's all about being more productive with the time


Jennifer Berglund 24:57

So surveying technology has improved a lot.


Dana Yoerger 25:01

As we mentioned, the 3D reconstruction, you know, rather than having all of this exotic instrumentation, if you just fly the vehicle, the ROV or even the AUV, over the wreck in a very organized way, you can build beautiful, beautiful 3D models. It's art meets science, it's beautiful. And it's extremely useful.


Jennifer Berglund 25:22

Yeah, and I mean, how much of the stuff would you even recover today? Cuz I know what the Titanic I mean, it's a different thing, but, and people have recovered objects from the Titanic, obviously.


Dana Yoerger 25:33

Okay, this is a very important point. This is not my field, but I learned from smart people. When you're recovering something from an ancient shipwreck, you don't know where that ship came from, you don't know where it was going. You don't know what it was carrying. You don't know who was on it. You bring stuff back, you're contributing fundamental knowledge about the history of mankind. We didn't learn very much by bringing stuff up from the Titanic. That has what historians call associative value, as opposed to scientific value. And someone made the point, if you have a letter from George Washington where he tells you things about how he was thinking and what his strategy was that you didn't know, that's got historical value. If you have a pair of his slippers, that has associative value. You can sell it for a lot of money, because they were George Washington's slippers, but it doesn't teach you anything about how we won the Revolutionary War. The letter has historical value, the slippers have associative value. And I know that people who run museums hate the associative value stuff because they can't get away from it. And it's expensive to conserve, and they have to deal with it. On the other hand, it connects to the public in important ways. So it has, I'm not saying it doesn't have value, but it has a different value. So when we're recovering stuff from an ancient shipwreck, people say, 'Well, you know, you didn't want us to recover stuff from the Titanic, you recovered from the ancient ship'. Yeah, because it helped us answer questions about the history of humanity that we don't understand. We have the manifest from the Titanic, we know everything that was on it, you know. Bring back a plate from the Titanic, it only has value because it was on the Titanic. We have the plates that didn't make the boat, and we know everything about early 20th century plate making. There's no scientific value for bringing stuff back for the Titanic, it has associative value. And people can judge whether that's important or not. For me, I was privileged to work on shipwrecks where recovering the objects contributed to our historical and scientific understanding of the past. And that's, that's real. 'Oh, people from this port, we're trading with people from that port, at this time, using this kind of ship technology', that's historical value that's not associative value. So I think there's a big difference. We didn't recover that stuff so we could sell it, or we could sell tickets to an exhibit. We brought it back because we want to know who these people were and what they were doing and what they were carrying and understanding ancient trade. Or, you know, in the case of the Black Sea shipwrecks, which were very well-preserved, there's probably clues about how the ancients built ships. That's, that's fascinating. There's different reasons for bringing things up. And, like I say, I feel privileged that I got to work on these projects where, you know, our goal was to contribute to our understanding of history, not to bring something up because we could auction it off or sell a ticket for people to get in to see it.


Jennifer Berglund 28:28

What do you think was the most important thing you learned from that cruise?


Dana Yoerger 28:32

And the most important thing? Well, you know, there was the technological lessons of how my eyes could fool me, or, there was another one, actually, if you remember the map, where, the sonar map, where the vehicle is in a depression? So it's kind of like a crater. I processed that map over and over and over trying to make the crater go away, because I thought it was an artifact of my processing. And then, finally, I think it was my colleague David Madell said, "Well, you know, I think it really is in a bowl." So you know, learning to trust the measurements because it's very common that you have systematic errors when you're making maps like that. And you create artifacts of appearance, and one of the things would be some kind of radial symmetric corruption where you made the whole world kind of distorted, but no, it was real. Everything was right. So there were some lessons there, but the best lessons were hanging out with the archaeologists who were different from the archaeologists I'd sailed with before. They were biblical archaeologists, they were interested in stuff, like, from the Iron Age. They weren't interested in Classical Greek and Roman, in fact, they had a hilarious expression for that. They called that "post-interesting". Which I thought was awesome.


Jennifer Berglund 29:41

Not post-Iron Age, or, just post-interesting.


Dana Yoerger 29:45

Right. You know, they weren't interested in you know, and for us, you know, finding a Classical sculpture from the Golden Age of Greece or something, we'd be ecstatic, right? But they were like, yeah, I mean, we know everything about Classical history. We need to learn more about the Iron Age. So hanging out with those people was fantastic. You know, they were smart, and they knew all kinds of stuff they knew, like, four or five ancient languages. They were cool, you know, you had to worry about them falling overboard. They didn't necessarily have any operational, oceanographic sense, right. I mean, that was really cool. And I enjoyed that a lot. There was also some interesting dynamics, they were, like, if you hang out, if you go to an archeological dig, there might be some people around who are sort of more from the collector community than from the history community. And there's some dramas there, which I don't fully understand. But it's kind of an interesting point.


Jennifer Berglund 30:41

Yeah, that is, well, it's kind of like the stuff we were talking about earlier with the Titanic. And what's interesting, historically, and what's interesting,


Dana Yoerger 30:50

Interesting because someone will pay a lot of money for it, right? And oh and then we got to spend some time at some land digs and see how that process worked. I learned a lot on that trip. It was just a great bunch of people technologically, historically, archaeologically.


Jennifer Berglund 31:07

As a scientist and a technologist, how do you feel this expedition changed your understanding of trade across the Mediterranean in the ancient past?


Dana Yoerger 31:18

I came away with a deeper understanding that this endeavor that Bob Ballard had taken us on was going to bear fruit. Which, I sort of felt that going in, but now there was a lot more meat on those bones, if you will. And then, as the analysis came in, in the years after the expedition, Oh, those amphoras came from this clay pit in Lebanon or wherever, they were pretty sure they were going to this port, and they were carrying probably carrying this. We've done some analysis of the residue and the dunnage, the material that you pack in the hold of the ship. Turns out, there's information in that. They find out where they pick that, you know, it's some kind of brambly, brushy stuff, right? It's a technical term. But they analyze that. There's scraps of pollen, and there's residue of what was in the amphoras. And so I think that there wasn't any particularly stunning, okay, they were going from somewhere around Lebanon to somewhere around North Africa. Well, that's not necessarily a revelation. But the fact is that the methodologies were being proven. And of course, one of Ballard's other things was, there's lots of wrecks in deep water, because one of the criticisms of his work early on was, 'Well, no, we know they hug the coast, they're not going to find any wrecks and deep water'. Well, saying stuff like that before you look is kind of silly because, sure enough, maybe a lot of them hugged the coast. Some of them said, 'Well, you know, my uncle taught me that if you follow this star, or whatever for navigation, you can cut across, and you can save a week'. And so they had celestial navigation techniques, and whatever to cope with crossing the open ocean, at least in the Mediterranean. Well, we know the Vikings sailed to Greenland and Iceland and all the way to North America. People had impressive, I'm not even talking about the Pacific Islanders and their unbelievable ability to navigate the ocean. The ancients were far more clever about navigating in the ocean than one would think. But to me, the big thing was, we're bringing the methodology along. And the methodologies have evolved so much since 1999. I mean, there was a recent expedition in the Black Sea that actually a friend of ours, John Adams, was the chief archaeologist for. I think they found dozens and dozens of ships. They made these beautiful 3D renderings of them quickly, efficiently. We made pretty nice renderings, but it was at great expense with all of our brainpower out there. And, you know, students and postdocs, and, and now it's much more routine, and so more cost effective and the results are beautiful. So, it was cool to be part of that evolution, even if most of the methods that we employed are kind of obsolete at this point. You know, you got to start somewhere.


Jennifer Berglund 33:57

So cool that you've been a part of so many incredible expeditions, archeological scientific, you've just had the most impressive career.


Dana Yoerger 34:08

Sometimes I feel like I've just been so lucky. But you know, the old expression, the harder you work, the luckier you get. I think we earn our luck.


Jennifer Berglund 34:16

I think that's fair. Dana Yoerger, thank you so much for being here. This has been fascinating.


Dana Yoerger 34:27

It's been my pleasure, and I've enjoyed our journey back to 1999. Great fond memories of the people and the work and the beautiful places that we went.


Jennifer Berglund 34:42

Today's HMSC Connects podcast was edited by Amanda Fish and produced by me, Jennifer Berglund, and the Harvard Museums of Science and Culture. Special thanks to the Woods Hole Oceanographic Institution and to Dana Yoerger for his wisdom and expertise. And thank you so much for listening. If you liked today's podcast, please subscribe on Apple podcasts, Spotify, Podbean or wherever you get your podcasts. See you next month!