How Heather McKillop preserves Mayan artifacts with 3D printing
How do you discover ancient Maya artifacts buried underwater? And what do you do with the artifacts once you discover them? Heather McKillop, Thomas & Lillian Landrum Alumni Professor in the Department of Geography and Anthropology, presented her research on ancient Mayan civilizations during LSU’s Science Cafe in September 2017. We later sat down with Dr. McKillop, where she shared how her team has been able to study submerged Mayan villages, excavate artifacts and preserve those artifacts through 3D printing so we can better understand the livelihood of the Maya.
Learn more about what is happening with Dr. McKillop on Twitter @underwatermaya or by heading over to underwatermaya.com to catch the latest adventures in science from the DIVA lab! You can also watch Dr. McKillop's LSU Science Cafe Talk and see the incredible artifacts and locations where she conducts her research. (Transcript below.)
Listen to the full episode below, and subscribe to LSU Experimental on Apple Podcasts, Google Play, Stitcher, Spotify, TuneIn or anywhere you get your podcasts.
Transcript
Becky Carmichael
[0:00] This is LSU Experimental, where we explore exciting research occurring at Louisiana State University and learn about the individuals posing the questions. I'm Becky Carmichael. How do you discover ancient Mayan artifacts buried underwater? And what do you do with the artifacts once you locate them? Dr. Heather McKillop, Thomas and Lillian Landrum Alumni Professor in the Department of Geography and Anthropology, presented her research on ancient Mayan civilizations during September 2017's LSU Science Cafe. She presented how her team has been able to study submerged Mayan villages, and excavate and preserve those artifacts through 3D printing so we can better understand the livelihood of the Maya.
Heather McKillop
[0:49] My research—I have a website in case you don't want to listen to me and you want to look at some pictures, any more detail or videos—underwatermaya.com. And this will take you to our website. So anytime you want to check anything, you want more details while I'm talking, just get out your cell phone, get out your laptop. And we even have a 3D head scan of President Alexander on the website. It was approved by him. And we have a 3D printed replica of Dean Haney who was here. In the exhibit outside the diva lab in Howe Russell if you want to see her when she's in person, but if you don't want to talk to her, you just want to talk to a 3D printed replica. That's fine. Okay, so I want to talk about salt, I going to talk a little bit about my research, I'm not going to do any math, or anything archaeologists do with statistics and things. But we're not going to talk about that today. I want to talk about salt. And some of you may be on a salt reduced diet. And if a medical- okay, I'm a doctor, but I gotta tell you salt is good. But if a medical doctor told you to reduce the amount of salt, listen to them. But generally in a healthy individual, your kidneys moderate, regulate the amount of salt. If you have too much salt, they excrete it. If you don't have enough salt, the kidneys will hoard it. So you have enough. Salt is a basic component of the intracellular system of the human body. You need salt and I don't have to tell an audience in Louisiana about salt. Salt is also one of the four taste sensations on the tongue. It is a flavor enhancer. And it certainly is an important ingredient in the cuisine of Louisiana. So why do I say salt is so important? I have seen on my archaeological projects and some people can vouch for this, that there are- salt. Not enough salt, you get kind of achy joints. And if you're involved in sports, you may have experienced this achy joints, kind of weak and delirious a little bit. It gets worse from that on but I'm not going to talk about that. But yeah, I found if you just put a little salt in the Kool Aid, it perks them right up just like pouring water on flowers. So its, salt is very important. And one of the things that I have found is that the great ancient Mayan civilization, now I don't work here, I have been here. I took this picture at the top of one of the temples, temple one at Tikal. But the Maya, the classic Maya, Central America had great cities of over 100,000 people in the rainforest, but they didn't have salt. And so they needed to get salt. Some of their cities were over 100,000 people. So where did they get the salt? How did they organize the distribution patterns to make sure that they got enough salt every day, so they wouldn't get achy weaky-weak joints and, and feel delirious and ultimately die. So that's what my research is about. It was scarce on the coast. So where do people get salt? In general, if you're a hunting and gathering society, so let's go way back in time or go to faraway places like the Kalahari Desert in Africa, or the Australian Aborigines, hunting people generally get enough salt from eating meat in their diet. But once you get farming populations, and certainly ancient civilizations are founded on carbohydrates: corn, rice, potatoes, millet, barley in the various places in the world, and those are deficient in salt, so they need to find some extra salt. You can get rock salt, that's under Detroit. In the Maya area, you can get (came up) the Yucatan Peninsula, you can see an insert map here, which shows Mexico and Belize which is where I'm, my research in the larger map is in the southeast corner of Belize. And then it's adjacent to Guatemala and Honduras. But on the north coast of the Yucatan of Mexico, it's really hot and dry. It's arid, in fact, there's droughts out there, and they have solar evaporation of salt. But once you get farther south into the rainforest, it rains a lot. And you can't do that solar evaporation. And so they use a technique, which you see pictured here, from an artist reconstruction, of evaporating brine and pots over fires to make salt. This is very common around the world, from China to Thailand, to Africa to England. In modern times, right here in Louisiana, in fact, and so this was a way that they produce salt. This is Payne's Creek National Park, it's an underused park, this is a typical day in the park. No one's there. It's my, our whole research area is devoid of people during the day. It's a little bit of Import/Export activity at night. But we generally work in the day. And so we don't communicate with them. They know we're they though, of course. So I had written a book on three sites that we found underwater. "Salt, White Gold of the Ancient Maya". But I thought "Three sites, that doesn't really make an impact on the amount of salt that would have been needed." So I thought, "We need to go and systematically searched the lagoon to see if there are more sites." So I got a faculty research grant from the Office of Research and Economic Development at LSU, which allowed me to hire someone with a fast boat and you see my boat driver there, more than a boat driver, he jumps in the water and look at that big piece of pottery he's got. That's because the sites are underwater. And there's no one trampling on the sites and breaking up the pottery. It's on the sea floor embedded in the sea floor. So we were systematically walking back and forth looking for more sites and finding them. It's, it's kind of difficult, we're in the Caribbean, we've got rubber boots and bathing suits and hats and every step is like the Stairmaster. But we did find sites and we recorded them. Then we found an unexpected discovery, we found a peat bog in the eastern arm of the lagoon. Now some of you may know about peat bogs in Europe, where they find bodies preserved for 5000 years, perfectly preserved: the skin, the hair, the eyelashes, the fingernails. Well, we weren't going to find that because it's a different kind of peat. And also the temperature difference and the chemistry is a bit different. But we found a peat bog created by mangroves, red mangroves, you know the ones that grow in the water, in the salt water. And they are a proxy for sea level rise because as sea level rises, they grow taller to keep their leads above water, and they trap sediment and other leaves and things and that provides a proxy record of actual sea level rise. So we are rec- we record, we study the peat and we look at the relationship of the of the sites, which have obviously now been submerged by sea level rise. If the sea level rises too quickly, the leaves- the plants can't grow fast enough and they're flooded out and they die. And clearly, that's what happened here eventually. But when we first started, we didn't know. So we didn't find bodies. What did we find? We found wooden buildings dated to the classic Maya. You see here the photo of- that's, that's my uh... tired team. I'm taking the photos, someone has to do that. The first post we found- there's our group photo, and I'm, I'm big on taking photos of everything like 2D photos, not just 3D. So we radiocarbon data them. And they date to the lake classic, that's AD 600 to 900. And we found hundreds of them, we have mapped individually mapped, out over 4000. We have 110 underwater sites. It's a massive salt industry. It's really incredible. And it's LSU undergraduate and graduate students. And, and me and I've had other colleagues also working on the project. So the significance of this is, you saw that first picture that I showed you of Tikal with the stone temples. There's lots of Maya sites that have stone buildings in the center of the city. So that's what tourists see when they go to the Maya ruins. You see the temples, the palaces, but what you don't see are the hundreds and thousands of houses and workshops and storage facilities that were made of pole and thatch, like these modern- this modern Mayan village today in southern Belize. And you look here, and there's- there is a stone church. But that's it, all the other things would have decayed just like in Louisiana, where wood does not preserve normally. So we have the peat, which is very organic, and there's no oxygen to decay, the wood. And you saw the picture, it looked pretty nice, except it's waterlogged and full of salt. So I realized that we had to stop walking through the mud and destroying the sights. I also realized when my, I asked my colleagues, after I announced this at a conference "Did they think I was going to be able to get any funding?" And they said, "Oh, yeah, you're going to get funding." And I was- I did work hard. But we got funding and also got National Science Foundation funding to have a multi year project mapping ancient wooden architecture on the seafloor. And we had, we started a new technique of systematic survey, instead of pedestrian survey, we were traversing on research flotation devices, RFD, back and forth systematically. And if you can click the right image there, it's a movie that might come up. Okay, so here you can see, this is my first DVD. I'm standing in the water, imaging them, and it's like 10 minutes, 18 minutes per traverse, and they turn around systematically, mark things as they find them. And if you want to watch this movie, it's my all time most popular movie, maybe because it's my only really good one. But I have a lot. And so you can see this movie or a clip of it is on our underwatermaya website. So then we take the total station and individually map each artifact or each post and download the digital data at our jungle camp in the evening and produce- use GIS to display and analyze the material. And so here you can see on the top right, a outline- the post locations. And then what we did is we- this is GeoMedia by Hexagon Intergraph Hexagon, largest geospatial company in the world. And then we took GeoMedia 3D and extruded those 2D posts. And because we measured them, we knew the size, extruded them into buildings and then put thatched roofs on them. So if you press the, that's a video, it's a fly through augmented reality based on our actual finds using air photographs in GeoMedia 3D. So I'm pretty happy about that. So the next, then I got another grant with colleagues Dr. Karen McKeon, who's a mangrove ecologist, Dr. Harry Roberts, many of you know him, marine geologist at LSU. And Dr. Terry Winemiller, a former student, and we collaborated on interdisciplinary research, as well as a lot of LSU, current and former students. And so we did excavations, and you note that excavation tool of choice, if you know anything about archaeology, forget it, but it's an 18 inch stainless steel kitchen knife. One of the most important things to remember when you're excavating with such an implement is where it is underwater. And if you are excavating with someone you want to know where their big stainless steel knife is, but we're cutting the peat because it's solid. We also, Dr. McKee came down and we did coring using a Russian Peat core to reconstruct the vegetation history. And Harry Roberts had his tech design an automated research vessel, which came in parts and we brought it down, put it together, programmed it from the computer. And it was going independently, as you see here, across the lagoon, and getting sonar information of the sea floor. So that was pretty cool. And no one got to see it because this park is underuse. A typical day, there's no one there except us. So no one has seen that from the local area. So what do we have? We have an infrastructure of production. It wasn't that kind of beach party that you saw the beginning where people were wearing cute National Geographic outfits and making salt. No, it was an industry where people were, were making salt inside buildings where they could store firewood and the brine and the salt cakes. And this is based on a model from modern day salt making, this picture is from Sacapulas in Highland Guatemala. And so this is the model that we're using. And on the bottom you can see the briquetage, the broken bits of the pots. That's what we find, by overwhelmingly 90 to 98 percent of the artifacts that we find abundantly in our excavations are this broken salt making material. And we also found an infrastructure of transportation. At first it sounds like "Woah, one canoe paddle? Then you're going to call it an infrastructure of transportation?" Well, people were pretty amazed because no one had ever found an ancient Maya wooden canoe paddle. And so it was made of sapodillas, four foot seven, we exported it under temporary export permit, had it conserved at Texas A&M by a new polymer process. And before we returned it, we did 3D imaging of it. But we've since then found other canoe paddles, and we found a canoe. So there's, I think you're getting towards an infrastructure of transportation as well. Anyway, no one else has this evidence. And it's made of sapodilla, I actually have exported, under permit, a big piece of sapodilla wood, that's the chewing gum wood, to make a 3D replica out of wood. So we have two big printers in the LSU DIVA lab. But we also work with mechanical engineering, and we have done with our same 3D files, we can run the CNC machines. So they take a piece of wood and carve it out. So it's a exact replica driven by our 3D model. So we'll be taking that over soon, I need probably, need to pay them. So I'm looking for some financial support for this idea. So eventually, there was rapid sea level rise, which drown the mangroves and left the sites underwater until we came and recorded them and excavated and, and so forth. And what this has left us with is a conservation nightmare. The waterlogged wooden post, waterlogged pottery. You think "Pottery, well, its pottery. It's okay." Oh, no. The pottery dries, the salt comes to the surface, and just cracks everything and exfoliates it. And the wood, it dries and cracks and it's gone. So anything we take out of the water that we want to keep to study, or to 3D image, we have to keep in water. So anybody who's been to the archaeology lab, which I share with Dr. Chicoine over there, works in the coast of Peru. It's a Tupperware party with thousands of little plastic cheap containers with samples of wood and pottery, we desalinate them and have to keep them in water, or they will decay. So, and you see those nice sharpened ends of the post. So I realized that the way to study things was to do 3D digital imaging. And so I applied for a grant from the Board of Regents in 2008, with colleagues in the Department of Geography and Anthropology to start the digital imaging and visualization and archaeology DIVA lab, and I thought that name DIVA lab was catchy. And they went for it. But I think we've done well by the name. And so here's Roberto, he's in 3D, if you want to click that little white print, you can see him in 3D, and in 2D scanning, doing a 3D image of the canoe paddle. And then, despite the conservation, the paddle continued to deteriorate, it was cracking. So we called over the conservators and they were coming to Louisiana to see the people at the archaeologists at state of Louisiana, and they stopped by and they said, "It's just going to continue to deteriorate, you just have to put some glue in the cracks and fill it up." And at that point, I realized that our digital images were the record that was going to endure, because the actual artifact, despite the most sophisticated polymer conservation, which is really nice, that the artifacts are deteriorating. So we became very careful then with our research, quality 3D imaging. And over on, if you can make that movie go, you can see a CT scan of the canoe paddle, and you can see all the cracks, and you can see the shaft has kind of a peel on it like it's just exfoliating, it's just going to fall apart. And so I didn't tell that to the government of Belize. When I returned the canoe paddle, I just said it's fragile, here's a kit to repair it. So then we started scanning in Belize, we took our 3D scanners to the Belize. And here we are, you can see on the top left, there's one of my former students, Dr. Corey Sills is, is now an assistant professor at University of Texas at Tyler. Here she is in the field. And she's found something, she's holding in her hands a little boat model. And so we would typically, when we find things that are scan worthy we will say, "Wow, that's scantastic!" No, we don't say that, but uh, got your attention. Anyway. Yeah, I might say that on a bad day. So we put it in a bag of plastic- plastic bag full of water, take it back to our lab and at night. In the jungle, under a house with no walls infested with bugs using a generator, we do science, we do a lot of other kinds of science there too, with the portable XRF, and so forth. But we, we scan the things and then we no longer take things back to LSU unless they're really important and have to be conserved. We cache them in deep silt in secret places in the lagoon with permission of the governmentative police. And so, then we take our 3d models, our digital files back to LSU. And then sometimes we print them. So here on the top left, you can see that little boat model, we printed it. And then we sometimes print them bigger, so people can see them. And so we can, we can vary what we do. And here you see on the top right. This is a, the dimension elite. It's a big 300 pound printer that does ABS plus plastic, really high quality, we can control it really well. And on the bottom, if you can make that movie go with that pretty pottery vessel. This is a photorealistic 3D color printer. This is a 3D scan. But I brought a print of that pot that was supported by the... the 3D printers supported by the College of Humanities and Social Science. And we have wowed people at conferences, and visitors who come to the lab or I bring things here. So we're very excited. It also has weight, it's made up gypsum. So it's, it weighs. Some of you have, uh, took something's around, I went up to strangers and said- they weren't really strangers, because we're all here for the talk. But so I felt an affinity to them. I said, "One of these is real." And you can't see this, you can try the test later. But this one is real, I had to really think about it. This is heavy, these plastic things are really accurate. But behind the display case, they're really good. As long as you don't pick them up, then you say other plastic, they look great. But the gypsum has weight to it. And it also has texture. So you can feel the grains of the pottery. So it's it's very cool. And other universities, archaeologists don't have these printers. So everybody wants us to print things for them. They don't realize there is a learning curve, a steep learning curve, to this process. And we spend a lot of time, my DIVA lab scientists tonight, undergraduates, Masters and PhD students. So here's the- here's an image that shows... the dark brown one is the conserved original paddle, I want to take some photos before I returned the original to Belize, so I don't have the whole paddle, I just have the end, the blade to compare them. See the dark brown has been discolored, that was not the original color of the wood. And then to its right, we have a 3D printed plastic replica. And then beside that one, painted, it looks pretty good. And then on the far right, we have a modern canoe paddle. Based on my drawing what I thought it would have looked like, had it been complete when we found it. And I got a woodworker, friend of mine and Belize to carve it out of sapodilla. And then we put it in the water. And well we put a canoe in the water, we used it to paddle and it's perfect. And I can say that because I am a- I used to be a- don't look like a wilderness canoe guide. But I'm from Canada, if you haven't realized that, and I have a lot- I know about canoeing as most, most Canadians do, even those from Toronto, where I'm from. And then on the far left, you see one that's been, it's a piece of wood. This is a Cypress that I got from some friends and facility services who spent a lot of time in the DIVA lab, repairing the building. And so we, we do things, they gave me a piece of Cypress, so we tried it out. Now we wanted the original wood. So we'll see how that works. And then we have also made 3D printed replicas of underwater Maya artifacts for exhibits. And we've done these in Belize with support from the archaeological Institute of America, a site preservation grant. And we're going to be doing some more exhibits. We've done artifacts, and then one featuring a full size 3D printed replica of the canoe paddle. And we have hired someone to make display cases, and we have laminated information to go along with it. And we put them in public places so the people can see things. One interesting thing with this, we do strive for exact 3D replicas. And when we print, and people have told me, they've seen the canoe paddle, and they're thinking, the real canoe paddle, the one that no one sees, I gave it to the government of Belize and it's in the museum somewhere. It's... they haven't seen it, they've seen the- so I say "No, you saw the 3D printed replica?" "No, I saw the real one!" When does the 3D printed replica actually become an artifact? If it's in use in a culture? Can we just say that it's real, I mean, it is 3D. And it is actually accurate. And I know that there are the Smithsonian, for example, is making 3D printed replicas of headdresses that are used in dances by the northwest coast Indians, and, or First Nation people I should say in Canada. And... because some of them were lost, or they were broken, and they use them, and they they identify them as the real thing. So I think the, the edges are blurred between what is the real thing, and what is a 3D printed replica. So it's interesting to us, I should say, for display purposes. There's no commercial value on the international antiquities market. My artifacts, artifacts from many countries in the world, have a high value on the illegal antiquities market. And so these don't have that. They also don't require permission from foreign governments, of small community, like the place where we put these exhibits in Belize, they don't have to get permission. They can just, we can do it. I mean, I told the government, they know what we're doing. But they're not interested in the fact that they're, they're not real. So they don't, they don't care that we're putting them there. They think it's okay. And so this also makes things more accessible to the public, and gets people involved and they might protect our sites, which are just out there. And they do. They're very invested in them, because they can take people out in small boats for fishing and birdwatching and manatee and dolphin and snorkeling. And it adds value, puts money in the pocket of the small boat owners, if they can also take them to an exhibit in Paynes Creek National Park, and talk about the archaeology. So the through- the 3D printed exhibits have great meaning to us to help protect our archaeological sites. So I have to thank particular National Science Foundation. I've got another grant proposal pending. Along with Dr. Corey Sills. We put this NSF proposal in to look for places where they may have lived, where were the salt makers living, were they doing other things, there were lots of activities that were related to salt production. And we have, we have several big sites with multiple buildings and plazas that look more like Maya sites than just workshops along shorelines. So we've also got money, uh, grant money from archaeological Institute of America, National Geographic, and other sources including LSU office of research for a faculty research grant, actually two of them, and humanities and social science and, and a lot of blood sweat and tears from LSU students. So I will take some questions if anyone has questions. Thank you very much.
Becky Carmichael
[28:57] We met up with Dr. McKillop following her LSU science cafe talk, to learn more about her research, how 3D printing is vital for the study of artifacts, and what it's like to conduct research on submerged buildings.
Heather, thank you so much for sitting down with me today, you really gave a great
science cafe talk. And I've really been looking forward to kind of catching up on
some of the things that you, you discussed. And so one of the pieces that you shared
was about salt. And so salts one of those, that that flavor, were always, were always
thinking about, we always need. How has salt been so influential in civilization?
Heather McKillop
[29:45] That's a good question. Especially since, as you said, salt gives flavor. And in Louisiana, we all know that you need salt. And it's a flavor enhancer. And it's one of the four taste sensations on the tongue. So it's something that's very attractive to us. But it's also something- it's a basic biological component of the intracellular system of the human body. It's something that's very important, you need salt if you, if you're doing sports, or my team, if we're out in the field and Belize and I've had volunteers or students who say, "Oh, they're on a solid reduce diet." And but we have a very basic diet, in Belize and I see the effects of lack of salt, if you get kind of, weak and achy joints and kind of tired and so forth. And I've found if I just put a little salt in the Kool Aid, it perks people up just like putting water on a plant. So you biologically need it. And it is, it was very important for, historically and pre historically, for the rise of civilizations, because earlier with hunting and gathering people, they generally had low populations, and they got enough salt from eating animal meat. This is the, you know, cultural anthropology shows us this, that people who are hunting and gathering people, they- they have meat in their diet, and they're getting their salt that way. But when you have people who are... beginnings of farming and living in permanent villages, and growing things, all civilizations are based on carbohydrates. So that's the calories, in order to support large populations. And so you've got corn or you've got rice, millet and other other kinds of carbohydrates that don't have salt. And so it's at that point where people need it biologically, to get salt. So you get rock salt, you could get sea salt, or in the case of the research that we've been doing, which is very common all around the world, is evaporating brine in pots over fires. And what we found in Belize is that they were doing it inside wooden buildings.
Becky Carmichael
[32:08] Wow. So you finding this out, not only were you finding maybe the residue of salt within pots, or you can kind of, could you find it in the pots? Were you also finding it in the wood is as an operating in these wooden buildings?
Heather McKillop
[32:21] Well, because our sites are underwater, everything is, and it's under salt water, everything is salt water saturated. The pots have salt, salt water in them from the salt water, the wood is saturated. But it's not the salt that was used. We don't have any, actually, traces of salt. So yeah, I've written all this and talked all about this. And there's no salt. I mean, there's no salt residue.
Becky Carmichael
[32:47] So then I wonder how, what- what were some of those clues that led you to how they were collecting and... how they were collecting, this process that they were going through?
Heather McKillop
[32:59] What do we think this as opposed to something else?
Becky Carmichael
[33:01] Yes.
Heather McKillop
[33:02] How do we interpret it?
Becky Carmichael
[33:03] Yes.
Heather McKillop
[33:03] That's a very good question. Because, well, first of all, there's a real redundancy of the kinds of artifacts. So it suggests that there was, they were focused on some kind of activity. Bowls and jars from poorly fired very fryable pots, and then these pot legs, just massive amounts of them. We found in our excavations, you know, up to 98% of the artifacts are this briquetage, this, this, this specialized pottery. And so something was going on. And it was really through ethnographic analogy, comparison with modern day and historic people around the world, from China to Germany to Africa to North America, the same process is used, which is putting brine, usually not just salt water, but you enhance, you increase the salinity, because then you use less firewood. But you're evaporating brine in pots over fires, and you might have 20 or- 20 or more pots over a fire and you pour the brine in and it evaporates with the, with the fire. And then you've got salt, or you can harden it further into salt cakes. And, and you can trade it then. So it's, so it's really the redundancy of the artifacts and the fact that the, you may have heard of Three Gorges Dam in, in China. Well, when- before they built the Three Gorges Dam, it was on top of a, there was an ancient salt works there. And so my colleagues who, from China and from UCLA who excavated there, they, they found pots very similar to what we have in Belize.
Becky Carmichael
[34:55] Oh, that's interesting.
Heather McKillop
[34:56] So it's a technology that's used around the world.
Becky Carmichael
[35:00] A technology that's common for once you start having those civilizations, in order to- getting that.
Heather McKillop
[35:04] Yeah people need, they need to find salt from somewhere.
Becky Carmichael
[35:07] That's interesting. So on that same line, as you've been doing this research, can you tell us a little bit about maybe your, your most unexpected discovery along the way?
Heather McKillop
[35:22] Well, I'd say we, my team is the master of unexpected discovery. I've used that in PowerPoint presentations, along with sparkly music to go along with it. But clearly the first unexpected discovery was when we first found a wooden building post from, from a building. Because we were working in a tropical landscape in the water. I knew there were salt making artifacts, because I'd already researched and we found lots of pottery, and I've written a book about it. But we hadn't found wood and we weren't looking for wood. Archaeologists don't find wood, except in rare cases in, in the rain forest because it decays. So dry caves or the tops of temple buildings where it's very dry, they have some beams. But in the setting we were, everything just rot. So we were walking through the water. And I had a team. And we were looking for this broken salt making pottery. And we came across just wood in the water. I mean, we're in a swamp. It's like walk Louisiana, there's stumps from Cypress, there's a stick in the mud. And so, you know, we're finding these things, but just on the seafloor. And so I said, finally I said "We're going to excavate one of these." And if it is a post, it's going to go straight down, it's going to be sharpened at the end. If it's a tree root, then it's going to branch out or if it's just a stick, it's going to, you know, go off on some weird angle. And so we were ill prepared for excavating, we're about up to our waist in water. We had no equipment, had a camera, and a measuring tape, and a notebook. And we had some plastic bags and some buckets to carry things that we found. And so we ... and a sharpie, of course.
Becky Carmichael
[37:22] Always a sharpie.
Heather McKillop
[37:23] So my technique was to take a few breaths, exhale, dive down, hold on to the seafloor and dig around the post, and my boat driver liked that. One of my, then a volunteer later came to LSU as a student, he liked to be held down underwater. And he did away until he starts thrashing. And he trusted that we would let him up. And I had a graduate student, he just didn't want to do any of it. But after a while it became loose, whatever it was, and I pulled it out of the water. And you can imagine the waist deep water. Finally it's coming straight and then end of it and it's pointed. And I said "It's a post." And then we started looking around, we found posts everywhere. That was site 15 that we had found, that was 2004. Site, site 15. And I'm like, Well, what about site 14 and down to 1 that we had already found and no wood? So we went back to site 14 and found the paddle, the canoe paddle. The most unexpected was the wood because we're not supposed to find it. And I had written a book, Salt: White Gold of the Ancient Maya, no wood. So we eventually went back to those sites. And there's wood everywhere.
Becky Carmichael
[38:36] Oh, my goodness.
Heather McKillop
[38:37] But it's... to me, it goes to the nature of scientific discovery that, you know, we are embedded in our culture and, and the knowledge that already exists. And so I had a hypothesis, I had ideas, and we changed them based on what we found. But we never expected to find wood. And so we weren't looking for it, I have to say in our defense, it is very hard to find. And, and you could go there and never find the wood. I mean, the sites themselves are underwater and no one's, you can't see them. And the water is murky. So and there's silt about the seafloor. So it's not a Caribbean vacation. Although we refer to it as the Caribbean vacation. It looks nice on the surface.
Becky Carmichael
[39:20] So tell me, since we're at this part of talking about your site, can you describe that for our listeners? What, where is it? You know, how remote is it?
Heather McKillop
[39:33] Well, I've been working in Southern Belize, used to be British Honduras, it's on the eastern side of the Yucatan Peninsula, the second longest Barrier Reef in the world is about 25 miles offshore in this area. So we're not really near the reef. And it's a mangrove, classic mangrove ecosystem. And so I have excavated at a number of sites, Wild Cane Caye, Frenchman's Caye and done survey, and we did survey, since I found evidence of sea level rise by excavating on islands where the deposits were. Archaeological deposit continued well below the water table. I knew that I said, I thought well, shallow areas in the water, actually may have been on land as well. So we started looking in shallow areas, and we went into a coastal lagoon nearby and, and just were looking over the side of our boat to find sites, to look for artifacts on the seafloor and found them. And this, but it's very remote. It's 30 miles from the nearest town. We, there are no roads. There's no float planes allowed in Belize. There's no people. Once we leave Punta Gorda, this, the capital of the Southern District, which is pretty remote itself. There's still people and we have, I hire a boat driver. And we go out and we stay with the only people who live in the whole area. There about midway between Punta Gorda and our research area. And we stay with them, they're our host family. They have an organic chocolate farm, which is pretty nice. Although, you know it doesn't, it's not chocolate bars, it's the cacao pod, so it's not processed or anything and still growing. But so then we go, we go each day by boat, small team, and no one around another 15 to 20 miles farther north to a national park Paynes Creek National Park. So we call our sites, the Paynes Creek Salt Works. And they're all underwater, you can't see anything. It just looks like water. And we generally have used research flotation devices to systematically go back and forth. And it's a very slow process and look for things and feel for things on the seafloor, individually map them or mark them, and then map them and produce maps using Geographic Information Science, and then we've excavated as well.
Becky Carmichael
[42:22] And so a couple things. So the float, those research flotation devices, they look, they look like a kind of a large mesh, kind of floaty, like you would just kind of lounge on in a pool.
Heather McKillop
[42:34] That's exactly what they are.
Becky Carmichael
[42:35] And that is awesome. I like that you, they're getting uses.
Heather McKillop
[42:39] Yes (Laughter). However we call them- in the literature they're known as RFD's. Research Flotation Devices.
Becky Carmichael
[42:47] I like this name "Research Flotation Devices." And one of the things that we had talked about before starting our interview was the type of peat where the wood has been found. That's, that's within these mangroves. Can you talk a little bit about why? Why that makes the finding of this wood even add to the excitement of being able to find it, too.
Heather McKillop
[43:17] Yeah, well, the wood, the reason that the wood was preserved was because it, like, if wood is in the sea. And anything that, any of the wood that was above the sea floor, is all wormy and decade. But where it hit the seafloor, from the sea floor down, it's perfectly preserved in looks just like modern wood. But if you feel it, it's waterlogged, and it's wet. And it's been perfectly preserved because of red mangrove peat and the lack of oxygen. The mangrove peat is, we don't have them in Louisiana, but in Florida, you have the red mangroves, or the mangroves that are in the, in the salt water, they have the prop roots. And they are a proxy for sea level rise, actually. And we've used them as a proxy for sea level rise. So sea level as the red mang- or as sea level rises, the red mangroves grow taller, because they have to keep their leaves above the water. And so as they grow taller, they trap whatever is around, usually the organic matter from the leaves. And the growing small, fine mangrove roots and any, anything that happens to come by, will be trapped in there. And, and built up. And so if, for example, near where we work in the lagoon system between the reef and mainland, there's as much as 11 meters that's like yards, 11 meters of mangrove peat from the sea floor down to the bedrock. That is a proxy for the sea level rise since the last place here. So what, with the mangrove peat? It not only preserved the word and we've actually mapped 4042 pieces of architectural wood.
Becky Carmichael
[45:18] 4042.
Heather McKillop
[45:20] Individually map 4042 pieces, like wooden post. Some of them are wedges for post, some of them are horizontal beams, but we've individually mapped. And we've got, they marked the outline of wooden structures. And we have lots more at- 30 more sites, but we haven't actually mapped them because they're either too remote or the waters too deep for us to, to map them to this point anyway. But we've also investigated the peat itself, because I'm, I've read, I know the literature, that it's a proxy for sea level rise. And so because, I've said a few times, our sites are in the water and the Maya didn't live underwater. They lived on land, and these sites were on land. So you know, why are they underwater? Did, were they just stuff that was thrown in the water? Did- was there tectonic activity or earthquakes or something, or just sea level rise. So we've actually... the first time we, we actually dug a hole in the seafloor and had a face and a straight wall, a meter and a half from the sea floor down and every 10 centimeters, which is about every four inches, we would take a cubic... 10 centimeter piece of mangrove peat and it's solid. We cut it with 18 inch stainless steel kitchen knives. So you cut it, and it's just sitting there like a piece of German pound cake although it doesn't taste good, and so- and it's kind of smelly, but so we sampled those, we'd take them, take them back. And so, so we had 15 samples going down. And so with, with those mangrove samples, and we um, we took little samples from the- took- started from the top and the bottom. And we burned them in a muffle furnace to see how organic the samples were, we found they were highly organic. And then we took another little sample from the same location, looked under... took all the dirt away and or settlement, and looked under a microscope to identify the plant material. We found it's overwhelmingly fine red mangrove roots.
Becky Carmichael
[47:45] Oh wow.
Heather McKillop
[47:46] Which means it is technically scientifically red mangrove peat and we had a meter, we, a meter and a half of red mangrove peat, a proxy of a meter and a half of sea level rise. Then we took those red, some of those red, fine mangrove roots, and sent them for radiocarbon dating by accelerator mass spectrometry and got dates. And then we filled in the blank. And so my students, subsequently at other places, have replicated this to try to see what's going on in the lagoon system.
Becky Carmichael
[48:25] And how much, how much sea level rise and approximately when that occurred.
Heather McKillop
[48:29] Yeah, when it occurred because we wanted to know did the maya build these wooden structures over the water and... or were they built on land and the sea level rose and from all evidence that we have they built them on land. And the sea level rose subsequently. And at some point sea level rose too quickly for the red mangroves to keep pace with them and they were drowned. And so that means there now- and that happened sometime after about AD 1200. Because we've got radiocarbon dates up to about that. And then the sites are underwater. So you go there today and you don't see anything. It's one of the, the best places for fly fishing in the world. So high end, fly fisher people come to this area occasionally, they're brought by a fish- people from a fishing lodge or from, you know, from nearby ,well from Punta Gorda area, for fly fishing and so occasionally when they don't find any fish, the tour guides, the boat drivers, they bring them over to see what the archaeologists have found, and he let them touch the post. Touch a 1500 year old wooden post.
Becky Carmichael
[49:48] And I think that that's exciting. I think that the, this piece that you are... have discussed about this approximate- the proxy for sea level rise. What's happened to this, this mayan civilization, it... it's telling in terms of what we've seen- you're seeing and showing from the past and potentially what we're seeing from future, see that projected sea level rise particularly around areas where they are coastal communities, areas that have similar mangrove ecosystems or just mangrove ecosystems as well. Um...
Heather McKillop
[50:27] Yeah, I mean it is, it's it's it's a kind of a sobering reminder of place- low lying places around the world, cities around the world from Miami to Belize City and elsewhere that are subject to global climate change and rising sea levels. I do have to say that in many cases, and we know this from Katrina, but we also know it from, I know it from my research in Belize, the sea level was rising but not all sites in the, in the area were abandoned. One thing that we're trying to figure out right now, it's got ongoing research, is the- a lot of these salt work buildings, these sea salt kitchens appear to be, they're in lines and they may have been along ancient shorelines so that when the sea level rose, they abandoned those and then just move farther inland away from the water to- and built, built them along the, you know, inland and to- and so we've got several lines of these. And then there's a very close, a very nearby trading port Wild Cane Cay that was not abandoned. But it's right there and then it's also subject to sea level rise. But they built stone foundations for buildings in, you know, after the classic periods. We're talking the salt works date to the classic Maya period. The height of the, of the civil- Mayan civilization with sites like Tikal that you know, if you've seen Star Wars movies or some people who've visited Guatemala, they see- or Belize or Mexico or Honduras, they've seen these beautiful stone temples in the jungle. There are beautiful stone temples in the jungle. Most of the people lived in wooden structures which haven't preserved, but we have them and they all needed salt. And they didn't have it. But Paynes Creek salt works and other similar salt works had it.
Becky Carmichael
[52:20] Yeah.
Heather McKillop
[52:21] So it's a, but after these sites were abandoned, and the civilization, the complex political economy of the classic Maya deteriorated, and you know, rose somewhere else in the northern Yucatan. A lot of sites like Wild Cane Cay was a major trading port. After that they tied into the coastal trading system around the Yucatan. But, so they adapted and they were subject to the sea level rise. Another nearby small island Pelican Cay. We, they didn't survive. They were dated the classic periods, it was a little village site. And I went there looking for the site. We didn't see anything on the surface. I did a shovel test and 40 centimeters below the surface. We found classic Maya, midden or garbage. So there was, so then we came and excavated. The whole site is underwater.
Becky Carmichael
[53:23] So when you say classic Mayan garbage, but what would have Mayan, what would Maya...
Heather McKillop
[53:26] Well broken pieces of pottery, yeah, stone tools, food remains...
Becky Carmichael
[53:32] Oh, you could still find food?
Heather McKillop
[53:34] ...fishbones...
Becky Carmichael
[53:34] Oh food remains, fish bones...
Heather McKillop
[53:36] Yeah so we have cohune nuts. Here's some cacao. We found cacao at Frenchman's Caye.
Becky Carmichael
[53:42] Oh, wow.
Heather McKillop
[53:44] This noise is me giving you some cacao seeds. You've got... you can give these to your kids. This is raw cacao without the sugar. But we've also got other plant remains. This is a mammee apple. This is the seed.
Becky Carmichael
[54:01] Oh, interesting.
Heather McKillop
[54:02] This is modern but we found prehistoric ones.
Becky Carmichael
[54:05] So you, so kind of doing the shovel test, this was able to extract and locate, either like you said, fish bones, the pottery and once you're seeing this all in collection, you're getting an idea. Civilization was there but this is underwater. You had this other space that had the stone.
Heather McKillop
[54:24] They decided they, they built stone foundations for their buildings. And at the salt works. What we think happened, well around- along the side of many of the places they have lines of Palmetto palm posts, long lines so there might be 100 of them closely placed together which I think we're used to shore up the sides just like they use them today in Belize. Yeah, they're water resistant and so they may have been trying to keep the sea out just like in New Orleans, they are pumping the water out. Or in Belize City, you know they're. It's also slightly below sea level. So there is a resilience to people living in these coastal areas. But it doesn't always work out well. The people at Pelican Caye, maybe they moved, hopefully they, they got on their, their little paddling Dory boat and came over to Wild Cane Caye and uh...
Becky Carmichael
[55:22] Participated in the trading culture.
Heather McKillop
[55:24] Yeah, yeah, yeah.
Becky Carmichael
[55:25] There's a lot here I think that could be reflected on and look at adaptations, how people adapted...
Heather McKillop
[55:33] That's right, that's what very- how people adopt or don't adapt, the complex interplay between human environmental factors and human adaptation is what we look at a lot.
Becky Carmichael
[55:44] And I think it's fascinating that all of these things could be found either by, you know, kind of peering in the water, getting in the water, but then also what you're finding both on land as, as in your sites. Um... because you're in a remote area and you are in the water. You're in a lagoon, you're in a national park, you said at one point, there's not very many visitors. Would you share what was the weirdest, the craziest or the most dangerous thing you've done in the name of your research?
Heather McKillop
[56:18] Well, unexpected things happen a lot. One time we, we went to attend field school, I took students, I had a sabbatical, I went to Frenchman's Caye and we lived on an uninhabited Caribbean island, Frenchman's Caye for six months, we didn't vote anyone off the island. It was beautiful, we lived there. We had a water tank. We brought in our, our water, all our food. We, we could swim in the sea. It was really wonderful. I had an archaeological field school. I had volunteers come down. And then on Sundays we, we have the day off and some people will do their laundry or go swimming. And occasionally, sailboats like yachts come nearby, and they would- more at the, an island nearby. And so one time, I said to one of my graduate students, we had two boats, we have two, we had two boats at a time, one 32 foot dugout canoe made of mahogany with the 20 horsepower that I drove and another 24 foot dugout canoe made of another hardwoods called Santa Maria, again, with the 20 horsepower engine on the back that I'd have one of my graduate students drive. And we always travel with two boats, because then if one broke, boat broke down, you had you could tow the other one, you could tow the one that had broken down. And we also had two meter radios, so we could call. We set up a two meter radio station on Frenchmen Caye and we had a portable one in our boat. And so we're pretty much into safety. But I said to one of my now former graduate students, Melissa. "I see the yachts maybe they have some ice, do want to go and check it out?" And so we each got in a boat. So here am I driving a 32 foot dugout canoe. It's painted Fiesta blue on the inside and white on the outside. And I had a bandana, red bandana over my hair. I was wearing dark glasses, gold hoop earrings, and shorts. And I had a machete like this without the case. This big blade stuck in the side because you know, you need a machete. In case, I don't know, something happens. And so Melissa, my graduate student was in, a former graduate student, was in the other boat and we're making a b-line to these yachts. And we're like, "maybe they brought ice, we could just talk to them, we've been remote and isolated." And so as we approached, they all started going inside their boats and closing down the hatches. And we circled around and I realized they thought we were pirates.
Becky Carmichael
[59:07] (Laughter) You scared the heck out of them.
Heather McKillop
[59:10] We did. And we just wanted ice. And then we did hear, you know later that, there were reports of pirates in the area. And there are pirates in the area. I used to sleep near the boat I had, the Adele II, and I had another graduate students sleep near the other one. And I had a machete beside my bed and a flare pistol.
Becky Carmichael
[59:37] Oh, wow.
Heather McKillop
[59:38] And I, all of the sudden, my dog tiger, who just roamed around the island. And so I would listen for anything. One time at Wild Cane Caye, another island where I first started excavating down there. Tiger, I got Tiger there. He's from Belize. When I came to LSU I had a dog named tiger, which is kind of interesting. But Tiger would follow us around and no one could come on the island. He would just, he was a really good watch dog. And so at one point, I heard, heard some voices. Someone had gotten on the island plus because they were they were downwind. And suddenly the dog heard them and he ran after them. And so I got up, left the excavations and ran after the dog. And so I got to the place where the dog was, and the dog was barking and looking up. And there were two guys, each up a different coconut tree.
Becky Carmichael
[1:00:37] Oh, really?
Heather McKillop
[1:00:38] So the story. So I put the dog on a leash.
Becky Carmichael
[1:00:43] Yeah.
Heather McKillop
[1:00:43] But the dog would run into the water and bark aggressively at any boat that approached. And so we well, there was one scary time, I guess that, those are just stories. But there was one time, a couple of scary times, when we were, ah, I just had one boat. And we're going to the, we had been at the lagoon. We're right beside Wild Cane Caye. We're going back to Frenchman's Caye. And I saw this big boat coming directly to us. And we're in the middle of nowhere. And we're a small boat. And this is a big, big boat going fast, coming directly to us. And so I don't know what you would do in a situation like that. But I decided the best defense is an offense. So I turned our boat around and headed directly towards it. And so they had to move out of the way. And apparently, I discovered, it was the Coast Guard and their generally twenty five miles offshore. They don't, you know, they don't come into these waters. And so the captain came up beside, it was like a 35 foot, big skiff, with two 200 horsepower engines, big boat. And they're all in military gear, camouflage. And he came up and he said, "Where are your permits?" Well, I wasn't going to tell him. I didn't have, he didn't, I wasn't going to show him my permits.
Becky Carmichael
[1:02:09] Yeah.
Heather McKillop
[1:02:10] And so I said, "You don't know who we are, do you?" And then I said "We're the archaeologists who stay on, on Frenchman's Caye." I mean, I had a permit for the boat and I had my archaeological permit.
Becky Carmichael
[1:02:24] Yeah.
Heather McKillop
[1:02:25] And eventually it came out that he was lost and they were looking for directions. And only later did I find that the people, the guys at the front of his boat, had submachine guns and they had them pointed at my team. Oh, yeah, I thought that was a little unsavory.
Becky Carmichael
[1:02:41] That. No, that's...
Heather McKillop
[1:02:42] That was unacceptable.
Becky Carmichael
[1:02:43] Unacceptable. And yeah, unnecessary.
Heather McKillop
[1:02:45] Yeah. unnecessary. So we had the, I guess it was the Coast Guard or some people arrived in they had a big boat on, near Wild Cane Caye and they came in in a rubber dinghy and they all had plastic raincoats and black submachine guns. So I picked up Tiger and pointed him at them.
Becky Carmichael
[1:03:08] Uh huh.
Heather McKillop
[1:03:08] They wanted to know who the owner of the island was. So I I took them to the house and there was this old lady, Adele - our boat was named after her, the Adele II.
Becky Carmichael
[1:03:16] Uh huh.
Heather McKillop
[1:03:17] And I said, before they entered the kitchen, I said, there's an older lady in here. I think you should put your guns down before you go in there. So they did, I mean, they were a little embarrassed. But, they, ah, they were looking for people who were trying to illegally enter the country, apparently.
Becky Carmichael
[1:03:39] Oh, wow.
Heather McKillop
[1:03:39] They didn't tell us that. They don't tell you anything. But I said, how would you like to have a tour of the island? So I toured them to the excavations. That's a really good way to get rid of people is to describe your excavations, and especially in an insect infested location.
Becky Carmichael
[1:03:55] Let them stand in there for a little bit. Let them get bit.
Heather McKillop
[1:03:58] They were, yeah, sand flies. Mosquitoes yeah. So so they left. They, I think they wanted a bribe, but I wasn't gonna give it to them.
Becky Carmichael
[1:04:07] Yeah.
Heather McKillop
[1:04:08] So we have ter- we have some other stories like the time we were attacked by the British Navy.
Becky Carmichael
[1:04:12] OH MY G-!
Heather McKillop
[1:04:13] Or the time when green vine snake started falling from the bushes while we were mapping on another island. I have described, so I wrote a book called In Search of Maya Sea Traders, which I wouldn't talk about to anyone until I sent it off. And my editor said it was reflexive archaeology. But I tell, it's about the archaeology we did, principally at Wild Cane Caye, but also the story about doing archaeology, because I've worked with students and volunteers a lot. So you get the experience of what archaeology is like.
Becky Carmichael
[1:04:50] So you've had you've had these dangerous, weird, crazy experiences throughout your career, it sounds like. What keeps you coming back to doing this research?
Heather McKillop
[1:05:04] Well, I like discovering things. I like working on the water. I like Belize. I like swimming, snorkeling, I like finding things. We've got spectacular remains. So we have, we have the only wooden architecture from the Maya area. And we have tons of it. We have such incredible preservation. And we have occasionally, you know, unusual finds like the canoe paddle. And then we found other pieces of, broken pieces of canoe paddles and, and other wooden artifacts. And because the sea level rose, and there was no and traveling over the artifacts, the art, the pieces of pottery are big. So that we can, we can actually see what things were as opposed to the little bits and pieces that don't, it's hard to interpret. So the finds are spectacular, and unusual, and I, I like the jungle and I'd like the sea, I like being on the water, I grew up in the water. I like, I feel confident in the water, although I respect the dangers of the sea.
Becky Carmichael
[1:06:12] And I think that you've encountered several of those with this, with your particular research.
Heather McKillop
[1:06:17] Yeah but I think one of the things that I always tell my students is that the number one thing is safety. And we have, we have a lot of safety rules. So my students, often I think, feel like "Wow, this is like everything is just natural", well it's very controlled. I mean, we- I have a cell phone, which actually is at home, that only works in Belize, and I, I call back every, every day at noon, from the field to our host family, they have a, they have a phone with an antenna. And just as a radio check, just as a safety check. And if I can't reach that I'll call someone in town. So we, and you know, we have, we're very regular, in what we do, and we drink a lot of water. And we eat a lot of salt. (Laughter) And we have a lot of fun.
Becky Carmichael
[1:07:15] It sounds like it. I, I'm very excited that you, you sat down with me today, you've shared your story about the work, and the importance of this type of research. I also want to thank you for showing me around the DIVA lab, you've got some really remarkable prints that you've captured from the different artifacts. I'm, I think that I would encourage others to kind of come by even the disp- and see the displays that you've got outside of the DIVA lab so they can see the detail that's been able to be captured from these 3D prints and the scans that you've done.
Heather McKillop
[1:07:54] One of the things we, I realized with the canoe paddle, and with the other things, we, I wanted, the reason I got into 3D imaging, was so as I wanted to have a research record, because the artifacts decay, everything saturated with salt water, and if you dry them, take them out of the water, they start to dry out decay, or with the pottery, the salt comes to the surface and exfoliates and destroys the whole thing. So if we make a 3D scan, then we could study it, what I didn't realize initially was that the the 3D scans are actually the record that is going to endure because even though, like the canoe paddle, which I- we had professionally conserved at the, one of the best places for conservation at Texas A&M, it continues to deteriorate because there were cracks in antiquity that were there. And so it's going to continue to crack. So what we have in the 3D scan is actually the record. That is, it's, so it's more important than I thought. Also I should say, encouraged a lot of women, students, undergraduates and graduate students, and I'm collaborating with a former student, now he's assistant professor at University of Texas, Tyler, and continuing the research, and that we do science.
Becky Carmichael
[1:09:23] I completely agree. It's nice to, when you see other women in science doing a range of science across the many disciplines and, and then when you see them collaborating across disciplines to really tell a story about what has happened in the past and do this projections for the future. Heather, thank you so much for sitting down with me today. It's been a pleasure.
Heather McKillop
[1:09:48] Well, it's always great, you know to talk about research. And it's a great time for the end of the semester.
Becky Carmichael
[1:10:00] This episode of LSU Experimental was recorded at the Varsity Theater in Baton Rouge, Louisiana, near the campus of Louisiana State University. LSU Experimental is supported by LSU's communication across the curriculum, and the College of Science in collaboration with the Office of Research and Development. Today's interview was conducted by me, Becky Carmichael and edited by Kyle Sirovy. Theme music is “Brumby At Full Gallop” by PC3. To learn more about today's episode, subscribe to the podcast, ask questions, and recommend future investigators, visit CXC that LSU.edu/Experimental. And while you're there, subscribe to the podcast. We're available on SoundCloud, iTunes, Stitcher and Google Play.