Unearthing Secrets of the Past (Full Episode) - Drain the Oceans - National Geographic

Alaska is a frontier. It's a powerful place. In the 20th century, it was oil. In the 19th century, gold. But this land lured fortune seekers long before then. Caves are super important to understand a civilization like the Maya. I'm going deeper and deeper and deeper. Before I knew I was 35 meters below, the first thing I saw is this skull. It was staring at me. I think that we're closer to uncovering the truth of the age of dinosaurs than we've ever been. My first exposure to dinosaurs was probably the Flintstones, which is not a very accurate portrayal of dinosaurs. You know, like all kids, I was sort of immersed in this dinosaur culture. I've always been fascinated by the biggest, the smallest, the highest flying, the lowest diving. That's where you really start to learn the limits of evolution. I wanted to find creatures that were among the largest to ever walk the face of the earth. Usually the largest dinosaurs are also among the worst preserved, because it's so hard for a creature that size, the size of a house, to become a fossil. There's a group of plant-eating dinosaurs called titanosaurs that we know relatively little about. So I was very attracted to finding one of those. How do you find a dinosaur? It's the number one question I get asked. The world is geologically mapped. And so to find dinosaurs, you have to find rocks from the Triassic, the famous Jurassic or Cretaceous period. I'm looking for the green colors that are Cretaceous age deposits, rocks that are at least 66 million years old. There are some rocks here, but this is the Congo Basin, too many plants here. Northern Patagonia, rocks of the right age, but quite a bit of work has been done here. But here, down in southern Patagonia, we have everything that I was looking for. Patagonia is an amazing place. Vast, sweeping landscapes. Sometimes it's called Fin del Mundo, the end of the world. It's the last stop before Antarctica. This is the field area and you get yourself on the ground and you walk and you just look for bones sticking out of the rocks. That year in 2004, we were about a month into the expedition and we hadn't found anything that I would say was really great. So at this point, the pressure's on. You start to worry. We had a week left and then finally we found something. A piece of bone exposed. It had weathered out of a cliff face, so it was super easy to excavate. So it doesn't take us long before we uncovered a very, very large femur. 2.2 meters long, that's about seven feet, one inch long. We know that we're looking at one of the largest dinosaur bones that had ever been seen. This was an incredible result. But where are the rest of the bones? We dug and dug and dug around there, but there wasn't another bone to be found. But still, that told us giant dinosaurs lived here. And that was enough for us to know that we had to come back to this place. A year later, I was ready for a return expedition, but I needed a bigger team. And I called up my friend, Matt Lamonte. This was somewhat of a professional gamble, I would say, for Ken. Ken, in a lot of ways, was putting all of his eggs in one basket. I think that there was some pressure upon arrival that second year in 2005. We're not there for a month-long vacation in the desert. We're there to find dinosaurs. On the first morning, I was prospecting for bones and saw a dinner plate-sized piece of bone exposed in the desert. I GPS the location, I give it a field number, and I move on and I start to prospect for some other sites. This is 2005, so I put on my iPod and put on some heavy metal. And I walked basically up the side of a mountain, thinking that I was going to find the next big thing. But I turned around when I got to the top of the mountain, and I saw my three Argentine colleagues, Marcelo Luna, Lucio Iboricu, and Gabriel Casal, all kind of gathered around this spot that didn't really look like it was much of anything. And so I go down there because they're lingering there. Maybe they'd found something interesting. I returned to the spot where I had found the bone and I saw something astonishing. They have about a half of a leg bone exposed, half a femur. That bone is six foot three long, so we knew we had a giant titanosaur. And soon, other bones start appearing. When we began to excavate the tail, it was really a thing of beauty. It was articulated, meaning that the bones were still touching each other like they were in life. We started to see that this was giving us our best window yet into the anatomy of the largest creatures to walk the planet. To protect the bone and transport, we wrap it with bandages of burlap and plaster. This is what we call jacketing the bones. We had excavated about 200 square meters of rock as hard as concrete. After four more really grueling field seasons, so that's five years, we end up with 70% of the skeleton from the neck down, which was almost three times more complete than the next best preserved supergiant. We had this huge creature, maybe the most massive dinosaur ever discovered. Where does this thing rank compared to other giant titanosaurs? There's an equation you can use based off of modern animals that allows you one way to calculate an estimate of the weight of an extinct animal using the circumference, so the upper arm bone, the humerus, and the femur, the thigh bone. But for most of these dinosaurs, they don't have the fossil remains, so the weight is more of a guess. But we have the two bones that we need. Now we have the key to understanding the mass of this great creature. We start to do the math. We know this individual is one of the largest ever discovered. Is it the largest? When we finally did crunch the numbers, the number that came out was something like 59 metric tons, 65 short tons that we use here in the U.S., which was mind-boggling to me. An animal that's 65 tons is the mass of 13 African elephants, the most massive land animal for which we can calculate a weight. This was a very exciting and very tantalizing result. Our next question was, is this a new species of titanosaur? And the only way to find out was to study it in minute detail. I love dinosaurs so much. By the time I was 13, I was volunteering at our local dinosaur museum. That's when I started hearing whispers of this giant dinosaur that was coming from the edge of the world. And you know, it's the biggest dinosaur. Really? Okay. I'll believe it when I see it. And we went into the basement. When we opened the door and saw 300 containers, all with bones, it was way more than I ever could have expected. I was a fossil preparator, and my job was to extract the bones out of the rock so we could examine them in close detail. We didn't know whether it's a new species, so we had to look for novel features in its skeleton. You're making maybe a dime size of progress a day, but little by little, day after day, it's all just coming together. It's really slow, but I love it. To establish a new species of dinosaur, you have to see at least one feature in its bones that hasn't been seen in any other dinosaur. Eventually, after three years, we have the full skeleton just laid out on every tabletop. The 30-foot tail was laid out along one wall and down part of a next. The humerus standing by the door. Now we could see this 77-million-year-old skeleton in all its glory, and finally work out what it was. We began to get a full set of measurements. This animal would have been 85 feet long. That's almost the size of a basketball court. At the shoulder, it would stand two stories high. This was an immense animal. Now, based on all our lab work, we could see that it had unique features that hadn't been seen in any other dinosaur. So this was a new species of titanosaur. Now we need a name. What would this animal have to fear in its landscape? Essentially, nothing. And I come up with the name Dreadnoughtus, which means fears nothing. The first chance we got, we ran outside, screamed it as loud as we could. Dreadnoughtus! It was like the best feeling. That's such a cool name. Now we had identified this dinosaur as a new species, but we still had so many questions about how an animal so large could live. The largest animals today are the whales. They don't have to contend with walking on land. And it really sparked in me this question of, how is this animal moving? All the parts that would tell us everything that we need to know, like muscle, cartilage, tendons, don't preserve. You can't just open a book and look up the muscles for a new dinosaur. We have to discern those from the bones themselves. The big limb bones are six foot two, about 800 pounds. We can't move that and try and figure out how it moves. So our solution was to go digital. We used a 3D scanner to capture all the bones. This was one of the first dinosaurs to be captured in a 3D scan. So this area right here, that is a palm-sized muscle scar, which means the muscle was pulling on this part of the bone so much that it left an imprint. Now with these scans, we could begin to reconstruct retinitis. It enabled us to have these 3D bones that we can easily manipulate in a virtual environment and do our biomechanical experiments with. One of my colleagues, Kristen Vogeli, has mapped out those muscle scars, attached virtual muscles to test how these dinosaurs move. Let's contract this muscle, let's contract this muscle, and we'll see what the limb does. And so we're actually letting the anatomy inform us about its life. Our analysis of its largely complete skeleton helped us put flesh on the bones of this amazing creature. First, we could see that the bones themselves were big and strong. It could easily walk on land. There's really nothing like these creatures on the planet today. But there was one strange anomaly in the tale that puzzled us. Underneath each of the tail vertebrae was a pair of bones that were hanging down, and instead of tapering to a point like they do in other dinosaurs, they flare out into this big paddle for muscle attachment. It was housing these hugely powerful muscles that would go from its leg to its tail. When we looked at it carefully, we realized that these muscles would have provided powerful leverage in the tail. We thought, oh, if they pull on this fast enough, that's gonna hurt. It's not only that it was so big that nothing wanted to eat it, it was that it was weaponized in the case that something did try. This was something we hadn't seen before in titanosaurs. This was a tail that could kill or maim the largest predators. I think in comparison to other titanosaurs, Dreadnoughtus looks like about the toughest that I've ever seen. I think that plant-eating dinosaurs probably are often made out to be these, you know, like sort of gentle giants. But we're starting to understand that just eating plants does not by nature make you docile. I think it's time to recast these giant animals as the surly beasts that they were. Look out, meat-eating dinosaurs, because you do not want to mess with a Dreadnoughtus. I have that dream quite often that my house got flooded. I think I was four. And in Mexico City, we have this old house. I remember I could see the bathroom down there and I'm diving on top of it. Then I knew I wanted to be a diver. It's only through diving that I have been able to explore these great mysteries of the Maya, of how they lived and died. Chichen Itza is a spectacular Maya city in the same region as Cancun. When you're right in front of El Castillo, it's such an amazing sensation and you realize its power and the architectural talent of the ancient Maya. People lived here several hundred years after the cities of the South had fallen. Beneath these great monuments, there's a hidden world of underwater caverns called cenotes, and the Yucatan has thousands of them. Caves are super important to understand a civilization like the Maya. I was asked to look at a particular cave called Cenote Joltun and be the very first to dive it. Many cenotes have natural entrances. This one had a man-made opening. This perfectly square hole that looked like it has been carved. Instantly, I was intrigued about what might be inside. I take a look into the water some 25 meters below and the sun was shining off the surface. I had the privilege to go there, down there by myself. As I was going down on the rope, it was so beautiful. There was stalactites all over and then the sunbeam going in. I'm going deeper and deeper and deeper before I knew I was 35 meters below. Suddenly, at the bottom of the cenote, at 40 meters, I could see what looked like a sculpture looming out of darkness, a head with fangs. I was stunned. How did this get here? Did someone throw it in? Did it fall? I really wanted to stay on the bottom. Then I realized I had to go up as I was running out of air. Suddenly, something woke me up. It was this ceiling that I hit with my head and I'm going to the edge of this ceiling and as I go up, that ceiling was a big platform. As I looked over the ledge, nothing could quite prepare me for what I saw. I saw this skull and I'm like, wow, what a beautiful skull. I could see the shelf was littered with lots of other items which indicated human activity. There's so many ceramic vessels and there's charcoal there is bones, human, animal, there's a dog cranium, there's flint knives. It's wow, what is this? How it got here? Then I thought, what are these artifacts doing here? So deep underwater. I knew I had to come back to investigate in more detail. So after this first, actually shocking dive, I really wanted to go there again. I continued my journey into this shelf and I located this beautiful skull which I believe it's a female, a young female, early 20s and I started looking much, much closer and I saw this big hole on the back part of the skull and that's so intriguing because that can give us clues on how this person probably died. We started examining it and then I knew we needed more information but we are always trying not to disturb places, not to take anything out or even move. That's a big responsibility as well for us. We gotta be super careful. New technology can help us understand the places and the artifacts. We started doing photogrammetry, a photographic technique which constructs a 3D model and we wanted that particular piece, this skull. So we take it very carefully into this turntable, turn it around, take pictures from every possible angle, hundreds of pictures and then that's the easy part because the hard part is to go it, to put it back just as it was originally. This was a very, very successful photogrammetry because we learned much more about this skull. We used it to create a 3D printed skull, an exact replica of the skull in the cenote. When you see a 3D scan, you see things that you could not see underwater even though you have it right here. It's a super aid for archaeology. It enabled me to look really in detail at the shape of the hole in the skull and what I could see is that it was too deep and angular to have just been caused by the impact of a fall. It looked much more like the result of an injury caused by a man-made object. So it made me wonder, could she have been killed? On my next dive, I found another skull. We found that it has a very similar injury in the same area on the right-hand side and it has this big fracture. This could not be a coincidence. We might be looking at a pattern of doing rituals and sacrifices in this area. The ancient Maya believed that human sacrifice would please their gods and prevent chaos and disaster. Could we find out the reason for the sacrifices here at Chichen Itza? There was something that really puzzled me about Cenote Joltun. It's so many meters to the entrance. There's no current here. There's no way these elements have been tossed from the surface. We had signs of sacrifice and these objects here. But surely the Maya could not dive all the way here. How did they get over to this shelf at the far side of the cenote? I needed to find out what was happening when the Maya had come here. We analyzed samples of the ceramics which gave a date of around the 9th century AD. Definitely Maya. What we believe happened is that during the 9th century, end of 9th century, beginning of 10th, there was a huge drought that paleoclimatologists have been telling us about in the Maya lowlands. There's lots of speculations on how long it was. But I think it was a long one enough to make the aquifer level go down a few meters. The thing about the cenotes is that the Maya used them for water supply. So this could have caused a real problem for them. I mean, they still have water to drink but they don't have water for agriculture. So they must have been desperate. And then I found something that confirmed it. I saw one element that I didn't know what it was in the beginning. And looking closer, this is a stingray spine. The priests used them to perform a ritual related with rain producing. What they did is that they used the stingray spines and they passed them through their penis. Fortunately, I was not a Maya priest or maybe I was, I'm not alive. But anyway, that must have been painful. And this is a very important ceremony because of course there's a lot of blood. It's a bloodletting ritual. And this bloodletting is trying to make some empathetic magic to produce, to provoke rain. The evidence of the stingray spine used for rain making rituals and its location below the current waterline told me these offerings were placed here intentionally when the water level was lower during a period of drought to bring rain. Their world was ending. If it was a drought and there's no agriculture, that's it. There's no way you can feed the population. My feeling is they started doing rituals. They bring offerings, human victims of sacrifice. But despite long periods of drought, I knew Chichen had survived for several hundred years after. How? Then I remembered what I'd seen on my very first dive deep in the cenote. The sculptor I found was an important key. It wasn't Maya. It was from a completely different civilization, probably Aztec. This is Tlaloc, Central Mexico water god. How this sculptor got here? When you think about Chichen Itza having a port 90 kilometers to the north, probably it came from Central Mexico, which is a fascinating idea. We know it was an important trade place. Merchandise from all over Mesoamerica got there. Jade, feathers, ceramics, and probably Tlaloc sculptures. This relationship with other areas such as Central Mexico through trade, I think it was a very important part of the surviving strategy of Chichen Itza after this terrible drought. It's possible the Maya started to farm crops that were more resistant to drought. Small subsistence farming. But ongoing trade was also very important to the survival of Chichen Itza, allowing it to grow and thrive even after an environmental crisis. There's some people that still say that, well, yeah, they throw them in the cenote as a sacrifice for the gods and that's it. Let's close that page. No, no, no. This could be much more sophisticated. They must have come all the way here, the ancient Maya, and placed all these elements. That makes it unique. This is why we are so in love with Hortún Cenote. We are still investigating this site. This is just the beginning of the story. I ran across the story of the 1871 whaling disaster very early on. And it really captured my imagination. This is the logbook of Captain Ballantyne Lewis of the whaling ship, the Thomas Dickinson. And on Thursday, the 14th of September of 1871, he writes this. With light winds from the south, good weather, and the ship still icebound, may God please send us a northeast wind or all will be lost. After that, the logbook ends. For the locals, the 1871 whaling disaster must have been like a hardware store washing up along the beach. Talking to the residents in Alaska's north coast, I discovered they'd been salvaging debris from the wrecks for generations. They recycled the components of these ships. I knew the ships must have been lost close to where this debris had come ashore. Among the items we found on the beach was a flensing tool. And a flensing tool is a broad blade that is used to remove the blubber from the whale before it is boiled down for oil. This tool had been found on a beach just west of Point Franklin on Alaska's north coast. In winter, ice covers up the sea and the shore. But in the summer, it melts back to reveal the beach. In August, along the shoreline, when the wind is calm, it's absolutely beautiful. We enjoyed 24-hour daylight. But we also had an awful lot of down days where the winds were howling. So we started looking upon the shoreline. There is quite a bit of driftwood up there. But we started noticing in and amongst all this driftwood were ship's timbers. Amongst all the artifacts we found on the beach were portions of the hulls that are virtually intact. And it's impressive. There's an awful lot of it. We knew we were on the right track, but we had no proof that these ships were from the 1871 fleet. We needed to search for wreckage offshore. We used a small inflatable boat and the best survey instruments I could mount on that vessel. But in the area we searched, we couldn't find anything. Out of a 14-foot inflatable boat, we were forced to use a very compact sonar. This area deserved an expedition with more sophisticated equipment. And in 2015, that's what NOAA brought to the table. The story of the lost whaling fleet of 1871 is perhaps the most incredible to me. 32 ships lost with more than a thousand people aboard. Not only crew, but also some of the captain's wives and children. Amazingly, everyone escaped. Each winter as the Arctic freezes, icebergs form and sea ice pushes right up to the North Alaskan coast. This is what trapped the whaling fleet of 1871 in the area we now call Alaska's North Slope. Before they could reach warmer southern waters. There was a big question. Would that grinding sea ice have left anything intact on the seabed? This chart with soundings and fathoms would suggest, if you didn't know better, that this area is charted and we know what's on the bottom. But the reality is, is that there's whole areas that are blank and they're uncharted. You've got gaps here and here and gaps in here. There's no data here. This is blank. To stand any chance of finding remains, we had to plan for total data capture to map the seabed. I had known about this story for decades. The disaster of 1871 was one of the things that basically ended Yankee whaling in the early 20th century. Because it was such a devastating loss. What was still there, if anything, was still there? It was a question that needed to be answered. I was the mission coordinator. Once we got there, it was deeply personal. We were going out. We were going to essentially develop a map of the seabed between Point Franklin and Wainwright. One of the first things we did was to scan using sonar. With sonar, you're basically bouncing sound waves off the seabed and building a picture from the returning signal. What you're looking for are straight lines, which are rare in nature. What's it look like on the screen? Suddenly you see these straight lines and then more horizontal figures, like blocks. That looks interesting. That could be a piece of a shipwreck. The sonar picked up six features that appeared to be man-made. But the sonar can be a bit misleading. Is it a provocatively shaped group of rocks? Or is that the outline of a hull? That's when you need to put eyes on it. Diving was not an option. You're literally in water that's just above freezing. You get into that water and it hurts. To avoid diving, we created a drop camera system that could be lowered to the seabed. We started to drag the drop camera around, trying to get a better view of what was there. See that? What is that? Suddenly this structure appeared. It was a mass of heavy wood. You could see sections of the hull that were there, indicating some of that structure had survived. You had the broken ends of the ribs of the frames that had been gnawed by the ice. But it's covered in marine growth. You had some stone ballast as well that helped stabilize that ship when it was afloat. You go, okay, we've got a shipwreck. But were these the remains of a whaling ship? We needed more than just an empty hull. So we turned our attention to another of the most promising of the six sites. Ten miles up the coast. What we saw on the bottom were basically large timbers that were ribs of a vessel. And then we really saw the cool stuff. You're seeing clear structure that had survived being in the ice. And with that, artifacts scattered around it. What this wreck showed us that the other didn't was the actual ship's hardware. You begin to see things like an anchor. And then another feature which shows up, which is a metal bar, two bars that come around into a loop. Right beside there was a piece of iron shaped like a corner bracket, a couple of feet long. The question was, did we have enough in those wrecks to prove that these were the remains of the largest wrecking event in the history of American whaling? To try to make sense of what we were seeing on the seabed, we decided to study the last 19th century whaling ship still in existence. This loop of iron is very similar to what we saw in that wreckage. They're called chain plates. This is all part of the standing rigging that supports the mast. This is something that speaks directly to the fact that we've got a 19th century ship lying in pieces. That metal bar with the loop was a clear indicator that our wrecks were of the right period. But did any of these artifacts prove that these were whalers? This is a smoking gun. Oh, absolutely. I mean, they would only be on vessels that had Triworks installations. Yeah. That explained the bracket-shaped piece of iron that we found in our survey. The Triworks is the big furnace with its huge pots for taking whale fat and making it whale oil. They were held in place with iron brackets called knees. That's bolted in place, and that's bolted down through the deck. They go out to sea. They get onto the whaling grounds. Out come the pots. Out come the bricks. They lay all the bricks. They make this big Triworks, and then they start whaling. Seeing the chain plate and the iron knees at Mystic Seaport confirmed we had 19th century vessels. And we had a 19th century vessel that clearly had been used as a whaler. With this evidence and these clues, the wrecks, the artifacts that Randy had found on the beach, everything was consistent with 19th century whaling vessels. There's no doubt in my mind that we had finally found the submerged remains of the greatest disaster in the history of American whaling. The common sense assumption would be that the Arctic eats ships and leaves very little. No. Things have been preserved despite the violence of the disaster and the intervening century and a half of ongoing storms and ice. Things survive just as powerfully as human stories survive. The 1871 whaling disaster was a major blow to the industry. The loss made news around the world, but we still had one final question. How did everyone actually escape? The ice was in, and it wasn't going anywhere. Their ships were caught. The reports say that the crews managed to make their way to another group of whaling ships 90 miles away. In the ice-locked Arctic in poor weather, that's a very hazardous trek. When we looked again at our mapping data, we found an important clue. Where we did the seabed mapping close enough to the shoreline, we did see evidence of the raised feature that runs parallel to the shoreline. The sonar clearly shows this sandbar or reef offshore. It was maybe five feet below the surface of the water. We wondered, did that sandbar play a role in the escape? We went through all the evidence we could find. If you look at the pictures based on first-person accounts, there are pictures of the shore, open water, ice pounded up, and then the vessels stuck in the ice. Looking at everything, it all became very clear. The ships are offshore, and as the ice comes in, many of them are caught. As the ships are racing to get south, they're encountering more and more ice. They're stuck. And as the days pass, fangs of ice begin to pierce hulls. Water floods in. Pressure begins to crack and break frames. But that sandbar stops the ice. It leaves a gap between the sandbar and the beach. It's an open channel of water, and that's the escape route. That sandbar literally, I think, helped save lives. The ships themselves are trapped, and some are crushed. But they still have their little whale boats. They get into those boats and row to where ships that have not been caught in the ice are waiting for them, and now packed in, in large numbers, they all get to go home. The weather was awful. The ice was bad. And it's an incredible story of human endurance.