We are in Southeast Alaska right now because we want to use an autonomous underwater vehicle, basically an underwater robot, to explore and map and help archeologists search for caves that might have been used by humans a long time ago, when sea level was much lower. New discoveries are fueling fierce debates among archeologists about when and how humans first arrived in the Americas.
Textbook descriptions of hunters stalking animals across a land bridge connecting Asia to America, and passing through a gap between two massive ice sheets during the last ice age and traversing an ice free corridor through modern Canada have been upended by mounting evidence indicating humans were in the Americas thousands of years before that migration route was possible. When people get to Southeast Alaska, we know that they settled here and that they've been here since at least 10,200 years ago, thanks to an approximately 21 year old male found in Shuká Káa cave.
Other archeological sites in North and South America are more than 20,000 years old. Because most people think that people got up one day and decided to walk to America, and that's not really what would have happened. People would have settled and expanded their home range in a small area. Many archeologists now think America's first people were maritime hunters and fishers, who arrived by walking or paddling via a coastal route called the Kelp Highway.
Direct evidence for the Kelp Highway remains scarce, because it occurred when continental ice sheets lowered sea level by at least 400 feet, putting key archeological evidence underwater when the ice melted. But a team of archeologists, cave divers and robotics engineers spent two summers on a pioneering quest called Our Submerged Past Expedition. Their goal? Find and map caves in southeast Alaska that would have been dry and potentially used as shelters.
When the America's first people journeyed along the Kelp Highway. You gotta love southeast Alaska. Wait five minutes. The weather will change. It's a temperate rainforest here with warm ocean currents, high rainfall, and mild temperatures, which produce a rich, diverse and rare biome. Most people, when they think about Alaska, think about the snow. But I equate Southeast Alaska much more to the coastline of British Columbia.
It's much more like a cold Vancouver. It's also the traditional homeland of the Tlingit and Haida, and scientists like Doctor Kelly Monteleone aim to use archeology to help local communities learn about their ancestors. Doctor Monteleone is an underwater archeologist. Advances in diving equipment and underwater robotics have opened vast areas of the seafloor that were inaccessible to archeologists just a few decades ago.
I'm going to look for something called microdebitage. Little itsy bitsy flakes that flake off whenever a stone tool is used or sharpened. First year we came out and we ran something called side scan sonar from a small fishing vessel, and that let us see what the seafloor looked like. I picked out a number of places based on that to look with more sophisticated tools.
And that's why I've partnered with Sunfish. Just outside of Austin, Texas, at the headquarters of Sunfish, Inc., Doctor Kristof Richman and his team of robotics engineers and technicians test and prepare Sunfish before sending it out into the field. We've taken Sunfish, you know, kind of all around the world. Antarctica explored the world's largest underground lake in Namibia. Sea caves in the Channel Islands.
Springs in northern Florida. We like to go places where there's some sort of three dimensional feature that we can map with the robot and help scientists understand that environment better. Work here in Alaska with Our Submerged Past, it's really kind of been the first time we've done underwater archeology. Possibly helping to explore the origins of the human colonization of this whole half of the world.
Vicky Siegel is a field operations manager for Sunfish, Inc.. Vicki's job is to figure out how to get her team and their robot into some of the world's most remote and inaccessible places. This kind of work is something that cave divers could do. But by using a robot, we're able to make a very detailed three dimensional map of the cave that we're that we're taking samples from.
It can move in all six degrees of freedom, we call it, so it can translate forward, backward, side to side, up, down. The most unique aspect of Sunfish? It can work without any remote pilot entirely autonomously. And then Sunfish decides, within that, you know, view that it's seen where is it safe to go? Where it's an empty space that, you know, I can move into.
It's built up a map and we can tell it like, hey, go to this spot that you saw before, and it can use its map to navigate its way back. We are working on developing a sampling behavior with Sunfish. We added a little sediment sampler. You know, having an underwater vehicle actually be able to interact with its environment and try to get, sample from a spot is a pretty new capability.
Sunfish is able to expand the range of human exploration underwater because it doesn't get tired. It doesn't get cold cave divers up here in Alaska. I think the water is something like 48 degrees. All of this research is made possible because underwater environments can have higher preservation rates for organic materials, and caves protect archeological sites and the artifacts they contain from erosion.
What I love about being an underwater archeologist is I get to learn about the past and how people lived in the past. And with underwater archeology, I get to see it in a place that few people ever get to see or experience. The frontier of research and underwater archeology has been expanding through North America, Alaska especially, has just started to scratch the surface.
Projects like this have the potential to rewrite our understanding of how and when people came to the Americas.