Doggerland Never Made Sense – Until NOW

Okay, have a look at this map. Now, you may well be aware of Doggerland, this vast swathe of land here that once connected what is now Britain to mainland Europe, but that eventual sea rise would take generations, centuries to cut Britain off. But what if within that sea level rise, there was one single moment, a catastrophic event that didn't necessarily cut Britain off physically at that point, but it sparked a transition? Now, when we talk of eras in human history, I think it's really important to gauge the scale of time between those eras. Neolithic to Bronze Age to Iron Age and onwards, they didn't happen overnight. In fact, 43 AD, when the Romans rocked up on our shores, they would have probably just seen a bunch of farmsteads in a lot of cases, peacefully doing their thing. And I wonder if the change for them was very dramatic at all. Now, let's have a look at a change that might well have been different. In fact, stop the car. I've got a theory or a hypothesis. But back to the map, the map of Doggerland. And we know that Britain wasn't isolated overnight. It wasn't flooded in one immediate hit, gone, broken forever. Instead, perhaps something more fragile was broken. Confidence, a memory, and an assumption the land was stable, predictable, and safe. Because if you're living on that land, hunting, gathering, moving seasonally, and the sea suddenly rises up, that very much changes how you see the world. And even if the land remained, well, it may never have felt the same again. You see, Britain didn't become an island overnight, but 6,200 BC, an event took place that may have made it feel very much like one. So join me today on the Ridgeway and a special guest who I'm trying to find a couple of miles up ahead as we tell you the story of the day Britain was cut off. Now, long before anyone tried to map the seabed, well, the fishermen knew that something strange lay beneath the North Sea. Throughout the 19th and 20th centuries, trawlers working the Dogger Bank repeatedly hauled up blocks of peat, tree stumps, and bones of animals that should have never been underwater. Mammoths, giant deer, forest soils. The sea was giving back fragments of land just one piece at a time. The most famous of these finds came in 1931 when a fishing vessel dragged up a barbed antler harpoon from the North Sea floor, and it posed a question. If people were making tools out there, where exactly had they been living? That question was sort of vague and moderately unsatisfying. Britain was once connected to Europe by a land bridge. How on earth could that be the case? For decades, this was as far as it went. Archaeologists could see the edge of the puzzle, but the deep North Sea remained effectively invisible. For now, Doggerland was just an idea. Now, we're gonna go and take a look in this field, if we can get in this field. That sarsen stone just there, it's quite important. That changed at the turn of the 21st century when archaeologists began borrowing tools designed for a very different purpose. Oil and gas companies had spent decades mapping the underground structures in extraordinary detail. When researchers like Vince Gaffney gained access to this data, something remarkable appeared. Beneath the North Sea, we now see a complete landscape, rivers hundreds of kilometers long, lakes, wetlands, valleys, an entire country preserved in geological slices. Doggerland wasn't just this route or this pathway between Britain and Europe. It was a lived place. It was a place where the Mesolithic people thrived. It was an absolutely perfect environment for that existence. Vince Gaffney's work showed that Doggerland continually changed and as the retreat of that last ice age, well, the tundra would slowly turn to grassland and then to woodland. Rivers shifted, coastlines crept. Over time, the landscape would fragment into marshes and islands. Doggerland slowly unraveled. Not that one. Sure, we'll find the right one in a moment. So what happened next is key to today's story. It broke the rhythm of this slow change, an event that took place so sudden that it still leaves its mark around the North Sea today. Okay, turns out I was in the wrong field there. I actually want to be in that field just there. Let's go take a look. So after the last ice age, where the global temperatures increased, global sea levels therefore increased as the ice melted. And in the North Sea basin, where land had been once exposed to air for thousands of years, now began to be submerged by the sea itself. Doggerland was low, flat, and wide. Vince Gaffney describes it as a landscape where small rises in the sea levels caused enormous changes. The change wasn't dramatic day to day, but it was relentless. Well, Gaffney and his team were able to now start seeing this process unfold beneath the seabed. They identified hundreds of ancient rivers, some for hundreds of miles, along with dozens of large lakes and marshes, some covering hundreds of square kilometers. The guesswork had been removed. We now have clear, visible mapped features of country frozen in geological cross sections. Gaffney makes an important point here. Inundation is not linear. The sea doesn't simply rise and stay put. It advances, it pauses, it pulls back, and then advances again. And for people living here, well, this would have been confusing rather than catastrophic. Familiar places changing shape, but not disappearing entirely. Crucially, this was good land. Gaffney and his team are very clear about this. The land that this was now becoming and turning into, in some ways, wetlands, well, that is prime real estate for the hunter-gatherers of the time. Freshwater, fish, birds, reeds, seasonal resources, you name it, this was a place where the Mesolithic people wanted to live. It was a place that was worth adapting to as it changed. But adaption has its limits. Dogland thinned out in many places, and routes that once connected groups now became bottlenecks. Crossing points become tidal. River mouths widen into unpredictable estuaries. Knowledge of safe paths, where to cross, where to camp, become harder to maintain across generations. Dogland was becoming unstable, still usable, still inhabited, but increasingly difficult to read. Dogland was becoming stretched. Wow, right, finally. Finally found it, never had the opportunity to see this in person for real. This is the stone age, the Neolithic stone axe sharpener, and you polish the stones in this part here for hours on end, probably over two, two and a half thousand years in use after this event that we are talking about today. And speaking of that event, well, this is a crucial turning point for me now because that event came, well, when the landscape of Dogland was already hugely under pressure. Wow. Around 6,200 BC, something gave way off of the coast of Norway. So let's get right to the end. Strega. A section of the continental shelf, roughly the length of Scotland, collapsed and slid down into the deep ocean. Geologists call this the Strega slide, and it moved an estimated 3,500 cubic kilometers of sediment. That sudden movement displaced a huge volume of water, as you can imagine, and sent this tsunami surging out into the North Atlantic and, of course, the North Sea. And in the North Sea, that's where it left its biggest trail. In Western Norway, in Shetland, and along the coast of Northeast Scotland, you find thin sheets of sand and gravel sitting where they don't really belong, laid over peat bogs and lake sediments high above former shorelines. At Shetland, tsunami deposits sit more than nine meters above the present high tide, which, once you adjust for the fact that the sea level was lower, well, that implies run-up heights of 20 meters. For a long time, though, the southern part of the North Sea, the heartland of Doggerland, well, it left no evidence of this tsunami. Okay, so that's where Vince Gaffney and his team stepped back in once again as part of the Europe's Lost Frontiers project. Now, they took cores from drowned river valleys in the southern North Sea, and they found something they really didn't expect. In one core known as ELF-1, well, they found a lake or marsh sequence with fine annular layers of mud, and right through the middle, a 40-centimeter-thick mess of broken shell ripped up peat and sand. Radiocarbon and other dating methods placed this around 8,150 years ago, and that date lines up very well with the Strega slide. Now, when the team looked more closely, they saw that even this chaotic layer wasn't uniform in itself. Grain sizes and shell concentrations change bands within the 40 centimeters, and the geochemical signals flip back and forth between marine and more terrestrial material. Now, Gaffney and his team interpreted this as three separate tsunami events, and perhaps the most unsettling part of all of this is where this core sits within the Mesolithic landscape. When you restore sea levels and topography, ELF-1 is not on the ancient shoreline. It's roughly 40 kilometers inland from the then coast, at the head of the drowned river system of what Gaffney calls the Southern River. The only way to get marine sand and shell into that basin is for the tsunami to have been funneled up the estuary and over the low ground, effectively driving the sea into the surviving part of Doggerland. Now, for anyone living within that landscape, even remotely coastal or low-lying valleys, where all of a sudden that predictability of the landscape, the predictable tides and the rivers, all of a sudden they would have seen that devastating surge of water rise up and tear through their world. Now, on this part of the journey, we've almost reached Wayland Smithy. I can see it just in the distance. I can also see Marie, a special guest this week, also has a YouTube channel. I'll tell you about that in a little bit, and Marie's gonna join us for the rest of the journey today. So back to Doggerland, because it gets stranger. Now, I've described what sounds like a simple apocalypse gone forevermore, but pollen and environmental DNA show a return of the meadow and woodland species, not a permanent marine environment. The basin goes back to being freshwater, a mildly brackish landscape. Tsunami waters, by their nature, withdraw. The wave does enormous damage within that hour, day, week, but the land and the ecosystem can reestablish over the following years and decades. So we have this landscape already under pressure, and then we have a series of tsunamis, a series of destructive waves, powerful enough to go tens of kilometers inland, and, of course, leave a 40-centimeter layer of chaos on the ground. Britain didn't become an island in that single one moment. The land connections would linger on, of course, but all of a sudden, their world was no longer one of safety and continuity, and that very much changes what happens next. Doggerland would keep thinning into wetlands, islands, narrow crossings, and the routes, therefore, would become much more unreliable and knowledge much harder to pass on. Britain didn't become an island in that one day, but after it, crossing this landscape may no longer have felt worth the risk. What was once home became uncertain. And that, for me, more so than the water, may be what finally set Britain apart. Human movement doesn't stop in that era, too. There's archeological records that show that after 6,200 BC, well, the activity does continue in areas that would have been affected by the tsunami. Even on Britain's modern coastline, sites like Sea Henge tell us that people were still building and moving and adapting in landscapes that were actively changing. And yet, here's the problem. This landscape should appear in every archeological record that we have. There is a significant timeline here that works with everything else. It's a rich, productive landscape, lived in for thousands of years. And yet, when we look offshore, well, the people of Doggerland almost vanish, not because they weren't there or lived there, but because something about the story is, of course, missing. Below that 20 meters of water, well, excavation in archeological becomes extremely rare, if not impossible. What we have comes from chart fishing nets. It comes from other areas of industry, such as gas and oil exploitation, as we have seen in this video so far. As Vince Gaffney has pointed out, we know less about this landscape than we do about the surface of the moon, not because it matters less, but because it's hidden below. Britain didn't suddenly become an island overnight, but the world that used to connect it to mainland Europe slowly slipped beneath the seas, along with the stories of the people that used to live there. I've been Paul. Don't forget, go and subscribe to Marie's channel. I'll put the link below. Hi, I'm the Hippie Chick Historian. Today, I'm filming the Uffington White Horse and also Weyland's Smithy. We'll see you this time next week.