In this video, we're going to be using the National Library of Scotland's side by side map viewer to investigate, visualise, and measure coastal erosion. Now this GIS system is really useful for geographers because it allows us to compare maps and satellite imagery side by side. So we can see on the left hand side of this screen, we've got a map and we can see in this menu box that it says select map and it says OS six inch, 1888 to 1915. Now if I click on this, I can change this map into lots of different maps. We're actually gonna stay on this map. And on the right hand side we've got a present day Esri World Imagery. So that's satellite imagery from the present day. So what we're able to compare here is an old map on the left with new satellite imagery on the right. So, what we're going to start with, we've got to find a place where we can investigate coastal erosion. So I'm going to come to this top left hand corner and you can see the mouse cursor coming across to the left. And I'm going to click on the search, the magnifying glass, and I'm going to type into here Skipsea. Oops, spelled it wrong, let's try again. Skipsea. And it says there East Riding of Yorkshire, Yorkshire and Humber, and that's correct. Now, if I zoom out for a second, and I'm just using the scroll wheel of the mouse, I could come to the top left hand corner and press this zoom out button here, and we can see that this is on the east of England. It's along what we call the Holderness Coast. And so we can see we've got something called Flamborough Head up here. It goes down to something called Spurn Point, and Hull, major city is just down here. So we're going to investigate this part of the world. This is Skipsea. So I'm going to zoom back in and it should take it straight back to Skipsea. There we go. So, this is Skipsea here. Now, if I zoom in, what we can do, is we can actually look at coastal erosion visually. And so, if you notice where my mouse cursor is, the little arrow on the left. And when I move it around this map, there's also a little cross that moves around the map, of the satellite imagery on the right. If I go to this corner, the sharp corner on the road, you'll notice it's also the sharp corner on the satellite imagery on the right, which suggests that this road was here back when this map was produced between 1888 and 1915. And it's still there now. Now they're in the same point, which basically, which means that they are what we call geo-referenced. And that means it's using the exact coordinates to work out that they're the same location on both of these, on the map on the left and the imagery on the right. So, if I come down to the coastline, what I can do is I can put my mouse on here and you'll notice that where my mouse cursor is on the left, on the left hand map, it's still quite a long way from the sea. You can see there's a road here and there's car parking, but the cross on the right is right on the beach. And what this is suggesting is, well, it's not suggesting, it's telling us, that coastal erosion has meant that this land has been eroded, this section here, in between the periods of these two different maps. What I can do is I can go to the top and click on swipe. I can actually go to this middle point here and drag this handle over and look at the land that's been lost. So this land here that I'm dragging across has now become sea, but back when that map was produced, that bit was land. And that's an incredible visual reference of coastal erosion. But we can be more accurate than that and we can be more accurate, better than that, by using the measuring tool. So what I'm going to do is I'm gonna come up to the right hand corner and we can see there's a little tool there saying measure tools. I'm going to click on that measure tool. I'm going to go down to the bottom one where it says measure distance and I'm going to click on it. What I can do is I can go, and look, I'm using the satellite imagery on the right here. You'll see the mouse cursor with a little orange circle on it. I'm going to click on where the edge of the coastline is. So I'm just gonna come to about here, which is on this sort of cliff line, And I'm going to take it, I'm gonna come out into the sea, up until the point where if we look on the map on the left, you can see the cross on the left, to where the old coastline used to be, where the old cliff line, you can see those sort of arrows pointing, with the black line there. And I'm going to click somewhere on this. I'm going to double click, and it gives me a distance. And you can see there it says 118 metres. And that is the distance that has been lost, the coast, the amount of land that's been lost between the map on the left, when that was produced, and the satellite imagery when that image was taken, which is around the present day.