Transcript

INSTRUCTOR

Finally, let's look at some other layers in the Google Earth file you downloaded from the course website. The different layers have different information. If you left click in the North Atlantic Transect, you get a yellow line across the Atlantic Ocean. And Figure 3 in the course shows the water depth along this line.

So if you were to right click and select Show Elevation Profile, you'd get the same plot that comes out. And you can see down the centre of the Atlantic Ocean is the Mid-Atlantic Ridge. Now, if we scroll down, you can see there's Earth's Tectonic Plates and also another layer called the Vent InterRidge.

First we'll select the Tectonic Plates. And you can see I've got red lines, and that red line marks the Mid-Atlantic Ridge across the Atlantic Ocean. And if I now select the Vents and then zoom in a little bit, you can see the location of lots of deep-sea vents in the North Atlantic.

And the different colours represent different things. If I click on one, you can see that that is the Vent Field Southern Oceanographer. It's an active field. It gives the position, the water depth, and there is actually a web link in there as well so you can click on it.

Now, if we unselect those two and select the Scotia Sea and then double click on it, we'll go down to the Southern Hemisphere across an oceanic trench. There's our oceanic trench. And so if we right click our Scotia Sea layer, Show Elevation Profile, perhaps the water depth and on the yellow profile.

So how deep is the oceanic trench? If you put your mouse there, you can see the red arrow, or the deepest point, 7245 metres, 7458, 7446. So a remarkably deep part of the world's ocean.