Created by Earthquakes - the Tora Coast | Discovery Geology

Today I've driven over to the east coast of the North Island of New Zealand. This is the Torah coast, a little settlement called Torah. And I'm going to show you something that I think is one of the most mind-boggling landscape features that you can see in this area. So in order to illustrate what we're going to look at, the very first thing I'm doing is I'm going down to the shoreline to show you some of the processes that are going on. And as the waves come in, they are washing sand and gravel up onto the beach. So in really, really big storms, it's not just these pebbles that get washed up, but these really big rocks get washed up as well. Because you can see there are rock outcrops there, so the sea will erode some of that rock. And the big blocks, the big boulders, will get washed up to form a ridge. And you can see the ridge running along with this kind of pale coloured vegetation running along the shoreline. You can see that ridge in the distance. So that is the general process that's going on here. The creation of a storm ridge, okay. So I've come a little bit inland and I've got my little drone. You can see the lines in the landscape. The light coloured lines are the ridges and the darker coloured areas are swamps in between. These are beach ridges like the one we just saw. And these have been created because the original coastline was way up towards the hillside, washing up a ridge over there. And then what happened was an earthquake pushed the land up and the sea retreated a little bit and made a new beach ridge. And then after that, as another earthquake, it pushed the land up again and the sea retreated once more to create yet another beach ridge and so on. I think I can see something like six ridges. And this area here is probably about 7,000 years old. 7,000 years ago the sea reached its present level after the ice age. So from that we are getting earthquakes pushing up this landscape roughly every thousand years and creating these ridges. I think that is one of the most spectacular things that you can see here in this area. To me it's extraordinary that the landscape has these records in it. So these earthquakes are pushing up the landscape maybe one to two metres at a time every thousand years or so as a really rough guideline. So there you have it, a fantastic sequence of raised beach ridges on the east coast of New Zealand.