 Tidal currents also strongly influence the redistribution of sediments from deltas. The Brahmaputra River drains off the Tibetan plateau and through here. It has so much sediment that it's a braided river. And then the Ganges River drains the foothills of the Himalayas and part of the Indian subcontinent and comes down here. And they join to build this very, very significant delta that's sort of squeezed in this area right in here. So the tides in this area are very high and they're what give this delta its distinctive shape. So we can zoom in and let's zoom into the area first where the rivers flow into the Indian Ocean. So the main river flows are coming down into here. And again this color change is the change in imagery in Google Earth and is an artifact of their process. One of the things that's distinctive about the tidal influenced rivers is that there are a huge number of islands. So the river is flowing out and at times the tide is flowing out. So you end up with a very, very large flow in this case to the south and offshore that causes a lot of erosion. When the tide turns it acts against the river flow and so in this area here it'll slow the river flow down but it's such a big river it may not actually entirely stop the flow. But that flow going back and forth in these channels shapes these islands. So we can zoom in to an area further to the west where the tides really dominate the channels. So one of the characteristics here is there are these channels at all different scales from large to small. And as the tide flows in the water level goes up throughout this whole area and it's fed into even these very, very thin channels into these marshy wetlands. And then when the tide comes out again that water will flow back out of the marshes and turn down into larger and larger channels and back into the Indian Ocean. So that flow back and forth creates the characteristic deposits of tidal flows such as the Heronbone Cross stratification. And then when the tides are high or low you can get the mud drapes and of course reactivation surfaces. So let's zoom in to this coastline here. And one of the things that's happening along this coastline is these peninsulas of vegetation are getting eroded and so the tide comes in and then it's flowing out. And there are actually little trails of sediment coming off the tips of these peninsulas that represent the sediment that's getting eroded. And we know that the tide is flowing out because these trains of sediment are flowing to the south, in the direction of the Indian Ocean. So if we take a look at this again one of the characteristics of these tidal deltas is the abundance of islands and the geometry of the channels which show that flow going back and forth and the sedimentary structures within them. So let's take a look at a smaller river. Let's go to Papua New Guinea. And if we look along this coastline here again it has, it's strongly influenced by tides and we're going to start by looking at the fly river which is shown right here. It's much smaller but it has the characteristic islands that are shaped by the flow going in and out of the river mouth. And it is building out into the standing water here. The islands are projecting out into the water which makes it a delta. And we're going to go look a little to the northeast though for more detail because there's a channel there that really shows a little bit about how irregular the tidal flows and the bottoms of these channels can be. So this is a tidal area. I'm not sure whether it's a delta or not but it's very highly shaped by tides. And you can see the red color here which is probably some sort of iron oxides are likely showing areas where the flow is currently very low. It looks like suspended sediment. You can also see these linear features within the channel that likely represent tidal bars from the flow going up and down in those channels. So if you sort of summarize the features of tide influenced deltas they have the flow going back and forth which creates elongate islands and really in terms of the sedimentary structure they'll show those characteristics of tidal flows. Thanks for watching.