A delta is a landform that forms when river sediment is deposited at the mouth of a river when entering a large body of water that is either slow-moving or standing-still such as an ocean, estuary, or lake. Some of the more famous deltas are the Mississippi River Delta in Louisiana or the Nile River Delta in Egypt. If you Google these deltas, you will notice that they have two different morphologies. The different morphologies of deltas are produced depending on three main forces: 1) the amount of river discharge, 2) tidal strength, and 3) wave strength (Fig. 1).
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| Figure 1 - Ternary diagram of deltas based on sediment input, wave energy flux, and tidal energy flux. The shape of the delta is determined by these forces. Image is from https://media1.britannica.com/eb-media/66/7766-004-3DB51702.jpg |
The different morphologies of deltas based on the dominating force are generally described as elongate, cuspate (or arcuate), lobate or estuarine (Fig. 2). The names of deltas are listed in the ternary diagram to show what their shape is and what environmental factors control that shape.
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Figure 2 - Morphology of deltas. Image from http://armyengineer.tpub.com/En5341a/En5341a0064im.jpg
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To take a tour of the deltas listed in Figure 1, download the following .kmz files that I have created and placed in Google Drive. The Deltas.kmz file has the location and names of the deltas, while the other Delta Tour.kmz is the actual tour. You will view the delta for 20 seconds before the tour goes to the next delta. This time includes the "flight" time, so that is why it will seem like you are viewing the first delta longer. The tour will begin with deltas created by strong sediment input, and then tide-dominated, finishing with wave dominated deltas. Enjoy!
https://drive.google.com/drive/folders/0B4iABJVeC4jFZnpkMjl0dUtTMjQ?usp=sharing
