Best geomorphology books according to redditors
We found 1 Reddit comment discussing the best geomorphology books. We ranked the 1 resulting product by number of redditors who mentioned them. Here are the top 20.
We found 1 Reddit comment discussing the best geomorphology books. We ranked the 1 resulting product by number of redditors who mentioned them. Here are the top 20.
Barrier islands are very well-studied in the field of coastal geomorphology. They are created primarily by longshore drift, which is essentially the prevailing current that hits a coastline at some angle. The current moves sediment shoreward at an angle (say, northeast). Because most of the flow is aimed shoreward, the sand is essentially smeared along the coastline at that angle. You can tell the direction of longshore currents by the way sediment builds up along groins. In the referenced image (Long Beach Island, NJ), the sediment builds up on the south side of the groins, indicating a northeastern longshore current.
Barrier islands are reinforced by wind-blown (eolian, or aeolian for the non-Americans) sediment. If you've ever on one of these islands, you'll notice the strong wind moving sand grains around. Vegetation stabilizes the dunes, which effectively act like armor for the island when storms batter the poor darlings.
The area behind the barrier island is referred to as the "back bay" or "lagoon." These form because rivers flow off continents and meet the ocean. Due to very low gradients in coastal areas, the rivers tend to meander and, eventually, split into multiple channels (distributaries).
Picture the barrier island as a big, elongate lump of sand shaped by the ocean. The rivers flow toward them and can't just overtop that pile of sand, so they flow along the backside of the barrier islands until they find an inlet. Tidal pumping of water maintains inlets, and large storms can create or destroy them.
The sediment on barrier islands is sourced from rivers. When freshwater hits salt water, the suspended clays stick together from the change in electrical conductivity in the water (flocculation), and drop out of suspension in marshes. Some are also swept out to sea. The sand is moved to the coastline and smashed all around, up and down the coast, by waves and shallow marine currents.
Here's a seminal paper on the topic. Sorry, it's behind a paywall, but the abstract provides a nice summary at least.