Headlands

What are some interesting facts about coastal erosion?

i need this answer 4 a project

Public Comments

1. Your question is very general so that makes it hard to answer well, but I will try because you have asked for help. Coastal erosion is a natural process that can be accelerated by improper land use. It has become a large problem in the Gulf of Mexico, especially in Louisiana and Texas for several reasons. In Texas and along most coasts there is a process known as longshore drift. This means that the ocean currents move a specific direction and so sand and other sediment is moved longshore (along the shore) in one prevailing direction. When rivers are dammed they no longer supply sand to the river deltas and this longshore drift cannot resupply the beaches with sand. The beaches eventually become starved of sand and begin to erode. On the eastern coast of the United State longshore drift is northward, so barrier islands and other beaches tend to migrate northward. On the west coast of the US the drift is southward and so beaches lose sand where anything blocks the southward movement. Some jetties have been built that began to starve the beaches southward of sand supply and this has become a problem for those beaches. In Louisiana the problem is a little different because there are several factors known to be causing a very rapid rate of coastal erosion. Louisiana is losing 18,500 acres of wetlands each year to coastal erosion. One large part of the problem is that this area was once part of the Mississippi River delta floodplain, and as levees have been built to prevent flooding, the areas have been deprived of additional sediment supply from the river. Another part of the problem is that the sediments that the area is built on tend to settle over time. The Mississippi River has built a pile of sediments of sand and mud that is several miles thick. With time this sediment compacts and sinks, causing flooding where the surface is no longer being resupplied from the river. Even another factor has been discovered that this part of the North American continent is sinking possibly as a response to the melting of glaciers on the upper part of the continent about 10,000 years ago. Since the northern part of the continent is still rising because of the weight of the ice removed when the glaciers melted, it works like a teeter-totter and the southern part is going down This coastal erosion is in large part the cause of much of the damage to New Orleans during last years hurricanes, as it created storm surge conditions that were more extreme than expected. Other types of coastal erosion are prevalent in states like California where large storms can move waves across the beach and erode the base of cliffs that are along the beaches. This often causes very nice houses to slide down the cliff in a landslide. To some extent it is a natural process that should have been anticipated by those homeowners, but it probably is also being affected by sea level rise and beach starvation. Earthquakes are even a factor in these coastal bluff landslides. http://www-csgc.ucsd.edu/STORIES/coastalerosion.html I've added some links to resources about Louisiana coastal erosion below.