Science Behind Coastal Erosion

To define coastal erosion, first you must explore its namesake. The “coastal” aspect refers to the part of land adjoining or near the ocean. The coastal area on and off shore is a very important part of a local ecosystem. The mixture of fresh water and salt water in coastal estuaries provides many nutrients for sustaining marine life. Beaches also host a vast diversity of plants, animals, and insects that are crucial to the food chain. Not unlike the ocean, which defines them, coastal areas are environments that are always changing. This leads to the second aspect of the namesake. Sea level rise, bigger waves and other weather issues have caused the erosion and thus reshaping of coasts. The “erosion” aspect deals with the science of geology. Erosion is defined as the displacement of solids (soil, mud, rock and other particles) by wind, water or ice. In the case of coastal erosion, water from storm-generated waves is the source of the erosion. Excessive amounts of coastal erosion can cause problems, such as receiving water sedimentation, or harsh ecosystem damage.

The branch of science that deals with coastal erosion is geology, the study of the physical matter that constitutes the earth. The sub branch of geology that deals more closely with coastal erosion is sequence stratigraphy, a relatively new branch of geology that attempts to link prehistoric sea-level changes to sedimentary deposits. The purpose of sequence stratigraphy is to seek knowledge about the processes by which sedimentary deposits form and how those deposits change over time.

The severity of coastal erosion has been growing steadily over the past few years, and it is thought to be linked to global warming. Global warming is the cause of the melting ice caps and consequently the rise in sea level. Also, global warming could be the cause of harsher storms. With the combined effect of higher sea level and harsher storms, coastal erosion is at an all time high. The harsh storm-generated waves pound into the coastal sedimentary rocks, and progressively remove pieces of rock, eroding it.

Scientists say that coastal erosion is almost inevitable. It has been building up over the years, and so far, there is only one way for it to stop. That one way is not really in human control. Without drastic climate change to halt the rising sea levels and harsh storms, coastal erosion will undoubtedly happen. But, there are processes to drastically slow down the effects of the erosion. There are many scientists working on the topic of coastal management. One method of slowing coastal erosion was by building man-made structures, or walls to combat the waves before they hit the coast. This was effective in the short term, but had adverse effects in the long term, ultimately adding to increased erosion. The best method now, although extremely expensive, is called beach nourishment. This is the process of taking sand and sediment from off shore sites or the ocean floor, and transplanting it to the coast. The question might be posed, “Are the offshore sites badly affected because of this loss of sediment?” It is true that a poorly planned beach nourishment can result in a severely impacted ecosystem, so much caution must be taken.