The Importance Of Barrier Island

Introduction

Barrier islands are much more important than people realize. Barrier islands are sandy islands that are separated from the mainlands by lagoons, estuaries, or tidal environments. Barrier islands are very important not alone to help the beaches and land not erode, but also because these barrier islands help show the differences in sea level change. Sea level change controls barrier islands so by observing the barrier islands determining the sea level and past sea level can be determined.

Sea level change can be determined from the stratigraphy of these barrier islands. Looking at the layers of the stratigraphy there are normally telltale signs where the sea level started to change. If there is well-sorted sand in the stratigraphy it can be deduced that at this point the sea level was low and that this were near the dunes and backbeach. However, if there is shelly gravel then this will show that now the barrier was near water or underwater to some degree.

Wave-dominated barriers tend to be very narrow and long. Also, few tidal inlets can be found and there are normally small ebb tidal deltas too. South Carolina is also a passive continental margin. A passive continental margin is when these margins are developed near coastlines that are not tectonically active. Therefore, someone would not find any volcanos in South Carolina because volcanoes form over active continental margins. The beach during the winter is typically a lot smaller than the beach in the summer. This is because the waves in the winter tend to increase a little (along with the wind) the beach and dunes tend to erode causing the sand to be deposited in the offshore sandbars. Because of this, the beach will tend to be flatter as well. During the summer, there is more beach space and more noticeable dunes because of the calmer waves. There is also a more noticeable berm during the summer as