In nature, there is a continuous process of wear and tear known as erosion. This erosion occurs in different natural environments and ecosystems. Today we're going to talk about marine erosion . This refers to the wearing away of coastal land and the removal of sediment from sand dunes due to ocean currents, waves, and sea currents.
In this article we are going to tell you about all the characteristics, causes and effects of marine erosion.
Key features
Marine erosion is simply the continuous wearing away of the Earth's surface by ocean currents, waves, and tidal currents that constantly batter the coast. Waves are one of the most visible erosive elements. However, tides and marine life also play a significant role in this erosion process. This type of erosion can also occur on rocks and sand.
When erosion occurs on coastlines with few rocks, it is much more pronounced and rapid. We must understand that rocks are much harder and, therefore, more difficult to wear down over time. If an area lacks rocks, erosion occurs much more quickly. When there is a softer area than another within a small region, we find formations such as springs, tunnels, or natural pools. For more information on erosion, you can consult the definition of erosion at this link.
How marine erosion occurs
Let's look at the main steps and causes of marine erosion. The primary reason for the continuous erosion of the coastline is due to natural phenomena: waves and ocean currents. Additionally, it is often caused by the action of some living organisms, although this process is not as significant in the final erosion of an ecosystem. Let's analyze the aspects of marine erosion step by step.
Surf
Waves are the elements that reach the coast and can erode the ecosystem. They have two stages of movement. The first occurs when the wave is constructive. This means it is uplifted and crashes against the shoreline. The second stage is when it becomes an undertow, acting like a blanket and carrying all the sediment out to sea. This process produces a continuous compression and decompression effect, which in turn creates a suction effect capable of causing cliff collapses.
We must keep in mind that marine erosion occurs on a geological time scale. This means that thousands of years must pass before a coastline is eroded by the action of waves. You can learn more about the effects of climate change in this area in the article on the effects of climate change in Spain.
Ocean currents
This is another aspect of marine erosion to consider. Its main role is that of drag . The backwash of waves produces bottom currents, which are perpendicular to the current along the coast. Currents can produce parallel movement when waves strike the coast at an angle. The difference between high and low tides also generates irregular currents. These tides depend on the location and the time of year. They are strongest when there is a large difference between low and high tide. To better understand the movement of currents, you can read about oceanography here.
Types of marine erosion
As we have mentioned before, marine erosion depends on where it occurs. Therefore, there are different types:
- Hydraulic starters: They occur when waves crash against loosely settled sediments and carry them away. The sediments are carried by rivers and usually end up at their mouths. Furthermore, by contrast, they often act on cracked rocks, destroying them as the waves forcefully penetrate and compress the air present. Thus, over time, rocks are destroyed.
- Abrasion: This type of marine erosion is generated as a product of friction on the coastline of the rock fragments that are transported by both waves and tides. Depending on the size and speed with which they are displaced, they can cause more or less erosion. This type of erosion is essential in the formation of adult crusts, cliffs and abrasion platforms.
- Corrosion: Corrosion occurs due to the mineral salt content present in the sea. These salts are capable of dissolving many materials. They primarily dilute the limestone rock found within the sea. They then transform into coral reefs or contribute to the abrasion process through their small particles. Corrosion also tends to occur in areas surrounding the sea. This is caused by fog. Fog is the same salts that damage buildings and coastal transportation through humidity.
- Biological processes: It is another type of marine erosion, although less significant. Animals are responsible for erosion. The sea has rock-eating animals known as lithophages. Others are animals that transport the limestone dissolved in the sea to form coral reefs. Flora and vegetation also play a role by lodging in rock crevices and facilitating their breakup.
Causes and effects of marine erosion
Among the causes of marine erosion we find the following:
- Attraction of the moon: the attraction on the part of the moon is what generates the tides. According to the phases of the moon and the point of terrestrial translation, the behavior of the tides varies.
- Storms: Storms are another important factor to consider. Waves with a force of 9765 kg/m² can increase threefold during heavy rains.
Let's see now what the effects are:
- Cliffs: Marine erosion is reflected in coastal relief. Cliffs are vertical rocky slopes formed by the pounding of waves. They are the result of the erosion of eroded rock.
- Abrasion platforms: they are eroded rocky platforms that appear when the tide is at low tide. It is an entire extension of the coastline.
- Marine acts: They form when erosion from the sea emphasizes a particular area of ​​the cliff.
- Sea caves: They are created to injure the materials with a lower hardness.
- Peninsula: they are pieces of land joined by isthmus.
- Littoral arrows: they are formed by the accumulation of sediments.
I hope that with this information you can learn more about marine erosion, its causes and its effects.