Coastal Processes

Coastal Processes

The earth experiences different impacts that influence the build-up or breakdown of various landmarks or environmental systems. The impacts we see daily in our coastal areas typically refer to coastal processes. Waves, wind, and tides, for example, impact on the landscapes and change them every minute of the day. The different processes play a role to ensure occurrences of natural or habitat balances in the coastal zones.

Specific areas impacted by these coastal processes include dunes, beaches, barrier islands or mouths. To allow for a clearer understanding of the coastal processes we experience daily, let us see what it means.

The typical size of impact at the coastal zone occurs within at least 5km of the coast. These coastal zone areas play a considerable role in housing different habitats, organisms, ecological systems and animals we sometimes notice when visiting the beach. The article aims to focus on key coastal processes namely waves coastal erosion, destructive and constructive waves, coastal transport and coastal deposition. So, what are these coastal processes we continue to refer to?

What are coastal processes?

Some typical aspects researchers look for include sediment transport, beach face erosions of small particles, large shell occurrences, and other physical examples.

Waves, wind, and tides continue to change the shapes of our coastal zones. These processes involve significant complexities and the constant use of energy resources. Some main impacts that influence the beach or marine areas involve the instances of deposition, erosion, and transportation.  

Transportation happens when tides and waves transfer pieces of material to alternative areas. Deposition occurs when tides and waves lose their energy and lost the ability to transport varied materials.

Every coastal zone consists of its balance to break down, built up and transport sediment to different stretches.

Waves 

Waves play a constant role in the coastal processes and allow for regular erosion or constructive waves to happen. Waves carry the energy of the ocean and allow for the equilibrium of the seashore as well as the surrounding areas. Without waves, the natural shifts of sand and particles may not happen. Let us see what waves coastal erosion means.

Waves offer the main process that changes our beaches continuously. It also carries a significant amount of energies to move the sand and sediment evident in the coastal areas. The continuous movement of sediment allows for the beach morphology to transform and allow for different shapes every day, we notice when visiting the beaches.

Waves offer a massive body of water that transfers energy but not mass. Mostly waves appear because of the constant wind energy transferred to the ocean bottom. The outcome of this relates to the creation of water peaks and downwind trends.

Destructive and Constructive Waves

Constructive waves build up our beaches and they carry large sand deposits and drop them at our beaches. The wavelength to reach a peak seems longer and normally we notice them during calm weather days. We also find destructive powerful waves that happen during a storm, hurricane or typhoon. They play a significant role in erosion in the ocean zone areas. The distances between the wave peaks seem shorter. The waves tend to look higher as well.

Different waves exist, and they play a key role during the execution of coastal processes.

These waves include the following:

Open Ocean Wave: These waves come around and allow for particles to rise and move with the wave until the peak relaxes. 

Waves at the Shoreline: This happens when a wave reaches the shore and slows down. The waves come closer to each other and also taller. Different concentrations of molecules occur at the bottom. 

Coastal Sedimentation: When particles or sediments from the actual shore and nearby beach area stay suspended, it leaves behind sand and gravel.

Tides happen because of gravitational attractions by the moon or the sun and play a significant role to manage constructive destructive waves. The tidal force aligns with the mass of the attracting object and the distance. The force takes into account the size and distances of both the sun and the moon. Research shows that the moon uses twice the force than the sun because of the mentioned reasons.

To understand the creation of waves, the understanding of wind as part of the coastal processes play an important role. Wind in combination with waves causes different effects on the coastal area landscapes and these include experiences of wind stress. The surface area experience varied pressures, especially during major storms, typhoons or hurricanes. It results in creating short waves at harbours as well as the upwelling and downsizing processes in the coastal areas.

Wind stress on water easily creates occurrences of storm surge and plays a significant part in the execution of ocean processes. The intensity of wind impacts the wave swells and automatically increases the erosion levels. 

Coastal Erosion

Tides and waves use different methods to contribute to coastal erosion, and these include:

  • The solution that happens when seawater acids dissolve sediments surface and rocks, for example.
  • Abrasion when pieces of sand or rock hit the surrounding landscapes, they subsequently chip into the cliff surfaces.
  • Hydraulic activities trapped into different cracks experience compression when waves break. It weakens the cliff and erodes during the process. 
  • Attrition happens when waves create small pebbles or pieces of rocks because of grinding activities by the waves. The particles become smaller each day and transported by the waves. 

Coastal Transportation and Coastal Deposition

The built-up and break down of coastal zones only happen with the help from transport and deposition activities. The following actions result in transportation and deposition caused by waves and tides:

  • Saltation: The occurrence of small pieces of sand particles currents struggle to maintain the heavier components, and these particles fall to the bottom of the ocean. Heavy particles transported by waves also reaches the shore and ensure the constant build-up of our beaches. 
  • Suspension: Currents tend to collect large quantities of sediment during stormy weather. These particles make the water look brown or dirty. Normally after a while, these particles experience deposition when the sea becomes calmer.
  • Traction happens when sediment moves along on the seabed.
  • The solution occurs when minerals dissolve in the ocean water and they experience transportation in suspension. Some of these solutions include limestone. The limestone for example experience deposition at another area alongside the shoreline. 

Frequently Asked Questions

What are Coastal Processes?

Coastal processes allow for the build-up and breakdown of coastal areas. Meaning the processes ensure for constant change to happen by the use of energy. These energy resources one finds in the wind, waves or tides. Climate and weather patterns play a key role during these processes. Stormy weather increases the influences of coastal courses, for example.

What drives the Coastal Processes?

The key drivers in coastal processes involve wind, tides, and waves that carry the energies. They also play a significant role to transport the different sediments or particles at the surface.  

What do we mean by the transportation of sediment? 

Transportation of sediment happens when the waves, for example, pick up the particles and drop them in another area. It particularly happens if the waves cannot continue to carry heavy fragments. They, therefore, drop to reach the seabed.

What is Coastal Erosion? 

Coastal erosion happens when waves, wind, or tides break pieces of rock. For example, the constant crashing of the waves against a cliff, allowing the surface to slowly erode and the pieces fall into the sea.

What role does Climate or Weather Patterns play? 

In the event, climate or weather patterns evolve, the intensity and density of the particles increases. For example, in the event of a storm, the waves carry more particles and place them in other areas along the shore. These additional particles increase levels of erosion.

References 

  1. Frost Gregory, 2011, Review of Coastal Processes and Evaluation of the Impact of the Constructed Groynes along Lady Robinsons Beach, Botany Bay, New South Wales, Australia, University of Wollongong, pp. 1 – 109.
  2. http://thebritishgeographer.weebly.com/coastal-processes.html 
  3. http://www.columbia.edu/~vjd1/coastal_basic.htm 
  4. Healy T.R. (2005) Coastal Wind Effects. In: Schwartz M.L. (eds) Encyclopedia of Coastal Science. Encyclopedia of Earth Science Series. Springer, Dordrecht
  5. Dingler J.R. (2005) Beach Processes. In: Schwartz M.L. (eds) Encyclopedia of Coastal Science. Encyclopedia of Earth Science Series. Springer, Dordrecht