Coastal erosion of Banuang Daan
Tasks:
1. Wave-cut notches: Estimate their depth and width and describe how the notch is formed. What factors could have contributed to its formation?
2. Landslides: Look for signs of landslides along the cliffs. How large are the rock fragments you find at the base of the cliffs? What might have caused the collapse? Is your assessment based on recent or long-term erosion?
3. Cliff overhangs: Find an overhanging section of the cliff. Describe what it looks like and what you think might happen if the undercutting continues.
4. Optional: Take a photo of yourself or an object with the cliffs in the background and upload it with your log.
Please send your answers to the questions to "silka03.earthcache@gmail.com". Do not include them in your log!
You can log your find immediately after sending your answers. You don't need to wait for logging permission!
Enjoy your visit!
What is coastal erosion?
Coastal erosion is the process by which rock and soil are worn away by the constant action of waves, wind, and tides. This erosion can take various forms, from the gradual wearing down of rock over thousands of years to sudden collapses and landslides.
Particularly notable is the undercutting of cliffs, a process where waves hollow out the base of the cliff. This often leads to the formation of wave-cut notches and can eventually cause parts of the cliff to collapse into the sea.
The cliffs you are standing on are composed of volcanic rock that formed about 20 million years ago. These rocks are now subject to the relentless attack of the sea. Over time, the strong Atlantic surf has carved deep notches into the cliffs, and at certain points, you can clearly see the advanced undercutting.
Observable geological formations:
-
Wave-cut notches: These arch-shaped depressions at the base of the cliffs are a direct result of constant wave activity. The waves crash with tremendous force against the cliffs, wearing away the rock at the base and creating these notches.
-
Landslides: Due to continued erosion, the cliffs gradually lose their stability. When the undercutting progresses too far, large sections of the cliff can break off and fall into the sea. These events often leave debris piles and new sharp edges on the cliffs.
-
Tide pools: These small pools that form in rock depressions near the cliffs are also a result of the sea's erosive forces. They provide a unique microhabitat and an opportunity to observe the diversity of marine life.
-
Cliff overhangs: These overhanging parts of the cliffs are also a sign of advanced erosion. They can offer spectacular photo opportunities, but it is important not to get too close as they can suddenly collapse.
Scientific explanation:
The coastline of Fuerteventura is a prime example of the dynamic nature of coastal erosion and undercutting. The process begins when waves strike the cliffs and erode the softer layers of rock at the base. This type of erosion is particularly strong during storms when the waves are more intense and the water level rises.
Over thousands of years, these processes have led to the formation of the impressive cliff landscapes we see today. However, the erosion and undercutting of the cliffs are not uniform, resulting in the formation of overhangs, caves, and sudden landslides.
The wave-cut notches you see here are a direct result of this undercutting. They are not only impressive geological formations but also a testament to the power of the sea and its ability to shape even the hardest rocks.
https://de.wikipedia.org/wiki/K%C3%BCstenerosion
https://www.esys.org/rev_info/Geographie/Steilkueste.html
https://de.wikipedia.org/wiki/Brandungshohlkehle
https://www.spektrum.de/lexikon/geowissenschaften/brandungsformen/2304