Table of Contents
How are cliffs formed?
Cliffs are usually formed because of processes called erosion and weathering. Weathering happens when natural events, like wind or rain, break up pieces of rock. In coastal areas, strong winds and powerful waves break off soft or grainy rocks from hardier rocks.
What three things cause Cliffs to collapse?
The process of cliff erosion Weather weakens the top of the cliff. The sea attacks the base of the cliff forming a wave-cut notch. The notch increases in size causing the cliff to collapse. The backwash carries the rubble towards the sea forming a wave-cut platform.
What factors affect cliff profiles?
Cliff profiles are influenced by geology, especially the resistance (to erosion) of the rock, and the dip of rock strata in relation to the coastline.
What can force of water do to the cliff and other materials?
Wave pounding is the ‘sledge hammer’ effect of tonnes of water crashing against cliffs. It shakes and weakens the rocks leaving them open to attack from hydraulic action and abrasion. Eroded material gets carried away by the wave. Along with energy, the water chemistry will also affect the rock exposed to the erosion.
How were Cliffs of Moher formed?
During the time of their formation between 313 and 326 million years ago, a river dumped sand, silt and clay into an ancient marine basin. Over millions of years, the sediments collecting at the mouth of this ancient delta were compacted and lithified into the sedimentary strata preserved in the now-exposed cliffs.
What is a coastal cliff?
Coastal cliffs are very steep rock faces near the sea that are greater than 5 m in height. They may ascend in steps and have ledges, crevices and overhangs. Coastal cliffs may rise directly from the sea or be separated from it by a narrow shore.
What causes cliff slumping?
Cliffs collapse for a range of reasons. While the most common reason is weathering, there are other factors to consider, such as water crashing against the cliff face, what the cliff is made of, and the climate of the area. Bad weather naturally erodes the foundations of a cliff, and can cause it to collapse.
How do you stop cliff collapse?
Method
- Artificial smoothing of the slope, if there is enough space at the foot as well as at top of the cliff for this.
- Smoothing of the slope by filling with granular material at the foot of the cliff.
- Establish a vegetation cover on the cliff.
- Drainage of groundwater.
What is main factor controlling cliff erosion?
This simple diagram shows the factors that can affect coastal cliff erosion, including sea level rise, wave energy, coastal slope, beach width, beach height, and rock strength.
How can rock structure influence the cliff profile?
Both rock type and structure can have a significant impact on coastal landforms. More resistant rocks (e.g. chalk, limestone) erode more slowly. Weaker rocks (e.g. clays and sands) have less structural, strength and are eroded easily, producing a lower cliff profile with mudslides and slumping.
How do waves enable to shape the rock?
Erosion by waves can create unique landforms (Figure below). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff.
Which type of rock might make up a coastal cliff?
Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually formed by rock that is resistant to weathering and erosion. Sedimentary rocks most likely to form cliffs include sandstone, limestone, chalk, and dolomite. Igneous rocks such as granite and basalt also often form cliffs.