<<

Leaving Certificate Physical Geography 2006 Q 2 (b) Q: With the aid of a labelled diagram examine the processes that have lead to the formation of any one Irish of your choice.

A stump is formed after being eroded by the sea over time by the four processes of marine , hydraulic action, compression, attrition and abrasion.

At the beginning of the formation, a notch is cut by the waves in the in an area of active erosion. The process of compression traps the air in the notch and upon the water's retreating, the rock expands under the pressure and explodes. This forces the rock to shatter into the sea as tiny fragments or larger chippings.

After a lot of erosion by hydraulic action or the sheer power of the waves, the notch develops into a sea in the headland. The process of abrasion helps to erode the as many of the rock particles, and rocks made from the process of compression are hurled up against the sea cave. Gradually the sea cave gets eroded and lengthened and some may erode back to back in the sea . When the cave is eroded until it cuts through the promontory of the headland, it forms a sea arch.

The sea continues to erode it with the processes combined. Eventually the arch gets too wide as the processes all eroding at the same time increase it's width and height in the cliff. Soon, the land above the arch gets unsteady and becomes weak as it cannot support itself any longer above the sea. It collapses into the water below and leaves a piece of vertical-standing cliff jutting out of the sea from the headland. This piece of land is called a sea .

When the sea stack stands upright by itself in the sea, it is more vulnerable to the processes of erosion. It is exposed to the weather elements such as frost, rain, wind and snow. The process of attrition smoothens the products of the wave's load and these too are hurled up against the sea stack. After this constant erosion, the sea stack gets eroded into a small lump of land sitting just above the sea level.

In conclusion, this is the formation of a sea stump. There are processes such as hydraulic action, compression, abrasion and attrition that make the various sea features such as a sea notch, a sea cave, a sea arch, a sea stack and finally, a sea stump of the . An Irish example of a sea stump is off the coast of Mullaghmore in North Sligo.

Labelled diagram: