Sea Levels

Sea levels are not constant. Throughout the past, sea levels have risen and fallen, the proof of this can be seen on the Cornish coast, such as the raised beach deposit at the far end of Praa Sands beach. The deposit is a remnant of an ancient beach and lays up in the cliff showing that the sea level during this period must have been higher than it is currently.

Raised Beach Deposit at Praa Sands

Adit Walls Comprised of Beach Deposit

Over the last million years there have been a series of glacial periods. During these periods the ice caps have expanded tying up the earth's water so that the sea had less and sea levels dropped. When a glacial period ended the climate warmed and the ice caps melted and sea levels rose. To complicate matters the UKs mainland itself has risen and fallen. As in the glacial periods the land was covered with ice its immense weight compressed the land mass. As the ice melted and the water washed into the sea the loss of the weight allowed the land to "bounce back", raising land level.

Currently the world’s sea levels are rising, possibly increasing due to global warming. This process is putting a growing strain on Cornwall’s sea defences. The changes in the coastline will cause dire problems for man but the process is hopefully slow enough for sea life to adapt.