Holocene epoch[edit]
The last twelve thousand years are known as the Holocene Epoch. Amongst the most significant geological features created during this period are the peat deposits of Ireland and Scotland, and of coastal and upland areas of England and Wales. Many of the lowland deposits, such as the Somerset Levels, The Fens and Romney Marsh have recently been artificially drained.
Since humans began clearing the forest during the New Stone Age, most of the land has now been deforested, speeding the natural processes of erosion. Large quantities of stone, gravel and clay are extracted each year, and by 2000 11% of England was covered by roads or buildings.
At the present time Scotland is continuing to rise as a result of the weight of Devensian ice being lifted. Southern and eastern England is sinking, generally estimated at 1 mm (1/25 inch) per year, with the London area sinking at double the speed partly due to the continuing compaction of the recent clay deposits.
In addition, rises in sea level thought to be due to global warming appear likely to make low-lying areas of land increasingly susceptible to flooding, while in some areas the coastline continues to erode at a geologically rapid rate.
Great Britain continues to be subject to several very minor earthquakes each month, and more occasional light to moderate ones. During the 20th century 25 earthquakes with a moment magnitude of 4.5 to 6.1 were felt,[2] many of them originating within the Isles themselves.