Northumberland - Physical Geography

Physical Geography

The physical geography of Northumberland is diverse. It is low and flat near the North Sea coast and increasingly mountainous toward the northwest. The Cheviot Hills, in the northwest of the county, consist mainly of resistant Devonian granite and andesite lava. A second area of igneous rock underlies the Whin Sill (on which Hadrian's Wall runs), an intrusion of Carboniferous dolerite. Both ridges support a rather bare moorland landscape. Either side of the Whin Sill the county lies on Carboniferous Limestone, giving some areas of karst landscape. Lying off the coast of Northumberland are the Farne Islands, another dolerite outcrop, famous for their bird life.

There are coal fields in the southeast corner of the county, extending along the coastal region north of the river Tyne. The term 'sea coal' likely originated from chunks of coal, found washed up on beaches, that wave action had broken from coastal outcroppings.

Being in the far north of England, above 55° latitude, and having many areas of high land, Northumberland is one of the coldest areas of the country. It has an average annual temperature of 7.1 to 9.3 °C, with the coldest temperatures inland. However, the county lies on the east coast, and has relatively low rainfall, between 466 and 1060 mm annually, mostly falling in the west on the high land. Between 1971 and 2000 the county averaged 1321 to 1390 hours of sunshine per year.

Approximately a quarter of the county is protected as the Northumberland National Park, an area of outstanding landscape that has largely been protected from development and agriculture. The park stretches south from the Scottish border and includes Hadrian's Wall. Most of the park is over 240 metres (800 feet) above sea level. The Northumberland Coast is also a designated Area of Outstanding Natural Beauty.