Cyrenaica - Geography

Geography

Geologically, Cyrenaica rests on a mass of Miocene limestone that tilts up steeply from the Mediterranean Sea and falls inland with a gradual descent to sea level again.

This mass is divided into two blocks. The Jebel Akhdar extends parallel to the coast from the Gulf of Sidra to the Gulf of Bomba, and reaches an elevation of 872 meters. There is no continuous coastal plain, the longest strip running from the recess of Gulf of Sidra past Benghazi to Tolmeitha. Thereafter, except for deltaic patches at Susa and Derna, the shore is all precipitous. A steep escarpment separates the coastal plain from a relatively level plateau, known as the Marj Plain, which lies at about 300 meters elevation. Above the Marj Plain lies a dissected plateau at about 700 meters elevation, which contains the highest peaks in the range.

The Jebel Akhdar and its adjacent coast are part of the Mediterranean woodlands and forests ecoregion, and have a Mediterranean climate of hot, dry summers and relatively mild and rainy winters. The plant communities of this portion of Cyrenaica include forest, woodland, maquis, garrigue, steppe, and oak savanna. Garrigue shrublands occupy the non-agricultural portions coastal plain and coastal escarpments, with Sarcopoterium spinosum, along with Asphodelus microcarpus and Artemisia herba-alba, as the predominant species. Small areas of maquis are found on on north-facing slopes near the sea, becoming more extensive on the lower plateau. Juniperus phoenicea, Pistacia lentiscus, Quercus coccifera and Ceratonia siliqua are common tree and large shrub species in the maquis. The upper plateau includes areas of garrigue, two maquis communities, one dominated by Pistacia lentiscus and the other a mixed maquis in which the endemic Arbutus pavarii is prominent, and forests of Cupressus sempervirens, Juniperus phoenicea, Olea europaea, Quercus coccifera, Ceratonia siliqua, and Pinus halepensis.

Areas of red soil are found on the Marj Plain, which has borne abundant crops of wheat and barley from ancient times to the present day. Plenty of springs issue on the highlands. Wild olive trees are abundant, and large areas of oak savanna provide pasture to the flocks and herds of the local Bedouins. Historically large areas of range were covered in forest. The forested area of the Jebel Akhdar has been shrinking in recent decades. A 1996 report to the UN Food and Agriculture Organization estimated that the forested area was reduced to 320,000 hectares from 500,000 hectares, mostly cleared to grow crops. The Green Mountain Conservation and Development Authority estimates that the forested area decreased from 500,000 hectares in 1976 to 180,000 hectares in 2007.

The southward slopes of the Jebel Akhdar occupied by the Mediterranean dry woodlands and steppe, a transitional ecoregion lying between the Mediterranean climate regions of North Africa and the hyper-arid Sahara Desert.

The lower Jebel el-Akabah lies to the south and east of the Jebel Akhdar. The two highlands are separated by a depression. This eastern region, known in ancient times as Marmarica, is much drier than the Jebel Akhdar, and here the Sahara extends to the coast. Historically, salt-collecting and sponge fishing were more important than agriculture. Bomba and Tobruk have good harbors.

South of the coastal highlands of Cyrenaica is a large east-west running depression, extending eastward from the Gulf of Sidra into Egypt. This region of the Sahara is known as the Libyan Desert, and includes the Great Sand Sea and the Calanshio Sand Sea. The Libyan Desert is home to a few oases, including Awjila (ancient Augila) and Jaghbub.