Eastern Desert

The Eastern Desert is the part of the Sahara desert that is located east of the Nile river. It spans 223 000 square km of North-Eastern Africa and is bordered by the Nile river to the west and the Red Sea and Gulf of Suez to the east. It extends through Egypt, Eritrea, Sudan and Ethiopia. The Eastern Desert is also known as the Red Sea Hills. The Desert consists of a mountain range which runs parallel to the coast, wide sedimentary plateaus extending from either side of the mountains and the Red Sea coast. The rainfall, climate, vegetation and animal life sustained in the desert varies between these different regions.The Desert has been a mining site for building materials, and precious and semi-precious metals throughout history. It has historically contained many trade routes leading to and from the Red Sea, including the Suez Canal.
Geography.
Historical formation.
Between 100 and 35 million years ago the area that is now the Eastern Desert was underwater, covered by the Tethys Ocean. During the Oligocene period, around 34 million years ago, the land began to tilt and the coastline was pushed back to the north and west. Concurrently, the basement complex to the east was uplifted, forming the mountain range of the Desert. In this same sequence of land movements, a rift which is now the Red Sea was opened up.
Mountains.
The mountain range of the Eastern Desert runs between 80 and 137 km inland from and parallel to the Red Sea Coast. It has peaks around 1500m above sea level. The southern mountains are predominantly igneous rock while the mountains to the north are limestone. Separating the mountains are wide wadis which allow for the runoff of rainfall from the mountains to the Red Sea and the Nile River. The tallest peak of the mountain range is Gebel Shayeb EI-Banat, at 2184m above sea level. Other significant peaks include Jebel Erba (2217m) Jabal Oda (2160m), Jabal Shaib al Banat (2087m), Jebel Hamata (1961m), Gebel Amm Anad (1782),  South Galala (1464m), and North Galala (1274m).
Plateaus.
Sedimentary plateaus run on either side of mountains. In general, the Northern sections of these plateaus have a limestone base while the Southern sections are sandstone. The plateaus between the Nile River and the mountains is also known as the inland Eastern Desert and is subdivided into four sections: The Cairo-Suez Desert, The Limestone Desert , The Sandstone (Idfu-Kom Ombo) Desert, and the Nubian Desert.
Red Sea Coast.
The Red Sea coastland is the easternmost part of the Eastern Desert, running between Eritrea and the Gulf of Suez. The coastline varies to be between 30–175 km in width from the base of the mountain range.
Climate.
The Eastern Desert has a semi-arid/arid/hyper-arid climate. On average, the region usually receives less than 25mm of rainfall per year in infrequent patterns . Most of the rainfall occurs during the winter months around the mountains. The presence of the mountains can create a rain shadow, for the rest of the Desert, contributing to the arid environment.
Average temperatures are between 14-21 °C in winter (November–March) and 23.1-46 °C in summer (May–September). The weather is typically sunny however, sandstorms can occur, usually between March and June. The storms (khamsins) are caused by tropical air moving up from Sudan, accompanied by strong winds and an increased temperature. 'Khamsin' comes from the Arabic word meaning fifty, as the storms occur on an average of fifty days in a year.
Historic climate.
Carbon dating of samples of fossil tufas, a type of limestone which is deposited in the presence of high groundwater levels, has revealed that there have historically been two periods when the Eastern Desert was significantly wetter than it is today. These occurred in the late Pleistocene age, around 100 000 and the mid Holocene age, around 6000 years ago. The most recent wet period is known to be a result of summer monsoonal rains that moved over the Desert from the Indian Ocean. During these times, some areas of the land was swamp. The mountains and desert plateaus were also able to sustain more vegetation and animals. In between these periods the desert climate has remained mostly arid, as it is today.
Flora.
Coastal vegetation.
There are three main ecosystems within the coastal region of the Eastern Desert: littoral salt marsh, coastal desert and coastal mountains. The presence of sea spray, tidal movements and salt water seepage means that vegetation in these areas must be well adapted to living in a saline environment.
Littoral Salt Marsh.
A salt marsh vegetation community is created as mud builds up on tidal flats and plants grow on the mud, making it a more stable and permanent ecosystem. The two main types of vegetation in this area are mangrove and salt marsh vegetation.
Mangrove.
"Avicennia marina", or grey mangrove is the dominant mangrove plant in the Red Sea area. It grows consistently along a large stretch of the Red Sea coast but is rarely seen to the North of the Egyptian city, Hurghada"." "Rhizophora mucronata", or loop-root mangrove, also grows co-dominantly with "A.Marina" in some areas along the coast but it is less prevalent. The loop-root mangrove is taller than the grey mangrove and thus, in areas where they do grow together, they form a two-tiered canopy of leaves. Small plants such as "Cymodocea ciliata" and "Halophila oualis" typically form the undergrowth of the mangrove community.
Salt Marsh.
There are multiple plant species, and further subspecies, that the grow together within this community. "Halocnemum strobilaceum" is a woody sub-shrub which grows in the mud flats and on the sandy shoreline. It is most common on the northern section of the coast, near the Gulf of Suez. "Arthrocnemum glaucum" is a flowering shrub which grows in similar areas to "H. strobilaceum" but is less prevalent in the North"."
"Limonium pruinosum" is a flowering shrub from the "Limonium" family, also known as sea lavender, which grows commonly around the Gulf of Suez. Also from this family, the sub-species of Limonium axillare contributes to up to 50% of vegetation cover on the South of the coast. "Halopeplis perfoliata" is a succulent species which commonly grows in the southern region of the Red Sea coast.
Natural resources and mining.
The mining of precious metals dates back to Ancient Egyptian times and has carried on in the Eastern Desert until present day. From the early Pharaonic era (3000BC) , copper and gold were mined from the Desert and used to make tools and for jewellery and embellishment. It was not until much later, around 1000 BC, that iron was also discovered and began to be mined. Wadis were used as routes to cart the mined materials back to the civilisation.There were also mines for precious rocks such as emeralds and amethysts that were discovered by the Ancient Egyptians, and used during the Roman and Islamic periods. As well as precious materials, valuable building and sculpting materials have also been mined from the Eastern desert such as limestone, granite and marble. Today, most of the mining that occurs in and around the Eastern Desert is for crude oil and natural gas.
History.
The earliest signs of humans in the desert was found in the form of flint tools from 250 000 BC.
The Mesolithic Period (10000-5000BC).
Around 25 000 BC, the land underwent significant climactic change which  transformed the grassy plains into desert. This made the land much less habitable and, as a result of this change, nomads which had inhabited the land that is now the Eastern Desert were driven towards the Nile River.
Pharaonic Egypt (3000BC-30BC).
The Ancient Egyptian people exploited the natural resources of the Eastern Desert and the Nile River through mining of metals, building materials and precious stones. This practice has extended throughout history to the present day. From the early Pharaonic era, copper and gold were mined from the Desert and used to make tools and for jewellery and embellishment. It was not until much later, around 1000 BC, that iron was also discovered and began to be mined. Wadis were used as routes to cart the mined materials back to the Ancient Egyptian civilisation.  There were also mines for precious rocks such as emeralds and amethysts that were discovered by the Ancient Egyptians, and used during the Roman and Islamic periods.
Trade routes from the Nile to the Red sea were established through the Desert. Notably, there was a route between the Nile River and Mersa Gawasis, an Ancient Egyptian port. There were also many mines and quarries along this route. Boats were carried in pieces across the desert through the wadis and then set up once they reached the port to embark on expeditions.
Features.
The Eastern Desert's main geographic features are the western Red Sea coastline—with the "Red Sea Riviera"—and the Eastern Desert mountain range that runs along the coast, the highest peak of which is Shaiyb al-Banat (2,187 m). Other notable ecological areas are Wadi Gamal National Park, Gebel Elba and the Wadi Dib ring complex. The Eastern Desert is a popular setting for safaris and other excursions.