The Sahara

The Sahara is the largest desert on Earth, located in North Africa, stretching from the Western Sahara on the Atlantic Ocean to the Red Sea in Egypt. On the northern side, it is bordered by the Mediterranean Sea and the Atlas Mountains. The southern boundary is formed by the Sahel, a semi-arid region. The name Sahara is derived from the Arabic word “saghara,” which means desert. Although the Sahara is now a vast desert, it was not always so. During the Pleistocene and Holocene periods, much of the Sahara consisted of savannah, supporting diverse plant species. In these periods, humans thrived as gatherers and hunters in these areas. Evidence suggests that various human species, such as Homo habilis and Homo australopithecus, inhabited the Sahara over five million years ago. Stone tools dating back up to two million years can still be found in the Sahara.

Between 18,000 and 10,000 BCE, the Sahara experienced an extremely dry period, expanding further southward. After 10,000 BCE, the Sahara became more humid again, and around 8,500 BCE, the Holocene Subpluvial began, characterized by a significantly moister climate and a denser human population in the Sahara. Approximately 6,000 to 4,000 years ago, an abrupt desertification occurred in the Sahara and Arabia. With the various ice ages, the climate, particularly precipitation, changed, altering vegetation. Gradually, the Sahara acquired the appearance we see today: a barren, sandy plain with sparse vegetation. In the summer of 2005, a severe thunderstorm complex even crossed the Sahara towards the Mediterranean Sea, a phenomenon previously considered impossible by many meteorologists and climatologists. Simultaneously, the Sahara seems to exert more influence on Southern Europe. These extremely warm upper air masses from the Sahara cause prolonged heatwaves in Europe, leading to large wildfires in Spain, Portugal, Italy, and Greece in recent years.

The surface area of the Sahara is approximately 9,065,000 square kilometers. The Sahara encompasses, wholly or partly, the following countries: Morocco in the Western Sahara, Mauritania, Mali, Niger, Algeria, Tunisia, Libya, Chad, Egypt, and Sudan. The strip just south of the Sahara is called the Sahel, and the countries in which this semi-desert lies are called the Sahel countries. The Sahara is very dry, with average rainfall of less than 100 millimeters per year. The days are extremely hot, and the nights relatively cold. When it does rain, it can happen quite unexpectedly and in heavy downpours. These downpours can be dangerous for travelers as the wadis through which the water drains are used by them as roads or paths. It occasionally happens that an unfortunate traveler cannot leave the wadi in time and drowns in the desert. Not all of the Sahara consists of the characteristic sand dunes; there are also many rocky areas. In fact, only 20 percent of the Sahara is sand; the rest is rocky.

Oases, places where drinking water comes to or near the surface, occur in various places in the desert. In the middle of the desert lies Lake Chad, the second-largest freshwater lake in Africa. Sahara dust is dust from sandstorms in the Sahara that can reach as far as Belgium and the Netherlands or even further north and fall to Earth with the rain. Most of the dust, however, ends up in the Atlantic Ocean. The dust contains a quantity of iron that fertilizes a large part of that ocean. This increases the photosynthesis of plankton. Very rarely, snow falls in the Sahara. However, higher-altitude parts of the Sahara experience snow more frequently. Although located on the edge of the desert, the Atlas Mountains even have some ski resorts. But even mountain ranges in the center of the Sahara occasionally experience snowfall. The relative humidity may be low, but the absolute humidity is enough to form snow when the air is pushed up against the mountains. The Tibesti Mountains receive snow on the highest peaks every 7 years on average, and the Tahat in the Ahaggar Massif receives snow every 3 years on average.

The Sahara is home to a wide variety of animal species, including the addax (Addax nasomaculatus), Barbary sheep (Ammotragus lervia), cheetah (Acinonyx jubatus), and striped hyena (Hyaena hyaena). The plants are also adapted to the large temperature fluctuations, with long roots to extract water more easily from the ground and small, thick leaves.

THE LIBYAN OR WESTERN DESERT

A part of this desert is called the Great Sand Sea. This area is the northeastern part of the Sahara desert. Located on the territory of Libya, Egypt, and the northwest of Sudan. It is more or less a rectangular area. In 1924, the Western Desert was accurately mapped by Ahmed Hassanein after his expedition, during which he traveled 5,635 km on foot through the desert. The desert consists mainly of sand and stones and is inhabited by the Sanusi.