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Qattara Depression
The Qattara Depression () is a depression (geology), depression in northwestern Egypt, specifically in the Matruh Governorate. The depression is part of the Western Desert (Egypt), Western Desert of Egypt. The Qattara Depression lies below sea level, and its bottom is covered with salt pan (geology), salt pans, sand dunes, and Inland salt marsh, salt marshes. The depression extends between the latitudes of 28°35' and 30°25' north and the longitudes of 26°20' and 29°02' east.El Bassyony, Abdou. 1995. ''"Introduction to the geology of the Qattara Depression,"'' International Conference on the Studies and Achievements of Geosciences in Egypt, 69 (85-eoa) The Qattara Depression was created by the interplay of salt weathering and wind erosion. Some west of the depression lie the oases of Siwa Oasis, Siwa in Egypt and Jaghbub, Libya, Jaghbub in Libya in smaller but similar depressions. The Qattara Depression contains the second lowest point in Africa at an elevation of below s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Qattara Depression (March 2007)
The Qattara Depression () is a depression in northwestern Egypt, specifically in the Matruh Governorate. The depression is part of the Western Desert of Egypt. The Qattara Depression lies below sea level, and its bottom is covered with salt pans, sand dunes, and salt marshes. The depression extends between the latitudes of 28°35' and 30°25' north and the longitudes of 26°20' and 29°02' east.El Bassyony, Abdou. 1995. ''"Introduction to the geology of the Qattara Depression,"'' International Conference on the Studies and Achievements of Geosciences in Egypt, 69 (85-eoa) The Qattara Depression was created by the interplay of salt weathering and wind erosion. Some west of the depression lie the oases of Siwa in Egypt and Jaghbub in Libya in smaller but similar depressions. The Qattara Depression contains the second lowest point in Africa at an elevation of below sea level, the lowest point being Lake Assal in Djibouti. The depression covers about , a size comparable wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northern coast of Egypt, the north, the Gaza Strip of Palestine and Israel to Egypt–Israel barrier, the northeast, the Red Sea to the east, Sudan to Egypt–Sudan border, the south, and Libya to Egypt–Libya border, the west; the Gulf of Aqaba in the northeast separates Egypt from Jordan and Saudi Arabia. Cairo is the capital, list of cities and towns in Egypt, largest city, and leading cultural center, while Alexandria is the second-largest city and an important hub of industry and tourism. With over 109 million inhabitants, Egypt is the List of African countries by population, third-most populous country in Africa and List of countries and dependencies by population, 15th-most populated in the world. Egypt has one of the longest histories o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Egyptian Sand Sea
The Great Sand Sea is an approximately sand desert (erg) in the Sahara that stretches from western Egypt to eastern Libya, in North Africa. Most of the area is covered by sand dunes. Geography The Great Sand Sea stretches about from north to south and from east to west. On satellite images, this desert shows a pattern of long sand ridges running in a roughly north-south direction. However, despite the apparent uniformity, the Great Sand Sea has two large areas with different types of megadunes.Besler, Helga (2008) ''The Great Sand Sea in Egypt: Formation, Dynamics and Environmental Change: A Sediment-Analytical Approach'' Elsevier, Amsterdampage 1 - 3 The Egyptian sand sea lies parallel to the Calanshio Sand Sea of Libya, with which it is contiguous in the north. The dunes of the Great Sand Sea cover about 10% of the total area of the Egyptian Western Desert. Siwa is an oasis located in Egypt, about east of the Libyan border, in the eastern part of the Great Sand Sea or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Biodiversity
Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distributed evenly on Earth. It is greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are latitudinal gradients in species diversity for both marine and terrestrial taxa. Since Abiogenesis, life began on Earth, six major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic aeon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion. In this period, the majority of Multicellular organism, multicellular Phylum, phyla first appeared. The next 400 mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Phragmites
''Phragmites'' () is a genus of four species of large perennial plant, perennial reed (plant), reed Poaceae, grasses found in wetlands throughout temperate and tropical regions of the world. Taxonomy The World Checklist of Selected Plant Families, maintained by Kew Garden in London, accepts the following four species: * ''Phragmites australis'' (Antonio José Cavanilles, Cav.) Carl Bernhard von Trinius, Trin. ex Steud. – The cosmopolitan common reed * ''Phragmites japonicus'' Steud. – Japan, Korea, Ryukyu Islands, Russian Far East * ''Phragmites karka'' (Anders Johan Retzius, Retz.) Trin. ex Steud. – tropical Africa, southern Asia, Australia, some Pacific Islands, invasive in New Zealand * ''Phragmites mauritianus'' Kunth – central + southern Africa, Madagascar, Mauritius Wildlife in reed beds ''Phragmites'' stands can provide food and shelter resources for a number of birds, insects, and other animals. Habitat benefits are often optimal when stands are thinner, and ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Vachellia Tortilis
''Vachellia tortilis'', widely known as ''Acacia tortilis'' but now attributed to the genus ''Vachellia'' of the Mimosa Family ( Mimosaceae), is the umbrella thorn acacia, also known as umbrella thorn and Israeli babool, a medium to large canopied tree native to most of Africa, primarily to the savanna and Sahel of Africa (especially the Somali peninsula and Sudan), but also occurring in the Middle East. Distribution and growing conditions ''Vachellia tortilis'' is widespread in Africa, being found in countries like Tunisia, Morocco, Uganda, Angola, Zimbabwe, Djibouti, and Botswana. It tends to grow in areas where temperatures vary from and rainfall is anywhere from about per year. Characteristics In extremely arid conditions, it may occur as a small, wiry bush. In more favorable conditions, it grows up to in height. The tree carries leaves that grow to approx. in length with between 4 and 10 pair of pinnae each with up to 15 pairs of leaflets. Its most interesting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sand Dunes (Qattara Depression)
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ''ergs'' or ''sand seas''. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter ''slip face'' in the lee side. The valley or trough between dunes is called a ''dune slack''. Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in other areas where poorly cemented sands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, transports it to another location where it is deposit (geology), deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by Solvation, dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and Wind wave, waves; glacier, glacial Plucking (glaciation), plucking, Abrasion (geology), abrasion, and scour; areal flooding; Aeolian processes, wind abrasion; groundwater processes; and Mass wastin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Weathering
Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Weathering processes are either physical or chemical. The former involves the breakdown of rocks and soils through such mechanical effects as heat, water, ice and wind. The latter covers reactions to water, atmospheric gases and biologically produced chemicals with rocks and soils. Water is the principal agent behind both kinds, though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important. Biological chemical weathering is also called biological weathering. The materials left after the rock breaks down combine with organic material to create so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Quaternary Period
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the Phanerozoic eon. It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today); a proposed third epoch, the Anthropocene, was rejected in 2024 by IUGS, the governing body of the ICS. The Quaternary is typically defined by the Quaternary glaciation, the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
