The world's earliest civilizations developed in Western Asia. For most of the last three millennia, the region has been united under one or two powerful states; each one succeeding the last, and at times, eastern and western based polities. The main states in this regard were the Assyrian Empire, the Babylonian Empire, the Achaemenid Empire, the Seleucid Empire, the Parthian Empire, the Roman Empire, the Sassanid Empire, theByzantine Empire, the Umayyad Caliphate, the Abbasid Caliphate, the Safavid Empire, and the Ottoman Empire.
Western Asia is the birthplace of Islam, Christianity, Judaism, and other monotheistic religions.
Western Asia is located directly south of Eastern Europe. The region is surrounded by seven major seas; the Aegean Sea, the Black Sea, theCaspian Sea, the Persian Gulf, the Arabian Sea, the Red Sea, and the Mediterranean Sea.
To the north, the region is delimited from Europe by the Caucasus Mountains, to the southwest, it is delimited from Africa by the Isthmus of Suez, while to the east, the region adjoins Central Asia and South Asia. The Dasht-e Kavir and Dasht-e Lut deserts in eastern Iran somewhat naturally delimit the region from Asia itself.
Western Asia is primarily arid and semi-arid, and can be subject to drought, but it also contains vast expanses of forest and fertile valleys. The region consists of grasslands, rangelands, deserts, and mountains. Water shortages are a problem in many parts of West Asia, with rapidly growingpopulations increasing demands for water, while salinization and pollution threaten water supplies. Major rivers, including the Tigris and Euphrates, provide sources for irrigation water to support agriculture.
There are two wind phenomena in Western Asia: the sharqi and the shamal. The sharqi (or sharki) is a wind that comes from the south and southeast. It is seasonal, lasting from April to early June, and comes again between late September and November. The winds are dry and dusty, with occasional gusts up to 80 kilometers per hour (50 miles per hour) and often kick up violent sand and dust storms that can carry sand a few thousand meters high, and can close down airports for short periods of time. These winds can last for a full day at the beginning and end of the season, and for several days during the middle of the season. The shamal is a summer northwesterly wind blowing over Iraq and the Persian Gulf states (including Saudi Arabia and Kuwait), often strong during the day, but decreasing at night. This weather effect occurs anywhere from once to several times a year.
Western Asia contains large areas of mountainous terrain. The Anatolian Plateau is sandwiched between the Pontus Mountains and Taurus Mountains in Turkey. Mount Ararat in Turkey rises to 5,137 meters. The Zagros Mountains are located in Iran, in areas along its border with Iraq. The Central Plateau of Iran is divided into two drainage basins. The northern basin is Dasht-e Kavir(Great Salt Desert), and Dasht-e-Lut is the southern basin.
In Yemen, elevations exceed 3,700 meters in many areas, and highland areas extend north along the Red Sea coast and north into Lebanon. A fault-zone also exists along the Red Sea, with continental rifting creating trough-like topography with areas located well-below sea level. The Dead Sea, located on the border between the West Bank, Israel, and Jordan, is situated at 418 m (1371 ft) below sea level, making it the lowest point on the surface of the Earth.
Rub' al Khali, one of the world's largest sand deserts, spans the southern third of the Arabian Peninsula in Saudi Arabia, parts of Oman, the United Arab Emirates and Yemen. Jebel al Akhdar is a small range of mountains located in northeastern Oman, bordering the Gulf of Oman.
Three major tectonic plates converge on Western Asia, including the African, Eurasian, and Arabian plates. The boundaries between the tectonic plates make up the Azores-Gibraltar Ridge, extending across North Africa, the Red Sea, and into Iran. The Arabian Plate is moving northward into the Anatolian plate (Turkey) at the East Anatolian Fault, and the boundary between theAegean and Anatolian plate in eastern Turkey is also seismically active.
Several major aquifers provide water to large portions of Western Asia. In Saudi Arabia, two large aquifers of Palaeozoic and Triassic origins are located beneath the Jabal Tuwayq mountains and areas west to the Red Sea. Cretaceous and Eocene-origin aquifers are located beneath large portions of central and eastern Saudi Arabia, including Wasia and Biyadh which contain amounts of both fresh water and saline water.[8] Flood or furrow irrigation, as well as sprinkler methods, are extensively used for irrigation, covering nearly 90,000 km² across Western Asia for agriculture.
The population of Western Asia is over 300 million. The most populous countries in the region are Iran and Turkey, each with around 75 million people, followed by Iraq with around 32 million people. The major languages are Arabic, which is an official language in 14 regional countries, followed by Turkish, and Persian. Islam is the major faith in Western Asia.
The economy of Western Asia is diverse and the region experiences high economic growth. Turkey has the largest economy in the region, followed by Saudi Arabia and Iran. Petroleum is the major industry in the regional economy, as more than half of the world's oil reserves and around 40 percent of the world's natural gas reserves are located in the region.