Tectonic Setting: The Arabian Gulf is located on the Arabian Plate, which is relatively stable compared to the Iranian Plate on the east. The collision of the Iranian Plate with the Eurasian Plate further east has resulted in the uplift of the Zagros Mountains, which is reflected in the narrow coastal plain on the eastern side of the Arabian Gulf.
Sedimentary Processes: The western side of the Arabian Gulf receives more sediment input from rivers such as the Tigris and Euphrates, which bring sediments from the Mesopotamian Plain. These sediments are then deposited along the coastline, contributing to the wider coastal plains. In contrast, the eastern side of the Arabian Gulf receives less sediment input from rivers, as it is bordered by the arid Arabian Peninsula, which has limited freshwater resources and sparse vegetation.
Sea Level Changes: During the last glacial maximum (LGM) around 20,000 years ago, sea levels were significantly lower, exposing vast areas of the continental shelf in the Arabian Gulf. As sea levels rose during the subsequent deglaciation, the western side of the Arabian Gulf experienced more extensive flooding and sediment deposition due to the larger sediment supply from the rivers. This resulted in the formation of broader coastal plains on the western side.
Coastal Processes: The western coast of the Arabian Gulf experiences higher energy wave action compared to the eastern coast. These waves erode and transport sediments, creating barrier islands and lagoons, which further contribute to the width of the coastal plains. In contrast, the eastern coast has lower wave energy, leading to less sediment transport and narrower coastal plains.
As a result of these factors, the west coast plains are generally wider than the east coast plains in the Arabian Gulf region. The tectonic setting, sedimentary processes, sea-level changes, and coastal processes all contribute to this disparity in coastal plain width.
