The Persian Gulf (also known as the Gulf) is a warm, semi-enclosed sea, mostly less than 330 ft (100 m) deep. It is connected to the Arabian Sea via the Strait of Hormuz and the Gulf of Oman. The shallow waters are well mixed and more productive than the Red Sea owing to the nutrient runoff from the land to the north and east. Corals have adapted to the very warm water temperature, which can reach 91°F (33°C).
The Arabian Plate, spreading from the Red Sea rift, is moving northeast and sliding under the Eurasian Plate, so the northeastern side of the Persian Gulf is deeper. This tectonic activity has folded and uplifted sediments up to 280 million years old and produced structural traps for oil, which has accumulated in large reservoirs beneath the Gulf and surrounding land. Oil now dominates the region’s economy.