High-pressure area Hadley cells help form the subtropical ridge, steer tropical waves and tropical cyclones across the ocean and is strongest during the summer. The subtropical ridge also helps form most of the world's deserts. On English-language weather maps, high-pressure centers are identified by the letter H. Weather maps in other languages may use different letters or symbols. The direction of wind flow around an atmospheric high-pressure area and a low-pressure area, as seen from above, depends on the hemisphere. High-pressure systems rotate clockwise in the northern Hemisphere; low-pressure systems rotate clockwise in the southern hemisphere. The scientific terms in English used
High pressure metamorphic terranes along the Bangong-Nujiang Suture Zone are generally associated with subduction zones. Protoliths of serpentinites are olivine- and pyroxene-dominated. The formation of serpentinites is caused by the release of fluids from subducting hydrated oceanic slabs as they become heated with depth to a maximum temperature of 650-700 °C. Eclogites are high-pressure (HP) to ultrahigh-pressure (UHP) metamorphic rocks that are indicative of subduction zone metamorphism. The eclogites in central Tibet are of Early Mesozoic origin, and they appear to be the result of diachronous collision between the eastern Qiangtang terrane and the western Qiangtang-Lhasa plate, along the linked eastern Bangong-Nujiang-central Qiangtang zone. Located along the western sector