Kueishan Island

Southernmost Part of Okinawa Trough; coastal, off NE Taiwan; Jeng et al. (2004): "vent discharges are highly acidic (pH 1.75–4.60) and sulphur-rich with up to nine large smokers (2–6 m in height) at any one time spewing sulphurous plumes and bubbles of gas (mainly carbon dioxide, nitrogen, oxygen, sulphur dioxide and hydrogen sulphide), which emerge at temperatures of 65-116 C"; Chen et al. (2005): "An estimated cluster of more than 30 vents were observed at depths of about 10-30 m. These vents were identified by scuba divers and their positions located by GPS"; "Hydrothermal fluids are mainly discharged out of edifices and yellow mounds about 2 m high and 2–3 m wide at the base. Almost pure sulfur with some α-phase crystals and trace amounts of pyrite comprise these mounds."; "The vents discharge waters as hot as 116 C and as acidic as pH 1.517."; Zhang et al. (2012): "Hydrothermal vents are located in a hilly terrain rich with hot spring water with gas erupting intermittently. There are two types of vents, roughly divided by color, yellow hot spring water with higher temperature >110 degC ejected from sulfur chimneys of various sizes, and colorless water with lower temperature ~80 degC ejected directly from the crevices of the andesitic bedrock. Natural sulfur solidifying in the mouth of a small chimney was captured by a video camera, and explosions were also observed at intervals of a few minutes."