Lake Segara Anak

About

Segara Anak is a crater lake in the caldera that formed during the explosive volcanic eruption of Mount Samalas in 1257. The caldera is next to Mount Rinjani on Lombok Island in Indonesia. "Segara Anak" means "child of the sea" and refers to the blue lake's resemblance to the sea. The volcanic cone Gunung Barujari is at the eastern end of the lake and is responsible for its crescent shape. Because magma flows beneath the lakebed, the water temperature is 20–22 °C (68–72 °F), 5–7 °C (9.0–12.6 °F) higher than normal for a lake at this altitude. Gas bubbles escape from the lakebed, helping the lake to have a pH of 7–8.

The surface of Segara Anak is 2,004 metres (6,575 ft) above mean sea level (AMSL) and is Indonesia's second-highest caldera lake with an active volcano. The peak of Gunung Baru Jari is 2,376 metres (7,795 ft) AMSL. The lake covers 45 square kilometres (17 sq mi), with dimensions of 7.5 by 6.0 kilometres (4.7 by 3.7 mi), and has a maximum depth of 230 metres (750 ft).

Adapted from Wikipedia (CC BY-SA)。Photography via Wikimedia Commons.