Segara Anak, Great Lakes Hot Water

Bathing in Lake Segara Anak is not as cold as one might imagine. Surface water of the lake at an altitude of 2003 meters above sea level was much warmer than room temperature. This is the magic of Segara Anak, one of the largest volcanic lake in the world's hot.
Daily temperature of the surface water of Lake Segara Anak 20-22 degrees celsius. The water temperature is much warmer than room temperature 14-15 degrees celsius.
Wonders of the lake in the caldera of Mount Rinjani which has a volume of up to 1.02 cubic kilometer is intriguing number of experts. In 2008-2009, researchers of Volcanology and Geological Hazard Mitigation (PVMBG) and Université Libre de Bruxelles conduct geochemical and thermodynamic studies on the Segara Anak.
The results, found the hot water (hydrothermal) of the magma chamber heating that goes into Lake Segara Anak. "The temperature of the surface of the lake which is well above room temperature, which is unusual for this height, reflecting a large supply of the hydrothermal fluid," wrote Akhmad Solikhin, PVMBG member of staff involved in the study.
Supply of hot water into the lake, according to Solikhin, identified from the geochemical composition of the hydrothermal showing the number of elements, such as clorid, sodium, potassium, and sulfate.
Indicators of volcanic
Monitoring Compass Lake Segara Anak while wading in late September 2011 found the number of bubbles or gas bubbles in the lake. This indicates a leak at the bottom of the lake of volcanic systems. In fact, discovered the hot springs flowing from the foot to Lake Segara Anak Barujari.
Research conducted Solikhin et al (2009) also found a close relationship between increasing temperature hot water in Lake Segara Anak Barujari and increased volcanic activity.
During monitoring, 10-14 April 2009, an increase in temperature and chemistry in a number of hot springs. Increased acidity of the water in two hot springs were believed due to increased gas sulfur dioxide (SO2) from the magma chamber Barujari. Signs that occur prior to the May 2009 eruption Barujari can be seen from the significant changes in temperature and chemical content of water in a hot spring and lake water surface temperature rise.
Water circulation
On the other hand, although rich with elements of the hydrothermal chemistry, lake with a maximum depth of 230 meters has very good water cycle. Thus, hydrothermal elements that go into the lake through a leak around the cone Barujari system does not settle to the bottom of the lake and harmful to life.
Rain water that enters the lake also helps thin the content of chemical elements. The study also found that the lake water is a mixture of hydrothermal and rainwater.
Lake water circulation takes place when the density of surface water is higher than at the base. Water with a high density layer of water will hit the bottom so the water moves upward and downward moving surface. Water circulation process is ongoing so that well-mixed water conditions.
Water with such good circulation, and the acidity of the neutral condition, suitable for breeding fish.
Volcanologists from the Directorate of Geology (London), Kama Kusumadinata, who examined this lake in 1969, recommended the cultivation of fish in the lake. At that time there has been no fish habitat in Lake Segara Anak.
In 1985, West Nusa Tenggara provincial government finally sowing the seeds of fish in this lake. Currently, tilapia fish species breed rapidly and amounted to millions and making a living from some residents.
Head of Post Monitoring Mount Rinjani in Sembalun Mutaharlim witness ecological changes in Rinjani. He first climbed Rinjani in 1980. "At that time there has been no fish in the lake, but a lot of grouse in the lake and the deer in the woods Rinjani. At that time, along the route often see big deer, "recalls Mutaharlim.
In those days, not many people who hike to the lake at an altitude of 2003 masl it. "Once the fish stocked in 1985 during Mr. Billy (NTB Governor of the time), more and more people are climbing into the lake. Initially, they only catch fish, but then catch grouse, deer hunting as well, "he said.
Now the remaining few grouse. Mutaharlim estimated 100 individuals remaining. As we were sailing down the leg Barujari, only seen three pairs of grouse. Deer were no longer found along the route. Human intervention has changed the ecology of Lake Segara Anak.