Mount Semeru is the highest volcano in Java, with a peak Mahameru, 3676 meters above sea level (mdpl). The crater at the peak of Mount Semeru known Jonggring Saloko.
The position of this mountain region located between the administration and Lumajang Regency, East Java with a geographic position between 8 ° 06 ‘S and 120 ° 55’ E.
In the year 1913 and 1946 crater dome Jonggring Saloka has a height of 3744.8 M until the end of November 1973. Adjacent to the south, the dome crater edge to break the flow of lava toward the south side of the area include the Pronojiwo and Lumajang Candipuro.
At the peak of Mount Semeru (top Mahameru) climbers are advised to not to Jonggring Saloko crater, also prohibited from ascending the south side, because of the poisonous gas and lava flows. Mahameru dipuncak temperature ranges from 4 to 10 degrees Celsius, at the peak of the dry season minus 0 degrees Celsius, and found ice crystals. The weather is often foggy, especially at lunch, afternoon and evening. The wind, the month of December to January is often a storm.
Wedus Gembel eruption every 15-30 minutes at the peak of Semeru mountain is still active. In November 1997 Mount Semeru erupted 2990 times as much. At noon the wind to the summit, to avoid it came in the afternoon peak, because the poisonous gas and the explosion led to the summit.
The eruption of white smoke, gray to black with the eruption of 300-800 meters high. Material that came out on every eruption of ash, sand, gravel, stones and even hot burning very dangerous if the climber is too close. In early 1994 the hot lava streaming down the southern slope Gn.Semeru and asked several casualties, hot river scenery, winding toward the sea has become a very interesting spectacle.
The mountain is entered in the National Park area Bromo Tengger Semeru. This National Park consists of mountains and valleys covering 50,273.3 hectares. There are several mountains in the Caldera Gn.Tengger among others; Gn.Bromo (2.392m) Mt. Batok (2.470m) Gn.Kursi (2.581 m) Gn.Watangan (2.662m) Gn.Widodaren (2.650m). There are four lakes (ranu): Ranu Pani, Ranu Regulo, Ranu Kumbolo, Ranu Darungan.
Flora in the Region of Mount Semeru diverse species but many dominated by pine, acacia, pine, and the type of Jamuju. As for the plants dominated by Kirinyuh, reeds, tembelekan, harendong and white Edelwiss, there is lots of Edelwiss on the slopes toward the Sumeru Peak. And also found several species of orchids endemic to living in the surrounding South Semeru.
Many of fauna which inhabit the mountain Sumeru, among others: Tiger Beetles, Budeng, Luwak, Kijang, Kancil, etc.. While in there Kumbolo Ranu Belibis wild living.