Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera.  The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises abruptly to 3676 m above coastal plains to the south.  Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas.  A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks.  Summit topography is complicated by the shifting of craters from NW to SE.  Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano.  Semeru has been in almost continuous eruption since 1967.

Semeru volcano
Volcano type	Stratovolcano
Location	East Java, Indonesia, 8.108°S / 112.92°E
Summit elevation	3676 m (12,060 ft)
Last eruptions	1818, 1829, 1830, 1832, 1836, 1838, 1842, 1844, 1845, 1848, 1849(?), 1851, 1856, 1857, 1865, 1866(?), 1887, 1887, 1888, 1889-91, 1892, 1893, 1893-94, 1895, 1896, 1897, 1899, 1899, 1900, 1901, 1903, 1904, 1905, 1907, 1908, 1909-10, 1910-11, 1911, 1912, 1913, 1941-42, 1945, 1946, 1946-47, 1950-64, 1967-ongoing (as of 2008)
Typical eruption style	Explosive. Near constant strombolian activity, occasionally stronger explosions, lava flows and pyroclastic flows.

 

  Source: GVP, Smithsonian Institution