Mount Gharat, Active stratovolcano in Banks Islands, Vanuatu

Mount Gharat is a somma volcano reaching 797 m at the centre of Gaua, the highest point of the island. It stands inside a 6 by 9 km caldera that also holds Lake Letas and several cones and thermal springs. The summit consists of four craters, one containing the crescent-shaped Lake Stimming. The volcano is built of andesite and basalt.

Mount Gharat was considered dormant until July 1962, after which it erupted more than fifteen times, releasing steam, sulphur dioxide and lava from the summit crater. In October 2009 a Strombolian eruption forced the evacuation of 300 people from three villages to nearby islands, raised the water of Lake Letas by 30 cm and sent ash to 3,000 m. Activity today takes the form of minor tremors, fumarole fields and ash emissions; a hazard map was drawn up in 2011.

The name varies by local language: Garet in Nume, Grāt in Dorig, Gerät in Koro, Gäräs in Lakon; the map spelling Gharat transcribes Mota or Olrat Garat. All descend from Proto-Torres-Banks *ɣarati, literally "itching, burning", perhaps referring to the volcano's toxic fumes.

Access to the summit is by boat from Espiritu Santo to Gaua, then on foot with a local guide who can organise the climb; allow enough time for the ascent. In October 2009, 300 people from three villages were evacuated during a strombolian eruption, so check volcanic activity reports and follow local safety advice before setting out.

The mountain displays solfataras on its southern flank and hot springs on its northern face, creating two contrasting thermal zones within the same volcano. This divided geothermal character along opposite sides is an unusual feature that sets this system apart.