Tanna
Mount Yasur: An Active Volcano on Tanna Island
June 2015
Mount Yasur is an active volcano near the southeastern coast of Tanna Island, Vanuatu. Rising 1,184 feet (361 meters), it is a largely unvegetated scoria cone with a nearly circular summit crater approximately 1,312 feet (400 meters) across.
Yasur is part of the New Hebrides volcanic arc, where the Australian Plate descends eastward beneath the region along the New Hebrides Trench. Magma generated above this subduction zone feeds the active volcanoes of Vanuatu.
The volcano produces frequent Strombolian explosions, in which expanding gases eject incandescent lava fragments, volcanic bombs, ash, and gases from vents within the crater. Stronger Vulcanian explosions can also occur. These eruptive processes have built the cone from accumulated layers of scoria, ash, and other fragmented volcanic material.
Yasur was already active when James Cook reached Tanna in August 1774. Members of his expedition recorded the volcano’s fire, smoke, repeated explosions, and falling ash. Although the eruption history before this encounter is not fully documented, geological evidence indicates that activity may have continued for centuries.
When these photographs were taken in 2015, eruptions illuminated the crater after dark and periodically projected incandescent material above its rim. The Vanuatu Meteorology and Geo-Hazards Department monitors Yasur through seismic observations, visual assessments, gas measurements, and other volcanic data.
Current Context
As of July 2026, Mount Yasur remains active and is classified by the Vanuatu Meteorology and Geo-Hazards Department at Volcanic Alert Level 2, indicating major unrest. Conditions and exclusion zones can change, and official volcanic bulletins provide the authoritative current safety information.
