Wapi Lava Field

Geography & Climate

Wapi Lava Field is located in United States, within the Yellowstone-Snake River Hotspot Volcano Group of the broader North America Volcanic Regions. Situated at 42.89° N, 113.22° W in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,597 meters above sea level, Wapi Lava Field is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a shield, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Wapi Lava Field is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Wapi Lava Field in United States generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Wapi Lava Field has 1 recorded eruption in the geological database, spanning from 300 BCE to 300 BCE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 300 BCE, reaching VEI 2 on the Volcanic Explosivity Index.

GVP Reference Summary

The Wapi Lava Field, SE of the Craters of the Moon, covers about 325 km2, and consists of a low shield volcano formed during an eruption around 300 BCE that produced ~6 km3 of pahoehoe lava flows. The small King's Bowl rift immediately to the north was also formed at about the same time along a central eruptive fissure flanked by two parallel non-eruptive fissures. This eruption produced a phreatic explosion that created Kings Bowl, an 80-m-long, 30-m-deep explosion crater. Eruptions overlapped with the last eruptive period of the Craters of the Moon lava field. The vent area lies along the Great Rift of the Craters of the Moon and consists of five major and a half-dozen minor vents covering an area of 0.5 km2. The largest of the vents contains several pit craters truncating lava lakes that filled the crater. Pillar Butte, a mass of layered lava flows and agglutinates, forms the high point of the lava shield. The Split Butte maar to the west is partially overlapped by flows of the Wapi field.

— Smithsonian Institution, Global Volcanism Program