Haleakala

Geography & Climate

Haleakala is located in United States, within the Hawaiian-Emperor Hotspot Volcano Group of the broader Eastern Pacific Volcanic Regions. Situated at 20.71° N, 156.25° W in the Northern Hemisphere, the volcano lies within a tropical climate zone. At 3,053 meters above sea level, Haleakala rises above the surrounding terrain into montane or subalpine conditions. The elevation creates distinct ecological zones along its flanks, from forested lower slopes to exposed rocky terrain near the summit. 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

Haleakala is an intraplate volcano, meaning it formed away from any plate boundary. These volcanoes are often powered by hotspots — plumes of abnormally hot mantle material rising from deep within the Earth. Hotspot volcanoes like Haleakala tend to produce effusive eruptions with lava flows that can be relatively predictable, giving nearby communities in United States more time to prepare. However, they can also produce explosive phases, particularly when magma interacts with groundwater. 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

Haleakala has 20 recorded eruptions in the geological database, spanning from 1310 BCE to 1750 CE. With an average interval of roughly 153 years between eruptions over a span of 3,060 years, this is one of the more frequently active volcanoes in the database. This persistent activity suggests a robust and well-supplied magma system beneath the volcano.

Significance

Its 20 recorded eruptions make it one of the most prolific volcanoes in our database, reflecting a persistent and well-documented eruptive history that has provided volcanologists with extensive data for understanding eruption patterns and forecasting future activity.

GVP Reference Summary

The massive Haleakala shield volcano forms the eastern portion of the island of Maui. The summit is at the NW end of a volcanic ridge and at the head of a large scarp that opens to the ENE, interrupting the ridge which continues 7 km across the valley, formed as a result of the coalescence of headward erosion of the Koolau and Kaupo valleys. Subsequently the valley has been partially filled by a chain of young cinder cones and lava flows erupted along the rift zone that extends across the basaltic volcano from the SW to the E flanks. The most recent eruption was thought to have occurred between the exploring voyages of La Perouse in 1786 and Vancouver in 1793, but uncertainty surrounds the date of this event, which could have occurred in about 1750 CE (anthropological evidence) or several centuries earlier (radiocarbon dates).

— Smithsonian Institution, Global Volcanism Program