Fayal

Geography & Climate

Fayal is located in Portugal, within the Azores-Terceira Rift Volcanic Province of the broader Atlantic Ocean Volcanic Regions. Situated at 38.58° N, 28.71° W in the Northern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,041 meters above sea level, Fayal is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Fayal 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 Fayal in Portugal 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 andesite / basaltic andesite, 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

Fayal has 2 recorded eruptions in the geological database, spanning from 1672 CE to 1957 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1957 CE, reaching VEI 2 on the Volcanic Explosivity Index. These eruptions span roughly 285 years of volcanic history. The most recent eruption in 1957 CE places this volcano within the modern era of volcanological observation.

GVP Reference Summary

The island of Fayal, also spelled Faial, is the nearest of the central Azorean islands to the Mid-Atlantic Ridge. The island is composed of a complex large andesitic-to-trachytic stratovolcano that contains a 2-km-wide summit caldera. Thick deposits of trachytic airfall pumice, pyroclastic flows, and lahars related to formation of the caldera cover the island. Formation of the steep-walled 400-m-deep caldera was followed by construction of fissure-fed basaltic lava fields and small volcanoes that form a peninsula extending to the west. This area is covered by the youngest volcanic products on the island. A submarine eruption at Capelinhos during 1957-58 created a new island that soon merged with the western peninsula.

— Smithsonian Institution, Global Volcanism Program