Santa Cruz

Geography & Climate

Santa Cruz is located in Ecuador, within the Galapagos Hotspot Volcano Group of the broader Eastern Pacific Volcanic Regions. Situated at 0.62° S, 90.33° W in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 864 meters above sea level, Santa Cruz 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

Santa Cruz 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 Santa Cruz in Ecuador 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.

GVP Reference Summary

The highlands of the broad Santa Cruz shield volcano rise to the N above the Charles Darwin Research Station at Academy Bay. The oval-shaped, 32 x 40-km-wide island is capped by youthful pit craters and cinder cones with well-preserved craters that largely bury a shallow summit caldera. Older uplifted submarine lava flows are found on the NE part of the island and at the fault-delimited offshore island of Baltra. The highland scoria cones are grouped along an E-W belt parallel to recent fault scarps that border Academy Bay. The youngest lava flows were erupted from vents along the summit fissure and on the N flank. Their fresh morphology and sparsely vegetated surfaces suggest they may be only a few thousand years old, although their ages are not known precisely.

— Smithsonian Institution, Global Volcanism Program