About Graciosa
Graciosa is a stratovolcano rising to 402 meters (1,319 feet) in Portugal's Atlantic Ocean Volcanic Regions. It last erupted in 1950 BCE, and volcanologists consider it an active volcanic system. The volcano has produced 1 recorded eruption.
Geography & Climate
Graciosa is located in Portugal, within the Azores-Terceira Rift Volcanic Province of the broader Atlantic Ocean Volcanic Regions. Situated at 39.02° N, 27.97° W in the Northern Hemisphere, the volcano lies within a temperate climate zone. At just 402 meters above sea level, Graciosa is a relatively low-elevation volcanic feature. Despite its modest height, it remains an active geological formation with the same underlying magmatic processes as its taller counterparts. 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
Graciosa 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 Graciosa 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 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
Graciosa has 1 recorded eruption in the geological database, spanning from 1950 BCE to 1950 BCE.
GVP Reference Summary
The SE end of Graciosa, the northernmost of the central Azorean islands, contains a 0.9 x 1.6 km caldera with active fumaroles. The SE caldera rim is the high point of the 7 x 12 km island. The caldera has been the source of eruptions producing significant tephra falls, pyroclastic flows, lahars, and lava flows. Fumaroles are present in a volcanic cave inside the caldera, and a submarine fumarole occurs off the NW coast. Scoria cones erupted along several widely spaced NE-SW-trending fissures fed a youthful lava field that forms the NW end of the island. The most recent eruption from Pico Tomao, NW of the caldera, produced a lava flow during the mid-to-late Holocene that reached the eastern coast NW of the village of Praia.
— Smithsonian Institution, Global Volcanism Program
1 Recorded Eruption
| Year | VEI | Type | Area |
|---|---|---|---|
| 1950 BCE | — | Confirmed Eruption | San Tamao |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Graciosa
Is Graciosa an active volcano?+
Graciosa is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 1950 BCE. However, no volcano is ever considered permanently extinct.
When did Graciosa last erupt?+
The most recent recorded eruption of Graciosa occurred in 1950 BCE. The eruption was classified as a "Confirmed Eruption." Graciosa has 1 recorded eruption in total.
How high is Graciosa?+
Graciosa has a summit elevation of 402 meters (1,319 feet) above sea level. At 402 meters, it is a relatively low-elevation volcano.
What type of volcano is Graciosa?+
Graciosa is classified as a Stratovolcano. Stratovolcanoes (also called composite volcanoes) are steep, conical volcanoes built up by many layers of hardened lava, tephra, and volcanic ash. They are among the most common and dangerous types, known for explosive eruptions.
Where is Graciosa located?+
Graciosa is located in Portugal, in the Atlantic Ocean Volcanic Regions. More specifically, it lies within the Azores-Terceira Rift Volcanic Province. Its exact coordinates are 39.020° latitude, -27.970° longitude.
Is it safe to visit Graciosa?+
Graciosa can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Portugal may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
