About Marion Island
Marion Island is a shield(s) rising to 1,230 meters (4,036 feet) in South Africa's Somalian-Antarctic Volcanic Regions. It has been active in recent decades, with its last eruption in 2004 CE. The volcano has produced 2 recorded eruptions, with a maximum Volcanic Explosivity Index (VEI) of 1.
Geography & Climate
Marion Island is located in South Africa, within the Marion Hotspot Volcano Group of the broader Somalian-Antarctic Volcanic Regions. Situated at 46.90° S, 37.75° E in the Southern Hemisphere, the volcano lies within a temperate climate zone. With a summit elevation of 1,230 meters above sea level, Marion Island 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
Marion Island 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 Marion Island in South Africa 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
Marion Island has 2 recorded eruptions in the geological database, spanning from 1980 CE to 2004 CE. The most powerful recorded event was a gentle, effusive event in 2004 CE, reaching VEI 1 on the Volcanic Explosivity Index. These eruptions span roughly 24 years of volcanic history. With eruptive activity as recently as 2004 CE, Marion Island remains an actively monitored volcano.
GVP Reference Summary
Marion Island lies at the SW end of a submarine plateau immediately south of the SW Indian Ocean Ridge, opposite Prince Edward Island. The low profile of the 24-km-wide dominantly basaltic and trachybasaltic volcano is formed by two young shields that rise above a flat-topped submarine platform. The island includes about 150 cinder cones, smaller scoria cones, and coastal tuff cones. The earliest dated eruptions took place about 450,000 years ago, but much of the island is covered by Holocene aa and pahoehoe lava flows, and more than 130 scoria cones formed during the Holocene. Many of these appear younger than the 4,020 BP peat layer overlying one of the flows (Verwoerd, 1981). Unvegetated lava flows appear to be only a few hundred years old (Verwoerd, 1967). An eruption in 1980 produced explosive activity and lava flows from a 5-km-long fissure that extended from the summit to the west coast.
— Smithsonian Institution, Global Volcanism Program
2 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 2004 | 1 | Confirmed Eruption | South side of island |
| 1980 | 1 | Confirmed Eruption | E-W fissure from summit to W coast |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Marion Island
Is Marion Island an active volcano?+
Yes, Marion Island is considered an active volcano. Its most recent eruption was in 2004 CE. The volcano is monitored by geological agencies, and its activity status is based on observed eruptions within recorded history.
When did Marion Island last erupt?+
The most recent recorded eruption of Marion Island occurred in 2004 CE with a Volcanic Explosivity Index (VEI) of 1. The eruption was classified as a "Confirmed Eruption." Marion Island has 2 recorded eruptions in total.
How high is Marion Island?+
Marion Island has a summit elevation of 1,230 meters (4,036 feet) above sea level. At 1,230 meters, it is a moderately sized volcanic peak, roughly comparable to Mount Vesuvius (1,281m).
What type of volcano is Marion Island?+
Marion Island is classified as a Shield(s). Shield volcanoes are broad, gently sloping volcanoes built by fluid lava flows. They produce less explosive eruptions compared to stratovolcanoes and tend to have effusive lava rather than violent blasts.
Where is Marion Island located?+
Marion Island is located in South Africa, in the Somalian-Antarctic Volcanic Regions. More specifically, it lies within the Marion Hotspot Volcano Group. Its exact coordinates are -46.900° latitude, 37.750° longitude.
Is it safe to visit Marion Island?+
Visiting Marion Island requires checking current volcanic activity and alert levels. As an active volcano with eruptions as recent as 2004 CE, conditions can change rapidly. Always consult local geological authorities and follow official warnings before visiting. Many active volcanoes have designated safe viewing areas and guided tour options.
