Geochemistry, Mineralogy, Volcanology Research Spotlight

Found: The Submarine Source of an 1891 Eruption Near Sicily

Analysis of a volcano may help explain why some eruptions produce volcanic balloons–hollow chunks of lava that encase a gas-filled cavity.


In 1891, an underwater volcano of the Pantelleria volcanic complex, located offshore of Italy’s Pantelleria Island in the Strait of Sicily, erupted. This is the only recorded volcanic eruption of this complex in history, and until now, no one knew which volcano had erupted.

More than 120 years after the fact, Conte et al. integrated different data from multiple sources to ultimately identify the location as well as the style of the eruption. Their results help improve scientists’ knowledge of underwater volcanic eruptions in shallow waters as well as the rare types of eruptions that produce lava balloons, the researchers explain.

Lava balloons are hollow chunks of lava that encase a gas-filled cavity. These chunks float to the surface, but they have been observed in only a handful of submarine eruptions, including the offshore eruptions near Pantelleria, Italy, in 1891; Mauna Loa, Hawaii, in 1877; Socorro Island, Mexico, in 1993; and El Hierro, Canary Islands, in 2011.

Using high-resolution bathymetry, the researchers studied the seafloor pertaining to the Pantelleria volcanic complex, as well as the texture, the chemistry, and the age of samples collected near the vent location of the 1891 eruption.

The team compared their chemical data with those reported by historical analyses of volcanic balloons taken in 1891, finding a significant match between the samples. Bathymetric data used to map the seafloor, along with volcanic products features, were combined to constrain the site of lava balloon emissions. Moreover, the team explained the formation of lava balloons, bombs, and glass ash-sized grains emitted during the 1891 explosive activity.

The results point to a small submarine volcanic vent located about 300 meters southwest of the location originally reported in 1891. The cone is 90 meters high and at least 250 meters deep and has a volume of 700,000 cubic meters. The vent sits within a newly discovered submarine volcanic field northwest of Pantelleria Island. (Geochemistry, Geophysics, Geosystems, doi:10.1002/2014GC005238, 2014)

—Jessica Orwig, Freelance Writer

Citation: Orwig, J. (2015), Found: The submarine source of an 1891 eruption near Sicily, Eos, 96, doi:10.1029/2015EO025221. Published on 3 March 2015.

© 2015. The authors. CC BY-NC 3.0