EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Magma chamber imaged beneath an arc volcano

Kajetan Chrapkiewicz1, Michele Paulatto1, Joanna Morgan1, Benjamin Heath2,6, Emilie Hooft2, Paraskevi Nomikou3, Constantinos Papazachos4, Florian Schmid5, Michael Warner1, and Douglas Toomey2
Kajetan Chrapkiewicz et al.
  • 1Department of Earth Science and Engineering, Imperial College London, United Kingdom (
  • 2Department of Earth Sciences, University of Oregon, Eugene, United States of America
  • 3Faculty of Geology and Geo-Environment, University of Athens, Greece
  • 4Geophysical Laboratory, Aristotle University of Thessaloniki, Greece
  • 5GEOMAR Helmholtz-Centre for Ocean Research Kiel, Germany
  • 6Now at National Tsunami Warning Center, Palmer, Alaska, United States of America
Arc volcanoes are underlain by complex systems of molten-rock reservoirs ranging from melt-poor mush zones to melt-rich magma chambers. Petrological and satellite data indicate that eruptible magma chambers form in the topmost few kilometres of the crust. However, no such a chamber has ever been imaged unambiguously, suggesting that large chambers responsible for caldera-forming eruptions are too short-lived to capture. Here we use a high-resolution imaging method based on finite-length seismic waveforms to detect a small, high-melt-fraction magma chamber embedded in a melt reservoir extending from ~2 to at least 4 km b.s.l. beneath Kolumbo – a submarine volcano near Santorini, Greece. The chamber coincides with the termination point of the recent earthquake swarms, and may be a missing link between a deeper melt reservoir and the high-temperature hydrothermal system venting at the crater floor. Though too small to be detected by standard seismic tomography, the chamber is large enough to threaten the nearby islands with tsunamigenic eruptions. Our results suggest that similar reservoirs (relatively small but high melt-fraction) may have gone undetected, and are yet to be discovered, at other active volcanoes.

How to cite: Chrapkiewicz, K., Paulatto, M., Morgan, J., Heath, B., Hooft, E., Nomikou, P., Papazachos, C., Schmid, F., Warner, M., and Toomey, D.: Magma chamber imaged beneath an arc volcano, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12184,, 2022.

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