Earthquake occurrence reveals magma ascent beneath volcanoes and seamounts in the Banda region
- 273 Downloads
Characteristic seismicity patterns beneath the volcanic arcs of the Banda region, SE Asia, suggest that magmatic processes have recently occurred beneath submarine portions of the arcs, forming yet-unrecognised submarine volcanoes. We have found that almost 50 % of earthquakes spatially associated with the Banda and Ambon volcanic arcs occurred in sequences with epicenters often concentrated in a small area and foci distributed in vertically elongated domains. The most pronounced occurrence of such earthquake series and swarms was observed in the area of the Manipa submarine basin (latitude 3.75°S, longitude 127.5°E, ESE of Buru Island), the remarkable morphology of which resembles a huge caldera (60 km in diameter) with a distinct cone seamount in its center, reaching almost 3000 m above seafloor. Another candidate for an unrecognised submarine volcano is an area between volcanoes Banda Api and Manuk, with a huge 1973/74 earthquake swarm. We assume that such a specific occurrence of earthquakes is induced by magma ascent and migration along faults above the subducting slab, with magma possibly occasionally reaching the sea floor. Utilization of teleseismic data can thus reveal activation of plumbing systems of submarine volcanoes, and highlight areas with the potential of near-future volcanic events.
KeywordsBanda region Global seismological data Earthquake swarms Magma ascent Calc-alkaline volcanism Seamounts
This research was supported by Ministry of Education, Youth and Sports of the Czech Republic grant No. ME09011 (KONTAKT program).
- Hall R, Metcalfe I, Smith JMB, Morwood M, Davidson ID (2001) Cenozoic reconstructions of SE Asia and the SW Pacific: Changing patterns of land and sea. In: Metcalfe I, Smith JMB, Morwood M, Davidson ID (eds) Faunal and floral migrations and evolution in SE Asia–Australasia. CRC Press, Boca Raton, pp 35–56Google Scholar
- Hamilton W (1979) Tectonics of the Indonesian Region. Geological Survey professional paper 1078, Washington, 345 pGoogle Scholar
- Siebert L, Simkin T (2002-) Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions. Smithsonian Institution, Global Volcanism Program Digital Information Series, GVP-3. http://www.volcano.si.edu/world/