Surt is an activevolcano onJupiter'smoonIo. It is located on Io's Jupiter-facing hemisphere at45°13′N336°29′W / 45.21°N 336.49°W /45.21; -336.49 (Surt).[1] Surt consists of an oblong volcanic pit (known as apatera), 75 by 40 kilometres (47 by 25 mi) in diameter, surrounded by reddishsulfur and brightsulfur dioxide deposits to its south and east.[2][3] The volcano was first observed in images acquired by theVoyager 1 spacecraft in March 1979.[4] Later that year, theInternational Astronomical Union named this feature afterSurtr, a leader of the fire giants ofNorse mythology.
Several eruptions have been observed at Surt since it was discovered byVoyager 1. The first eruption observed by Earth-based astronomers following the discovery ofIonian volcanism took place at Surt on June 11, 1979, between theVoyager 1 andVoyager 2 flybys.[2][5] WhenVoyager 2 encountered the Jupiter system in July 1979, the eruption appeared to have ceased, but a fresh, 600 kilometres (370 mi)-wide plume deposit was observed surrounding Surt.[4] This plume deposit was suggestive of an activePele-type plume at Surt between the two Voyager encounters.[2] In addition, dark material, thought to be lava erupted during the eruption, was visible within the eastern half of the patera.[5] When theGalileo spacecraft first took images of the area in 1996, the appearance of Surt and the surrounding terrain had reverted to its appearance as seen byVoyager 1, again suggestive of a short-lived eruption.[3]
Surt erupted again on February 22, 2001 in the most powerful volcanic eruption ever observed, in terms of the amount of power (in watts) output by the eruption.[6] The total power output observed at Surt (7.2–8.4 × 1013 W) during this eruption nearly matches the average total power output for all of Io's volcanoes. Despite such a violent eruption, few surface changes were observed in conjunction with the eruption in images acquired byGalileo six months later, suggesting that any changes had largely faded.[3] Fresh, sulfur-rich, reddish deposits were seen in images acquired by Galileo in August 2001 to the northeast of Surt.
References
edit- ^Blue, Jennifer (October 1, 2008)."Io Nomenclature: Eruptive center". USGS. Archived fromthe original on 2006-10-02. Retrieved2008-10-01.
- ^abcMcEwen, A. S.; Soderblom, L. A. (1983). "Two classes of volcanic plume on Io".Icarus.55 (2):191–217.Bibcode:1983Icar...55..191M.doi:10.1016/0019-1035(83)90075-1.
- ^abcGeissler, P.; et al. (2004)."Surface changes on Io during the Galileo mission".Icarus.169 (1):29–64.Bibcode:2004Icar..169...29G.doi:10.1016/j.icarus.2003.09.024.
- ^abSmith, B. A.; et al. (1979). "The Galilean Satellites and Jupiter: Voyager 2 Imaging Science Results".Science.206 (4421):927–950.Bibcode:1979Sci...206..927S.doi:10.1126/science.206.4421.927.PMID 17733910.S2CID 22465607.
- ^abSinton, W. M. (1980). "Io: Are Vapor Explosions Responsible for the 5-μm Outbursts?".Icarus.43 (1):56–64.Bibcode:1980Icar...43...56S.doi:10.1016/0019-1035(80)90087-1.
- ^Marchis, F.; et al. (2002). "High-Resolution Keck Adaptive Optics Imaging of Violent Volcanic Activity on Io".Icarus.160 (1):124–131.Bibcode:2002Icar..160..124M.doi:10.1006/icar.2002.6955.