Loki Patera

Io's lava lakes such as Loki Patera are depressions partially filled with molten lava covered by a thin solidified crust. These lava lakes are directly connected to a magma reservoir below.{{cite book |last=Davies |first=A. |title=Volcanism on Io: A Comparison with Earth |date=2007 |publisher=Cambridge University Press |isbn=978-0-521-85003-2 |pages=142–52 |chapter=Effusive activity: landforms and thermal emission evolution}} Observations of thermal emission at several of Io's lava lakes reveal glowing molten rock along Loki Patera's margin, caused by the lake's crust breaking up along the edge of the patera. Over time, because the solidified lava is denser than the still-molten magma below, this crust can founder, exposing fresh, hot molten rock.{{cite journal |title=Io: Loki Patera as a magma sea |journal=J. Geophys. Res. |last=Matson |first=D. L. |display-authors=etal |pages=E09002 |volume=111 |issue= E9|date=2006 |doi=10.1029/2006JE002703 |bibcode=2006JGRE..111.9002M}} At sites such as Loki Patera, this can occur episodically. During an overturning episode, Loki can emit up to ten times more heat than when its crust is stable.

During an eruption, a wave of foundering crust has been observed to spread out across the patera at the rate of about {{convert|1|km|ft|abbr=on|-2}} per day, until the crust of the lake has been resurfaced. Another eruption then begins once the new crust has cooled and thickened enough for it to no longer be buoyant over the molten lava.{{cite journal |title=Loki, Io: New ground-based observations and a model describing the change from periodic overturn |journal=Geophysical Research Letters |last=Rathbun |first=J. A. |author2=J. R. Spencer |pages=L17201 |volume=33 |issue= 17|date=2006 |doi=10.1029/2006GL026844 |bibcode=2006GeoRL..3317201R|arxiv = astro-ph/0605240 |s2cid=29626659 }}

On {{start date and age|2015|3|8|df=y|paren=y}}, a rare orbital alignment occurred between Io and Europa, two of the moons of Jupiter, that allowed researchers to distinguish heat being emitted from Loki Patera. They were able to accomplish this because Europa's surface is coated in water ice which reflects small amounts of sunlight at infrared wavelengths. Scientists were able to determine that there were two waves of resurfacing lava, which explains the change in brightness on Loki Patera every 400–600 days. The images that helped researchers discover this were captured by the Large Binocular Telescope Observatory in southeast Arizona. The observation also revealed that there is a difference in the magma supply of the two halves of Loki.{{Cite web|url=https://www.sciencedaily.com/releases/2017/05/170510132017.htm|title=Waves of lava seen in Jupiter's moon Io's largest volcanic crater|last=University of California|first=Berkeley|date=2017-05-10|access-date=2017-10-11}}

In December 2023 and February 2024, the Juno spacecraft completed extremely close flybys of Io, including the first closeup images of the northern latitudes, showing the islands within Loki Patera surrounded by a reflective glassy black surface.{{Cite web |date=2024-04-18 |title=NASA’s Juno Gives Aerial Views of Mountain, Lava Lake on Io - NASA |url=https://www.nasa.gov/missions/juno/nasas-juno-gives-aerial-views-of-mountain-lava-lake-on-io/ |access-date=2024-04-27 |language=en-US}}

{{commonscat|Loki Patera}}

• Volcanism on Io
• List of volcanic features on Io

{{reflist|1}}

• [http://photojournal.jpl.nasa.gov/catalog/PIA00856 "NIMS Observes Increased Activity at Loki Patera, Io", JPL Planetary Photojournal]
• [http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1950.pdf "An Impact Genesis for Loki Patera?" Lunar and Planetary Science XXXVI (2005)]

• [http://ciclops.org/view/4136/Loki_PateraNIMS?js=1 Loki Patera/NIMS at CICLOPS]

{{Io}}

Category:Volcanoes of Io (moon)

Category:Active volcanoes

Category:Lava lakes