Outlook
While these enormously powerful eruptions
are exciting and important for advancing
our knowledge of Io, a global understanding
requires studying the whole range of volcanic processes on this moon over time. With
this goal in mind, we have been monitoring
Io with Gemini North and the IRTF regularly
since the fall of 2013; we will continue our
Gemini observations into 2015. This program allows us to watch the week-to-week
variability in Io’s overall volcanic activity and
the evolution of specific active regions. The
study is key to understanding how the volcanic dissipation of Io’s tidally-generated
heat is di stributed spatially and temporally.
In addition, frequent observations increase
our chances of capturing major eruptions as
they occur. Our detection of three such energetic Ionian events in the same month (or
even the same year!) is extremely unusual.
Perhaps these events were physically linked
by an unknown mechanism, and clusters of
eruptions are more common than we think.
Or perhaps we fortuitously caught Io at a
unique point when three unrelated eruptions happened to coincide. Then again,
previous analyses may have simply underestimated the frequency of outburst eruptions
in general.
At this point in time, too few such events
have been detected to distinguish between
these possibilities. Future observations, including our ongoing program at Gemini
North, will help answer this question.
References:
Davies, A.G., et al., “Observing Iceland’s Eyjafjallajökull 2010 eruptions with the autonomous
NASA volcano sensor web,” Journal of Geophysical Research: Solid Earth, 118: 1–21, 2013
de Kleer, K., et al., “Near-infrared monitoring of
Io and detection of a violent outburst on 29 August 2013,” Icarus, in press, 2014
de Pater, I., et al., “Two new, rare, high-effusion
outburst eruptions at Rarog and Heno Paterae
on Io,” Icarus, in press, 2014
Marchis, F., et al., “High-resolution Keck adaptive
optics imaging of violent activity on Io,” Icarus,
160: 124–131, 2002
Katherine de Kleer is a Ph.D. student at UC Berkeley and can be reached at: [email protected]
Figure 4.
IRTF SpeX spectrum
of the August 29th
outburst with model
fits. The 1475 K model
assumes basaltic
magmas, while the
1900 K model assumes
an ultramafic magma
composition. Figure
adapted from de Kleer
et al., 2014.
October 2014
GeminiFocus
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