TY - JOUR
T1 - Prerequisites for explosive cryovolcanism on dwarf planet-class Kuiper belt objects
AU - Neveu, M.
AU - Desch, Steven
AU - Shock, Everett
AU - Glein, C. R.
N1 - Funding Information:
We thank J.M. Dick for modifying the CHNOSZ R geochemistry package to work at subzero temperatures, and D.C. Napolitano and A.D. Edwards for helping with preliminary CHNOSZ calculations. Comments from two reviewers helped significantly improve the “Predictions for Pluto and Charon” section of this manuscript. M. Neveu is grateful to the Keck Institute for Space Studies for hosting him during part of this study. This work was supported by the NASA Astrobiology Institute node at Arizona State University.
Publisher Copyright:
© 2014 Elsevier Inc..
PY - 2014/4/5
Y1 - 2014/4/5
N2 - Explosive extrusion of cold material from the interior of icy bodies, or cryovolcanism, has been observed on Enceladus and, perhaps, Europa, Triton, and Ceres. It may explain the observed evidence for a young surface on Charon (Pluto's surface is masked by frosts). Here, we evaluate prerequisites for cryovolcanism on dwarf planet-class Kuiper belt objects (KBOs). We first review the likely spatial and temporal extent of subsurface liquid, proposed mechanisms to overcome the negative buoyancy of liquid water in ice, and the volatile inventory of KBOs. We then present a new geochemical equilibrium model for volatile exsolution and its ability to drive upward crack propagation. This novel approach bridges geophysics and geochemistry, and extends geochemical modeling to the seldom-explored realm of liquid water at subzero temperatures. We show that carbon monoxide (CO) is a key volatile for gas-driven fluid ascent; whereas CO2 and sulfur gases only play a minor role. N2, CH4, and H2 exsolution may also drive explosive cryovolcanism if hydrothermal activity produces these species in large amounts (a few percent with respect to water). Another important control on crack propagation is the internal structure: a hydrated core makes explosive cryovolcanism easier, but an undifferentiated crust does not. We briefly discuss other controls on ascent such as fluid freezing on crack walls, and outline theoretical advances necessary to better understand cryovolcanic processes. Finally, we make testable predictions for the 2015 New Horizons flyby of the Pluto-Charon system.
AB - Explosive extrusion of cold material from the interior of icy bodies, or cryovolcanism, has been observed on Enceladus and, perhaps, Europa, Triton, and Ceres. It may explain the observed evidence for a young surface on Charon (Pluto's surface is masked by frosts). Here, we evaluate prerequisites for cryovolcanism on dwarf planet-class Kuiper belt objects (KBOs). We first review the likely spatial and temporal extent of subsurface liquid, proposed mechanisms to overcome the negative buoyancy of liquid water in ice, and the volatile inventory of KBOs. We then present a new geochemical equilibrium model for volatile exsolution and its ability to drive upward crack propagation. This novel approach bridges geophysics and geochemistry, and extends geochemical modeling to the seldom-explored realm of liquid water at subzero temperatures. We show that carbon monoxide (CO) is a key volatile for gas-driven fluid ascent; whereas CO2 and sulfur gases only play a minor role. N2, CH4, and H2 exsolution may also drive explosive cryovolcanism if hydrothermal activity produces these species in large amounts (a few percent with respect to water). Another important control on crack propagation is the internal structure: a hydrated core makes explosive cryovolcanism easier, but an undifferentiated crust does not. We briefly discuss other controls on ascent such as fluid freezing on crack walls, and outline theoretical advances necessary to better understand cryovolcanic processes. Finally, we make testable predictions for the 2015 New Horizons flyby of the Pluto-Charon system.
KW - Charon
KW - Interiors
KW - Pluto
KW - Satellites
KW - Volcanism
KW - formation
UR - http://www.scopus.com/inward/record.url?scp=84921496334&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84921496334&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2014.03.043
DO - 10.1016/j.icarus.2014.03.043
M3 - Article
AN - SCOPUS:84921496334
SN - 0019-1035
VL - 246
SP - 48
EP - 64
JO - Icarus
JF - Icarus
ER -