The University of Idaho's Outstanding Graduate Student Research Award for 2011 has been given to Alex Patthoff, a PhD candidate working with Professor Simon Kattenhorn in the Department of Geological Sciences. Alex, originally from West Virginia, came to UI in 2008 with undergraduate degrees in both Geology and Physics and a masters degree in structural geology. His work with Professor Kattenhorn on the planetary geology of Enceladus, an icy moon of Saturn, brings it all together. His work has been focused on analyzing fracture patterns in the ice near the south pole of Enceladus for clues about the processes at work there.
His work using ArcGIS techniques has identified four major sets of fractures, differentiated by their orientation and relative age. (While the actual age of the fractures cannot be identified simply from satellite imagery, the relative ages of intersecting fractures can be determined – a fracture that is offset by an intersecting fracture must be the older of the two.) The differences between the fracture sets indicate change in the stress field that caused the fractures. A likely explanation would be a gradual rotation of the ice shell caused by it spinning slightly faster than the moon itself. This motion would eventually change the face of ice subject to the greatest tidal pull from Saturn, opening the way for a new set of fractures to develop. The relative ages and orientations of the fracture sets seem consistent with this theory.
A significance of this finding would be the existence of a liquid layer beneath the ice sheet. Such a layer is known to exist on Jupiter's moon Europa, but Enceladus is much smaller and with a much smaller total volume of water present. The presence of a liquid layer there would raise new questions of where enough warming to create the layer might be coming from.
Alex expects to complete his PhD degree in May 2012. For now, his work on the ice of Enseladus continues.