Stretching Forces Shaped Jupiter Moon’s Surface Says New Research b4in.org/p5hr An image of a tabletop-size analog model (left) shows details of fault systems created by extension that visually match an image by spacecraft Galileo of faulted terrain on Ganymede (right). Left Image: Courtesy of Southwest Research Institute; Right Image: Courtesy of NASA/JPL SSI Processes that shaped the ridges and troughs on the surface of Jupiter’s icy moon Ganymede are likely similar to tectonic processes seen on Earth, according to a team of researchers led by Southwest Research Institute (SwRI). To arrive at this conclusion, the team subjected physical models made of clay to stretching forces that simulate tectonic action. The results were published in Geophysical Research Letters. Physical analog models simulate geologic structures in laboratory settings so that the developmental sequence of various phenomena can be studied as they occur. The team – including researchers from SwRI, Wheaton College, NASA’s Jet Propulsion Laboratory and NuStar Energy LP – created complex patterns of faults in their models, similar to the ridge and trough features seen in some regions of Ganymede. The models consisted of a “wet clay cake” material possessing brittle characteristics to simulate how the icy moon’s lithosphere, the outermost solid shell, responds to stresses by cracking. The laboratory models suggest that characteristic patterns of ridges and troughs, called grooved terrain on Ganymede, result from its surface being stretched. “The physical models showed a marked similarity to the surface features observed on Ganymede,” said co-author Dr. Danielle Wyrick, a senior research scientist in the SwRI Space Science and Engineering Division. “From the experiments, it appears that a process in which the crust breaks into separate blocks by large amounts of extension is the primary mechanism for creating these distinct features.” More b4in.org/p5hr
Posted on: Wed, 09 Jul 2014 02:29:31 +0000