Stephen Scheidt presented PSI research at the 54th Lunar and Planetary Science Conference in The Woodlands, Texas. Co-authors included PSI scientists David Crown and Dan Berman as well as Hannes Bernhardt and David Williams from Arizona State University. Their poster “Mapping Fluvial Systems on Martian Volcanoes: Investigations of Alba Mons and Amphitrites Patera” shows results from a series of projects that include geologic mapping of Martian volcanoes, in this case with a focus on fluvial dissection of volcanic flank materials.
Scheidt says that although fluvial systems are known to have shaped the surface at several points in Mars’ geological history, fluvial systems on some volcanoes can be outliers in age, morphology and geography (i.e., latitude and elevation). Valley networks were first identified and characterized by early satellite missions, including Mariner 9 and the Viking Orbiters. As part of detailed geological mapping projects of Martian volcanoes led by David Crown, current research maps fluvial systems using the latest, high spatial resolution imaging datasets – such as THEMIS, CTX and HiRISE – along with Martian topographic datasets.
Scheidt first used traditional photogeological mapping techniques to produce a database of fluvial valleys on the flanks of Alba Mons. He then used topography from MOLA (Mars Orbiter Laser Altimeter) to quantitatively characterize valley networks, delineate drainage basins, and model stream flow patterns. The combination of photogeologic mapping and hydrological modeling has allowed reconstructions of ancient watersheds now only partially preserved on Alba Mons’ flanks.
We’ve known since the days of exploring Mars’ surface that Alba Mons hosted a dense concentration of valleys arranged in integrated network patterns. The updated mapping and watershed reconstructions of the current research allow quantitative analyses of valley distribution (their presence is correlated with high local slopes) and network properties, showing how drainage density varies across the volcano and is comparable to watersheds on Earth. Our results from this detailed regional examination of Alba Mons’ fluvial valley networks have revealed inaccuracies in past work, including cases of false positives (volcanic lava tubes mapped as valley networks) and negatives (simply unmapped valleys). Global inventories of fluvial systems of the planet provide an important “big picture” of Mars’ fluvial history but detailed regional studies are needed to fully and accurately document the geological history recorded on the planet’s surface. Comparable studies of fluvial dissection have been initiated on the volcano. Amphitrites Patera, located on the rim of the Hellas impact basin in the southern highlands of Mars.
This research is supported by award numbers NNX15AM44G and NNX16AJ50G from NASA’s Mars Data Analysis Program. Work by S. P. Scheidt is partially supported by NASA under award number 80GSFC17M0002.