PG_logo Bridge to Mars:
Planetary Geophysics Lab

Colorado School of Mines
Department of Geophysics
Jeff Andrews-Hanna
Associate Research Prof.
Dept of Geophysics
Green Center, Rm 280K

Field trip
Our group uses a combination of numerical modeling, analysis of gravity and topography, and geomorphology to understand the interaction of a variety of processes responsible for shaping the surfaces and interiors the terrestrial planets and moons in our solar system. We are particularly interested in the interaction of geodynamic, tectonic, volcanic, climatic, and hydrologic processes at a variety of scales. Much of our research is focused in two main areas: the climatic and hydrological evolution of Mars and Titan, and the tectonic and geodynamic evolution of Mars and the Earth's Moon.

For a list of publications, click here

A brief discussion of some of my individual research projects follows.

Active projects:
GRAIL GRAIL Gravity: I am a guest scientist on the GRAIL science team, studying the gravity of the Moon. In one project with this data, I used gravity gradiometry to identify a population of giant dikes that were previously unknown. These reveal a period of early lunar expansion as the interior of the Moon was warming up during its first 500 Myr.
Rain Martian climate: Did it ever rain on Mars? If so, where, how much, and for how long? Post-doc Alejandro Soto is modeling the early martian climate to answer these questions. Combined with groundwater modeling, this work helps us understand how ancient sedimentary deposits formed in Meriidani Planum and Gale Crater, the future landing site of NASA's MSL mission.
Valles Marineris Valles Marineris: This enormous tectonic canyon system is 2000 km long, 200 km wide, and 8 km deep. I am investigating how and why it formed. Work is focusing on the relationship of Valles Marineris to the dichotomy and the mechanism of its formation.
(JGR 2012a, JGR 2012b)
Olympus Mons Olympus Mons: is the largest shield volcano in the solar system. We are investigating its formation history using topographic analyses, crater counting, and flexural modeling. Paleotopography reveals that it formed early, with only minor subsequent volcanism.
( LPSC 2011c)
Orientale Lunar impact basins: The topography and gravity of the moon are dominated by the effects of impact basins. I am studying the subsurface structure of these basins and the implications for their formation.
( LPSC 2011d)
Meridiani Meridiani Planum: We are investigating the origin, evolution, and climatic implications of the extensive playa deposits at Meridiani Planum. These evaporites formed as a result of groundwater upwelling on an arid early Mars.
( LPSC 2011e, JGR 2011, JGR 2010, Nature 2007)
Titan Titan's Lakes: Saturn's moon Titan has the only active hydrological system in the solar system other than Earth, with lakes and rivers of liquid methane. I am investigating the subsurface hydrology on Titan, and its role in the formation and stability of lakes.
(stay tuned for more)
dichotomy Martian hemispheric dichotomy: I am investigating the possibility that the dichotomy between the southern highlands and northern lowlands may have been the result of a giant impact. Current work is focusing on the Arabia Terra region as a ring structure around the basin
(Nature 2008, LPSC 2010)

Recent work:
strikeslip Strike-slip faults on Mars: I have mapped a new population of ancient strike-slip faults on Mars and used them to shed light on the thermal and tectonic evolution of the planet.
South Pole Mars south polar cap density: I used MOLA topography, gravity data from the MRO spacecraft, and radar sounding from MARSIS to calculate the density of the south polar layered deposits on Mars. More recently, Junlun Li has mapped out density variations within the SPLD.
Hellas Giant impact basins: The surfaces of Mars and the Moon are marred by several giant impact basins, including Hellas, Utopia, and the South Pole-Aitken basin. I am trying to understand why these basins appear the way they do.
chaos Martian outflow channel floods: Many of the martian outflow channels originate in regions of disrupted ground called "chaos regions". I have used numerical modeling to show that these floods would likely have been periodic.
Mangala Earthquake-triggered floods on Mars: Several Martian outflow channels originate within tectonic features (including Mangala and Athabasca Valles). I have demonstrated that the tectonism itself could have pressurized the aquifers and directly caused the flooding.
graph Climate change and hydrology: It has been suggested that dramatic changes in the Martian climate could have triggered the outflow channel floods. In modeling this process I have found that the required pore pressures and flood volumes could not likely be produced by this mechanism alone.

Publications and Presentations