Quantitative hydrologic and hydraulic models for jokulhlaup-type outflow channels on Mars: Application of Earth analogues, comparative geomorphology, and remote sensing

To better understand the geologic and hydrologic history of Mars, hydraulic models of catastrophic outflow channels on both Earth and Mars provides insight into the volumes of water necessary to create jokulhlaup-type outflow events. Applying these hydraulic models to Mars outflow channels serves to test hypotheses about the conveyance of water on Mars and if the water source was from air-fall precipitation that was contained in a source basin or if the water was derived from subsurface aquifers beneath a confining cryolithic (ground-ice) layer. Additionally, these models may provide insight to the climate dynamics of the Martian planet.;A one-dimensional standard step method hydraulic model is used for the estimation of catastrophic outflow from chaotic terrain on Mars. Jokulhlaup-type Earth analogue sites at Eddy Narrows, Montana, and Jokulsa a Fjollum channel in Iceland are used to refine and calibrate the model and to assess correlations between channel hydraulics and the fluvial geomorphology present. The model uses remote sensing data and geographic information system feature classes to create a more accurate hydraulic profile of the outflow channels. The derived channel geometry profile is input to the hydraulic model where subcritical to supercritical flow is computed under steady flow conditions.;A new method is developed as a guide to estimate the channel surface roughness coefficient, Manning's n, utilizing estimated thermal inertia from single-point temperature measurements from Mars orbital satellites and in situ collections from the Mars Exploration Rovers.;Earth analogue results show that a re-evaluation of the Glacial Lake Missoula paleoflood peak discharge at Eddy Narrows is less than originally estimated. The proposed new peak discharge is estimated at 8.9 x 10 6 m3 s-1, with a mean flow velocity of 16.5 m s-1 and a power of 4899 W m-2. Hydraulic modeling of the Jokulsa a Fjollum channel in Iceland resulted in the discovery of the largest Holocene paleoflood on Earth with a peak discharge of 2.2 x 107 m3 s-1 and mean flow velocity of 14.9 m s-1.;The first hydraulic modeling of the Aram Chaos channel on Mars indicates that the estimated peak discharge of 2.75 x 108 m3 s-1 and mean flow velocity of 27.6 m s-1 created enough power (24268 W m-2) to sculpt the channel in a single catastrophic event. The friable nature of the crater rim bedrock, extensive mass wasting, and slight sinuosity of the channel are morphological evidence of this event. The hydraulic model fits remarkably well to the observed high water lines to within 60 meters (sigma = 42).