Application of the Glacial Outburst Flood Model to Mars
Jökulhlaups are caused by the abrupt drainage of ice dammed lakes or subglacial volcanic eruption... more Jökulhlaups are caused by the abrupt drainage of ice dammed lakes or subglacial volcanic eruptions in polar latitudes. The probable causes of martian floods are either massive releases of groundwater or drainage of surface lakes.
Antarctic lakes (above and beneath the ice sheet): Analogues for Mars
Polar Regions of Mars Geology Glaciology and Climate History, 1992
The perennial ice covered lakes of the Antarctic are considered to be excellent analogues to lake... more The perennial ice covered lakes of the Antarctic are considered to be excellent analogues to lakes that once existed on Mars. Field studies of ice covered lakes, paleolakes, and polar beaches were conducted in the Bunger Hills Oasis, Eastern Antarctica. These studies are extended to the Dry Valleys, Western Antarctica, and the Arctic. Important distinctions were made between ice covered and non-ice covered bodies of water in terms of the geomorphic signatures produced. The most notable landforms produced by ice covered lakes are ice shoved ridges. These features form discrete segmented ramparts of boulders and sediments pushed up along the shores of lakes and/or seas. Sub-ice lakes have been discovered under the Antarctic ice sheet using radio echo sounding. These lakes occur in regions of low surface slope, low surface accumulations, and low ice velocity, and occupy bedrock hollows. The presence of sub-ice lakes below the Martian polar caps is possible. The discovery of the Antarctic sub-ice lakes raises possibilities concerning Martian lakes and exobiology.
New MOC Observations of Dorsa Argentea Sinuous Ridges
New photogeologic analysis of the enigmatic sinuous ridges of the Dorsa Argentea region near the ... more New photogeologic analysis of the enigmatic sinuous ridges of the Dorsa Argentea region near the Martian south pole have been conducted utilizing MOC data. These ridges have significant paleoclimatic implications whatever their origin.
Observation is the primary role of all field geologists, and geologic observations put into an ev... more Observation is the primary role of all field geologists, and geologic observations put into an evolving conceptual context will be the most important data stream that will be relayed to Earth during a planetary exploration mission. Sample collection is also an important planetary field activity, and its success is closely tied to the quality of contextual observations. To test protocols for doing effective planetary geologic fieldwork, the Desert RATS (Research and Technology Studies) project deployed two prototype rovers for two weeks of simulated exploratory traverses in the San Francisco volcanic field of northern Arizona. The authors of this paper represent the geologist crewmembers who participated in the 2010 field test. We document the procedures adopted for Desert RATS 2010 and report on our experiences regarding these protocols. Careful consideration must be made of various issues that impact the interplay between field geologic observations and sample collection, including time management; strategies related to duplication of samples and observations; logistical constraints on the volume and mass of samples and the volume/transfer of data collected; and paradigms for evaluation of mission success. We find that the 2010 field protocols brought to light important aspects of each of these issues, and we recommend best practices and modifications to training and operational protocols to address them. Underlying our recommendations is the recognition that the capacity of the crew to ''flexibly execute'' their activities is paramount. Careful design of mission parameters, especially field geologic protocols, is critical for enabling the crews to successfully meet their science objectives. Science Team that supports the crew during CC; Science Team, mission control personnel that support, guide, and direct the science operations done by the crew; SEV, space exploration vehicle; Station, location where SEV has stopped for science or operational work (with or without an EVA); Suitport, rear hatches on the SEV that allow quick egress/ingress for EVAs along with dust mitigation; Traverse, series of Stations and drives n Corresponding author. Tel.: þ1 915 747 5669; fax: þ1 915 747 5073. (J.M. Hurtado Jr.). Acta Astronautica ] (]]]]) ]]]-]]] Please cite this article as: J.M. Hurtado Jr. et al., Field geologic observation and sample collection strategies for planetary surface exploration:
A Comparison of MOC and MOLA Observations of Northern Plains ``Contacts'' with Coastal Landforms of the Bonneville Basin, Utah
Lunar and Planetary Science Conference, Feb 1, 2001
The Mars Global Surveyor has now completed its nominal mission. Among its many science objectives... more The Mars Global Surveyor has now completed its nominal mission. Among its many science objectives, the question of whether or not lakes or oceans existed on Mars is arguably one of the most provocative.
Amazonis and Utopia Planitiae are two large basins on Mars that have morphologic features commonl... more Amazonis and Utopia Planitiae are two large basins on Mars that have morphologic features commonly associated with former standing bodies of water. Like Elysium, the basins exhibit terraces and lineations resembling shorelines, etched and infilled floors marked by sinuous channels in places, inflow channels along their borders, and other geomorphic indicators believed to be related to the presence of water and ice. Moreover, most of the shoreline features have consistent elevations of about -1000 m, which suggests that the bodies of water thought to have occupied the basins may once have been connected. Although the concept of large paleolakes in the northern lowlands of Mars might be expanded to include inland seas, it is still premature to advance this hypothesis at the present stage of investigation. Even though these postulated paleolakes are very young in the Martian stratigraphic sequence, they are probably much older than large Pleistocene lakes on earth, and their shoreline features are less well preserved.
Evidence of the Presence of Jarosite and Diagenetic Activity in the Mawrth Vallis Region
CRISM and HiRISE data over the Mawrth Vallis region are examined and we find evidence for diagene... more CRISM and HiRISE data over the Mawrth Vallis region are examined and we find evidence for diagenetic activity and find a localized occurrence with a distinctive spectral signature which we identify as jarosite. Implications for the history of the region are discussed.
Overview of the Field Geologic Context of Mars Exploration Rover Spirit, Home Plate and Surroundings
This work provides field context for APXS, MB, MI results of Spirit at Home Plate. High silica /s... more This work provides field context for APXS, MB, MI results of Spirit at Home Plate. High silica /sulfates, nanophase iron oxides, and hematite occur mostly in the lowest stratigraphic unit exposed along the axis of breached antiformal bedding.
Facies on Mars: A Model for the Chryse Basin Outflow Sediments Based on Analog Studies of Icelandic Sandar and the Ephrata Fan of the Channeled Scabland, Washington
Mars Pathfinder Landing Site Workshop Ii Characteristics, Sep 1, 1995
Geomorphology of the Columbia Hills Complex: Landslides, Volcanic Vent, and Other Home Plates
Spirit has been exploring the Columbia Hills region of Gusev Crater for over five and a half year... more Spirit has been exploring the Columbia Hills region of Gusev Crater for over five and a half years. New observations from both the surface and orbit have revealed landslides, a possible volcanic vent, and additional Home Plate-like materials.
The goals of field study on Mars are nothing less than to understand the processes and history of... more The goals of field study on Mars are nothing less than to understand the processes and history of the planet at whatever level of detail is necessary. A manned mission gives us an unprecedented opportunity to use the immense power of the human mind to comprehend Mars in extraordinary detail. To take advantage of this opportunity, it is important to examine how we should approach the field study of Mars. In this effort, we are guided by over 200 years of field exploration experience on Earth as well as six manned missions exploring the Moon.
1] Glaciological observations of under-flooding suggest that fluid-induced hydraulic fracture of ... more 1] Glaciological observations of under-flooding suggest that fluid-induced hydraulic fracture of an ice sheet from its bed sometimes occurs quickly, possibly driven by turbulently flowing water in a broad sheet flow. Taking the approximation of a fully turbulent flow into an elastic ice medium with small fracture toughness, we derive an approximate expression for the crack-tip speed, opening displacement and pressure profile. We accomplish this by first showing that a Manning-Strickler channel model for resistance to turbulent flow leads to a mathematical structure somewhat similar to that for resistance to laminar flow of a power law viscous fluid. We then adapt the plane-strain asymptotic crack solution of and the power law self-similar solution of Adachi and Detournay for that case to calculate the desired quantities. The speed of crack growth is shown to scale as the overpressure (in excess of ice overburden) to the power 7/6, inversely as ice elastic modulus to the power 2/3, and as the ratio of crack length to wall roughness scale to the power 1/6. We tentatively apply our model by choosing parameter values thought appropriate for a basal crack driven by the rapid drainage of a surface meltwater lake near the margin of the Greenland Ice Sheet. Making various approximations perhaps relevant to this setting, we estimate fluid inflow rate to the basal fracture and vertical and horizontal surface displacements and find order-of-magnitude agreement with observations by associated with lake drainage. Finally, we discuss how these preliminary estimates could be improved.
Possible origins for phyllosilicate-rich materials observed at Mawrth Vallis: Evidence from fracture patterns and reflectance spectra
Agu Fall Meeting Abstracts, Dec 1, 2008
Al-OH and (Mg)Fe-OH absorptions attributable to phyllosilicate minerals have been observed in OME... more Al-OH and (Mg)Fe-OH absorptions attributable to phyllosilicate minerals have been observed in OMEGA and CRISM imaging spectrometer data from the Mawrth Vallis region of Mars. These deposits have been characterized in terms of their mineralogy and textural characteristics; however, the origin of these deposits is still very much a mystery. Here we consider possible origin hypotheses for these materials. A lithostratigraphic sequence has been determined for the light-toned Mawrth Vallis strata based on their reflectance characteristics. A basal layer of nontronite and/or (Fe)Mg bearing smectites is surmounted by materials with less well defined absorption bands. An absorption near 2.3 microns and a broad band centered near 1 micron in these layers suggest the presence of ferrous iron bearing phyllosilicates. These materials are surmounted by materials with different forms of 2.2 micron absorptions. Depending on where they occur in the sequence and where they occur laterally there are spectra more characteristic of montmorillonite, other materials with a broad 2.2 micron band which have been interpreted as hydrated silica, but which we suggest might be consistent with a kaolinite-smectite mixture, and other materials with a doublet at 2.2 microns consistent with kaolinite or dickite. These layers also have associated fracture patterns unique to the layers. Hypotheses for the nature of the fracture patterns have generally centered on hypotheses such as the desiccation of wet fine grained sediments (clays/silts) and/or the mechanism of ground ice contraction and expansion. Given that the Mawrth Vallis layered materials apparently were buried and are currently being uncovered, we suggest that the fractures might be the result of tectonic stresses imposed by an overburden. Terrestrial sedimentary rocks display different fracture patterns based on their different rheologic character which is in turn dictated by composition. An intriguing analogy might be that of layer-unique fracture patterns revealed from seismic surveys of smectite-rich mudstones (derived from a volcanic ash protolith) and overlying coarser-grained sediments in the North Sea. In the North Sea basin, fracture patterns, display several endmember fracture patterns including rectilinear, curved, and irregular. Similar patterns are observed in HiRISE images of Mawrth Vallis surfaces. Also, in the North Sea basin deposits, the fine-grained and fractured smectite-rich beds are overlain by coarser-grained (and mostly non- fractured) kaolinite, illite, and chlorite rich beds. It has been suggested that the Al-bearing phyllosilicate layers at Mawrth Vallis are draped over pre-existing topography so the North Sea analogy might be imperfect, but it shows how analysis of fracture patterns in association with lithology might provide insight into the origin of the Mawrth Vallis deposits.
Viking visible and thermal infrared observations and terrestrial catastrophic flood deposits prov... more Viking visible and thermal infrared observations and terrestrial catastrophic flood deposits provide clues to identify the outflow channel sediments that went into Chryse Basin on Mars. On Earth, sandar (outwash plains formed by coalescence of many j6kulhlaup floods) are described in terms of three laterally adjacent facies: proximal, midfan, and distal. The Missoula Flood sediments deposited in Quincy Basin, Washington, comprise a miniature analog of Chryse Basin. The terminology and general characteristics of the sandar facies model are applied to Quincy Basin, although the depositional environment and clast sizes are somewhat different (higher-energy flood, larger clasts, subaqueous rather than subaerial deposition). For example, the Ephrata Fan (a deposit of boulders, cobbles, and pebbles) forms the midfan facies analog; a downfan sandy deposit (reworked into a dune field) comprises the distal facies analog. In Chryse Basin the midfan is defined by a heterogeneous rocky (0-25%), intermediate-albedo 0.21-0.26), intermediate thermal inertia (260-460 J m -2 s -ø'5 K -•) surface, while the distal facies has a low albedo (0.14-0.16) and higher thermal inertia (340-700 J m -2 s -ø's K-X). The Chryse midfan unit has rocks and windblown dust exposed at the surface. The sand of the distal facies in Chryse/Acidalia is reworked by the wind, as in Quincy Basin. The Viking 1 and Mars Pathfinder landing sites are located on the midfan unit. Observations that can be made at the Mars Pathfinder site might help in reevaluating whether or not Viking 1 landed on outflow channel sediments. Introduction Mars Pathfinder and Chryse Basin The selection of a site at the confluence of Ares and Tiu Valles (19.5øN, 32.8øW) for the July 4, 1997, landing of Mars Pathfinder has prompted new interest in understanding the nature and results of the massive floods which emanated from the outflow channels around the margins of the Chryse Basin [Golombek et al., 1995a, b]. The Ares Vallis landing site was advocated by several investigators at a 1994 workshop [Rice, 1994a; Kuzmin et al., 1994]. A summary of the landing site selection process and its geologic characteristics is found in this issue [Golombek et al., this issue].
The first landing on Mars in over 20 years will take place July 4, 1997, near the mouth of the Ar... more The first landing on Mars in over 20 years will take place July 4, 1997, near the mouth of the Ares Vallis outflow channel located in southeastern Chryse Planitia, Mars Pathfinder, unlike Viking 1, is expected to land on a surface that has a distinct and unambiguous fluvial signature. For safety reasons, the landing site was selected within a broad plains region beyond the mouth of Ares Vallis so as to avoid large topographic obstacles that could pose hazards to the landing. However, this plain is not without its interesting, and in some cases rather problematic, land forms. The 100 km by 200 km landing ellipse contains the following features: (1) primary impact craters, (2) clusters of small secondary craters, (3) streamlined islands, (4) longitudinal grooves, (5) "scabland" or "etched" terrain, (6) pancake-like shields and dike-like structures, (7) knobs or buttes, and (8) a previously undetected, subtle undulating or hummocky texture to the plains surface. The nature of these kmdforrns has important bearing on how we will interpret what we see at the scale of the Pathfinder lander once the fust images are transmitted to Earth. With the exception of the craters, all of the remaining features described within the Mars Pathfinder landing ellipse can be interpreted as forming as a result of catastrophic flooding from Ares and Tiu Vanes into Chryse Pkmitia, either during the flood itself, or through secondary modification of thick flood deposits after the event.
Chasma Australe, 500 km long and up to 80 km wide, is the most remarkable of the martian south po... more Chasma Australe, 500 km long and up to 80 km wide, is the most remarkable of the martian south pole erosional reentrants carved in the polar layered deposits. We have interpreted Chasma Australe erosional and depositional features as evidence for a flood origin, which we have reconstructed using a modified Manning equation. The main characteristics of the flow are a water velocity between 30 and 50 m s −1 and discharge values between 7 × 10 8 and 3 × 10 9 m 3 s −1 , very near to MGS data-based estimations for martian outflow channels (D. E. Smith et al. 1998, Science 279, 1686-1692). We thus postulate that Chasma Australe originated in a catastrophic flood.
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