The Valles Marineris system empties into the Chryse region, one of the lowest regions on Mars. Any water from the canyon system would have flown into the lowlands, and it may have once contained an ancient lake or ocean. Over the years, scientists have proposed a number of theories about the formation of Valles Marineris. Erosion during a water-rich past and the withdrawal of subsurface magma were both early possibilities.
Today, most scientists think that the formation of the Tharsis region may have helped the canyon to form. The Tharsis region contains several large volcanoes that dwarf those found on Earth, including Olympus Mons. As molten rock pushed through the volcanic region to form the monstrous volcanoes 3. The strain cracked the crust, causing large faults and fractures across the planet's surface. Such fractures, growing over time, birthed the enormous canyon system. The spreading cracks caused the ground to sink and opened an escape for subsurface water.
The upward rushing liquid broke down the edges of the fractures, enlarging them and washing away more of the ground while flowing past. Signs of flooding are especially apparent at the eastern end, in the mesas and hills known as chaotic terrain. Rushing water poured through channels into the lowlands, carving a series of channels. Undermined cliffs and valley walls are usually unstable, and Valles Marineris has grown wider in many places through landslides.
This particular slide dropped thousands of feet and has a maximum length of about kilometers 60 miles. A closer look at it shows that several landslides have occurred here, with each now slide lying on top of the previous ones. As examples on Earth show, landslides can travel great distances, especially when the debris contains trapped water or air to lower friction. Scientists think it likely that even the thin air of Mars would have contributed to this slide's remarkable run.
Similar, if shorter, landslides lie throughout most of Valles Marineris, and helped to widen the canyon as it developed.
Leaves of History. The Valles Marineris story involves more than just erosion, however. In places such as Melas Chasma seen here and in Candor Chasma and Ophir Chasma, the valley floor is piled deep with sedimentary deposits. Geologists call these the interior layered deposits.
The origin - and nature - of these materials is perhaps the biggest mystery involving Valles Marineris. In places Hebes Chasma, for example the layers are stacked thick enough to reach almost to the valley's rim.
They display eroded ledges and benches, buttes and mesas. In some places they have been covered by landslide debris. Where do the layers come from? The flat-lying, uncontorted layers suggest the deposits accumulated in a geologically quiet environment. This points to sources such as volcanic ash falling from the sky, or sediments piling up in a lake or large body of standing water.
But if these are lakebed deposits, where the sediment originated - and how it got into the valley - remain unknown. Another enigma involves how wet martian history has been. The bottom of Ganges Chasma, a part of Valles Marineris, contains exposures of olivine-rich basalt. Olivine, a greenish mineral, weathers quickly into other forms when exposed to water.
Its existence in Ganges suggests that the valley may have seen relatively little water over its history. But in other portions of the canyon system, such as Candor Chasma, scientists have detected clay minerals.
Huge ancient river channels begin from the chaotic terrain and from north-central canyons and run north. Many of the channels flowed into a basin called Acidalia Planitia, which is the dark area in the extreme north of this picture.
The three Tharsis volcanoes dark red spots , each about 25 km high, are visible to the west. The large crater with two prominent rings located at the bottom of this image is named Lowell, after the Flagstaff astronomer. A variety of clouds appear as bright blue streaks and hazes, and probably consist of water ice. Long, linear clouds north of central Valles Marineris appear to emanate from impact craters. Images from Mars Express suggest that water ice fog may be present in Valles Marineris while absent from the surrounding plateau.
Using a regional atmospheric model, we investigate planetary boundary layer processes and discuss the implications of these potential water ice fog. Results from our simulations show that the temperature inside Valles Marineris appears warmer relative to the plateaus outside at all times of day. From the modeled temperatures, we calculate saturation vapor pressures and saturation mixing to determine the amount of water vapor in the atmosphere for cloud formation.
For a well-mixed atmosphere, saturated conditions in the canyon imply supersaturated conditions outside the canyon where it is colder. Consequently, low clouds should be everywhere. This is generally not the case. Based on potential fog observations inside the canyon , if we assume the plateau is just sub-saturated, and the canyon bottom is just saturated, the resulting difference in mixing ratios represents the minimum amount of vapor required for the atmosphere to be saturated, and for potential fog to form.
Under these conditions, we determined that the air inside the canyon would require a times enrichment in water vapor at saturation compared to outside the canyon.
This suggests a local source of water vapor is required to explain water ice fog appearing within the confines of Valles Marineris on Mars. Extensive recurring slope lineae RSL activity has been detected in Valles Marineris on Mars and coincides with regions where water ice fogs appear [1]. The origin of the water driving RSL flow is not well understood, but observational evidence suggests atmospheric processes play a crucial role [2].
Provided the atmospheric vapor concentration is high enough, water ice fogs can form overnight if the surface temperature cools below the condensation temperature. Correlations between dust storms and flow rates suggest that atmospheric dust opacity, and its influence on air temperature, also has a significant effect on RSL activity. We investigate planetary boundary layer processes that govern the hydrological cycle and dust cycle on Mars using a mesoscale atmospheric model to simulate the distribution of water and dust with respect to regional atmospheric circulations.
Our simulations in Valles Marineris show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside. For a well-mixed atmosphere, this temperature structure indicates that when the atmosphere inside the canyon is saturated and fog is present within Valles Marineris , fog and low-lying clouds should also be present on the cooler surrounding plateaus as well.
These results have important implications for the origin and concentration of water vapor in Valles Marineris , with possible connections to RSL. The potential temperatures from our simulations show a high level of stability inside the canyon produced dynamically by sinking air.
However, afternoon updrafts along the canyon walls indicate that over time, water vapor within the chasm would escape along the sides of the canyon.
Again, this suggests a local source or mechanism to concentrate water vapor is needed to explain the fog. Stratigraphy of the layered terrain in Valles Marineris , Mars. The layered terrain in Valles Marineris provides information about its origin and the geologic history of this canyon system. Whether the terrain is sedimentary material deposited in a dry or lacustrine environment, or volcanic material related to the tectonics of the canyon is still controversial.
However, recent studies of Gangis Layered Terrain suggests a cyclic sequence of deposition and erosion under episodic lacustrine conditions. The stratigraphic studies are extended to four other occurrences of layered terrains in Valles Marineris in an attempt to correlate and distinguish between depositional environments.
Although there are broad similarities among the layered terrains, no two deposits are exactly alike. This suggests that there was no synchronized regional depositional processes to form all the layered deposits. However, the similar erosional style of the lower massive weakly bedded unit in Hebes, Gangis, and Ophir-Candor suggests it may have been deposited under similar circumstances.
Evidence for ponding and catastrophic floods in central Valles Marineris , Mars. The Valles Marineris canyon system of Mars is closely related to large flood channels, some of which emerge full born from chaotic terrain in canyon floors.
Coprates Chasma, one of the largest Valles Marineris canyons , is connected at its west end to Melas Chasma and on its east end to chaotic terrain-filled Capri and Eos Chasmata. The area from central Melas to Eos Chasmata contains a km long and about 1 km deep depression in its floor. Despite the large volumes of groundwater that likely discharged from chaotic terrain in this depression, no evidence of related fluvial activity has thus far been reported. We present an analysis of the regional topography which, together with photogeologic interpretation of available imagery, suggests that ponding due to late Hesperian discharge of water possibly produced a lake mean depth m spanning parts of the Valles Marineris depression VMD.
Overflow of this lake at its eastern end resulted in delivery of water to downstream chaos regions and outflow channels. Our ponding hypothesis is motivated primarily by the identification of scarp and terrace features which, despite a lateral spread of about km, have similar elevations.
Furthermore, these elevations correspond to the maximum ponding elevation of the region m. The neighborhood of this overflow point contains clear indicators of fluvial erosion in a consistent east-west orientation.
Scarp development in the Valles Marineris. The scarps along the margins of the Vales Marineris display a complex assemblage of forms that have been related to a variety of mass wasting and sapping processes.
These scarp segments display variations in the degree of development of spur and gully topography, the number and density of apparent sapping features and the frequency of large scale landslides which reflect the age, geology and processes of slope development throughout the Valles Marineris.
This regional analysis should provide more information on the geologic evolution of the Valles Marineris as well as new insight into the relative importance of different processes in the development of the scarp forms. In order to evaluate the regional variation in scarp form and the influence of time and structure on scarp development geomorphic mapping and morphometric analysis of geologically distinct regions of Valles Marineris is being undertaken. The regional atmospheric circulation on Mars is highly influenced by local topographic gradients.
Terrain-following air parcels forced along the slopes of the major Tharsis volcanoes and the steep canyon walls of Valles Marineris significantly impact the local water vapor concentration and the associated conditions for cloud formation. The usage of a limited area regional model ensures that topographic slopes are well resolved compared to the typical resolutions of a global-coverage general circulation model.
The effects of shadowing and slope angle geometries on the energy budget is also taken into account. Diurnal slope winds in complex terrains are typically characterized by the reversal of wind direction twice per sol: upslope during the day, and downslope at night.
However, our simulation results of the regional circulation and diurnal water cycle indicate substantial asymmetries in the day-night circulation.
The convergence of moist air masses enters Valles Marineris via easterly flows, whereas dry air sweep across the plateau of the canyon system from the south towards the north. We emphasize the non-uniform vertical distribution of water vapor in our model results. Water vapor mixing ratios in the lower planetary boundary layer may be factors greater than the mixing ratio aloft. Water ice clouds are important contributors to the climatic forcing on Mars, and their effects on the mesoscale circulations in the Tharsis - Valles Marineris region significantly contribute to the regional perturbations in the large-scale global atmospheric circulation.
In this study, a model for the formation of hydrated sulfate salts Mg-Ca-Na sulfates in the Rio Puerco watershed of New Mexico, a terrestrial analog site from the semi-arid Southwest U. In this analog site, the surface accumulation of sulfate minerals along canyon walls, slopes and valley surfaces closely resemble occurrences of hydrated sulfates in Valles Marineris on Mars. Significant surface accumulations of Mg-Ca-Na sulfates are a result of prevailing semiarid conditions and a short-lived hydrological cycle that mobilizes sulfur present in the bedrock as sulfides, sulfate minerals, and atmospheric deposition.
Repeating cycles of salt dissolution and re-precipitation appear to be the underpinning processes that serve to transport sulfate from bedrock to sulfate salts e. This process occurs in the shallow surface environment and is not accompanied by deep groundwater flow because of prevailing dry conditions and low annual precipitation. Generally, close resemblance of surface occurrence and mineralogical composition of sulfate salts between the studied terrestrial analog and Valles Marineris suggest that a similar sulfate cycle, involving limited water activity during formation of hydrated sulfates, was once present in Valles Marineris.
Under semi-arid conditions similar to the studied analog in the Rio Pueurco watershed, it would take only to 1, years to activate an equivalent flux of aqueous sulfate in Valles Marineris , when comparing terrestrial annual sulfate fluxes from the Rio Puerco watershed with the amount.
Detailed mapping of the layered deposits in the Valles Marineris , Mars from high-resolution Viking orbiter images revealed that they from plateaus of rhythmically layered material whose bases are in the lowest elevations of the canyon floors, and whose tops are within a few hundred meters in elevation of the surrounding plateaus.
Four hypotheses for the origin of the layered deposits were considered: that they are eolian deposits; that they are remnants of the same material as the canyon walls; that they are explosive volcanic deposits; or that they were deposited in standing bodies of water. There are serious morphologic objections to each of the first three. The deposition of the layered deposits in standing bodies of water best explains their lateral continuity, horizontality, great thickness, rhythmic nature, and stratigraphic relationships with other units within the canyons.
The Martian climatic history indicated that any ancient lakes were ice covered. Two methods for transporting sediment through a cover of ice on a martian lake appear to be feasible. Based on the presently available data, along with the theoretical calculations presented, it appears most likely that the layered deposits in the Valles Marineris were laid down in standing bodies of water.
Water and ice on Mars: Evidence from Valles Marineris. An important contribution to the volatile history of Mars comes from a study of Valles Marineris , where stereoimages and a 3-D view of the upper Martian crust permit unusual insights. The evidence that ground water and ice existed until relatively recently or still exist in the equatorial area comes from observations of landslides, wall rock, and dark volcanic vents.
Valles Marineris landslides are different in efficiency from large catastrophic landslides on Earth. One explanation for the difference might be that the Martian slides are lubricated by water. A comparison of landslide speeds also suggests that the Martian slides contain water.
That Valles Marineris wall rock contained water or ice is further suggested by its difference from the interior layered deposits. Faults and fault zones in Valles Marineris also shed light on the problem of water content in the walls. Because the main evidence for water and ice in the wall rock comes from slides, their time of emplacement is important. The slides in Valles Marineris date from the time of late eruptions of the Tharsis volcanoes and thus were emplaced after the major activity of Martian outflow channels.
Amazonian volcanism inside Valles Marineris on Mars. The giant trough system of Valles Marineris is one of the most spectacular landforms on Mars, yet its origin is still unclear. Although often referred to as a rift, it also shows some characteristics that are indicative of collapse processes. For decades, one of the major open questions was whether volcanism was active inside the Valles Marineris.
Here we present evidence for a volcanic field on the floor of the deepest trough of Valles Marineris , Coprates Chasma. More than individual edifices resemble scoria and tuff cones, and are associated with units that are interpreted as lava flows. The spatial distribution of the cones displays a control by trough-parallel subsurface structures, suggesting magma ascent in feeder dikes along trough-bounding normal faults.
Spectral data reveal an opaline-silica-rich unit associated with at least one of the cones, indicative of hydrothermal processes. Our results point to magma-water interaction, an environment of astrobiological interest, perhaps associated with late-stage activity in the evolution of Valles Marineris , and suggest that the floor of Coprates Chasma is promising target for the in situ exploration of Mars.
Origin and evolution of the layered deposits in the Valles Marineris , Mars. Four hypotheses are discussed concerning the origin of the layered deposits in the Martian Valles Marineris , whose individual thicknesses range from about 70 to m. The hypothesized processes are: 1 aeolian deposition; 2 deposition of remnants of the material constituting the canyon walls; 3 deposition of volcanic eruptions; and 4 deposition in standing bodies of water.
The last process is chosen as most consistent with the rhythm and lateral continuity of the layers, as well as their great thickness and stratigraphic relationship with other units in the canyons. Attention is given to ways in which the sediments could have entered an ice-covered lake; several geologically feasible mechanisms are identified. High resolution stereoimages of the central Valles Marineris enabled detailed geologic mapping on Ophir and Candor Chasmata.
Abundant light colored deposits, both layered and massive, fill the chasmata in this region. Units within these deposits were identified by their erosional characteristics and superposition and cross cutting relations. The Valles Marineris beds reflect a history of repeated faulting, volcanic eruptions, and deposition and erosion, resulting in stratigraphic sequences with several unconformities.
Because of the preponderance of apparent volcanic deposits inside the troughs, the chasmata may not be simple grabens, but rather giant volcano tectonic depressions. Major events in chasmata development are examined. New evidence for a magmatic influence on the origin of Valles Marineris , Mars. Dohm, J. In this paper, we show that the complex geological evolution of Valles Marineris , Mars, has been highly influenced by the manifestation of magmatism e.
This is based on a diversity of evidence, reported here, for the central part, Melas Chasma, and nearby regions, including uplift, loss of huge volumes of material, flexure, volcanism, and possible hydrothermal and endogenic-induced outflow channel activity.
Long-term magma, tectonic, and water interactions Late Noachian into the Amazonian , albeit intermittent, point to an elevated life potential, and thus Valles Marineris is considered a prime target for future life detection missions.
Valles Marineris Landforms. Landslides and gullies observed throughout the image are evidence to the continued mass wasting of the martian surface. Upon close examination of the canyon floor, small ripples that are likely migrating sand dunes are seen on the surface. Some slopes also display an interesting raked-like appearance that may be due to a combination of aeolian and gully forming processes. Image information: VIS instrument. Latitude Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release.
An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter.
A magnetic map of Valles Marineris is interpreted in terms of left-lateral faulting, the first evidence for substantial strike-slip faulting here. Surface exposures of highly magnetic material may exist in the walls of Valles Marineris.
Additional information is contained in the original extended abstract. These flows have a set of characteristics consistent with shallow seeps of salty water. The image covers an area of ground one-third of a mile meters wide. These flows are called recurring slope lineae because they fade and disappear during cold seasons and reappear in warm seasons, repeating this pattern every Martian year.
The flows seen in this image are on a north-facing slope, so they are active in northern-hemisphere spring. The flows emanate from the relatively bright bedrock and flow onto sandy fans, where they are remarkably straight, following linear channels. Valles Marineris contains more of these flows than everywhere else on Mars combined.
At any season, some are active, though on different slope aspects at different seasons. Future human explorers and settlers? Bringing all of that water from Earth would be extremely expensive, so using water on Mars is essential. Although there is plenty of water ice at high latitudes, surviving the cold winters would be difficult. An equatorial source of water would be preferable, so Valles Marineris may be the best destination.
However, the chemistry of this water must be understood before betting any lives on it. Candor Chasm in Valles Marineris. Part of Candor Chasm in Valles Marineris , Mars, from about latitude -9 degrees to -3 degrees and longitude 69 degrees to 75 degrees. Layered terrain is visible in the scene, perhaps due to a huge ancient lake. The geomorphology is complex, shaped by tectonics, mass wasting, and wind, and perhaps by water and volcanism.
Evidence for precipitation on Mars from dendritic valleys in the Valles Marineris area. The geomorphic characteristics of these valleys, especially their high degree of branching, favor formation by atmospheric precipitation.
The presence of inner channels and the maturity of the branched networks indicate sustained fluid flows over geologically long periods of time. These fluvial landforms occur within the Late Hesperian units about 2.
Our results suggest a period of warmer conditions conducive to hydrological activity. Automated detection of Martian water ice clouds: the Valles Marineris. We need to extract water ice clouds from the large number of Mars images in order to reveal spatial and temporal variations of water ice cloud occurrence and to meteorologically understand climatology of water ice clouds.
However, visible images observed by Mars orbiters for several years are too many to visually inspect each of them even though the inspection was limited to one region. Therefore, an automated detection algorithm of Martian water ice clouds is necessary for collecting ice cloud images efficiently. In addition, it may visualize new aspects of spatial and temporal variations of water ice clouds that we have never been aware.
We derived one subtracted image and one cross-correlation distribution from two reflectance images. The difference between the maximum and the average, variance, kurtosis, and skewness of the subtracted image were calculated. Those of the cross-correlation distribution were also calculated. These eight statistics were used as feature vectors for training Support Vector Machine, and its generalization ability was tested using fold cross-validation.
F-measure and accuracy tended to be approximately 0. In the process of the development of the detection algorithm, we found many cases where the Valles Marineris became clearly brighter than adjacent areas in the blue band. It is at present unclear whether the bright Valles Marineris means the occurrence of water ice clouds inside the Valles Marineris or not. Therefore, subtracted images showing the bright Valles Marineris were excluded from the detection of. Mars Canyon with Los Angeles for Scale.
This canyon -- Valles Marineris , or the Mariner Valley -- is 10 times longer and deeper than Arizona Grand Canyon , and 20 times wider. Recurring slope lineae RSL are narrow, low-albedo seasonal flow features on present-day Mars that extend incrementally down warm, steep slopes, fade when inactive, and reappear annually over multiple Mars years [1,2]. Hypothesis for the sources of volatile by which RSL are recharged include seeping water, melting shallow ice, aquifers, and vapor from the atmosphere [].
The presence of fog may provide clues to the water cycle within the canyon , and could elucidate the processes related to the evolution of RSL. Using a regional atmospheric model, we investigate the atmospheric dynamics in and around Valles Marineris. Our simulation results show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside at all times of day. Formation of fogs requires the atmosphere to be saturated.
This can happen with the appropriate combination of cooling or addition of water vapor. The modeled temperature structure suggests that if water is well mixed and fog is present within the warmer canyon bottom, fog should be present on the cooler surrounding plateaus as well. Therefore, the only way to produce fog inside the canyon is to have a local water source. RSL may contribute to this atmospheric water through evaporation, or RSL may simply be a surface marker of a larger near-surface reservoir of water that can act as a source.
From the modeled temperatures, we calculated the corresponding saturation vapor pressures and saturation mixing ratios to determine the amount of water vapor in the air at saturation.
Sedimentation, volcanism, and ancestral lakes in the Valles Marineris : Clues from topography. The study showed that, if their interior layered deposits are lacustrine, the ancestral Valles Marineris must have consisted of isolated basins. If, on the other hand, the troughs were interconnected as they are today, the deposits are most likely to volcanic origin, and the mesas in the peripheral troughs may be table mountains.
The material eroded from the trough walls was probably not sufficient to form all of the interior layered deposits, but it may have contributed significantly to their formation.
Slumps and Fog in Valles Marineris. The first spectral evidence for H2O ice clouds on Mars came from the interferometer spectrometer on board the Mariner 9 spacecraft. Water ice clouds on Mars form by freezing of atmospheric water vapor, of which the main surface source is the seasonal sublimation of the polar caps, and have been observed around the Tharsis volcanoes, Olympus Mons, Alba Patera, Valles Marineris VM and the southern highlands. Cloud activity in some of these regions display a seasonal trend, where the cloud area increases in warmer seasons, and decreases during colder seasons.
The atmospheric hazes in VM are relatively small in areal extent, confined within canyon topography, and are difficult to replicate in models of global or regional vapor transport, indicating that they may be locally sourced.
This distinguishes the VM hazes from the global-scale clouds. Spectral data from the Planetary Fourier Spectrometer onboard the Mars Express orbiter have been reported as consistent with water ice in the atmospheric fog, however results from Mars Express favored dust as responsible for low-elevation hazes.
Here we report observations and spectroscopic analyses of low elevation haze in Juventae Chasma, which are spatially correlated with locations of seasonal flows thought to be caused by briny liquid water. Furthermore, we report the seasonality of the haze and explore its potential role in the creation of contemporary mass-wasting features on Mars.
Thin-skinned deformation of sedimentary rocks in Valles Marineris , Mars. Deformation of sedimentary rocks is widespread within Valles Marineris , characterized by both plastic and brittle deformation identified in Candor, Melas, and Ius Chasmata.
We identified four deformation styles using HiRISE and CTX images: kilometer-scale convolute folds, detached slabs, folded strata, and pull-apart structures. Convolute folds are detached rounded slabs of material with alternating dark- and light-toned strata and a fold wavelength of about 1 km. The detached slabs are isolated rounded blocks of material, but they exhibit only highly localized evidence of stratification.
Folded strata are composed of continuously folded layers that are not detached. Pull-apart structures are composed of stratified rock that has broken off into small irregularly shaped pieces showing evidence of brittle deformation. Some areas exhibit multiple styles of deformation and grade from one type of deformation into another.
The deformed rocks are observed over thousands of kilometers, are limited to discrete stratigraphic intervals, and occur over a wide range in elevations. All deformation styles appear to be of likely thin-skinned origin. CRISM reflectance spectra show that some of the deformed sediments contain a component of monohydrated and polyhydrated sulfates.
Several mechanisms could be responsible for the deformation of sedimentary rocks in Valles Marineris , such as subaerial or subaqueous gravitational slumping or sliding and soft sediment deformation, where the latter could include impact-induced or seismically induced liquefaction. These mechanisms are evaluated based on their expected pattern, scale, and areal extent of deformation. Deformation produced from slow subaerial or subaqueous landsliding and liquefaction is consistent with the deformation observed in Valles Marineris.
Impact craters and landslide volume distribution in Valles Marineris , Mars. Evidence suggests that subsequent landslides, magma flows and, yes, even some ancient rivers probably contributed to the canyon's continued erosion over the following eons. Further analysis of high-resolution photos like these will help solve the puzzling origin story of the solar system's grandest canyon.
Brandon has been a senior writer at Live Science since , and was formerly a staff writer and editor at Reader's Digest magazine. He holds a bachelor's degree in creative writing from the University of Arizona, with minors in journalism and media arts.
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