Static and dynamic angles of repose in loose granular materials under reduced gravity

Kleinhans, Maarten G.; Markies, H.; Vet, S.J. de; Veld, A.C. In 't; Postema, F. N.

doi:10.1029/2011je003865

Cited by 154 publications

(130 citation statements)

References 56 publications

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“…The latter approach was applied by Manga et al (2012) in their study of a volcanic bomb in the Home Plate outcrop in Gusev Crater. The model presented here may also be applied to other terrestrial bodies where results of explosive volcanism were described, for example to volcanic fields containing scoria cones in the Marius Hills on the Moon (Lawrence et al, 2013).…”

Section: Interpretation Of the Resultsmentioning

confidence: 97%

Shape of scoria cones on Mars: Insights from numerical modeling of ballistic pathways

Brož

Čadek

Hauber³

et al. 2014

Earth and Planetary Science Letters

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Morphological observations of scoria cones on Mars show that their cross-sectional shapes are different from those on Earth. Due to lower gravity and atmospheric pressure on Mars, particles are spread over a larger area than on Earth. Hence, erupted volumes are typically not large enough for the flank slopes to attain the angle of repose, in contrast to Earth where this is common. The distribution of ejected material forming scoria cones on Mars, therefore, is ruled mainly by ballistic distribution and not by redistribution of flank material by avalanching after the static angle of repose is reached. As a consequence, the flank slopes of the Martian scoria cones do not reach the critical angle of repose in spite of a large volume of ejected material. Therefore, the topography of scoria cones on Mars is governed mainly by ballistic distribution of ejected particles and is not influenced by redistribution of flank material by avalanching. The growth of a scoria cone can be studied numerically by tracking the ballistic trajectories and tracing the cumulative deposition of repeatedly ejected particles. We apply this approach to a specific volcanic field, Ulysses Colles on Mars, and compare our numerical results with observations. The scoria cones in this region are not significantly affected by erosion and their morphological shape still preserves a record of physical conditions at the time of eruption. We demonstrate that the topography of these scoria cones can be rather well (with accuracy of ∼10 m) reproduced provided that the ejection velocities are a factor of ∼2 larger and the ejected particles are about ten times finer than typical on Earth, corresponding to a mean particle velocity of ∼92 m/s and a real particle size of about 4 mm. This finding is in agreement with previous theoretical works that argued for larger magma fragmentation and higher ejection velocities on Mars than on Earth due to lower gravity and different environmental conditions.

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Section: Interpretation Of the Resultsmentioning

confidence: 97%

Shape of scoria cones on Mars: Insights from numerical modeling of ballistic pathways

Brož

Čadek

Hauber³

et al. 2014

Earth and Planetary Science Letters

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“…These results are questioned in Ref. [4]. In this paper, the Authors studied tumblers in parabolic flight.…”

Section: Introductionmentioning

confidence: 90%

“…Either, the apparent gravity g ⋆ is increased using a Large Diameter Centrifuge (LDC), see Granular material confined in rotating tumbler has been studied under various apparent gravity conditions [2][3][4]. The idea was to determine how avalanches are influenced by the gravity and to determine the role of the gravity in geomorphology of planets.…”

Section: Introductionmentioning

confidence: 99%

Influence of the gravity on the discharge of a silo

et al. 2013

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We performed a series of experiments to investigate the flow of an assembly of non-cohesive spherical grains in both high and low gravity conditions (i.e. above and under the Earth's gravity). In high gravity conditions, we studied the flow of glass beads out of a cylindrical silo and the flow of metallic beads out of a vertical Hele-Shaw rectangular silo. Both silos were loaded in one of the gondolas of the Large Diameter Centrifuge facility (located at ESTEC) in which an apparent gravity up to 20 times the Earth's gravity can be established. To simulate low gravity conditions, we submitted a horizontal monolayer of metallic beads to the centrifuge force of a small rotation device (located at University of Liege). The influences of both gravity and aperture size on the mass flow were analysed in these various conditions. For the three systems (cylindrical silo, the Hele-shaw silo and the monolayer of beads), we demonstrated that (i) the square root scaling of the gravity found by Beverloo is relevant and (ii) the critical aperture size below which the flow is jammed does not significantly increase with the apparent gravity. Moreover, we studied in more details the Hele-Shaw silo in high gravity because this configuration allowed to determine local properties of the flow at the level of the aperture. We measured the velocity profiles and the packing fraction profiles for the various aperture sizes and apparent high gravities. We demonstrate the existence of a slip length for the flow at the level of the aperture. This later fact seems to result from the geometrical configuration of the silo.

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“…Furthermore, this angle is less than the angle of repose of the sand on both Earth and Mars (Kleinhans et al 2011;Atwood-Stone & McEwen 2013), which means that the sediments do not fail with slight vibrations/perturbations. The tray contains black lines at 5 cm from its base and perpendicular lines every 10 cm on the side walls to assist in levelling the sand and to calibrate distances along the tray observed in images/videos.…”

Section: Experimental Set-up and Instrumentationmentioning

confidence: 99%

Downslope sediment transport by boiling liquid water under Mars-like conditions: experiments and potential implications for Martian gullies

Herny

Conway

Raack

et al. 2018

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Gullies are widespread morphological features on Mars for which current changes have been observed. Liquid water has been one of the potential mechanisms to explain their formation and activity. However, under present-day Martian conditions, liquid water is unstable and should only be transiently present in small amounts at the surface. Yet little attention has been paid to the mechanisms by which unstable water transports sediment under low atmospheric pressure. Here we present the results of laboratory experiments studying the interaction between liquid water flowing over a sand bed under Mars-like atmospheric pressure (c. 9 mbar). The experiments were performed in a Mars Simulation Chamber (at the Open University, UK), in which we placed a test bed of fine sand at a 25°slope. We chose to investigate the influence of two parameters: the temperature of the water and the temperature of the sand. We performed 27 experiments with nine different combinations of water and sand temperatures ranging from 278 to 297 K. Under all experimental conditions, the water was boiling. We investigated and compared the types and timing of sediment transport events, and the shapes, characteristics and volumes of the resulting morphologies. In agreement with previous laboratory studies we found that more intense boiling increased the volume of sediment transported for a given volume of water. We found four main types of sediment transport: entrainment by overland flow; grain ejection; grain avalanches; and levitation of saturated sand pellets. Our results showed that increasing sand temperature was the main driving parameter in increasing the sand transport and in modifying the dominant sediment transport mechanism. The temperature of the water played a negligible or minor role, apart from the duration of sand ejection and avalanches, which lasted longer at low water temperature. At low sand temperature the majority of the sand was transported by overland flow of the liquid water. At higher sand temperatures the transport was dominated by processes triggered by the boiling behaviour of the water. At the highest temperatures, sediment transport was dominated by the formation of levitating pellets, dry avalanches and ejection of the sand grains. This resulted in a transport volume about nine times greater at a sand temperature of 297 K compared with 278 K. Our heat transfer scaling shows that the boiling behaviour will be enhanced under Martian low gravity, resulting in more efficient transport of sediment by levitating sand pellets even at temperatures close to the triple point. Our results showed that the boiling intensity played an important role in the physics of sediment transport by liquid water. This implied that the amount of water required to produce morphological changes at the surface of Mars could be lower than previously estimated by assuming stable liquid water. Boiling is a critical process to be considered when assessing gully formation and modification mechanisms mobilized by liquid water. Our work could ha...

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Static and dynamic angles of repose in loose granular materials under reduced gravity

Cited by 154 publications

References 56 publications

Shape of scoria cones on Mars: Insights from numerical modeling of ballistic pathways

Shape of scoria cones on Mars: Insights from numerical modeling of ballistic pathways

Influence of the gravity on the discharge of a silo

Downslope sediment transport by boiling liquid water under Mars-like conditions: experiments and potential implications for Martian gullies

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