All Outputs (103)

The Dynamics of CO 2 ‐Driven Granular Flows in Gullies on Mars (2024)
Journal Article
Roelofs, L., Conway, S. J., van Dam, B., van Eijk, A., Merrison, J. P., Iversen, J. J., …de Haas, T. (2024). The Dynamics of CO 2 ‐Driven Granular Flows in Gullies on Mars. Journal of Geophysical Research: Planets, 129(6), Article e2024JE008319. https://doi.org/10.1029/2024je008319

Martian gullies are landforms consisting of an erosional alcove, a channel, and a depositional apron. A significant proportion of Martian gullies at the mid‐latitudes is active today. The seasonal sublimation of CO2 ice has been suggested as a driver... Read More about The Dynamics of CO 2 ‐Driven Granular Flows in Gullies on Mars.

How, when and where current mass flows in Martian gullies are driven by CO2 sublimation (2024)
Journal Article
Roelofs, L., Conway, S. J., de Haas, T., Dundas, C., Lewis, S. R., McElwaine, J., …Patel, M. R. (2024). How, when and where current mass flows in Martian gullies are driven by CO2 sublimation. Communications Earth & Environment, 5(1), Article 125. https://doi.org/10.1038/s43247-024-01298-7

Martian gullies resemble water-carved gullies on Earth, yet their present-day activity cannot be explained by water-driven processes. The sublimation of CO2 has been proposed as an alternative driver for sediment transport, but how this mechanism wor... Read More about How, when and where current mass flows in Martian gullies are driven by CO2 sublimation.

Fluid effects in model granular flows (2023)
Journal Article
Zhao, Y., Take, W. A., Kaitna, R., McArdell, B. W., McElwaine, J. N., & Bowman, E. T. (2024). Fluid effects in model granular flows. Granular Matter, 26(1), Article 2. https://doi.org/10.1007/s10035-023-01365-4

Pore fluid plays a crucial role in many granular flows, especially those in geophysical settings. However, the transition in behaviour between dry flows and fully saturated flows and the underlying physics that relate to this are poorly understood. I... Read More about Fluid effects in model granular flows.

Sensitive aerial hearing within a noisy nesting soundscape in a deep-diving seabird, the common murre Uria aalge (2023)
Journal Article
Smith, A. B., Fischer-McMorrow, I., Kolbeinsson, Y., Rasmussen, M., Shero, M. R., McElwaine, J. N., …Mooney, T. A. (2023). Sensitive aerial hearing within a noisy nesting soundscape in a deep-diving seabird, the common murre Uria aalge. Marine Ecology Progress Series, 714, 87-104. https://doi.org/10.3354/meps14346

Diving seabirds face a combination of sound exposure in marine and terrestrial environments due to increasing human encroachment on coastal ecosystems. Yet the sound-sensitivity and sensory ecology of this threatened group of animals is largely unkno... Read More about Sensitive aerial hearing within a noisy nesting soundscape in a deep-diving seabird, the common murre Uria aalge.

Influence of Pore Fluid on Grain‐Scale Interactions and Mobility of Granular Flows of Differing Volume (2022)
Journal Article
Taylor‐Noonan, A. M., Bowman, E. T., McArdell, B. W., Kaitna, R., McElwaine, J. N., & Take, W. A. (2022). Influence of Pore Fluid on Grain‐Scale Interactions and Mobility of Granular Flows of Differing Volume. Journal of Geophysical Research: Earth Surface, 127(12), https://doi.org/10.1029/2022jf006622

The presence of a pore fluid is recognized to significantly increase the mobility of saturated over dry granular flows. However, the mechanisms through which pore fluid increases mobility may not be captured in experimental flows of small volume typi... Read More about Influence of Pore Fluid on Grain‐Scale Interactions and Mobility of Granular Flows of Differing Volume.

Entrainment into particle-laden turbulent plumes (2021)
Journal Article
McConnochie, C. D., Cenedese, C., & McElwaine, J. N. (2021). Entrainment into particle-laden turbulent plumes. Physical Review Fluids, 6(12), Article 123502. https://doi.org/10.1103/physrevfluids.6.123502

We use laboratory experiments to investigate the entrainment of ambient fluid into an axisymmetric turbulent plume containing dense particles with a settling velocity that is considerably smaller than the plume velocity. We consider the effect of par... Read More about Entrainment into particle-laden turbulent plumes.

The formation of araneiforms by carbon dioxide venting and vigorous sublimation dynamics under martian atmospheric pressure (2021)
Journal Article
Mc Keown, L., McElwaine, J., Bourke, M., Sylvest, M., & Patel, M. (2021). The formation of araneiforms by carbon dioxide venting and vigorous sublimation dynamics under martian atmospheric pressure. Scientific Reports, 11, Article 6445. https://doi.org/10.1038/s41598-021-82763-7

The local redistribution of granular material by sublimation of the southern seasonal CO2 ice deposit is one of the most active surface shaping processes on Mars today. This unique geomorphic mechanism is hypothesised to be the cause of the dendritic... Read More about The formation of araneiforms by carbon dioxide venting and vigorous sublimation dynamics under martian atmospheric pressure.

Surface Expression of a Wall Fountain: Application to Subglacial Discharge Plumes (2020)
Journal Article
McConnochie, C. D., Cenedese, C., & McElwaine, J. N. (2020). Surface Expression of a Wall Fountain: Application to Subglacial Discharge Plumes. Journal of Physical Oceanography, 50(5), 1245-1263. https://doi.org/10.1175/jpo-d-19-0213.1

We use laboratory experiments and theoretical modeling to investigate the surface expression of a subglacial discharge plume, as occurs at many fjords around Greenland. The experiments consider a fountain that is released vertically into a homogeneou... Read More about Surface Expression of a Wall Fountain: Application to Subglacial Discharge Plumes.

Initiation and flow conditions of contemporary flows in Martian gullies (2019)
Journal Article
Haas, T., McArdell, B., Conway, S., McElwaine, J., Kleinhans, M., Salese, F., & Grindrod, P. (2019). Initiation and flow conditions of contemporary flows in Martian gullies. Journal of Geophysical Research: Planets, 124(8), 2246-2271. https://doi.org/10.1029/2018je005899

Understanding the initial and flow conditions of contemporary flows in Martian gullies, generally believed to be triggered and fluidized by CO2 sublimation, is crucial for deciphering climate conditions needed to trigger and sustain them. We employ t... Read More about Initiation and flow conditions of contemporary flows in Martian gullies.

CO2 sublimation in Martian gullies: laboratory experiments at varied slope angle and regolith grain sizes (2019)
Journal Article
Sylvest, M. E., Dixon, J. C., Conway, S. J., Patel, M. R., McElwaine, J. N., Hagermann, A., & Barnes, A. (2019). CO2 sublimation in Martian gullies: laboratory experiments at varied slope angle and regolith grain sizes. Geological Society Special Publications, 467(1), 343-371. https://doi.org/10.1144/sp467.11

Martian gullies were initially hypothesized to be carved by liquid water, due to their resemblance to gullies on Earth. Recent observations have highlighted significant sediment transport events occurring in Martian gullies at times and places where... Read More about CO2 sublimation in Martian gullies: laboratory experiments at varied slope angle and regolith grain sizes.

Cold-to-warm flow regime transition in snow avalanches (2018)
Journal Article
Köhler, A., Fischer, J., Scandroglio, R., Bavay, M., McElwaine, J., & Sovilla, B. (2018). Cold-to-warm flow regime transition in snow avalanches. The Cryosphere, 12(12), 3759-3774. https://doi.org/10.5194/tc-12-3759-2018

Large avalanches usually encounter different snow conditions along their track. When they release as slab avalanches comprising cold snow, they can subsequently develop into powder snow avalanches entraining snow as they move down the mountain. Typic... Read More about Cold-to-warm flow regime transition in snow avalanches.

The intermittency regions of powder snow avalanches (2018)
Journal Article
Sovilla, B., McElwaine, J., & Köhler, A. (2018). The intermittency regions of powder snow avalanches. Journal of Geophysical Research: Earth Surface, 123(10), 2525-2545. https://doi.org/10.1029/2018jf004678

Powder snow avalanches are typically composed of several regions characterized by different flow regimes. These include a turbulent suspension cloud of fine particles, a dense basal flow and an intermittency frontal region, which is characterized by... Read More about The intermittency regions of powder snow avalanches.

From episodic avalanching to continuous flow in a granular drum (2018)
Journal Article
Balmforth, N., & McElwaine, J. (2018). From episodic avalanching to continuous flow in a granular drum. Granular Matter, 20(3), Article 52. https://doi.org/10.1007/s10035-018-0822-1

Experiments are conducted to study the transition from episodic avalanching (slumping) to continuous flow (rolling) in drums half full of granular material. The width and radius of the drum is varied and different granular materials are used, ranging... Read More about From episodic avalanching to continuous flow in a granular drum.

GEODAR Data and the Flow Regimes of Snow Avalanches (2018)
Journal Article
Köhler, A., McElwaine, J., & Sovilla, B. (2018). GEODAR Data and the Flow Regimes of Snow Avalanches. Journal of Geophysical Research, 123(6), 1272-1294. https://doi.org/10.1002/2017jf004375

GEODAR, a custom radar system, images avalanches over the entire slope with high spatial and temporal resolution at the experimental test‐site Vallée de la Sionne in Switzerland. Between winter seasons 2009/10 and 2014/15, data has been acquired from... Read More about GEODAR Data and the Flow Regimes of Snow Avalanches.

Comments on avalanche flow models based on the concept of random kinetic energy (2017)
Journal Article
Issler, D., Jenkins, J. T., & McElwaine, J. N. (2018). Comments on avalanche flow models based on the concept of random kinetic energy. Journal of Glaciology, 64(243), 148-164. https://doi.org/10.1017/jog.2017.62

In a series of papers, Bartelt and co-workers developed novel snow-avalanche models in which random kinetic energy (RKE) RK (a.k.a. granular temperature) is a key concept. The earliest models were for a single, constant density layer, using a Voellmy... Read More about Comments on avalanche flow models based on the concept of random kinetic energy.

Granular flows at recurring slope lineae on Mars indicate a limited role for liquid water (2017)
Journal Article
Dundas, C. M., McEwen, A. S., Chojnacki, M., Milazzo, M. P., Byrne, S., McElwaine, J. N., & Urso, A. (2017). Granular flows at recurring slope lineae on Mars indicate a limited role for liquid water. Nature Geoscience, 10, 903-907. https://doi.org/10.1038/s41561-017-0012-5

Recent liquid water flow on Mars has been proposed based on geomorphological features, such as gullies. Recurring slope lineae — seasonal flows that are darker than their surroundings — are candidate locations for seeping liquid water on Mars today,... Read More about Granular flows at recurring slope lineae on Mars indicate a limited role for liquid water.

Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars (2017)
Journal Article
Mc Keown, L., Bourke, M., & McElwaine, J. (2017). Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars. Scientific Reports, 7(1), Article 14181. https://doi.org/10.1038/s41598-017-14132-2

Carbon dioxide is Mars’ primary atmospheric constituent and is an active driver of Martian surface evolution. CO2 ice sublimation mechanisms have been proposed for a host of features that form in the contemporary Martian climate. However, there has b... Read More about Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars.

Lobate impact melt flows within the extended ejecta blanket of Pierazzo crater (2017)
Journal Article
Bray, V. J., Atwood-Stone, C., Neish, C. D., Artemieva, N. A., McEwen, A. S., & McElwaine, J. N. (2017). Lobate impact melt flows within the extended ejecta blanket of Pierazzo crater. Icarus, 301, 26-36. https://doi.org/10.1016/j.icarus.2017.10.002

Impact melt flows are observed within the continuous and discontinuous ejecta blanket of the 9 km lunar crater Pierazzo, from the crater rim to more than 40 km away from the center of the crater. Our mapping, fractal analysis, and thermal modeling su... Read More about Lobate impact melt flows within the extended ejecta blanket of Pierazzo crater.

On the Chemical Mixing Induced by Internal Gravity Waves (2017)
Journal Article
Rogers, T., & McElwaine, J. (2017). On the Chemical Mixing Induced by Internal Gravity Waves. Astrophysical Journal Letters, 848(1), Article L1. https://doi.org/10.3847/2041-8213/aa8d13

Detailed modeling of stellar evolution requires a better understanding of the (magneto)hydrodynamic processes that mix chemical elements and transport angular momentum. Understanding these processes is crucial if we are to accurately interpret observ... Read More about On the Chemical Mixing Induced by Internal Gravity Waves.

Analytical solution for clay plug swelling experiments (2017)
Journal Article
Mathias, S., Greenwell, H., Withers, C., Erdogan, A., McElwaine, J., & MacMinn, C. (2017). Analytical solution for clay plug swelling experiments. Applied Clay Science, 149, 75-78. https://doi.org/10.1016/j.clay.2017.07.021

Clay swelling experiments frequently involve monitoring the one-dimensional displacement with time of an initially dry clay plug as it imbibes water from a supply at its base. This article presents a new analytical solution for interpreting such expe... Read More about Analytical solution for clay plug swelling experiments.