Slope streaks have been frequently observed in the equatorial, low thermal inertia and dusty regions of Mars. The reason behind their formation remains unclear with proposed hypotheses for both dry and wet mechanisms. Here, we report an up-to-date distribution and morphometric investigation of Martian slope streaks. We find: (i) a remarkable coexistence of the slope streak distribution with the regions on Mars with high abundances of water-equivalent hydrogen, chlorine, and iron; (ii) favourable thermodynamic conditions for transient deliquescence and brine development in the slope streak regions; (iii) a significant concurrence of slope streak distribution with the regions of enhanced atmospheric water vapour concentration, thus suggestive of a present-day regolith-atmosphere water cycle; and (iv) terrain preferences and flow patterns supporting a wet mechanism for slope streaks. These results suggest a strong local regolith-atmosphere water coupling in the slope streak regions that leads to the formation of these fluidised features. Our conclusions can have profound astrobiological, habitability, environmental, and planetary protection implications.
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http://dx.doi.org/10.1038/s41598-017-07453-9 | DOI Listing |
Sci Rep
October 2024
Civil and Environmental Engineering Department, United Arab Emirates University, P.O. Box 15551, Al Ain, UAE.
Floods accompanied by thunderstorms in developed cities are hazardous, causing damage to infrastructure. To secure infrastructure, it is important to employ an integrated approach, combining remote sensing, GIS and precipitation data. The model was developed based on the estimation of event-based runoff and investigated the relationship between runoff and impervious surfaces.
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June 2023
Department of Botany, Smithsonian Institution, P.O. Box 37012, Washington, DC, 20013-7012, USA Smithsonian Institution Washington United States of America.
H.Oppenheimer, Lorence & W.L.
View Article and Find Full Text PDFSci Rep
January 2023
USVI Department of Planning and Natural Resources, 84P5+PX3, Anna's Retreat, Charlotte Amalie, VI, 00802, USA.
The US Caribbean ocean circulation is governed by an influx of Atlantic water through the passages between Puerto Rico, Hispaniola and the Virgin Islands, and an interplay of the Caribbean Sea water with the local topography of the region. We present an analysis of the US Caribbean ocean flow simulated by the USCROMS; which is the ROMS AGRIF model configured for the US Caribbean regional ocean at a horizontal resolution of 2 km. Outputs from the USCROMS show a seasonal variability in the strength of submesoscale turbulence within a mixed layer whose depth varies from -70 to -20 m from winter to summer, and internal tides originating from the passages between the islands.
View Article and Find Full Text PDFRev Sci Instrum
October 2022
Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Astrobiology
July 2022
Department of Biology, University of Mississippi, University, Mississippi, USA.
Brines at or near the surface of present-day Mars are a potential explanation for seasonally recurring dark streaks on the walls of craters, termed recurring slope lineae (RSL). Deliquescence and freezing point depression are possible drivers of brine stability, attributable to the high salinity observed in martian regolith including chlorides and perchlorates. Investigation of life, which may inhabit RSL, and the cellular mechanisms necessary for survival, must consider the tolerance of highly variable hydration, freeze-thaw cycles, and high osmolarity in addition to the anaerobic, oligotrophic, and irradiated environment.
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