Abstract
Recurring Slope Lineae (RSL) are dynamic, low-albedo, slope-parallel
surface features on Mars that occur mainly on steep (>25°)
slopes. RSL typically display seasonal dynamics as they appear during
late Martian spring, progressively grow during summer, and subsequently
fade as summer ends. RSL formation mechanisms remain under debate with
proposed mechanisms involving either water/brines ("wet theories") vs.
dry granular flows within a surficial dust layer ("dry theories"). In an
attempt to distinguish between plausible RSL mechanisms, this study
compares the topographic and morphologic characteristics of hillslopes
with and without RSL. We suggest that a distinct topographic signature
for RSL hillslopes would argue against the "dry" RSL mechanisms, as RSL
dynamics within a thin dust layer are not expected to significantly
impact the hillslope-scale topography. In contrast, the presence of
fluids on RSL hillslopes could conceivably accelerate rock weathering
rates, which in turn may impact the hillslope-scale topography. Our
analyses are based on HiRISE, CTX and HRSC digital terrain models (DTMs)
together with geomorphic mapping using high-resolution orbital images.
We focus on inner crater hillslopes and compare the topographic
characteristics of RSL vs. non-RSL slopes. In addition, in order to
account for the potential influence of aspect-dependent solar
irradiation on hillslope processes, we also applied our analysis on
adjacent "control" craters that are devoid of RSL activity. Preliminary
results from Palikir (-41.6°/ 202.1°E) and Rauna (35.2°/
328°E) craters reveal that the topographic slope distribution along
crater walls with RSL activity is distinct from the slope distribution
along crater walls which are devoid of RSL activity. Our results appear
to support increased rock-weathering rates on crater walls that
presently experience RSL activity.
Original language | English |
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DOIs | |
State | Published - 1 Apr 2021 |
Event | EGU General Assembly 2021 - Duration: 19 Apr 2021 → 30 Apr 2021 |
Conference
Conference | EGU General Assembly 2021 |
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Period | 19/04/21 → 30/04/21 |