The Dartmouth planetary geomorphology group seeks to understand the rates and histories of processes that shape the Earth, as well as other planetary bodies, like Mars. We focus on understanding processes that have scales ranging from the motion of a single particle to how particles organize to form river bedforms to how rivers build fans and deltas. We use remote sensing data, field studies, and physical experimentation to constrain the rates and histories of these processes, which has implications for quantitatively reconstructing past climate conditions from preserved landforms, extracting the processes that dominate a landscape based on its shape, and determining the extent to which fluids modify a surface.

Our research falls within three main categories: sediment transport on steep slopes, landscape evolution of planetary surfaces, and periglacial geomorphology.

Contact me: marisa.c.palucis-at-dartmouth.edu

Sediment Transport on Steep Slopes

Sediment transport in steep mountain channels controls channel morphology and landscape evolution under changing climatic and tectonic regimes, and can pose major hazards to life and infrastructure. However, little is known regarding the mechanisms by which sediment is entrained and transported in steep mountain channels. Even more uncertain is our understanding of the transition from fluvial processes to debris flows. Debris flows have significantly higher sediment concentrations and both solid and fluid forces influence their downslope motion, making them destructive to both humans and infrastructure. Understanding the conditions under which debris flow versus fluvial processes dominate is a key research goal. Recent projects have focused on in-channel debris flow initiation post-fire, debris flow initiation at intermediate slopes (10% > S > 30%), the effect of fines on pore pressure generation and debris flow mobility, and long run-out debris flows on low gradient alluvial fans. 

Selected Papers:

Palucis MC, Ulizio T, and Lamb MP, 2021, Debris flow initiation from ravel-filled channel bed failure following wildfire in a bedrock landscape with limited sediment supply, GSA Bull., doi: https://doi.org/10.1130/B35822.1.

Palucis MC, Ulizio T, Fuller B, and Lamb MP, 2018, Flow resistance, sediment transport, and bedform development in a steep gravel-bedded river flume, Geomorphology, doi: 10.1016/j.geomorph.2018.08.003.

Palucis MC, Ulizio T, Fuller B, and Lamb MP, 2018, Intense granular sheet flow in steep river experiments, Geophys. Res. Lett., doi.org/10.1029/2018GL077526.

Prancevic J, Lamb MP, Palucis MC, and Venditti J, 2017, The role of three-dimensional boundary stresses in limiting the initiation and size of experimental landslides, JGR – Earth Surface, doi: 1002/2017JF004410.

Palucis MC and Lamb MP, 2017, What controls channel form in steep mountain streams?, Geophys. Res. Lett., 44, doi: 10.1002/2017GL074198.

Kaitna R, Palucis MC, Yohannes B, Hill KM, and Dietrich WE, 2016, Effects of coarse grain size distribution and fine particle content on pore fluid pressure and shear behavior in experimental debris flows, JGR – Earth Surface, 121(2), 415-441, doi: 10.1002/2015JF003725.

Planetary Landscape Evolution

Rarely is the full history of a landscape known such that it is possible to assess how much water was required to produce it. On Mars, the question of how much water has flowed across its surface (and when) has been central to Mars' exploration. Our group uses a mechanistic understanding of surface processes on Earth, through theory, modeling, and field work, to perform paleo-flow and climate reconstructions on Mars. 

Selected Papers:

*Putnam A and Palucis MC, 2021, The Hydrogeomorphic History of Garu Crater: Implications and Constraints on the Timing of Large Late-Stage Lakes in the Gale Crater Region, JGR-Planets, 126(5), 10.1029/2020JE006688.

*Roseborough V, Horvath D, and Palucis MC, 2021, Was Gale Crater Connected to a Regionally Extensive Groundwater System?, Geophys. Res. Lett, 48(6), 10.1029/2020GL092107.

Palucis MC, *Garczynski B, Jasper J, and Dietrich WE, 2020, Quantitative assessment of uncertainties in crater retention ages on small surface areas, Icarus, 341, doi.org/10.1016/j.icarus.2020.113623.

*Rivera-Hernandez F and Palucis MC, 2019, Do deltas along the crustal dichotomy boundary of Mars in the Gale Crater region record a northern ocean?, Geophys. Res. Lett., doi: 10.1029/2019GL083046

Palucis, MC, Hayes AG, Williams RME, Sumner D, Mangold N, Horton N, Parker T, Lewis K, and Dietrich WE, 2016, Sequence and relative timing of large lakes in Gale Crater (Mars) after the formation of Mt. Sharp, JGR – Planets, doi: 10.1002/2015JE004905.

Palucis MC, Dietrich WE, Hayes AG, Williams RME, Sumner D, Mangold N, Horton N, Gupta S, Calef F, and Hardgrove C, 2014, Origin and Evolution of the Peace Vallis fan system that drains to the Curiosity landing site, J. Geophys. Res., Planets, 119(4), 705-728, doi: 10.1002/2013JE004583.

Periglacial Geomorphology

Integrating terrestrial surface processes on steep slopes with landscape evolution of Mars has led our group to asking: How does climate change in periglacial regions (of Earth and Mars) affect rates and modes of sediment transport? A recently awarded NSF grant with Jill Marshall and Justin Strauss (Collaborative Research: Watershed- scale geomorphic response to climate change in the Aklavik Range, NWT (Canada)) will allow us to test three hypotheses relevant to how climate change affects cold and icy landscapes.

Namely, we predict a warming climate results in:

1) increased bedrock weathering and erosion due to frost cracking, 2) a switch from diffusive sediment transport to mass failures, and 3) increased sediment fluxes to depositional environments.

While relevant to modern-day climate change in the Arctic, this work can also elucidate the rates at which fan and delta catchments and gullies are incised into crater walls and rims on Mars, as well as what controls sediment supply and rates to martian fans, deltas, and crater lakes.

Selected Papers:

Palucis MC, Morgan AM, *Rivera-Hernandez F, Marshall J, *Menio E, *Miller R, and Strauss JV, Rates and processes controlling periglacial alluvial fan formation: Implications for martian fans, GSA Bull, in press.