CCNY Earth Surface Dynamics

Climatic controls on erosion & landscape evolution

Because global warming is raising temperatures and altering the frequency and magnitude of storms, quantifying erosional responses to glacier melting, rainfall, and waves are urgent problems in Earth science. Despite longstanding expectations for relationships between climate and erosion rates, measuring such a signal in field data has proven surprisingly difficult – partly because many non-climatic factors (e.g., lithology, rock uplift rates) also influence erosion rates and partly because surface processes may respond to weather and climate change in nuanced ways. Isolating the influence of climate on erosion rates and understanding the impact of hourly to million-year scale climate variability on earth surface processes are open challenges, so basic questions about how climate change will affect Earth’s surface remain unanswered. This knowledge gap also hinders efforts to infer tectonic history from topography, interpret sedimentary records, and understand feedbacks between erosion, weathering, CO2 drawdown, and climate change over geologic timescales. Some of the clearest relationships between climate and erosion have been measured in landscapes with relatively uniform lithology and tectonic uplift rates or in landscapes where these competing factors are well characterized. We use these natural laboratories and numerical models to quantify the influence of climate mean and variability on fluvial and coastal erosion and to examine the consequences of deglaciation on alpine landscape evolution over historic to million-year timescales.

Publications: Lai & Huppert 2024; Lai & Huppert 2023; Chan et al. 2023; Huppert et al. 2020; Ferrier et al. 2013

Topographic constraints on lithosphere & mantle dynamics

Topography can provide important observational constraints on the rheology, thermal evolution, and dynamics of the lithosphere and mantle – all of which have implications for understanding Earth's heat budget, the styles of deformation that develop at plate boundaries, and the surface expressions of mantle convection. Tectonic and geodynamic processes drive rock uplift and alter the base level of rivers and hillslopes by changing relative sea level. They consequently exert dominant control on terrestrial and submarine geomorphology; virtually all of Earth’s steepest landscapes are found in regions of rapid rock uplift, and conductive cooling of the lithosphere is the first-order control on global seafloor depths. Topo-bathymetry, paleoshorelines, and sedimentary records can therefore provide an invaluable window to deep earth processes operating today and in the geologic past. We use modeling and geomorphic observations - including the morphology of bedrock coasts, river profiles, seafloor topography, and drainage networks - to constrain plume-plate interactions at ocean hotspots, relative sea level histories, and paleotectonics.

Publications: Ott et al. 2023; Malatesta et al. 2022; Yuan et al. 2022; Huppert et al. 2020; Huppert et al. 2015

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