2024 CSDMS meeting-009: Difference between revisions

From CSDMS
(Created page with "{{CSDMS meeting personal information template-2024 |CSDMS meeting first name=Sean |CSDMS meeting last name=Gallen |CSDMS Pronouns=he/him |CSDMS meeting institute=Colorado State University |CSDMS meeting city=Fort Collins |CSDMS meeting country=United States |CSDMS meeting state=Colorado |CSDMS meeting email address=sean.gallen@colostate.edu |CSDMS meeting phone=(315) 729-7939 }} {{CSDMS meeting select clinics1 2024 |CSDMS_meeting_select_clinics1_2024=1) Solving the sea l...")
 
No edit summary
 
Line 26: Line 26:
}}
}}
{{CSDMS meeting abstract title temp2024
{{CSDMS meeting abstract title temp2024
|CSDMS meeting abstract title=A climate imprint on unglaciated hillslope morphology in the Colorado Front Range
|CSDMS meeting abstract title=Climate modulation of spatial and temporal fault slip in the Sangre de Cristo Mountains, Colorado
|Working_group_member_WG_FRG=Terrestrial Working Group, Critical Zone Focus Research Group
|Working_group_member_WG_FRG=Terrestrial Working Group, Geodynamics Focus Research Group
}}
{{CSDMS meeting authors template
|CSDMS meeting coauthor first name abstract=Cece
|CSDMS meeting coauthor last name abstract=Hurtado
|CSDMS meeting coauthor institute / Organization=Colorado State University
|CSDMS meeting coauthor town-city=Fort Collins
|CSDMS meeting coauthor country=United States
|State=Colorado
|CSDMS meeting coauthor email address=Cecilia.Hurtado@colostate.edu
}}
}}
{{CSDMS meeting abstract template 2024
{{CSDMS meeting abstract template 2024
|CSDMS meeting abstract=The role of climate in shaping unglaciated hillslope topography remains unclear, yet it can impact the transport and routing of surface water and sediment through its influence on surface slope, drainage density, and sediment transport efficiency. In this study, we take advantage of the dramatic altitudinal climate gradient in the Poudre Drainage Basin in Northern Colorado to evaluate the impact of climate on hillslope morphology. We hypothesize systematic changes in hillslope morphology exist across this elevation gradient, driven by climate-dependent variation in hillslope sediment transport efficiency. Using a 1-m resolution lidar-derived digital elevation model, we use existing methods to define stream channel heads, map drainage divides, and quantify hillslope length, relief, gradient, and curvature. From low to high elevation, hillslopes lengthen >300 m, while relief increases only ~50 m. Mean hillslope gradient and hilltop curvature systematically decrease from low to high elevation. Topographic proxies for bedrock exposure (an inverse proxy for regolith depth) systematically decline with increasing elevation. Because existing 10Be-derived erosion rates are consistently between ~15 – 20 m/Myr, spatial changes in erosion rates cannot account for the differences in hillslope morphology. To explain the variation in hillslope morphology as a function of elevation, we place our results in a non-dimensional, nonlinear hillslope diffusion modeling framework. This analysis suggests that topography at higher elevations is further from steady-state predictions of hillslope morphology relative to lower elevations. We interpret these results as indicating that the hillslope sediment transport efficiency systematically increases with increasing altitude, which can explain the longer, rounder hillslopes at higher elevations. We infer that late Cenozoic climate change might be forcing a transient adjustment of hillslope morphology by elevating regolith production and transport rates through increased frost cracking intensity at high elevations. These elevation-dependent changes in hillslope characteristics likely affect hydrology, sediment transport, and landscape connectivity in ways that might relate to post-wildfire and rainfall-triggered slope stability hazard potential in Colorado.
|CSDMS meeting abstract=The impact of climate on tectonics has been the muse of tectonic geomorphologists for more than 30 years. However, few natural examples exist where connections between climate and tectonics are clear. Here, we present a study of the Sangre de Cristo Mountains (SCM), CO, a normal fault system at the northern tip of the Rio Grande Rift. The SCM represents an ideal natural setting to explore the impact of climate on spatial and temporal slip patterns along the range-bounding fault. Preserved glacial moraines and trimlines are used with the Glacier Reconstruction (GlaRe) toolbox to model glacial extents during the last glacial maximum (LGM). A simple line load model is used to explore the impact of glacial melting on clamping stress along the range front fault, and a flexural isostatic model is applied to estimate the footwall response to deglaciation. Results show that glacial melting reduces fault clamping stress, perhaps enabling accelerated fault slip in the post-glacial period. Flexural isostatic results suggest modest footwall uplift of ~4 m due to ice removal. We compare our results to fault displacement, measured from scarps preserved in Pleistocene and Holocene alluvial fans. The spatial pattern and magnitude of Holocene fault displacement are consistent with our flexural isostatic results. Furthermore, Holocene slip rates are at least a factor of three higher than Pleistocene slip rates. We infer that the flexural isostatic response to footwall deglaciation primarily controls the spatial and temporal fault slip patterns during the Holocene. Our results show that climate-modulated glacial ice loading and unloading can pace the spatial and temporal slip on a range-bounding normal fault system.
}}
}}
{{blank line template}}
{{blank line template}}

Latest revision as of 15:19, 22 January 2024


Pay Pay registration

(if you haven't already)




Log in (or create account for non-CSDMS members)
Forgot username? Search or email:CSDMSweb@colorado.edu


Browse  abstracts


Climate modulation of spatial and temporal fault slip in the Sangre de Cristo Mountains, Colorado


Sean Gallen, (he/him),Colorado State University Fort Collins Colorado, United States. sean.gallen@colostate.edu
Cece Hurtado, Colorado State University Fort Collins Colorado, United States. Cecilia.Hurtado@colostate.edu



The impact of climate on tectonics has been the muse of tectonic geomorphologists for more than 30 years. However, few natural examples exist where connections between climate and tectonics are clear. Here, we present a study of the Sangre de Cristo Mountains (SCM), CO, a normal fault system at the northern tip of the Rio Grande Rift. The SCM represents an ideal natural setting to explore the impact of climate on spatial and temporal slip patterns along the range-bounding fault. Preserved glacial moraines and trimlines are used with the Glacier Reconstruction (GlaRe) toolbox to model glacial extents during the last glacial maximum (LGM). A simple line load model is used to explore the impact of glacial melting on clamping stress along the range front fault, and a flexural isostatic model is applied to estimate the footwall response to deglaciation. Results show that glacial melting reduces fault clamping stress, perhaps enabling accelerated fault slip in the post-glacial period. Flexural isostatic results suggest modest footwall uplift of ~4 m due to ice removal. We compare our results to fault displacement, measured from scarps preserved in Pleistocene and Holocene alluvial fans. The spatial pattern and magnitude of Holocene fault displacement are consistent with our flexural isostatic results. Furthermore, Holocene slip rates are at least a factor of three higher than Pleistocene slip rates. We infer that the flexural isostatic response to footwall deglaciation primarily controls the spatial and temporal fault slip patterns during the Holocene. Our results show that climate-modulated glacial ice loading and unloading can pace the spatial and temporal slip on a range-bounding normal fault system.


Retrieved from "https://csdms.colorado.edu/csdms_wiki/index.php?title=2024_CSDMS_meeting-009&oldid=438877"