Hydrologic impacts of the Slumgullion landslide on Lake Delta formation

Abstract

The Slumgullion landslide, located in southwestern Colorado near Lake City, has been an area of interest for many scientists for 300 years. Data on the movement of the slide indicates that the younger, active part of the landslide moves over the older, inactive part of the landslide. To further our understanding of the landslide dynamics, we integrated data previously collected from easy-to-access outcrops with our analyses of satellite imagery and hydrologic data. We see that on average the shallow area of the landslide moves 0.755 m/yr (+/- 0.078 m/yr) with faster movement to the south. Aerial data combined with precipitation and lake level data was used to determine if the amount of rainfall and the lake level have any effect on the average rate of movement determined. Based on our analyses of the annual precipitation data, we interpret that precipitation does impact the migration rate. This work demonstrates the necessity for more process-based linkages between surface and subsurface hydrology and mobility of the Slumgullion slide. We recommend future, priority measurements to further our understanding of the slide dynamics include water table levels along the slide, strength of materials in the slide, and higher resolution characterization of the hydrology and deformation.