Landscape evolution on conical landforms with applications to drainage development on volcanoes

Abstract

Volcanic edifices are subject to a range of constructional and degradational processes, from explosive eruptions and effusive lava emplacement, to fluvial incision, glacial carving, and mass wasting; acting over various spatial and temporal scales and shaping the edifice. Understanding how an edifice's morphology evolves to reflect the interdependency of these processes is still in its early stages, complicated by physical process laws that remain underdeveloped within volcanic regions. Numerical modeling provides a useful tool to analyze this evolution by generalizing many of the processes that exist on volcanoes and considering their overarching effects on morphology over 100–1000 kyr timescales. Yet, despite advancement in applying numerical models to quantify landscape evolution, a basic understanding of drainage development and evolution on conical landforms in general remains incomplete.

Using simplified landscape evolution modeling, we test the ability to recreate natural volcano morphology evolution broadly as a consequence of the competition between topographic growth, fluvial erosion, and soil creep on a conical landform. Conducting a suite of models for volcanic edifice evolution over a nondimensional parameter space and comparing numerical edifice landform and radial drainage basin morphology trends to nature, we find a significant degree of overlap. Furthermore, we perform a misfit analysis between nature and models to constrain best-fitting erosional parameters within our nondimensional framework. Finally, we explore the effect of edifice size on radial drainage development and discuss the effects of other processes on edifice morphology. Our results suggest that despite the intricacies of multiple spatiotemporally-varying processes that occur on volcanic edifices, natural edifice morphological evolution is consistent with generalized construction and erosion models. This work thus lays the foundation for more detailed studies to investigate volcano histories through numerical modeling of a volcano's morphology.