Non-Invasive Multiple-Method Approaches to Characterize Landforms in the Anthropocene: A Study of the Periglacial Critical Zone
Abstract
Prevalence of anthropogenic landforms and human impacts on geomorphic processes led to the development of Anthropogeomorphology and a proposed new geological epoch: the Anthropocene. Natural processes and environments are inherently complex, and anthropogenic influences increases the complexity of geomorphological problems. New approaches are required to study natural and anthropogenic processes. The intricate ways in which terrestrial systems are interconnected can be approached from a Critical Zone perspective, comprising interdisciplinarity, as well as multitemporal studies across spatial scales. A comprehensive understanding of form-process dynamics can only be reached by jointly interpreting subsurface and surface information. Multi-method approaches, strongly driven by technological advancements, are key to obtain data in modern geomorphology. Previously inaccessible areas are within reach, and scale issues are addressed using technology at varying resolutions. With growing interest in the built environment and in using cost-efficient and non-destructive techniques, non-invasive methods are increasingly preferred. Characterization of the subsurface has progressed from being accomplished by ground-truthing data from non-invasive methods, to solely depending on increasingly reliable non-destructive techniques, such as near-surface geophysics. A case study exemplifies the use of non-invasive methods in characterizing a rock glacier, a significant water source in the periglacial Critical Zone, where water resources are limited and severely impacted by climate change. The Upper Camp Bird rock glacier, located on level 3 of Camp Bird Mine in Ouray, Colorado, is the rock glacier of interest. This research integrated meteorological, geomorphological, geological, and geophysical information to characterize the internal structure and hydrology of the selected rock glacier, while evaluating the suitability of two controlled-source electromagnetic induction systems. Near-surface geophysical surveys conducted employing time-domain and frequency-domain electromagnetic induction systems were interpreted to determine the internal structure of the rock glacier. The frequency-domain system was highly susceptible to local environmental conditions and was inapplicable to resolve the internal makeup of the rock glacier. The time-domain system allowed for deep subsurface penetration and realistic modeling of the internal structure of the rock glacier, which consists of an outer debris shell (<3 m thick), a frozen component (50m-80m thick), and a meltwater component or varying thickness found at different depths.
Subject
Non-invasive methodsNear-surface geophysics
Critical Zone
Anthropocene
Anthropogeomorphology
Periglacial environment
Multiple-method approaches
Citation
Granados Aguilar, Raquel (2021). Non-Invasive Multiple-Method Approaches to Characterize Landforms in the Anthropocene: A Study of the Periglacial Critical Zone. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /195630.