Soil is a vital natural resource, and understanding how and why soil particles move has both practical and theoretical importance. This new collaboration takes a novel approach to studying soil and biotic processes from soundscapes by analyzing the seismic signals that can be readily measured by seismometers, which are usually used to monitor earthquakes. This work represents an exploratory phase in an interdisciplinary frontier to understand soil processes by bridging the fields of geology, geophysics, ecology and biology. The investigators will build capacity through training and integration of disciplines and linking established National Science Foundation-funded networks and datasets to probe soil movement and mixing processes in the arid University of California Reserve Ecological Research site (Elliott Chaparral Reserve) and a NSF-funded Critical Zone Observatory/Long-Term Ecological Research site: a humid, tropical forest site (Puerto Rico - the Luquillo Critical Zone Observatory). Listening to previously unheard soil soundscapes is a new horizon for interdisciplinary soil research that will facilitate scientific progress and learning opportunities for grant-supported trainees and the public. This project will include a series of public outreach and training activities focusing on earth sounds for students and community members, including those who are visually impaired. The investigators will also develop a display for the Birch Aquarium in La Jolla, CA to compare soil soundscapes and ocean soundscapes.
Over ninety-nine percent of the signals recorded by existing seismic arrays are traditionally considered 'noise' and ignored. Recent work, however, has highlighted the generation of elastic waves by processes in the atmosphere, hydrosphere, and soil. This research aims to explore and quantify the geo-, eco- and anthro-soundscapes in soils. Biological agents play an important role in landscape change as animals and plants erode, transport, and deposit rock, soil, and unconsolidated material. Despite the obvious role that biological agents play in driving surface processes, biology and geomorphology have largely worked independently of one another in the generation of quantitative geomorphic theories and models. The role that animals play in landscape evolution is either generally ignored or broadly classified because the non-uniform, non-steady nature of most biogeomorphic agents is difficult to document and thus quantify. Stochastic, 'patchy' geomorphic disturbances like tree fall and movement of sediment by animals can exert first-order influences on landscapes and cycling of nutrients and carbon sequestration in soils, but the rates and frequencies at which these disturbances mobilize, exhume and bury sediment are challenging to constrain. Seismic observations and methods offer complementary advantages for soil studies compared to traditional detection, monitoring and characterization techniques because they provide high temporal resolution and broad spatial coverage, are passive and non-invasive, and provide the ability to collect continuous, real-time observations from multiple sources and inaccessible environments. Though the seismic monitoring sensors capable of detecting bioturbation have been used for decades throughout the world, these data have not yet been exploited for such a purpose. The broader use of seismological capabilities may provide insight into the connections between mechanistic drivers and source processes, and promote new insights into the underlying physics and relationships between Earth surface and near-surface processes.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
