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Abstract Recent theoretical models and field observations suggest that fluvial bedload flux can be estimated from seismic energy measured within appropriate frequency bands. We present an application of the Tsai et al. (2012,https://doi.org/10.1029/2011gl050255) bedload seismic model to an ephemeral channel located in the semi‐arid southwestern US and incorporate modifications to better estimate bedload flux in this environment. To test the model, we collected streambank seismic signals and directly measured bedload flux during four flash‐floods. Bedload predictions calculated by inversion from the Tsai model underestimated bedload flux observations by one‐to‐two orders of magnitude at low stages. However, model predictions were better for moderate flow depths (>50 cm), where saltation is expected to dominate bedload transport. We explored three differences between the model assumptions and our field conditions: (a) rolling and sliding particles have different impact frequencies than saltating particles; (b) the velocity and angle of impact of rolling particles onto the riverbed differ; and (c) the fine‐grained alluvial character of this and similar riverbeds leads to inelastic impacts, as opposed to the originally conceptualized elastic impacts onto rigid bedrock. We modified the original model to assume inelastic bed impacts and to incorporate rolling and sliding by adjusting the statistical distributions of bedload impact frequency, velocity, and angle. Our modified “multiple‐transport‐mode bedload seismic model” decreased error relative to observations to less than one order of magnitude across all measured flow conditions. Further investigations in other environmental settings are required to demonstrate the robustness and general applicability of the model. 

The proposed study aims to deploy seismometers, tiltmeters, and other equipment at the Santa Fe River Sink-Rise system in FL to monitor geophysical responses to recharge events over a two-year period. Geophysical data collected as part of this project will leverage ongoing data collection efforts to enable the interpretation of geophysical responses that arise from hydrologic processes. The overall goal of this remote sensing study is to develop new techniques using data collected at the surface to identify the location of conduits and other subsurface features as well as to provide constraints on flow and hydrologic processes in karst aquifers. 

This is a pilot project to test feasibility of identifying seismic tremor associated with discharge into an aquifer. We are proposing to conduct three recharge experiments near Preston, MN. The site includes a sinkhole and spring that are ~100 m apart. Artificial recharge events will be conducted by filling a pool with water and then releasing the water into the sinkhole to produce a pressure pulse. For each experiment, the water will be released at a different rate to test aquifer response to a range of recharge rates. We will use a variety of geophysical sensors to probe the response to the recharge events in multiple ways.