Quantifying spatial peat depth with seismic micronodes and the implications for carbon stock estimates

Peatlands are a major store of soil carbon, due to their high concentration of carbon-rich decayed plant material. Consequently, accurate assessment of peat volumes are important for determining land-use carbon budgets. Determination of carbon stocks at the scale of individual peat sites has principally relied on either mechanical probing or electromagnetic geophysical methods. In this study, we investigated the use of seismic nodal instrumentation for quantifying peat depth. We used Stryde nodes for a deployment at the Whixall Moss in Shropshire, England. We measured seismic arrival times from peat-bottom reflections, as well as dispersive surface waves to invert for a model of variable peat depth along a linear cross-section using level-set based interface inversion for peat depth. We found that the results from seismic surveying corresponded well with manual probe depths, and delivered high spatial resolution. The use of very small seismic nodes (micronodes) allows for particularly rapid deployment on challenging terrain.