Abstract

Rock slope failures are hazardous erosional events that result from a range of processes, including both direct environmental forcing and progressive rock fracture. In this study, we present a novel 4D dataset compromising three years of continuous laser scanner monitoring based on hourly change detection of the cliff-face topography undertaken on a vertical cliff (Whitby, North Yorkshire, UK). We developed a computational workflow to automatically process a total of 20,098 collected scans to undertake automatic pairwise change detection measurements. We used our data to examine in detail the evolution and timing of rock slope failure and how this is manifest as short- and long-term rates of material loss and cliff retreat. We found that the average rate of cliff retreat over a three-year monitoring period is ~11 mm y-1. Periods of higher erosional activity (~140 – 300 mm y-1 within five day internals) punctuate periods of slower erosion (~2.5 – 9.3 mm y-1), where the rate of volume loss during slower erosion is controlled by small-magnitude rock slope failures. Our research characterizes the retreat rates at both high resolution and long-term monitoring, and holds implications for the understanding of the drivers of rock slope erosion.