A 15 year record of frontal glacier ablation rates estimated from seismic data

We present a unique time series of continuous glacier frontal ablation rates with weekly resolution over 15 years estimated from seismic calving observations at Kronebreen, Svalbard. Using linear statistical models, we calibrate the seismic record with 7 years of satellite‐derived frontal ablation measurements. The two basic input parameters required for our models are the cumulative duration of individual seismic calving events and the incompleteness of the seismic record to correct for the effect of seismic background noise. Frontal ablation follows the seasonal glacier speedup, peaking 1–2 months after the melt season maximum. Short‐lived peaks are associated with melt and rain events. Cumulative frontal ablation of Kronebreen between 2001 and 2015 is about 4.0 km3 (3.7 Gt), with the greatest annual loss (0.45 km3) between 2013 and 2014 at the onset of the recent accelerated retreat of the glacier. Our approach provides a potential method for monitoring tidewater glaciers worldwide that have sufficiently close seismic instrumentation. Plain Language Summary Glaciers that flow into the sea lose ice through iceberg calving which present a formidable contribution to global sea level rise. However, ice loss through calving is one of the most difficult ice loss terms to measure because it occurs over a period of a few seconds. When calving occurs, a small earthquake caused by the impact of the iceberg into the water can be measured on seismometers. These seismic measurements do not tell us directly how much ice the glacier has lost. However, the ice loss from glacier terminus processes including calving can be determined using repeat satellite images that capture changes at the glacier terminus. Combining satellite and seismic observations of calving at the same time, we can develop methods to determine the ice loss directly from the seismic data. This allows us to quantify ice loss with high temporal resolution continuously and back through time in glaciated regions. For the first time, we quantify calving ice loss continuously, and at weekly resolutions, for over a decade from nearby seismometers at Kronebreen, a glacier on the Arctic archipelago of Svalbard. Our results open a treasure chest for better understanding calving processes. Key Points Seven years of satellite‐derived glacier frontal ablation are used to develop models that estimate weekly frontal ice loss from seismic data Duration of seismic calving signals and catalog incompleteness mainly co