Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Earth Surface
Increases in global erosion rates over the past few million years have been linked to long-term cooling of Earth’s climate, but this relationship is complicated by biases in sedimentary records. Glaciers, which are highly efficient agents of erosion in high-altitude and polar landscapes, are particularly sensitive to climate change. Short-term glacial erosion rates are often much higher than long-term rates due to processes such as glacial retreat, basal sliding, and surging. This time-averaging bias often muddles interpretations of long-term trends in landscape evolution.
Fedotova and Magnani [2024] investigate glacial erosion in Lago Argentino, a proglacial basin that receives sediment from the Southern Patagonia Ice Field. By combining sedimentation rate data from cores with seismic reflection imaging of sediment layers, they calculate erosion rates over the past 20,000 years. Their findings show that glacial erosion was intermittent, occurring in distinct pulses separated by periods of quiescence. By compiling global glacial erosion rate data, the authors show that rates averaged over decadal timescales appear much higher than rates averaged over thousand-to-million-year timescales. These results emphasize the importance of accounting for time-averaging biases in erosion rate studies to better interpret landscape evolution and climate change over Earth’s history.
Citation: Fedotova, A., & Magnani, M. B. (2024). Glacial erosion rates since the last glacial maximum for the former Argentino glacier and present-day Upsala glacier, Patagonia. Journal of Geophysical Research: Earth Surface, 129, e2024JF007960. https://doi.org/10.1029/2024JF007960
—Marisa Repasch, Associate Editor, JGR: Earth Surface