Spatio-Temporal Characteristics and Responses to Environmental Forcings of Rift Propagation on the Ross Ice Shelf, Antarctica: Insights From Satellite Imagery and Seismic Observations

Abstract

The Antarctic ice shelves significantly influence global sea level changes by buttressing the grounded ice sheet and regulating ice flux discharge. Rift propagation and coalescence can lead to large tabular iceberg collapse, thereby altering ice shelf stability and accelerating ice flux discharge into the ocean. To explore rift propagation patterns on the Ross Ice Shelf, we extracted rift geometry over the past two decades using satellite imagery and analyzed transient rift propagation dynamics and energy release using seismic observations. We also discussed the relationship between rift propagation and environmental forcings, and identified rift propagation mechanisms through strain rates. The results indicate significant differences in rift propagation patterns, with rifts being more sensitive to environmental forcings than crevasses. Rift propagation exhibits distinct seasonal and diurnal patterns, where seasonal variations are regulated by ice surface temperature, sea ice concentration, and significant wave height from combined wind waves and swell, while diurnal variations are closely related to ocean tidal fluctuations. Rift elongation is primarily driven by tensile stress but is effectively constrained by ice flow suture zones. In contrast, rift widening is enhanced through the combined effects of ice rise shear stress and oceanic erosion. By integrating satellite imagery and seismic observations, this study explores rift propagation patterns across both decadal-scale changes and transient dynamic processes, providing key insights into the impact of rift propagation on ice shelf stability. These findings contribute to improving predictions of Antarctic ice sheet mass balance and global sea level change.