The Greenland and Antarctic ice sheets are losing mass at increasing rates and are projected to become the dominant contributors to global sea-level rise throughout the 21st century, with widespread impacts on coastal communities. Large uncertainties in future projections of the contributions of ice sheet mass loss make it challenging for policymakers and coastal planners to adopt adequate adaptation strategies. This uncertainty stems from poorly understood mass loss processes, many of which are driven by surface melt and meltwater pooling in supraglacial lakes, which can drastically affect ice sheet stability but are not yet well represented in models of future ice sheet evolution. To better understand these processes, continuous monitoring of supraglacial lakes across the ice sheets is critical. Given the vast and remote nature of the ice sheets, satellite remote sensing is the only feasible tool for this task. While methods for monitoring meltwater extent are well established, determining meltwater volumes has been more difficult due to large uncertainties in indirect estimates of water depths. The launch of NASA’s ICESat-2 laser altimeter in 2018 enabled the first direct measurements of water depths from space. This dissertation develops an automated framework for detecting supraglacial lakes and determining their depths using ICESat-2 data. Applied to both ice sheets from November 2018 to September 2023, this framework produces a comprehensive dataset of lake depths. The data are then used to train a machine learning model that estimates lake depths from passive optical imagery, reducing errors by 60 % compared to traditional methods. Additionally, the dissertation provides observational evidence of ice shelf flexure due to ice doline formation and submerged benches along calving fronts, which cause buoyancy-driven flexure and calving. These results highlight the value of using multi-sensor, high-resolution satellite data in observing critical meltwater-driven ice sheet processes. We expect that they will contribute to improving model projections of sea level rise by providing a better understanding of complex ice sheet processes that have potentially dramatic impacts on mass loss and stability.