Ice sheets are massive expanses of ice that cover large portions of a continent. They form when snow accumulation exceeds melting and eventually compacts into thick layers of ice. Ice sheets are primarily found in Antarctica and Greenland, where they can be several kilometers thick. These ice sheets play a crucial role in regulating global climate and sea level. Scientists study ice sheets to understand how they respond to climate change, how they contribute to sea-level rise, and how they may impact global climate in the future. Research on ice sheets often involves using satellite observations, field measurements, and computer modeling to track changes in ice sheet extent, thickness, and mass balance over time.