Ice is a powerful force that shapes the landscape through weathering, erosion, transportation, and deposition of rock material. Freeze-thaw weathering causes cracks in bedrock to enlarge when water freezes and expands. Glacial erosion occurs primarily through plucking, where blocks of rock are torn away from fractures, and abrasion, where rock fragments scrape and gouge the landscape. Rock material is transported and later deposited as moraines when glaciers melt, forming lateral, medial, terminal, and recessional moraines along the sides and at the terminus of the glacier.