A glacial delta forms when a glacier melts and deposits sediment at its terminus, where the ice meets a body of water, such as a lake or ocean. As the glacier retreats, it leaves behind a mix of sand, gravel, and silt, creating a fan-shaped landform. This process can occur rapidly, especially during warm periods when melting accelerates. These deltas are important for ecosystems, as they provide habitats for various plants and animals. Additionally, glacial deltas can influence local geography and hydrology, affecting how rivers and lakes behave. They are often studied in relation to climate change and glacial retreat.