Active vs Inactive Volcanoes: Understanding Volcanic Eruptions for Grade 9 Earth Science This educational whiteboard explainer video introduces Grade 9 students to the differences between active and inactive volcanoes. It highlights key signs of volcanic activity such as gas emissions and seismic events, and clearly explains the eruption process including magma movement, lava flows, ash clouds, and pyroclastic surges. Designed for clarity and engagement, the video provides a solid foundation in