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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

One of the most tragic volcanic events of the 20th century occurred in Colombia, in 1985, when an eruption of Nevado del Ruiz produced lahars that swept down river valleys and destroyed communities in its path. With little warning, the volcano began erupting on the afternoon of November 13, 1985. Ash and muddy rain began to fall. Communities were alerted but no formal decision was made to evacuate. Later that evening, a stronger eruption produced pyroclastic flows and surges that mixed with snow