After months of pre-eruptive activity, Alaska's Mount Redoubt has erupted 6 times since Sunday night. Telegraphing its eruption with massive shallow earthquake activity in the range of 26 earthquakes every 10 minutes, the volcano, located around 100 miles southwest of Anchorage, spewed an ash column 10km high, and is expected to continue erupting for weeks or months. The last time this massive volcano erupted in 1989 a commercial airliner was caught in the ash column, causing the engines to seize and the plane to lose two miles of altitude before the engines were restarted. That eruption, which lasted for 5 months, produced this spectacular photo. Follow this amazing event at the Alaska Volcano Observatory. [more inside]
Where does your water come from? Global water supply chart. Global freshwater resources from the UN.
An erupting stratovolcano poses numerous hazards for nearby habitation, but none nearly so terrifying and deadly as the pyroclastic flow. Pyroclastic flows, comprised of tons of superheated sulfuric gases, particulate rock materials and ash, can reach temperatures of 1,830 °F and travel at alarming speeds up to 450mph. Convection of materials within the clouds causes them to become a suspension, fluidizing and thundering noxiously across the surrounding landscape for miles, in some cases even uphill or across open water. Wherever these clouds come in contact with humans the result is catastrophe, as the residents of Herculaneum and St. Pierre, Martinique learned within minutes of the eruptions of Vesuvius in 79AD and Pelee in 1902-- both towns were overwhelmed by pyroclastic clouds, igniting all flammable materials and incinerating and suffocating the inhabitants. None survived Herculaneum, while just two of St. Pierre's 26,000 survived, one of whom was a prisoner condemned to death and awaiting his execution in a dungeon cell. Despite their incredible capacity for violence, pyroclastic flows are also capable of producing mesmerizing, awe-inspiring beauty.