Mount St. Helens' 24 Megaton Blast to Naples' Supervolcano - Mega Disaster

From St. Helens' 24 megaton lateral blast to Naples' hidden supervolcano, this episode tracks how eruptions create and destroy, and the risk of the next mega event. We begin in Hawaii, where Kilauea’s 1983 eruption sent lava fountains 80 meters high and crept for seven years. In 1990, the flow reached Kalapana, burying the village under more than 15 meters of lava and wiping out about 150 homes, even as it added over 200 hectares of new land. Ocean entries build unstable lava deltas that can collapse without warning. Cameraman Jeff Mackley captures the beauty and danger at the edge of the flow. Across the Atlantic, Iceland’s Eldfel eruption in 1973 threatened the village of Vessmanja on the island of Kime. Crews fought back by pumping around 6 million cubic meters of seawater onto the advancing lava, converting nearly 4 million cubic meters into solid rock and saving the town. Then to the Caribbean: in 1995 the Sufria Hills volcano on Montserrat reawakened. On June 25, 1997, a 10 km ash column rose as 800-degree pyroclastic flows sped downhill at over 100 km/h, killing 19 and destroying the island’s only airport. Roy Daley narrowly escaped as darkness and hot ash engulfed his neighborhood. Dr. Sue Locklim and colleagues documented months of repeated explosions. In Bari, Italy, large-scale experiments using Vesuvius ash reveal how force and magma volume drive deadly flows, helping map evacuation zones. Monsoon rains then transformed ash into lahars that progressively buried Plymouth. In 1980, Mount St. Helens delivered a rare lateral blast. A magnitude 5.1 quake triggered a 2.8 billion cubic meter landslide at 257 km/h, uncorking a 24 megaton explosion that hurled debris at 483 km/h. Pyroclastic flows reached 129 km/h and up to 37 meters thick. Fifty-seven people died, 600 square kilometers were flattened, and 508 million tons of ash spread across the U.S. Jess Hageman’s helicopter crew found survivors amid moonscape devastation. Volcanologist Rick LaHousen’s air-dropped “spider” instruments now track a growing lava dome rising about 5 meters per day and more than 200 meters across. Pinatubo’s 1991 VEI 6 eruption blasted 5 cubic kilometers of debris 35 km high. Dr. Kelvin Rodolfo recalls tremors and lightning in the ash as a typhoon turned tephra into roof-crushing cement, despite evacuations of over 58,000. Global temperatures fell by about one degree for more than two years. Over the next months, more than 200 lahars scoured valleys; in 1995, Father Nestor Tayek warned as a roaring lahar buried much of Baccalaure. Thousands of lahars have since killed nearly 400 and destroyed over 42,000 homes. A 100 million cubic meter caldera lake still threatens 46,000 below. Finally, scientists model a VEI 7 scenario at Campi Flagrei near Naples, a 13 km-wide caldera with 350,000 residents inside and 5 million nearby. A super eruption could eject around 242 cubic kilometers of material, unleash near-supersonic pyroclastic flows, bury a city, drop 20 cm of ash on Rome, and cool global climate for 4 to 5 years. Experts say such an event will happen sometime in the future, possibly with about a 1% chance in the next century. Preparation through monitoring, mapping, and timely evacuation is our only defense. #MegaDisaster #Volcanoes #MountStHelens #Pinatubo #Montserrat #Kilauea #CampiFlagrei #Supervolcano