НОВАРУПТА: Самое мощное извержение XX века, о котором забыли почти все

On June 6, 1912, the most powerful volcanic eruption of the twentieth century took place in Alaska. And for fifty-six years, it carried the wrong name. The eruption of Novarupta released 13.5 cubic kilometers of magma in 60 hours — thirty times more than Mount St. Helens in 1980, three times more than Pinatubo in 1991, more than Krakatoa in 1883. The shockwave was heard 1,500 kilometers away, in the Yukon. Over Kodiak, 170 kilometers from the vent, noon became night — and stayed night for 60 hours. Thirty centimeters of ash collapsed roofs. In the stratosphere, an aerosol layer settled that cooled the average temperature of the Northern Hemisphere by one degree Celsius for the next year and a half. But that isn't the strangest part. Mount Katmai, 2,300 meters tall, the mountain everyone was watching, was at that same moment collapsing into its own emptied chamber — without erupting. The magma beneath it had traveled sideways and emerged ten kilometers away through a vent that, that morning, physically did not exist. For fifty-six years, geological science pointed at the wrong volcano. And when in 1968 a map of ashfall thickness finally overturned the textbooks, it revealed physics that no volcanology manual had described until then. Four Alutiiq villages at the foot of Katmai evacuated two full days before the strike. With no instruments. By reading the earthquakes — a skill the local people had mastered for two thousand years. Ethnographers fifty years later would try to understand exactly which system worked in the place where no seismograph would have worked. Because there were no seismographs in that region. This is the story of what it means when a mountain falls without erupting. And why what came out of the ground came out somewhere other than where everyone was looking. CHAPTERS 00:00 A mountain falls without erupting 03:06 The two mysteries of Novarupta 04:15 Seven days before the catastrophe 05:25 How the Alutiiq read the earthquakes 06:57 The magma chamber beneath Katmai 08:19 The first strike and the steamer Dora 10:18 The collapse of Mount Katmai 11:40 The birth of the Novarupta vent 12:41 60 hours of darkness over Kodiak 15:07 Ash and global consequences 16:40 The Valley of Ten Thousand Smokes 20:00 Why science blamed Katmai 21:41 The 1968 map that exposed the error 23:54 The lessons of Novarupta and Pinatubo 24:44 Katmai today and the unsolved mystery SOURCES Hildreth, W. & Fierstein, J. (2012). The Novarupta-Katmai eruption of 1912 — Largest eruption of the twentieth century: Centennial perspectives. U.S. Geological Survey Professional Paper 1791, 259 p. Fierstein, J. & Hildreth, W. (1992). The plinian eruptions of 1912 at Novarupta, Katmai National Park, Alaska. Bulletin of Volcanology, 54, 646–684. Hildreth, W. (1991). The timing of caldera collapse at Mount Katmai in response to magma withdrawal toward Novarupta. Geophysical Research Letters, 18, 1541–1544. Curtis, G. H. (1968). The stratigraphy of the ejecta from the 1912 eruption of Mount Katmai and Novarupta, Alaska. Geological Society of America Memoir, 116, 153–210. Abe, K. (1992). Seismicity of the caldera-making eruption of Mount Katmai, Alaska, in 1912. Bulletin of the Seismological Society of America, 82, 175–191. Martin, G. C. (1913). The recent eruption of Katmai volcano in Alaska. National Geographic Magazine, 24, 131–181. Griggs, R. F. (1922). The Valley of Ten Thousand Smokes. National Geographic Society, Washington. Alaska Volcano Observatory (AVO). Eruption details: Novarupta 1912 and Katmai 1912. National Park Service. Katmai National Park and Preserve — geological and ethnographic archives. Project Jukebox (1998). Katmai's witnesses — Alutiiq oral histories. University of Alaska Fairbanks.