Hernández P A, Notsu K, Salazar J M, Mori T, Natale G, Okada H, Virgili G, Shimoike Y, Sato M, Pérez N M
Laboratory for Earthquake Chemistry, Graduate School of Science, University of Tokyo, Bunkyo-Ku 113-0033, Tokyo, Japan.
Science. 2001 Apr 6;292(5514):83-6. doi: 10.1126/science.1058450.
Magmatic carbon dioxide (CO2) degassing has been documented before the 31 March 2000 eruption of Usu volcano, Hokkaido, Japan. Six months before the eruption, an increase in CO2 flux was detected on the summit caldera, from 120 (September 1998) to 340 metric tons per day (September 1999), followed by a sudden decrease to 39 metric tons per day in June 2000, 3 months after the eruption. The change in CO2 flux and seismic observations suggests that before the eruption, advective processes controlled gas migration toward the surface. The decrease in flux after the eruption at the summit caldera could be due to a rapid release of CO2 during the eruption from ascending dacitic dikes spreading away from the magma chamber beneath the caldera.
在日本北海道有珠火山2000年3月31日喷发之前，已有关于岩浆二氧化碳（CO₂）脱气的记录。喷发前六个月，在火山口顶部检测到CO₂通量增加，从1998年9月的120吨/天增至1999年9月的340公吨/天，随后在喷发后3个月，即2000年6月，突然降至39公吨/天。CO₂通量的变化和地震观测表明，喷发前，平流过程控制着气体向地表的迁移。火山口顶部喷发后通量的减少可能是由于喷发期间来自从火山口下方岩浆房向外扩展的上升英安岩脉的CO₂快速释放所致。
