Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, Oxford OX1 3TG, United Kingdom;
Sezione di Bologna, Istituto Nazionale di Geofisica e Vulcanologia, Bologna 40128, Italy;
Proc Natl Acad Sci U S A. 2020 Oct 20;117(42):26061-26068. doi: 10.1073/pnas.2003008117. Epub 2020 Sep 28.
The Tierra Blanca Joven (TBJ) eruption from Ilopango volcano deposited thick ash over much of El Salvador when it was inhabited by the Maya, and rendered all areas within at least 80 km of the volcano uninhabitable for years to decades after the eruption. Nonetheless, the more widespread environmental and climatic impacts of this large eruption are not well known because the eruption magnitude and date are not well constrained. In this multifaceted study we have resolved the date of the eruption to 431 ± 2 CE by identifying the ash layer in a well-dated, high-resolution Greenland ice-core record that is >7,000 km from Ilopango; and calculated that between 37 and 82 km of magma was dispersed from an eruption coignimbrite column that rose to ∼45 km by modeling the deposit thickness using state-of-the-art tephra dispersal methods. Sulfate records from an array of ice cores suggest stratospheric injection of 14 ± 2 Tg S associated with the TBJ eruption, exceeding those of the historic eruption of Pinatubo in 1991. Based on these estimates it is likely that the TBJ eruption produced a cooling of around 0.5 °C for a few years after the eruption. The modeled dispersal and higher sulfate concentrations recorded in Antarctic ice cores imply that the cooling would have been more pronounced in the Southern Hemisphere. The new date confirms the eruption occurred within the Early Classic phase when Maya expanded across Central America.
伊洛潘戈火山的年轻特埃里布兰科（TBJ）喷发，在玛雅人居住时，在很大程度上覆盖了萨尔瓦多的大部分地区，并使火山 80 公里以内的所有地区在喷发后的数年至数十年内都无法居住。尽管如此，由于喷发规模和日期没有得到很好的限制，这次大型喷发的更广泛的环境和气候影响还不太为人所知。在这项多方面的研究中，我们通过在距离伊洛潘戈 7000 多公里的一个有良好年代记录的高分辨率格陵兰冰芯记录中确定了喷发层，将喷发日期确定为公元 431 年±2 年；并通过使用最先进的火山灰扩散方法模拟堆积物厚度，计算出从喷发的共角砾岩柱中分散出 37 至 82 公里的岩浆。一系列冰芯的硫酸盐记录表明，与 TBJ 喷发有关的平流层注入了 14±2Tg S，超过了 1991 年历史上皮纳图博火山喷发的量。根据这些估计，TBJ 喷发可能在喷发后几年内导致全球气温下降约 0.5°C。模拟的扩散和南极冰芯中记录的更高硫酸盐浓度意味着，在南半球，冷却效应会更加明显。新的日期证实了这次喷发发生在早期经典时期，当时玛雅人在中美洲扩张。
