The magnitude and impact of the 431 CE Tierra Blanca Joven eruption of Ilopango, El Salvador

Abstract

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 km3 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.

Cryptotephra from the Icelandic Veiðivötn 1477 CE eruption in a Greenland ice core: confirming the dating of volcanic events in the 1450s CE and assessing the eruption's climatic impact

“…Marshall et al, 2019). While the majority of the potential chronological mismatches have been resolved using new ice-core chronologies and long-term hemispheric-wide treering-based climate reconstructions (Sigl et al, 2015;Stoffel et al, 2015;Wilson et al, 2016), several enigmas re-main. The most notable of these unsolved questions is the apparent discrepancy between the timing of two major sulfuremitting volcanic eruptions, including the largest sulfateloading event in the last 700 years, and large-scale climatic cooling observed during the 1450s CE (Esper et al, 2017).…”

“…Briffa et al (1998) subsequently identified a distinct cooling event in 1453 CE, recorded at multiple sites within their circum-northern hemispheric network of tree-ring chronologies from the northern boreal forest, while Salzer and Hughes (2007) identified evidence for anomalous tree-ring growth in the early and late 1450s CE in western USA bristlecone pines. More recently, warm-season temperature reconstructions from Northern Hemisphere tree-ring networks have revealed spatially coherent and exceptional cooling in 1453 CE, with cooling ranging spatially between −0.4 and −6.9 • C, marking the onset of a 15-year cold period (Stoffel et al, 2015;Esper et al, 2017;Guillet et al, 2017).…”

“…In addition to the ice-core and tephra analysis, we quantified the cooling induced by the V1477 eruption using the NVOLC v2 dataset of Guillet et al (2020) and compared it to other major Icelandic eruptions of the Common Era. The NVOLC v2 dataset includes 13 tree-ring width (TRW) and 12 maximum latewood density (MXD) chronologies spread across the Northern Hemisphere (NH; for further details see Stoffel et al, 2015, andGuillet et al, 2017). All chronologies in NVOLC v2 have either been calibrated against regional instrumental climate data and transferred into temperature units or have been interpreted by the original authors as a temperature proxy.…”

Evidence for old carbon contamination in <sup>14</sup>C wiggle-match age series for the 946 CE eruption of Changbaishan volcano

“…Dates for eruptions that are not historically attested by a literate society are rarely known to a decade or century, let alone a calendar year. However, decadal or better accuracy dating of eruptions assumes great significance for events such as the Bronze Age eruption of Thera in the eastern Mediterranean (Friedrich et al, 2006;Pearson et al, 2018;Pearson et al, 2020;Friedrich et al, 2020) or the Tierra Blanca Joven eruption of Ilopango in Central America (Dull et al, 2019;Smith et al, 2020), which both occurred close to a literate society that may have been directly or indirectly affected.…”

Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)

“…The release of tens to thousands of cubic kilometers of magma producing widespread fallout and ground-hugging hot and turbulent pyroclastic flows are potential threats to life within large areas from the source (>100 km; Koch & Mclean, 1975;Wilson et al, 1995), while emissions of climate-forcing gases can have a global impact (Self & Blake, 2008;Sheets, 2015;Brenna et al, 2020Brenna et al, , 2021. One such devastating eruption was the variably dated 431-545 CE Tierra Blanca Joven (TBJ) eruption (∼106 km 3 ) from Ilopango caldera in El Salvador, Central America (Dull et al, 2019;Pedrazzi et al, 2019;Smith et al, 2020). During this eruption, densely populated Maya settlements were buried under pyroclastic deposits (∼40,000-80,000 casualties; Dull et al, 2019;Hart & Steen-McIntyre, 1983) causing a profound reorganization of the Maya society at political, economic, and demographic levels (Dull et al, 2001(Dull et al, , 2019Sheets, 2015).…”