A late Pleistocene-Holocene record of explosive eruptions from central Sumatra (Indonesia) in the western Sunda volcanic arc

Abstract

<p><span>The island of Sumatra within the Indonesian archipelago is home to over 130 active or potentially active volcanoes with a history of explosive eruptions. Highly explosive eruptions with volcanic explosivity index (VEI) ≥ 6 in Sumatra, such as those originating from the massive Toba caldera, have been well-documented in the literature. However, moderately explosive eruptions with VEI 3–5 have received inadequate attention due to their limited preservation within the proximal stratigraphic record. This gap in knowledge hinders existing attempts to conduct hazard assessments for these potentially impactful eruptions. In this study, we address this knowledge gap by presenting a combination of geochemical, geochronological and tephrochronological datasets associated with distal tephra layers sampled from deep-sea cores collected off the coast of West Sumatra, as well as proximal pyroclastic deposits throughout central Sumatra. Our datasets reveal geochemical and stratigraphic correlations between seven distal tephra layers and their proximal sources, allowing for the quantification of their eruption ages and volumes. Notably, we identified the ~ 1.53 ka Lubuk King Tephra (LKT) eruption from Malintang volcano that discharged ≥ 1.4 km</span>³<span> dense-rock equivalent (DRE) of magma, representing the youngest known VEI 5 eruption in Sumatra. In addition, we determined Tandikat volcano as the proximal source for a pair of temporally proximate (~ 580 yr apart) VEI 5 eruptions (Tandikat II and I Tephra, TDK II and I; ~ 4.36 and ~ 4.94 ka) that produced ≥ 1.1 and ≥ 2.7 km</span>³<span> DRE of magma, respectively. We also ascertained that at least two VEI 4 eruptions occurring within the last ~ 36 kyr can be correlated to the active Marapi volcano. Furthermore, we traced distal tephra layers AB4 (~ 36.8 ka) and AB5 (~ 41.0 ka) to two distinct VEI ≥ 5 eruptions at volcanic centres in neighbouring provinces (Ranau Tuff, RAN from South Sumatra; Djudjun Tephra, DJT from Jambi). Volcanic source provenances for another six distal tephra layers remain unknown due to the lack of known proximal correlatives. Overall, our study provides an improved tephrochronological framework for late Pleistocene-Holocene explosive volcanism in central Sumatra that will help refine existing volcanic hazard assessments and enhance the integration of terrestrial and marine palaeoenvironmental archives regionally.</span></p>