Eruptive history of the last-1300-years activity of Kelud volcano, Indonesia: Inferences from stratigraphy, chronology, sedimentology, componentry, and geochemistry

Abstract

Kelud is considered one of the deadliest volcanoes in Indonesia due to its proximity to three cities in East Java (Malang, Kediri, and Blitar) and violent eruptions over the last century. Regardless of the frequently witnessed eruptions, the volcanic stratigraphy for the historical ages has been poorly understood. Here, we provide the first documentation of volcanic stratigraphy for the last 1300 years of activity at Kelud. Componentry and 14C data are coupled with detailed field observations to develop a comprehensive stratigraphy and characterize the main eruption types. The volcanic succession can be subdivided into ten bed-sets composed of pyroclastic density current (PDC) and tephra fallout deposits. A total of twelve fallouts and ten individual PDC units were identified between ∼1.3 and 0.1 cal. ka B.P. One of these units may be attributed to the 1481C.E. eruption. The fallout layers are generally thin, derived from short-sustained eruption columns. By contrast, PDC deposits are massive to stratified, suggesting variable particle concentrations typically resulting from low-column collapses. This complex stratigraphy suggests that Kelud is capable of producing a wide spectrum of eruptions with an increasing eruptive frequency over time and shorter dormancy periods than those between witnessed eruptions (from once /∼100 years to once/∼10 years). This stratigraphic framework, which documents extended records from the oldest witnessed eruption in Kelud (1000C.E.), sheds new insights into Kelud's activity during historical time. Since the products share similar characteristics with those from the most recent activities at Kelud (e.g., 1990, 2007–2008, and 2014), similar eruptions may also occur in the future.