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The Carnian Pluvial Episode (CPE) was a global environmental change and biotic crisis that occurred during the Carnian (Late Triassic). The climate during the CPE was characterized by a short-lived period of extreme rainfall, and an extinction of marine taxa is known to have occurred during the latest Julian (i.e. early Carnian). Although these events are considered to have been caused by the Wrangellia Flood Basalt (FB) volcanism, existing studies have found little direct evidence to support this. We investigated the temporal relationship between the eruption of Wrangellia FB and CPE using high-resolution microfossil biostratigraphy and paleo-seawater Os isotope data of an Upper Triassic bedded chert succession from an accretionary complex in Japan, which accumulated in a pelagic deep-sea environment in an equatorial region of the Panthalassa Ocean. Our biostratigraphic analysis, based on conodonts and radiolarians, and osmium isotope data show: (i) a continuous decline of initial Os isotope ratios (187Os/188Osi) in the early Julian; (ii) low 187Os/188Osi ratios during the late Julian; and (iii) an abrupt increase in 187Os/188Osi ratios at the end of the Julian. The decrease in 187Os/188Osi ratios throughout the Julian suggests an increased input of unradiogenic Os from the eruption of the Wrangellia FB into the ocean. Moreover, redox-sensitive elements, such as V and U, increased abruptly at the end of the Julian, which is the first evidence of reducing conditions during the CPE within the pelagic deep-sea Panthalassa Ocean. Marine anoxic event in the late Julian has been recognized from widespread deposition of black shales and organic-rich marls in intermediate to shallow water Tethyan sections. Thus, oxygen-depleted conditions occurred at the Tethyan shallow continental margin, as well as in the pelagic deep-sea Panthalassa Ocean, at the end of Wrangellia FB volcanism.

International Ocean Discovery Program Expedition 369 drilled four sites on the southwestern Australian continental margin, in the deep water Mentelle Basin (MB) and on the neighboring Naturaliste Plateau (NP). The drillsites are located on continental crust that continued rifting after seafloor spreading began further north on the Perth Abyssal Plain (PAP) between magnetochrons M11r and M11n (133‐132 Ma), ending when spreading began west of the NP between chrons M5n and M3n (126‐124 Ma). Drilling recovered the first in‐situ samples of basalt flows overlying the breakup unconformity on the NP, establishing a magnetostratigraphically constrained eruption age of >131‐133 Ma and confirming a minimal late Valanginian age for the breakup unconformity (coeval with the onset of PAP seafloor spreading). Petrogenetic modeling indicates the basalts were generated by 25% melting at 1.5 GPa and a potential temperature of 1380‐1410 °C, consistent with proximity of the Kerguelen plume during breakup. Benthic foraminiferal fossils indicate that the NP remained at upper bathyal or shallower depths during the last 6 Myr of rifting and for 3‐5 Myr after breakup between India and Australia. The limited subsidence is attributed to heat from the nearby Kerguelen plume and PAP spreading ridge. The margin subsided to middle bathyal depths by Albian time and to lower bathyal (NP) or greater (MB) depths by late Paleogene time. Periods of rapid sedimentation accompanied a westward jump of the PAP spreading ridge (108 Ma), rifting on the southern margin (100‐84 Ma), and opening of the southern seaway between Australia and Antarctica (60‐47 Ma).

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Volcanoes in the East Asian/Pacific region have been the source of some of the largest magnitude eruptions during the Quaternary, and accurately evaluating their eruptive histories is essential for hazard assessments. To overcome difficulties in resolving and precisely dating eruptions in the near‐source realm, the high‐resolution (varved) sediments of Lake Suigetsu (central Honshu, Japan) were examined for the presence of non‐visible (cryptotephra) layers from 50 ka up until the 30 ka AT caldera‐forming event of Aira volcano. Cryptotephra layers are four times more frequently preserved than visible markers in the Suigetsu sediments, meaning that this archive provides a unique and unprecedented record of eruptions that were dispersed towards the densely populated regions of central Honshu. Major and trace element volcanic glass chemistry is used to fingerprint the ash layers and pinpoint their volcanic origin. Tephras are found throughout the investigated sediments, but the highest abundance of ash fall events are recorded between 39 and 30 ka, capturing a period of intense volcanism at calderas on Kyushu Island (Japan). The augmented Suigetsu tephrostratigraphy records at least seven eruption events from Aso caldera (southern Kyushu) that post‐date the widespread ACP‐4 Plinian eruption (ca. 50 ka), and four explosive events from Aira (central Kyushu) that occurred leading up to the catastrophic caldera‐forming AT eruption (ca. 30 ka).

Accurately evaluating the tempo and magnitude of pre-historic eruptions is essential for hazard assessments. Here we demonstrate the importance of integrating records from locations close to the volcano with those in distal regions to generate more comprehensive event stratigraphies. The annually laminated (varved) and intensely radiocarbon dated lacustrine sediments of Lake Suigetsu (SG06 core), Japan are used to place chronological constraints on the tempo of volcanism at two stratovolcanoes located favourably upwind of the lake along the South-West Japan Arc, Sambe and Daisen. Major and trace element glass compositions are used to assign visible ash (tephra) layers preserved in the SG06 sediment core to past explosive eruptions from these volcanoes. Integrating these stratigraphies confirm that the ~150 ka long lake sequence records nine visible ash layers from Daisen and five from Sambe. The SG06 record captures two periods of closely spaced eruptions at Daisen volcano. The first period begins at ~61.1 ka with three explosive eruptions over ~10 ka, with two events separated by as little as 1.5 ka. One layer (SG06–4281), dated at 59.6 ± 5.5 ka (95.4% probability), relates to the large magnitude, and widely dispersed Daisen Kurayoshi Pumice (DKP) eruption. The other period of frequent activity began at 29,837 ± 96 IntCal13 yrs. BP (95.4% probability) with five widely dispersed ash fall events associated with explosive eruptions separated by approximately 6, 936, 5 and 438 years. The integrated proximal-distal event stratigraphy and the high-precision SG06 chronology provide unique insights into the timing and frequency of past explosive volcanism from Daisen and Sambe, which has implications for the prediction of future eruption scenarios.