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New insights into the ∼ 74 ka Toba eruption from sulfur isotopes of polar ice cores
- Source :
- Climate of the Past, Vol 17, Pp 2119-2137 (2021), Climate of the Past, Climate of the Past, 2021, 17 (5), pp.2119-2137. ⟨10.5194/cp-17-2119-2021⟩
- Publication Year :
- 2021
-
Abstract
- The ∼74 ka Toba eruption was one of the largest volcanic events of the Quaternary. There is much interest in determining the impact of such a large event, particularly on the climate and hominid populations at the time. Although the Toba eruption has been identified in both land and marine archives as the Youngest Toba Tuff, its precise place in the ice core record is ambiguous. Several volcanic sulfate signals have been identified in both Antarctic and Greenland ice cores and span the Toba eruption 40Ar/39Ar age uncertainty. Here, we measure sulfur isotope compositions in Antarctic ice samples from the Dome C (EDC) and Dronning Maud Land (EDML) ice cores at high temporal resolution across 11 of these potential Toba sulfate peaks to identify candidates with sulfur mass-independent fractionation (S-MIF), indicative of an eruption whose plume reached altitudes at or above the stratospheric ozone layer. Using this method, we identify several candidate sulfate peaks that contain stratospheric sulfur. We further narrow down potential candidates based on the isotope signatures by identifying sulfate peaks that are due to a volcanic event at tropical latitudes. In one of these sulfate peaks at 73.67 ka, we find the largest ever reported magnitude of S-MIF in volcanic sulfate in polar ice, with a Δ33S value of −4.75 ‰. As there is a positive correlation between the magnitude of the S-MIF signal recorded in ice cores and eruptive plume height, this could be a likely candidate for the Toba super-eruption, with a plume top height in excess of 45 km. These results support the 73.7±0.3 ka (1σ) 40Ar/39Ar age estimate for the eruption, with ice core ages of our candidates with the largest magnitude S-MIF at 73.67 and 73.74 ka. Finally, since these candidate eruptions occurred on the transition into Greenland Stadial 20, the relative timing suggests that Toba was not the trigger for the large Northern Hemisphere cooling at this time although we cannot rule out an amplifying effect.
- Subjects :
- 010504 meteorology & atmospheric sciences
Stratigraphy
3705 Geology
010502 geochemistry & geophysics
01 natural sciences
Environmental protection
Environmental pollution
Latitude
chemistry.chemical_compound
Paleontology
Ice core
TD169-171.8
SDG 13 - Climate Action
GE1-350
SDG 14 - Life Below Water
Stadial
Sulfate
0105 earth and related environmental sciences
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Global and Planetary Change
geography
13 Climate Action
GE
geography.geographical_feature_category
Northern Hemisphere
DAS
37 Earth Sciences
3709 Physical Geography and Environmental Geoscience
Plume
3703 Geochemistry
Environmental sciences
chemistry
Volcano
TD172-193.5
13. Climate action
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology
Quaternary
Geology
GE Environmental Sciences
Subjects
Details
- Language :
- English
- ISSN :
- 18149332 and 18149324
- Database :
- OpenAIRE
- Journal :
- Climate of the Past, Vol 17, Pp 2119-2137 (2021), Climate of the Past, Climate of the Past, 2021, 17 (5), pp.2119-2137. ⟨10.5194/cp-17-2119-2021⟩
- Accession number :
- edsair.doi.dedup.....d5d8da25b5da412388af72fcb8d90c09