New insights into the ~74 ka Toba eruption from sulfur isotopes of polar ice cores

<p>The ~74ka Toba eruption in Indonesia was one of the largest volcanic events of the Quaternary and loaded an estimated 100 million tonnes of H<sub>2</sub>SO<sub>4</sub> into the atmosphere. Understanding the precise timing of this colossal eruption is vital to unravelling the climatic and environmental impacts of the largest volcanic events on Earth. Sulfur aerosols injected into the stratosphere following large volcanic events scatter incoming radiation and lead to global cooling, and in the case of Toba it has been suggested that it led to cooling of 1 &#8211; 5&#176;C and extinctions of some local hominin populations. One of the most enigmatic features of the Toba eruption is that the S peak has yet to be identified in the ice core records, although numerous candidate sulfate peaks have been identified in both Arctic and Antarctic ice cores. To address this, we analysed the sulfur isotope fingerprint (&#948;<sup>34</sup>S and &#916;<sup>33</sup>S) of 11 Toba candidates from two Antarctic ice cores by multi-collector inductively coupled plasma mass spectrometry. This approach allows us to evaluate injection altitudes and to distinguish large tropical eruptions from proximal eruptions because stratospheric sulfur aerosols undergo UV photochemical reactions that impart a sulfur mass-independent isotopic fractionation (S-MIF). In contrast, tropospheric sulfur aerosols do not exhibit S-MIF because they are shielded from the relevant UV radiation by the ozone layer.</p><p>We identify three stratospheric, tropical eruption candidates with two recording the largest &#916;<sup>33</sup>S signals measured to date in the ice core archives. The largest of these &#916;<sup>33</sup>S signals is >2 &#8240; more negative than previous measurements of the 1257 Samalas eruption (the largest eruption of the last 2000 years), despite having a similar integrated sulfate flux for this event to the ice core. These three candidates are within uncertainly of the Ar<sup>40</sup>/Ar<sup>39 </sup>age estimates for the Toba eruption and when considered with other paleoclimate proxies place the event during the transition into Greenland Stadial 20. &#160;Finally, we further analyse the relationship between the Toba eruption candidates and these proxies to determine the precise timing and potential climatic impacts of one of the largest eruptions of the Quaternary period.</p>

[1]  C. Bonadonna,et al.  The Independent Volcanic Eruption Source Parameter Archive (IVESPA, version 1.0): A new observational database to support explosive eruptive column model validation and development , 2021 .

[2]  D. Fleitmann,et al.  Synchronous timing of abrupt climate changes during the last glacial period , 2020, Science.

[3]  J. McConnell,et al.  Extreme climate after massive eruption of Alaska’s Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom , 2020, Proceedings of the National Academy of Sciences.

[4]  N. Boivin,et al.  Human occupation of northern India spans the Toba super-eruption ~74,000 years ago. , 2020 .

[5]  Sacha C. Jones,et al.  Human occupation of northern India spans the Toba super-eruption ~74,000 years ago , 2020, Nature Communications.

[6]  R. Muhammad,et al.  Tephra glass chemistry provides storage and discharge details of five magma reservoirs which fed the 75 ka Youngest Toba Tuff eruption, northern Sumatra , 2019, Journal of Quaternary Science.

[7]  J. McConnell,et al.  Stratospheric eruptions from tropical and extra-tropical volcanoes constrained using high-resolution sulfur isotopes in ice cores , 2019, Earth and Planetary Science Letters.

[8]  R. Edwards,et al.  Timing and structure of the weak Asian Monsoon event about 73,000 years ago , 2019, Quaternary Geochronology.

[9]  J. Gamble,et al.  The Huckleberry Ridge Tuff, Yellowstone: evacuation of multiple magmatic systems in a complex episodic eruption , 2019, Journal of Petrology.

[10]  H. Shamloo,et al.  Decadal transition from quiescence to supereruption: petrologic investigation of the Lava Creek Tuff, Yellowstone Caldera, WY , 2019, Contributions to Mineralogy and Petrology.

[11]  B. Delmonte,et al.  Multiple sources for tephra from AD 1259 volcanic signal in Antarctic ice cores , 2019, Quaternary Science Reviews.

[12]  C. Timmreck,et al.  Disproportionately strong climate forcing from extratropical explosive volcanic eruptions , 2019, Nature Geoscience.

[13]  F. Albarède,et al.  2600-years of stratospheric volcanism through sulfate isotopes , 2019, Nature Communications.

[14]  E. Gautier,et al.  SO2 Oxidation Kinetics Leave a Consistent Isotopic Imprint on Volcanic Ice Core Sulfate , 2018, Journal of Geophysical Research: Atmospheres.

[15]  M. Thiemens,et al.  Five-S-isotope evidence of two distinct mass-independent sulfur isotope effects and implications for the modern and Archean atmospheres , 2018, Proceedings of the National Academy of Sciences.

[16]  B. Peucker‐Ehrenbrink,et al.  Sulfur isotopes in rivers: Insights into global weathering budgets, pyrite oxidation, and the modern sulfur cycle , 2018, Earth and Planetary Science Letters.

[17]  C. Bronk Ramsey,et al.  Connecting the Greenland ice-core and U / Th timescales via cosmogenic radionuclides: Testing the synchronicity of Dansgaard-Oeschger events , 2018 .

[18]  Eugene I. Smith,et al.  Humans thrived in South Africa through the Toba eruption about 74,000 years ago , 2018, Nature.

[19]  A. Cohen,et al.  Subdecadal phytolith and charcoal records from Lake Malawi, East Africa imply minimal effects on human evolution from the ∼74 ka Toba supereruption. , 2018, Journal of human evolution.

[20]  A. Costa,et al.  Understanding the plume dynamics of explosive super-eruptions , 2018, Nature Communications.

[21]  B. Binder,et al.  The partitioning of sulfur between multicomponent aqueous fluids and felsic melts , 2018, Contributions to Mineralogy and Petrology.

[22]  Sarah K. Brown,et al.  The global magnitude–frequency relationship for large explosive volcanic eruptions , 2018 .

[23]  C. Buizert,et al.  Synchronous volcanic eruptions and abrupt climate change ∼17.7 ka plausibly linked by stratospheric ozone depletion , 2017, Proceedings of the National Academy of Sciences.

[24]  M. Lachniet,et al.  Rapid speleothem δ13C change in southwestern North America coincident with Greenland stadial 20 and the Toba (Indonesia) supereruption , 2017 .

[25]  M. Toohey,et al.  Volcanic stratospheric sulfur injections and aerosol optical depth from 500 BCE to 1900 CE , 2017 .

[26]  N. Dunbar,et al.  Advancements and best practices for analysis and correlation of tephra and cryptotephra in ice , 2017 .

[27]  P. Renne,et al.  High-precision 40Ar/39Ar dating of Pleistocene Tuffs and temporal anchoring of the Matuyama-Brunhes Boundary , 2017 .

[28]  M. Reid,et al.  Fitful and protracted magma assembly leading to a giant eruption, Youngest Toba Tuff, Indonesia , 2017 .

[29]  F. Lavigne,et al.  The 1257 Samalas eruption (Lombok, Indonesia): the single greatest stratospheric gas release of the Common Era , 2016, Scientific Reports.

[30]  R. Edwards,et al.  Strong coupling of Asian Monsoon and Antarctic climates on sub-orbital timescales , 2016, Scientific Reports.

[31]  Insights into the formation and dynamics of coignimbrite plumes from one‐dimensional models , 2016 .

[32]  M. Toohey,et al.  Climatic and societal impacts of a volcanic double event at the dawn of the Middle Ages , 2016, Climatic Change.

[33]  Larry G. Mastin,et al.  Results of the eruptive column model inter-comparison study , 2016 .

[34]  H. Keppler,et al.  Fluid-melt partitioning of sulfur in differentiated arc magmas and the sulfur yield of explosive volcanic eruptions , 2016 .

[35]  Richard J. Brown,et al.  Was millennial scale climate change during the Last Glacial triggered by explosive volcanism? , 2015, Scientific Reports.

[36]  J. Savarino,et al.  Variability of sulfate signal in ice core records based on five replicate cores , 2015 .

[37]  M. Winstrup,et al.  Timing and climate forcing of volcanic eruptions for the past 2,500 years , 2015, Nature.

[38]  Geoffrey M. Hargreaves,et al.  Precise interpolar phasing of abrupt climate change during the last ice age , 2015, Nature.

[39]  H. Fischer,et al.  A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy , 2014 .

[40]  R. Sparks,et al.  New estimates of the 1815 Tambora eruption volume , 2014 .

[41]  G. Macedonio,et al.  The magnitude and impact of the Youngest Toba Tuff super-eruption , 2014, Front. Earth Sci..

[42]  D. Barfod,et al.  A high-precision 40Ar/39Ar age for the Young Toba Tuff and dating of ultra-distal tephra: Forcing of Quaternary climate and implications for hominin occupation of India , 2014 .

[43]  M. Leuenberger,et al.  Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core , 2014 .

[44]  Sarah K. Brown,et al.  Characterisation of the Quaternary eruption record: analysis of the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database , 2014, Journal of Applied Volcanology.

[45]  R. Sparks,et al.  Physical characteristics of tephra layers in the deep sea realm: the Campanian Ignimbrite eruption , 2014 .

[46]  J. McConnell,et al.  Ash from Changbaishan Millennium eruption recorded in Greenland ice: Implications for determining the eruption's timing and impact , 2014 .

[47]  Surono,et al.  Source of the great A.D. 1257 mystery eruption unveiled, Samalas volcano, Rinjani Volcanic Complex, Indonesia , 2013, Proceedings of the National Academy of Sciences.

[48]  T. Johnson,et al.  Ash from the Toba supereruption in Lake Malawi shows no volcanic winter in East Africa at 75 ka , 2013, Proceedings of the National Academy of Sciences.

[49]  R. Sparks,et al.  The 1815 Tambora ash fall: implications for transport and deposition of distal ash on land and in the deep sea , 2013, Bulletin of Volcanology.

[50]  M. Thiemens,et al.  Tales of volcanoes and El-Niño southern oscillations with the oxygen isotope anomaly of sulfate aerosol , 2013, Proceedings of the National Academy of Sciences.

[51]  J. McConnell,et al.  A new bipolar ice core record of volcanism from WAIS Divide and NEEM and implications for climate forcing of the last 2000 years , 2013 .

[52]  F. Parrenin,et al.  The Antarctic ice core chronology (AICC2012): an optimized multi-parameter and multi-site dating approach for the last 120 thousand years , 2012 .

[53]  M. Loutre,et al.  An optimized multi-proxy, multi-site Antarctic ice and gas orbital chronology (AICC2012): 120--800 ka , 2012 .

[54]  J. Schwander,et al.  Direct linking of Greenland and Antarctic ice cores at the Toba eruption (74 ka BP) , 2012 .

[55]  P. Abbott,et al.  Volcanism and the Greenland ice-cores: the tephra record , 2012 .

[56]  M. Storey,et al.  Astronomically calibrated 40Ar/39Ar age for the Toba supereruption and global synchronization of late Quaternary records , 2012, Proceedings of the National Academy of Sciences.

[57]  Martin Nayembil,et al.  Global database on large magnitude explosive volcanic eruptions (LaMEVE) , 2012, Journal of Applied Volcanology.

[58]  S. Self,et al.  The 1963–1964 eruption of Agung volcano (Bali, Indonesia) , 2012, Bulletin of Volcanology.

[59]  Sacha C. Jones,et al.  The Toba volcanic super-eruption, environmental change, and hominin occupation history in India over the last 140,000 years , 2012 .

[60]  M. Williams,et al.  The ∼73 ka Toba super-eruption and its impact: History of a debate , 2012 .

[61]  C. Chesner.  The Toba Caldera Complex , 2012 .

[62]  F. Costa,et al.  Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano , 2012, Nature.

[63]  J. Luhr,et al.  A melt inclusion study of the Toba Tuffs, Sumatra, Indonesia , 2010 .

[64]  E. Wolff,et al.  Millennial-scale variability during the last glacial: The ice core record , 2010 .

[65]  R. Röthlisberger,et al.  Changes in environment over the last 800,000 years from chemical analysis of the EPICA Dome C ice core , 2010 .

[66]  M. Thiemens,et al.  Cold decade (AD 1810–1819) caused by Tambora (1815) and another (1809) stratospheric volcanic eruption , 2009 .

[67]  R. Sparks,et al.  The variation of large-magnitude volcanic ash cloud formation with source latitude , 2008 .

[68]  V. K. Rai,et al.  Anomalous sulfur isotope compositions of volcanic sulfate over the last millennium in Antarctic ice cores , 2008 .

[69]  C. Wilson.  Supereruptions and Supervolcanoes: Processes and Products , 2008 .

[70]  H. Fischer,et al.  Synchronisation of the EDML and EDC ice cores for the last 52 kyr by volcanic signature matching , 2007 .

[71]  A. Robock,et al.  Atmospheric volcanic loading derived from bipolar ice cores: Accounting for the spatial distribution of volcanic deposition , 2007 .

[72]  M. Thiemens,et al.  Mass-Independent Sulfur Isotopic Compositions in Stratospheric Volcanic Eruptions , 2007, Science.

[73]  J. Grooß,et al.  Modelling the budget of middle atmospheric water vapour isotopes , 2006 .

[74]  P. Baines,et al.  Dynamics of giant volcanic ash clouds from supervolcanic eruptions , 2005 .

[75]  Stephen Self,et al.  Magma volume, volatile emissions, and stratospheric aerosols from the 1815 eruption of Tambora , 2004 .

[76]  W. Rose,et al.  Re‐evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared satellite sensors , 2004 .

[77]  Margarita López Martínez,et al.  Unified equations for the slope, intercept, and standard errors of the best straight line , 2004 .

[78]  North Greenland Ice Core Project members.  High-resolution record of Northern Hemisphere climate extending into the last interglacial period , 2004 .

[79]  S. Bekki,et al.  UV induced mass‐independent sulfur isotope fractionation in stratospheric volcanic sulfate , 2003 .

[80]  R. Röthlisberger,et al.  Evolution of chemical peak shapes in the Dome C, Antarctica, ice core , 2003 .

[81]  C. Oppenheimer.  Limited global change due to the largest known Quaternary eruption, Toba ≈74 kyr BP? , 2002 .

[82]  S. Airieau,et al.  Observation of wavelength‐sensitive mass‐independent sulfur isotope effects during SO2 photolysis: Implications for the early atmosphere , 2001 .

[83]  R. L. Edwards,et al.  A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China , 2001, Science.

[84]  G. Wei,et al.  Records of Toba eruptions in the South China Sea , 2001 .

[85]  Wallace S. Broecker,et al.  Abrupt climate change: causal constraints provided by the paleoclimate record , 2000 .

[86]  A. Robock.  Volcanic eruptions and climate , 2000 .

[87]  H. Schmincke,et al.  Volatile emission during the eruption of Baitoushan Volcano (China/North Korea) ca. 969 AD , 2000 .

[88]  M. Rampino,et al.  Volcanic winter in the Garden of Eden: The Toba supereruption and the late Pleistocene human population crash , 2000 .

[89]  G. Zielinski.  Use of paleo-records in determining variability within the volcanism climate system , 2000 .

[90]  W. Rose,et al.  An improved age framework for late Quaternary silicic eruptions in northern Central America , 1999 .

[91]  B. W. Evans,et al.  Redox control of sulfur degassing in silicic magmas , 1998 .

[92]  C. Chesner.  Petrogenesis of the Toba Tuffs, Sumatra, Indonesia , 1998 .

[93]  L. D. Meeker,et al.  Major features and forcing of high‐latitude northern hemisphere atmospheric circulation using a 110,000‐year‐long glaciochemical series , 1997 .

[94]  Stephen Self,et al.  Satellite observations and interpretation of the 1991 Mount Pinatubo eruption plumes , 1996 .

[95]  Kendrick C. Taylor,et al.  Potential atmospheric impact of the Toba Mega‐Eruption ∼71,000 years ago , 1996 .

[96]  W. Rose,et al.  Eruptive history of Earth's largest Quaternary caldera (Toba, Indonesia) clarified , 1991 .

[97]  H. Sigurdsson,et al.  Plinian and co-ignimbrite tephra fall from the , 1989 .

[98]  A. Robock.  Volcanoes and Climate , 1989 .

[99]  R. Sparks,et al.  The exceptional magnitude and intensity of the Toba eruption, sumatra: An example of the use of deep-sea tephra layers as a geological tool , 1978 .