Direct linking of Greenland and Antarctic ice cores at the Toba eruption (74 ka BP) 1Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark
19 Mar 2013
2Climate and Environmental Physics, Physics Institute & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
3National Institute of Polar Research, Tachikawa, Tokyo, Japan
4Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany
5Geoscience Center, University of Göttingen, Göttingen, Germany
6Laboratoire Chrono-environnement, Besancon, France
7Laboratoire de Glaciologie et Geophysique de l'Environnement, Grenoble, France
8Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy
9Department of Chemistry, Biology, and Marine Science, University of the Ryukyus, Okinawa, Japan
Received: 24 September 2012 – Published in Clim. Past Discuss.: 05 November 2012 Abstract. The Toba eruption that occurred some 74 ka ago in Sumatra, Indonesia, is
among the largest volcanic events on Earth over the last 2 million years.
Tephra from this eruption has been spread over vast areas in Asia, where it
constitutes a major time marker close to the Marine Isotope Stage 4/5
boundary. As yet, no tephra associated with Toba has been identified in
Greenland or Antarctic ice cores. Based on new accurate dating of Toba
tephra and on accurately dated European stalagmites, the Toba event is known
to occur between the onsets of Greenland interstadials (GI) 19 and 20.
Furthermore, the existing linking of Greenland and Antarctic ice cores by
gas records and by the bipolar seesaw hypothesis suggests that the Antarctic
counterpart is situated between Antarctic Isotope Maxima (AIM) 19 and 20.
Revised: 06 March 2013 – Accepted: 06 March 2013 – Published: 19 March 2013
In this work we suggest a direct synchronization of Greenland (NGRIP) and
Antarctic (EDML) ice cores at the Toba eruption based on matching of a
pattern of bipolar volcanic spikes. Annual layer counting between volcanic
spikes in both cores allows for a unique match. We first demonstrate this
bipolar matching technique at the already synchronized Laschamp geomagnetic
excursion (41 ka BP) before we apply it to the suggested Toba interval. The
Toba synchronization pattern covers some 2000 yr in GI-20 and AIM-19/20
and includes nine acidity peaks that are recognized in both ice cores.
The suggested bipolar Toba synchronization has decadal precision. It thus
allows a determination of the exact phasing of inter-hemispheric climate in
a time interval of poorly constrained ice core records, and it allows for a
discussion of the climatic impact of the Toba eruption in a global
perspective. The bipolar linking gives no support for a long-term global
cooling caused by the Toba eruption as Antarctica experiences a major
warming shortly after the event. Furthermore, our bipolar match provides a
way to place palaeo-environmental records other than ice cores into a precise
Citation: Svensson, A., Bigler, M., Blunier, T., Clausen, H. B., Dahl-Jensen, D., Fischer, H., Fujita, S., Goto-Azuma, K., Johnsen, S. J., Kawamura, K., Kipfstuhl, S., Kohno, M., Parrenin, F., Popp, T., Rasmussen, S. O., Schwander, J., Seierstad, I., Severi, M., Steffensen, J. P., Udisti, R., Uemura, R., Vallelonga, P., Vinther, B. M., Wegner, A., Wilhelms, F., and Winstrup, M.: Direct linking of Greenland and Antarctic ice cores at the Toba eruption (74 ka BP), Clim. Past, 9, 749-766, doi:10.5194/cp-9-749-2013, 2013.