USAP-DC

Dunbar/1142115

This award supports a project to investigate the extremely rich volcanic record in the WAIS Divide ice core as part of this ongoing tephrochronology research in Antarctica. Ice cores in Polar Regions offer unparalleled records of earth's climate over the past 500,000 years. Accurate chronology of individual ice cores and chronological correlations between different ice cores is critically important to the interpretation of the climate record. The field of Antarctic tephrochronology has been progressing steadily, and is on the cusp of having a fully integrated tephra framework for large parts of the continent. Major advances in this field have been made due to the acquisition of a number of ice cores with strong volcanic records, improvement of analytical techniques and better characterization of source eruptions due in part to through studies of englacial tephra from several major blue ice areas. The intellectual merit of this work is that the tephrochonological studies will provide independently dated time-stratigraphic markers in the ice core, particularly for the deepest ice, linking tephra layers between the WAIS Divide core and the Siple Dome core which will allow detailed comparisons to be made of coastal and inland climate. It will also contribute to a better understanding of eruption magnitude, dispersal patterns and geochemical evolution of West Antarctic volcanoes. The work will also contribute to a new tephra dataset to the literature for use in future ice core studies. The broader impacts of this project fall into the areas of education, outreach and international cooperation. This project will employ one New Mexico Tech graduate student, but will also be featured in outreach programs for NMT undergraduates, as well as teacher and student groups and outreach for the general public in New Mexico. NMT is an Hispanic serving institution (25% Hispanic students) and also found by NSF to rank 15th nationwide in "baccalaureate-origin" institutions for doctoral recipients in science and engineering, thereby having a disproportionately large effect on producing Hispanic scientists and engineers. However, probably the most significant broader impact of this project will be the continued efforts of the PI in fostering and promoting of international cooperation in the tephra-in-ice community. Dunbar has been collaborating with European tephra researchers for a number of years, sharing data and working collaboratively on tephra correlations, and these activities have lead to, and will continue to promote, forward progress in integrating the Antarctic tephrochronology record. This proposal does not require field work in the Antarctic.

Person	Role
Dunbar, Nelia	Investigator

Antarctic Glaciology

Award # 1142115

USAP-1142115_1

None in the Database

Repository	Title (link)	Format(s)	Status
in progress	No data submitted yet, but submission to Antarctic tephra database is planned	None	exist

1. Iverson, N.A., Kalteyer, D., Dunbar, N.W., Kurbatov, A., and Yates, M.. 2016. Advancements and best practices for analysis and correlation of tephra and cryptotephra in ice, Quaternary Geochronology, http://dx.doi.org/10.1016/j.quageo.2016.09.008. (doi:10.1016/j.quageo.2016.09.008)
2. Sigl M, Fudge TJ, Winstrup M, Cole-Dai J, Ferris D, McConnell JR, Taylor KC, Welten KC, Woodruff TE, Adolphi F, Bisiaux M, Brook EJ, Buizert C, Caffee MW, Dunbar NW, Edwards R, Geng L, Iverson N, Koffman B, Layman L, Maselli OJ, McGwire K, Muscheler R, Nishiizumi K, Pasteris DR, Rhodes RH, Sowers TA. 2016. The WAIS Divide deep ice core WD2014 chronology -Part 2: Annual-layer counting (0.31 ka BP). Climate of the Past, 12, p. 769-786. doi: 10.5194/cp-12-769-2016. (doi:10.5194/cp-12-769-2016)
3. Sigl, M., Fudge, T. J., Winstrup, M., Cole-Dai, J., Ferris, D., McConnell, J. R., … Sowers, T. A. (2015). The WAIS Divide deep ice core WD2014 chronology – Part 2: Annual-layer counting (0–31 ka BP). Climate of the Past Discussions, 11(4), 3425–3474. (doi:10.5194/cpd-11-3425-2015)
4. Lee, M. J., Kyle, P. R., Iverson, N. A., Lee, J. I., & Han, Y. (2019). Rittmann volcano, Antarctica as the source of a widespread 1252 ± 2 CE tephra layer in Antarctica ice. Earth and Planetary Science Letters, 521, 169–176. (doi:10.1016/j.epsl.2019.06.002)
5. Dunbar, N. W., Iverson, N. A., Smellie, J. L., McIntosh, W. C., Zimmerer, M. J., & Kyle, P. R. (2021). Chapter 7.4 Active volcanoes in Marie Byrd Land. Geological Society, London, Memoirs, 55(1), 759–783. (doi:10.1144/m55-2019-29)