Title: Core handling, transportation and processing for the South Pole ice core (SPICEcore) project
Abstract An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highest-resolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, which was likely due to site characteristics and, to a lesser extent, to drill technology and core handling procedures. more »« less
Johnson, Jay A.; Kuhl, Tanner; Boeckmann, Grant; Gibson, Chris; Jetson, Joshua; Meulemans, Zachary; Slawny, Kristina; Souney, Joseph M.(
, Annals of Glaciology)
null
(Ed.)
Abstract Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751 m deep ice core at the South Pole. This core provided a high-resolution record of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. The drilling and core processing were completed using the new US Intermediate Depth Drill system, which was designed and built by the US Ice Drilling Program at the University of Wisconsin–Madison. In this paper, we present and discuss the setup, operation, and performance of the drill system.
Winski, Dominic A.; Fudge, Tyler J.; Ferris, David G.; Osterberg, Erich C.; Fegyveresi, John M.; Cole-Dai, Jihong; Thundercloud, Zayta; Cox, Thomas S.; Kreutz, Karl J.; Ortman, Nikolas; et al(
, Climate of the Past)
Abstract. The South Pole Ice Core (SPICEcore) was drilled in 2014–2016 to provide adetailed multi-proxy archive of paleoclimate conditions in East Antarcticaduring the Holocene and late Pleistocene. Interpretation of these recordsrequires an accurate depth–age relationship. Here, we present the SPICEcore (SP19) timescale for the age of the ice of SPICEcore. SP19 is synchronized to theWD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) icecore using stratigraphic matching of 251 volcanic events. These eventsindicate an age of 54 302±519 BP (years before 1950) at thebottom of SPICEcore. Annual layers identified in sodium and magnesium ionsto 11 341 BP were used to interpolate between stratigraphic volcanic tiepoints, yielding an annually resolved chronology through the Holocene.Estimated timescale uncertainty during the Holocene is less than 18 yearsrelative to WD2014, with the exception of the interval between 1800 to 3100BP when uncertainty estimates reach ±25 years due to widely spacedvolcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rateof 7.4 cm yr−1 (water equivalent). The time variability of accumulation rateis consistent with expectations for steady-state ice flow through the modernspatial pattern of accumulation rate. Time variations in nitrateconcentration, nitrate seasonal amplitude and δ15N of N2 in turn are as expected for the accumulation rate variations. The highlyvariable yet well-constrained Holocene accumulation history at the site canhelp improve scientific understanding of deposition-sensitive climateproxies such as δ15N of N2 and photolyzed chemicalcompounds.
The National Science Foundation Ice Core Facility (NSF-ICF, fka NICL) is in the process of building a new facility including freezer and scientist support space. The facility is being designed to minimize environmental impacts while maximizing ice core curation and science support. In preparation for the new facility, we are updating research equipment and integrating ice core data collection and processing by assigning International Generic Sample Numbers (IGSN) to advance the “FAIR”ness and establish clear provenance of samples, fostering the next generation of linked research data products. The NSF-ICF team, in collaboration with the US ice core science community, has established a metadata schema for the assignment of IGSNs to ice cores and samples. In addition, in close coordination with the US ice core community, we are adding equipment modules that expand traditional sets of physical property, visual stratigraphy, and electrical conductance ice core measurements. One such module is an ice core hyperspectral imaging (HSI) system. Adapted for the cold laboratory settings, the SPECIM SisuSCS HSI system can collect up to 224 bands using a continuous line-scanning mode in the visible and near-infrared (VNIR) 400-1000 nm spectral region. A modular system design allows expansion of spectral properties in the future. The second module is an updated multitrack electrical conductance system. These new data will guide real time optimization of sampling for planned analyses during ice core processing, especially for ice with deformed or highly compressed layering. The aim is to facilitate the collection of robust, long-term, and FAIR data archives for every future ice core section processed at NSF-ICF. The NSF-ICF is fully funded by the National Science Foundation and operated by the U.S. Geological Survey.
Kahle, Emma C.; Steig, Eric J.; Jones, Tyler R.; Fudge, T. J.; Koutnik, Michelle R.; Morris, Valerie A.; Vaughn, Bruce H.; Schauer, Andrew J.; Stevens, C. Max; Conway, Howard; et al(
, Journal of Geophysical Research: Atmospheres)
Abstract
Data from the South Pole ice core (SPC14) are used to constrain climate conditions and ice‐flow‐induced layer thinning for the last 54,000 years. Empirical constraints are obtained from the SPC14 ice and gas timescales, used to calculate annual‐layer thickness and the gas‐ice age difference (Δage), and from high‐resolution measurements of water isotopes, used to calculate the water‐isotope diffusion length. Both Δage and diffusion length depend on firn properties and therefore contain information about past temperature and snow‐accumulation rate. A statistical inverse approach is used to obtain an ensemble of reconstructions of temperature, accumulation‐rate, and thinning of annual layers in the ice sheet at the SPC14 site. The traditional water‐isotope/temperature relationship is not used as a constraint; the results therefore provide an independent calibration of that relationship. The temperature reconstruction yields a glacial‐interglacial temperature change of 6.7 ± 1.0°C at the South Pole. The sensitivity ofδ18O to temperature is 0.99 ± 0.03 ‰°C−1, significantly greater than the spatial slope of 0.8‰°C−1that has been used previously to determine temperature changes from East Antarctic ice core records. The reconstructions of accumulation rate and ice thinning show millennial‐scale variations in the thinning function as well as decreased thinning at depth compared to the results of a 1‐D ice flow model, suggesting influence of bedrock topography on ice flow.
Coggon, R.M.; Teagle, D.A.H.; Sylvan, J.B.; Reece, J.; Estes, E.R.; Williams, T.J.; Christeson, G.L.(
, Proceedings of the International Ocean Discovery Program Expedition reports)
The South Atlantic Transect (SAT) is a multidisciplinary scientific ocean drilling experiment designed to investigate the evolution of the ocean crust and overlying sediments across the western flank of the Mid-Atlantic Ridge. This project comprises four International Ocean Discovery Program expeditions: fully staffed Expeditions 390 and 393 (April–August 2022) built on engineering preparations during Expeditions 390C and 395E (October–December 2020 and April–June 2021, respectively) that took place without science parties during the height of the Coronavirus Disease 2019 (COVID-19) pandemic. Through operations along a crustal flow line at ~31°S, the SAT recovered complete sedimentary sections and the upper ~40–340 m of the underlying ocean crust formed at a slow- to intermediate-spreading rate at the Mid-Atlantic Ridge over the past ~61 My. The sediments along this transect were originally spot cored more than 50 y ago during Deep Sea Drilling Project Leg 3 (December 1968–January 1969) to help verify the theories of seafloor spreading and plate tectonics.
The SAT expeditions targeted six primary sites on 7, 15, 31, 49, and 61 Ma ocean crust that fill critical gaps in our sampling of intact in situ ocean crust with regard to crustal age, spreading rate, and sediment thickness. Drilling these sites was required to investigate the history, duration, and intensity of the low-temperature hydrothermal interactions between the aging ocean crust and the evolving South Atlantic Ocean. This knowledge will improve the quantification of past hydrothermal contributions to global biogeochemical cycles and help develop a predictive understanding of the impacts of variable hydrothermal processes and exchanges. Samples from the transect of the previously unexplored sediment- and basalt-hosted deep biosphere beneath the South Atlantic Gyre are essential to refine global biomass estimates and examine microbial ecosystems' responses to variable conditions in a low-energy gyre and aging ocean crust.
The transect, located near World Ocean Circulation Experiment Line A10, provides records of carbonate chemistry and deepwater mass properties across the western South Atlantic through key Cenozoic intervals of elevated atmospheric CO2 and rapid climate change. Reconstruction of the history of the deep western boundary current and deepwater formation in the Atlantic basins will yield crucial data to test hypotheses regarding the role of evolving thermohaline circulation patterns in climate change and the effects of tectonic gateways and climate on ocean acidification.
During engineering Expeditions 390C and 395E (5 October–5 December 2020 and 6 April–6 June 2021, respectively), a single hole was cored through the sediment cover and into the uppermost rocks of the ocean crust with the advanced piston corer and extended core barrel systems at five of the six primary proposed SAT sites. Reentry systems with casing were then installed either into basement or within 10 m of basement at each of those five sites.
Expedition 390 (7 April–7 June 2022) conducted operations at three of the SAT sites, recovering 700 m of core (77% recovery) over 30.3 days of on-site operations. Sediment coring, basement coring, and wireline logging were conducted at two sites on ~61 Ma crust (Sites U1556 and U1557), and sediment coring was completed at the 7 Ma Site U1559. During Expedition 390, more than 1.2 km of sediments was characterized, including 793 m of core collected during Expeditions 390C and 395E at Sites U1556, U1557, and U1559 as well as Expedition 395E Site U1561, which was cored on thinly (<50 m) sedimented ~61 Ma crust. The uppermost ~342 and ~120 m of ~61 Ma ocean crust was cored at Sites U1556 and U1557, respectively. Geophysical wireline logging was achieved at both sites, but the basement hole at Site U1556 was not preserved as a legacy hole because of subsidence of the reentry cone below the seafloor. At Site U1557, the drill bit was deposited on the seafloor prior to downhole logging, leaving Hole U1557D available for future deepening and establishing a legacy borehole for basement hydrothermal and microbiological experiments.
Expedition 393 (7 June–7 August 2022) operated at four sites, drilling in 12 holes to complete this initial phase of the SAT. Complete sedimentary sections were collected at Sites U1558, U1583, and U1560 on 49, 31, and 15 Ma crust, respectively, and together with 257.7 m of sediments cored during earlier operations, more than 600 m of sediments was characterized. The uppermost ocean crust was drilled at Sites U1558, U1560, and U1583 with good penetration (~130 to ~204 meters subbasement); however, at the youngest ~7 Ma Site U1559, only ~43 m of basement penetration was achieved in this initial attempt. Geophysical wireline logs were achieved at Sites U1583 and U1560 only. Expeditions 390 and 393 established legacy sites available for future deepening and downhole basement hydrothermal and microbiological experiments at Sites U1557, U1560, and U1559 on 61, 15, and 7 Ma crust, respectively.
Highlights of the SAT expeditions include (1) recovering abundant altered glass, hydrothermal veins, complex breccias, and a wide range of alteration halos in the volcanic sequences of the uppermost ocean crust formed at 7–61 Ma, indicating low-temperature hydrothermal processes and exchanges between seawater and basalts across the western flank of the southern Mid-Atlantic Ridge for millions to tens of millions of years; (2) documenting extended redox gradients from both the seafloor and the sediment/basement interface that indicate significant subsurface fluid flow and may support a diversity of microorganisms and metabolisms; and (3) recovering an almost complete stratigraphic record of the Cenozoic (including the Paleocene/Eocene Thermal Maximum and other key climate events) composed of nannofossil oozes with varying amounts of clay indicating the shoaling and deepening of the calcite compensation depth.
Souney, Joseph M., Twickler, Mark S., Aydin, Murat, Steig, Eric J., Fudge, T. J., Street, Leah V., Nicewonger, Melinda R., Kahle, Emma C., Johnson, Jay A., Kuhl, Tanner W., Casey, Kimberly A., Fegyveresi, John M., Nunn, Richard M., and Hargreaves, Geoffrey M. Core handling, transportation and processing for the South Pole ice core (SPICEcore) project. Retrieved from https://par.nsf.gov/biblio/10215548. Annals of Glaciology . Web. doi:10.1017/aog.2020.80.
Souney, Joseph M., Twickler, Mark S., Aydin, Murat, Steig, Eric J., Fudge, T. J., Street, Leah V., Nicewonger, Melinda R., Kahle, Emma C., Johnson, Jay A., Kuhl, Tanner W., Casey, Kimberly A., Fegyveresi, John M., Nunn, Richard M., & Hargreaves, Geoffrey M. Core handling, transportation and processing for the South Pole ice core (SPICEcore) project. Annals of Glaciology, (). Retrieved from https://par.nsf.gov/biblio/10215548. https://doi.org/10.1017/aog.2020.80
Souney, Joseph M., Twickler, Mark S., Aydin, Murat, Steig, Eric J., Fudge, T. J., Street, Leah V., Nicewonger, Melinda R., Kahle, Emma C., Johnson, Jay A., Kuhl, Tanner W., Casey, Kimberly A., Fegyveresi, John M., Nunn, Richard M., and Hargreaves, Geoffrey M.
"Core handling, transportation and processing for the South Pole ice core (SPICEcore) project". Annals of Glaciology (). Country unknown/Code not available. https://doi.org/10.1017/aog.2020.80.https://par.nsf.gov/biblio/10215548.
@article{osti_10215548,
place = {Country unknown/Code not available},
title = {Core handling, transportation and processing for the South Pole ice core (SPICEcore) project},
url = {https://par.nsf.gov/biblio/10215548},
DOI = {10.1017/aog.2020.80},
abstractNote = {Abstract An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highest-resolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, which was likely due to site characteristics and, to a lesser extent, to drill technology and core handling procedures.},
journal = {Annals of Glaciology},
author = {Souney, Joseph M. and Twickler, Mark S. and Aydin, Murat and Steig, Eric J. and Fudge, T. J. and Street, Leah V. and Nicewonger, Melinda R. and Kahle, Emma C. and Johnson, Jay A. and Kuhl, Tanner W. and Casey, Kimberly A. and Fegyveresi, John M. and Nunn, Richard M. and Hargreaves, Geoffrey M.},
editor = {null}
}
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