Chronostratigraphy of the Larsen blue-ice area in northern Victoria Land, East Antarctica, and its implications for paleoclimate

In blue-ice areas (BIAs), deep ice is directly exposed at the surface, allowing for the cost-effective collection of large-sized old-ice samples. However, chronostratigraphic studies on blue-ice areas are challenging owing to fold and fault structures. Here, we report on a surface transect of ice with an undisturbed horizontal stratigraphy from the Larsen BIA, northern Victoria Land, East Antarctica. Ice layers defined by dust bands and ground-penetrating radar (GPR) surveys indicate a monotonic increase in age along the ice flow direction on the downstream side, while the upstream ice exhibits a potential repetition of ages on scales of tens of meters, which result from a complicated fold structure. Stable water isotopes (δ18Oice and δ2Hice) and components of the occluded air (i.e., CO2, N2O, CH4, δ15N–N2, δ18Oatm (=δ18O-O2), δO2/N2, δAr/N2​​​​​​​, 81Kr, and 85Kr) are analyzed for surface ice and shallow ice core samples. Correlating δ18Oice, δ18Oatm, and CH4 records from the Larsen BIA with ice from previously drilled ice cores indicates that the gas age at various shallow vertical coring sites ranges between 9.2–23.4 kyr BP, while the ice age sampled from the surface ranges from 5.6 to 24.7 kyr BP. Absolute radiometric 81Kr dating for the two vertical cores confirms ages within acceptable levels of analytical uncertainty. A tentative climate reconstruction suggests a large deglacial warming of 15 ± 5 ∘C (1σ) and an increase in snow accumulation by a factor of 1.7–4.6 (from 24.3 to 10.6 kyr BP). Our study demonstrates that BIAs in northern Victoria Land may help to obtain high-quality records for paleoclimate and atmospheric greenhouse gas compositions through the last deglaciation, although in general climatic interpretation is complicated by the need for upstream flow corrections, evidence for strong surface sublimation during the last glacial period, and potential errors in the estimated gas age–ice age difference.</p

Surface Temperature in Twentieth Century at the Styx Glacier, Northern Victoria Land, Antarctica, From Borehole Thermometry

International audienc

Improvement and performance testing of melting system for measurement of trace elements in firn core drilled at NEEM site, Greenland

<p>A melting system was improved for measurement of trace elements in a firn core drilled at the North Greenland Eemian Ice Drilling (NEEM) site (77.45°N, 51.06°W). The melting heads of the melting system were specifically constructed with fluorinated ethylene propylene (FEP)-coated copper (type A) and pure nickel (type B) to reduce percolation of melted samples. Firn core sections with densities in the range of ~0.76–0.86 g cm⁻³ (depth interval: ~58.10–88.83 m) and ~0.56–0.76 g cm⁻³ (depth interval: ~17.32–58.10 m) were successfully decontaminated by the melting system with type A and B melting heads, respectively, as verified by the volume ratios of melted samples from inner and outer zones and video recorded during the melting procedures. Systematic performance tests of the type A melting head melter were performed using artificial ice cores. The procedural blanks and detection limits of V, Cr, Co, Rb, Cd, Ba, Tl, Th and U were generally lower than those in previous studies, whereas the levels of Mn, Sr and Pb were similar to those reported elsewhere. The concentration ratios of these elements from inner and outer zones of the melting head indicated that the melting system had good decontamination efficiency. Finally, the concentrations of elements in the NEEM firn core measured following mechanical removal of the outer layer with chisels and the type A melting head melter showed a good agreement with each other.</p

Ice age uncertainty in ice cores from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere

CO2 in ice cores at core depth 1.95 m from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere

Properties of ice core #23 from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere

CO2 in ice core #23 from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere

Ice properties at core depth 1.95 m in ice cores from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere

Temperature and accumulation rate in ice cores from Larsen blue ice area, East Antarctica

Blue ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the areas hinders constraining the age. We apply state-of-the-art techniques and show that the ages cover the last deglaciation for Larsen BIA. Our study demonstrates that Larsen BIA in Northern Victoria Land helps in reconstructing the past climate during the last deglaciation. This data set presents gas composition (CO2, CH4, N2O, δ18Oatm, δ15N-N2, δO2/N2, δAr/N2), stable water isotopes (δ2Hice, δ18Oice), and the chronology of Larsen BIA. The ice cores were collected in January 2019 in Northern Victoria Land, East Antarctica. Gas composition analysis was conducted at Seoul National University and National Institute of Polar Research. Stable water isotopes were analyzed at Korea Polar Research Institute. Data sets were also published as a supplement of Lee et al. (2022) titled with “Chronostratigraphy of Larsen blue ice area in Northern Victoria Land, East Antarctica, and its implications for paleoclimate”, The Cryosphere