A record of volcanic eruptions over the past 2,200 years from Vostok firn cores, central East Antarctica

Introduction: The products of volcanic eruptions found in the snow, firn and ice deposits of the polar ice sheets are precious sources of information on the volcanic forcing of the climate system in the recent or remote past. On the other hand, the layers containing the traces of well-known eruptions serve as absolute age markers that help to construct the depth-age scale for the snow-firn thickness.Methods: In this study we present new records of the sulfate concentrations and electrical conductivity (ECM) from three shallow (up to 70 m depth) firn cores drilled in the vicinity of Vostok station (central East Antarctica).Results: In the non-sea-salt sulfate and ECM profiles we were able to identify 68 peaks that can be interpreted as traces of volcanic events.Discussion: 22 of these peaks can be unambiguously attributed to well-known volcanic eruptions (including Tambora 1816 CE, Huaynaputina 1601 CE, Samalas 1258 CE, Ilopango 541 CE and others), which allowed to construct a robust depth-age scale for the cores. 37 events have their counterparts in other Antarctic cores, but cannot be associated with welldated eruptions. Finally, 9 peaks do not have analogues in the other cores, i.e., they may be traces of so far unknown volcanic events. According to the newly constructed depth-age function, the deepest studied firn layers (70.20 m) are dated by 192 BCE

Meteorological information at three hydrological stations in the European part of Russia

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region.The amount of precipitation and the precipitation-weighted air temperature corresponding to the sampling intervals are given according to observations at meteorological stations in the basins of the studied rivers

Stable isotope composition (δ18O, δ2H) of river runoff, groundwater and precipitation at three hydrological stations in the European part of Russia

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region. Samples of river water, groundwater and precipitation were collected at weekly intervals from September 2019 to October 2021. The analysis was performed by a Picarro L2130-i isotope analyzer. The accuracy was 0.04‰ for δ18О and 0.1‰ for δ2Н. The values are calibrated in the VSMOW-VSLAP scale

Stable isotope composition (δ18O, δ2H) of river runoff, groundwater and precipitation at the Zakza River, Bol. Sareevo

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region. Samples of river water, groundwater and precipitation were collected at weekly intervals from September 2019 to October 2021. The analysis was performed by a Picarro L2130-i isotope analyzer. The accuracy was 0.04‰ for δ18О and 0.1‰ for δ2Н. The values are calibrated in the VSMOW-VSLAP scale

Stable isotope composition (δ18O, δ2H) of river runoff, groundwater and precipitation at the Sosna River, Elets

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region. Samples of river water, groundwater and precipitation were collected at weekly intervals from September 2019 to October 2021. The analysis was performed by a Picarro L2130-i isotope analyzer. The accuracy was 0.04‰ for δ18О and 0.1‰ for δ2Н. The values are calibrated in the VSMOW-VSLAP scale

Stable isotope composition (δ18O, δ2H) of river runoff, groundwater and precipitation at the Dubna River, Verbilki

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the southwest of the Moscow region, the Dubna river in the north of the Moscow region and the Sosna river in the Voronezh region. Samples of river water, groundwater and precipitation were collected at weekly intervals from September 2019 to October 2021. The analysis was performed by a Picarro L2130-i isotope analyzer. The accuracy was 0.04‰ for δ18О and 0.1‰ for δ2Н. The values are calibrated in the VSMOW-VSLAP scale

Pingo Nori (Spitsbergen) massive ice isotope and chemical content of permafrost core Grondalen 13

The drilling of the 10.5 m high Nori pingo that stands at 32 m asl in Grøndalen Valley (Spitsbergen) performed in April 2019 reached a depth of 21.8 m bs (core #13, starting from 42.5 m asl, 77.99483 °N, 14.59009 °E) and revealed 16.1 m thick massive ice. The core was obtained with a portable gasoline-powered rotary drilling rig (UKB 12/25, Vorovskiy Machine Factory, Ekaterinburg, Russia). The core pieces with diameter 112-76 mm were lifted for sampling to the surface every 30–50 cm. After documentation and cryolithological description core pieces were sealed in zip lock bags. Ice samples were split in two parts - one part for stable isotope analyses, another part for ion content measurement. They were kept frozen for transportation while sediment samples were kept unfrozen. Moisture content was analyzed in laboratory by measuring sediment samples weight before and after drying. The stable water isotope composition (δ18O and δD) of massive pingo ice was analyzed at the Climate and Environmental Research Laboratory (CERL, Arctic and Antarctic Research Institute, St. Petersburg, Russia) using a Picarro L2120- i analyzer. After every five samples the working standard (SPB-2, δ18O = -9.66 ‰ and δD = -74.1 ‰) was measured. SPB-2 is made of distilled St. Petersburg tap water and is calibrated against the International Atomic Energy Agency (IAEA) standards VSMOW-2 (Vienna Standard Mean Ocean Water 2), GISP (Greenland Ice Sheet Precipitation), and SLAP-2 (Standard Light Antarctic Precipitation 2). The reproducibility of the results is 0.08 ‰ for δ18O and 0.4 ‰ for δD and was assessed by re-measuring a random selection of 10% of the total samples. The measurement error is thus 1-2 orders of magnitude less than the natural isotopic variability of pingo ice, which is satisfactory for the purpose of this study. The δ18O and δD values are given as per mil (‰) difference to the VSMOW-2 standard. The deuterium excess (d) is calculated as d = δD - 8δ18O29. The ion content of sedimentary permafrost samples from core #13 was estimated after water extraction at the analytical laboratory of RAE-S, Barentsburg. The material was dried and sieved at 1 mm. About 20 g of the sediment were suspended in 100 ml of de-ionized water and filtered through 0.45 μm nylon mesh within 3 minutes after stirring. Electrical conductivity (EC, measured in μS cm-1) and pH values were estimated with a Mettler Toledo Seven Compact S 220. EC values were transformed automatically by the instrument into general ion content (mineralization) values given as mg L-1. Major anions and cations in the water extracts were analyzed by an ion chromatograph (Shimadzu LC-20 Prominence) equipped with the Shimadzu CDD-10AVvp conductometric detector and ion exchange columns for anions (Phenomenex Star-ion A300) and for cations (Shodex ICYS-50). Bicarbonate content was measured by a Shimadzu TOC-L analyzer via catalytic oxidizing at +680o C and subsequent infrared detecting. Melted pingo ice samples from core #13 and spring water samples were analyzed after filtration through 0.45 μm nylon mesh on the same equipment using the same techniques for pH, EC, and ion composition as for sedimentary permafrost samples. Analyses and research were aimed at determining major characteristics of the Nori pingo including its internal structure, groundwater source, and geochemical and isotopic stages of formation

The Components of the Glacial Runoff of the Tsambagarav Massif from Stable Water Isotope Data

The aim of this study was to determine the contribution of snow and glacial ice to the river fluxes, and to identify the type of ice formation in the Tsambagarav massif (the northwestern part of Mongolia). The main method for this study was isotopic analysis of water samples. The isotopic separation showed that the shares of the main components in the total runoff differed for different rivers of the massif. Alongside with that, glacial meltwater prevailed in all the investigated fluxes. The share of snow and firn in the meltwater coming from the surface of the large valley glaciers in the middle of the ablation season in 2017 changed by only 10%—from 20% to 30%. Thus, further reduction of glaciation caused by global climate change could significantly affect the water balance of the study area. The isotopic composition of glacial ice proves that its alimentation primarily comes from precipitation during the transitional seasons. Superimposed ice is not the basis for nourishment of the glaciers of the Tsambagarav massif