scholarly journals Acidity of Polar Ice Cores in Relation to Absolute Dating, Past Volcanism, and Radio–Echoes

1980 ◽  
Vol 25 (93) ◽  
pp. 359-372 ◽  
Author(s):  
C. U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Electrical Current ◽  
Polar Ice ◽  
Initial Current ◽  
Simple Method ◽  
High Acidity ◽  
Polar Ice Sheets ◽  
Absolute Dating

Abstract A simple method is described for detecting annual stratification of ice cores, and layers of high acidity due to violent volcanic eruptions in the past. The method is based on a relationship between the H3O+ concentration (pH) of melted samples and the electrical current between two brass electrodes moved along the cleaned ice-core surface. The “conductivity” is explained in terms of the initial current in the build-up of space charges. Acidity and current profiles are shown through layers deposited soon after historically well-known volcanic eruptions, such as Katmai, a.d. 1912, Tambora, a.d. 1815, Laki, a.d. 1783, Hekla, a.d. 1104, and Thera (Santorin) c. 1400 b.c. High-acidity layers seem to be the cause for the internal radio-echo layers in polar ice sheets.

scholarly journals Acidity of Polar Ice Cores in Relation to Absolute Dating, Past Volcanism, and Radio–Echoes

1980 ◽  
Vol 25 (93) ◽  
pp. 359-372 ◽  
Author(s):  
C. U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Electrical Current ◽  
Polar Ice ◽  
Initial Current ◽  
Simple Method ◽  
High Acidity ◽  
Polar Ice Sheets ◽  
Absolute Dating

AbstractA simple method is described for detecting annual stratification of ice cores, and layers of high acidity due to violent volcanic eruptions in the past. The method is based on a relationship between the H3O+concentration (pH) of melted samples and the electrical current between two brass electrodes moved along the cleaned ice-core surface. The “conductivity” is explained in terms of the initial current in the build-up of space charges. Acidity and current profiles are shown through layers deposited soon after historically well-known volcanic eruptions, such as Katmai, a.d. 1912, Tambora, a.d. 1815, Laki, a.d. 1783, Hekla, a.d. 1104, and Thera (Santorin)c. 1400 b.c. High-acidity layers seem to be the cause for the internal radio-echo layers in polar ice sheets.

scholarly journals The Influence On Atmospheric Composition of Volcanic Eruptions as Derived From Ice-Core Analysis

1985 ◽  
Vol 7 ◽  
pp. 125-129 ◽  
Author(s):  
C.U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Atmospheric Composition ◽  
Core Analysis ◽  
Polar Ice ◽  
Ice Caps ◽  
The Past ◽  
Polar Ice Sheets

Polar ice cores offer datable past snow deposits in the form of annual ice layers, which reflect the past atmospheric composition. Trace substances in the cores are related to the past mid-tropospheric impurity load, this being due to the vast extent of the polar ice sheets (or ice caps), their surface elevations and remoteness from most aerosol sources. Volcanic eruptions add to the rather low background impurity load via their eruptive products. This paper concentrates on the widespread influence on atmospheric impurity loads caused by the acid gas products from volcanic eruptions. In particular the following subjects are discussed: acid volcanic signals in ice cores, latitude of eruptions as derived by ice-core analysis, inter-hemispheric dating of the two polar ice sheets by equatorial eruptions, volcanic deposits in ice cores during the last glacial period and climatic implications.

scholarly journals The Influence On Atmospheric Composition of Volcanic Eruptions as Derived From Ice-Core Analysis

1985 ◽  
Vol 7 ◽  
pp. 125-129 ◽  
Author(s):  
C.U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Atmospheric Composition ◽  
Core Analysis ◽  
Polar Ice ◽  
Ice Caps ◽  
The Past ◽  
Polar Ice Sheets

Polar ice cores offer datable past snow deposits in the form of annual ice layers, which reflect the past atmospheric composition. Trace substances in the cores are related to the past mid-tropospheric impurity load, this being due to the vast extent of the polar ice sheets (or ice caps), their surface elevations and remoteness from most aerosol sources. Volcanic eruptions add to the rather low background impurity load via their eruptive products. This paper concentrates on the widespread influence on atmospheric impurity loads caused by the acid gas products from volcanic eruptions. In particular the following subjects are discussed: acid volcanic signals in ice cores, latitude of eruptions as derived by ice-core analysis, inter-hemispheric dating of the two polar ice sheets by equatorial eruptions, volcanic deposits in ice cores during the last glacial period and climatic implications.

scholarly journals Post-drilling recrystallization of the Byrd Station deep ice core and its relevance to current and future deep-core drilling on polar ice sheets

1994 ◽  
Vol 20 ◽  
pp. 231-236
Author(s):  
A.J. Gow
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
The United States ◽  
Polar Ice ◽  
Thin Sections ◽  
Full Extent ◽  
Drill Site ◽  
Polar Ice Sheets ◽  
Highly Strained

Cores of highly strained ice recovered from depths of 1200–1800 m at Byrd Station in 1967–68 have been found to have recrystallized while in storage in the United States. Such recrystallization, inferred to have occurred when temperatures in the storage facility rose above about – 14°C, would not have been discovered if thin sections of the cores had not been prepared and photographed at the drill site within hours of pulling the cores to the surface. It was only after new sections of the long stored cores were compared with the original sections that the full extent of recrystallization was revealed. The recrystallized structure emulates in both texture and fabric those observed in naturally annealed ice in the bottom 350 m at Byrd Station. It is concluded that polar ice cores should be stored at temperatures of –20°C or colder in order to inhibit or minimize post-drilling recrystallization.

scholarly journals A Review of the Microstructural Location of Impurities in Polar Ice and Their Impacts on Deformation

2021 ◽  
Vol 8 ◽  
Author(s):  
Nicolas Stoll ◽  
Jan Eichler ◽  
Maria Hörhold ◽  
Wataru Shigeyama ◽  
Ilka Weikusat
Keyword(s):  
Deformation Behaviour ◽  
Ice Core ◽  
Measurement Techniques ◽  
Ice Sheets ◽  
Ice Cores ◽  
Holistic Approach ◽  
Triple Junctions ◽  
Polar Ice ◽  
Theoretical Approaches ◽  
Polar Ice Sheets

Insoluble and soluble impurities, enclosed in polar ice sheets, have a major impact on the deformation behaviour of the ice. Macro- and Micro-scale deformation observed in ice sheets and ice cores has been retraced to chemical loads in the ice, even though the absolute concentration is negligible. And therefore the exact location of the impurities matters: Allocating impurities to specific locations inside the ice microstructure inherently determines the physical explanation of the observed interaction between chemical load and the deformational behaviour. Both, soluble and non-soluble impurities were located in grain boundaries, triple junctions or in the grain interior, using different methods, samples and theoretical approaches. While each of the observations is adding to the growing understanding of the effect of impurities in polar ice, the growing number of ambiguous results calls for a dedicated and holistic approach in assessing the findings. Thus, we here aim to give a state of the art overview of the development in microstructural impurity research over the last 20 years. We evaluate the used methods, discuss proposed deformation mechanisms and identify two main reasons for the observed ambiguity: 1) limitations and biases of measurement techniques and 2) the physical state of the analysed impurity. To overcome these obstacles we suggest possible approaches, such as the continuous analysis of impurities in deep ice cores with complementary methods, the implementation of these analyses into established in-situ ice core processing routines, a more holistic analysis of the microstructural location of impurities, and an enhanced knowledge-transfer via an open access data base.

scholarly journals Post-drilling recrystallization of the Byrd Station deep ice core and its relevance to current and future deep-core drilling on polar ice sheets

1994 ◽  
Vol 20 ◽  
pp. 231-236 ◽  
Author(s):  
A.J. Gow
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
The United States ◽  
Polar Ice ◽  
Thin Sections ◽  
Full Extent ◽  
Drill Site ◽  
Polar Ice Sheets ◽  
Highly Strained

Cores of highly strained ice recovered from depths of 1200–1800 m at Byrd Station in 1967–68 have been found to have recrystallized while in storage in the United States. Such recrystallization, inferred to have occurred when temperatures in the storage facility rose above about – 14°C, would not have been discovered if thin sections of the cores had not been prepared and photographed at the drill site within hours of pulling the cores to the surface. It was only after new sections of the long stored cores were compared with the original sections that the full extent of recrystallization was revealed. The recrystallized structure emulates in both texture and fabric those observed in naturally annealed ice in the bottom 350 m at Byrd Station. It is concluded that polar ice cores should be stored at temperatures of –20°C or colder in order to inhibit or minimize post-drilling recrystallization.

scholarly journals Application of AMS 14C Dating to Ice Core Research

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 637-641 ◽  
Author(s):  
A T. Wilson
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
Unexpected Result ◽  
Polar Ice ◽  
14C Dating ◽  
The Past ◽  
Accelerator Mass Spectrometer ◽  
Polar Ice Sheets ◽  
Ams 14C Dating

I describe here the use of the accelerator mass spectrometer (AMS) sublimation technique to 14C-date polar ice cores. An unexpected result of this work has been to extend the understanding of how polar ice sheets entrap and record the past composition of the Earth's atmosphere. This work has led to the discovery of a new phenomenon in which CO2 and other greenhouse gases can be entrapped in cold (never melted) polar ice sheets.

scholarly journals How well can we parameterize past accumulation rates in polar ice sheets?

1997 ◽  
Vol 25 ◽  
pp. 418-422 ◽  
Author(s):  
Eric J. Steig
Keyword(s):  
Accumulation Rate ◽  
Order Approximation ◽  
Ice Core ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Ice Cores ◽  
Accumulation Rates ◽  
Polar Ice ◽  
Polar Ice Sheets ◽  
First Order Approximation

An important component of models of the cryosphere is the calculation of accumulation rates over polar ice sheets. As a first-order approximation, many models rely on the assumption that temperature is the main controlling factor for precipitation. However, compilation of available ice-core data, including a new core from Taylor Dome, East Antarctica, suggests that precipitation is significantly decoupled from temperature for a large proportion of both the Greenland and Antarctic ice sheets. While the estimated glacial-to-interglacial change in temperature does not differ greatly among ice cores from each ice sheet, the estimated change in accumulation rate varies by more than a factor of 2. A simple vapor-pressure parameterization gives reasonable estimates of accumulation in the ice-sheet interior, but this is not necessarily the case close to the ice-sheet margin, where synoptic weather systems are important.

scholarly journals Ice–core records of atmospheric sulphur

1997 ◽  
Vol 352 (1350) ◽  
pp. 241-250 ◽  
Author(s):  
Michel Legrand
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Oxidative Capacity ◽  
Ice Age ◽  
Marine Biota ◽  
Polar Ice ◽  
Volcanic Emissions ◽  
High Northern Latitude ◽  
Air Temperatures

Sulphate and methanesulphonate (MSA), the two major sulphur species trapped in polar ice, have been extensivelyh studied in Antarctic and Greenland ice cores spanning the last centuries, as well as the entire last climatic cycle. Data from the cores are used to investigate the past contribution of volcanic and biogenic emissions to the natural sulphur budget in high latitude regions of both Hemispheres. Sulphate concentrations in polar ice very often increased during one or two years after large volcanic eruptions. Sulphate records show that fossil fuel combustion has enhanced sulphate concentrations in Greenland snow by a factor of 4 since the beginning of this century, and that no similar trend has occurred in Antarctica. At present, sulphate in Antarctic snow is mainly marine and biogenic in origin and the rate of dimethyl sulphide (DMS) emissions may have been enhanced during pst developments of El Niño Southern Oscillations (ENSO). Marine biota and non–eruptive volcanic emissions represent the two main contributors to the natural high northern latitude sulphur budget. Whele these two sources have contributed equally to the natural sulphur budget of Greenland ice over the last 9000 years BP, non–eruptive volcanic emissions largely dominated the budget at the beginning of the Holocene. A general negative correlation is observed between surcace air temperatures of the Northern Hemisphere and Greenland snow MSA concentrations over the last two centuries. Positive sea–ice anomalies also seem to strengthen DMS emissions. A steady decrease of MSA is observed in Greenland snow layers deposited since 1945, which may either be related to decreasing DMS emissions from marine biota at high northern latitudes or a changing yield of MSA from DMS oxidation driven by modification of the oxidative capacity of the atmosphere in these regions. Slightly reduced MSA concentrations are obvserved in Greenland glacial ice with respect to interglacial levels. In contrast, sulphate and calcium levels are strongly enhanced during the ice age compared to the present day. These long–term variations in Greenland cores are opposite in sign to those revealed by Antarctic ice cores. Such a difference suggests that climate changes led to a quite different sulphur cycle response in the two Hemispheres.

scholarly journals A method for analysis of vanillic acid in polar ice cores

2015 ◽  
Vol 11 (2) ◽  
pp. 227-232 ◽  
Author(s):  
M. M. Grieman ◽  
J. Greaves ◽  
E. S. Saltzman
Keyword(s):  
Biomass Burning ◽  
Vanillic Acid ◽  
Ice Core ◽  
Ice Cores ◽  
Reversed Phase ◽  
Polar Ice ◽  
Core Samples ◽  
Wide Range ◽  
Polar Ice Sheets ◽  
Arctic Ice

Abstract. Biomass burning generates a wide range of organic compounds that are transported via aerosols to the polar ice sheets. Vanillic acid is a product of conifer lignin combustion, which has previously been observed in laboratory and ambient biomass burning aerosols. In this study a method was developed for analysis of vanillic acid in melted polar ice core samples. Vanillic acid was chromatographically separated using reversed-phase liquid chromatography (HPLC) and detected using electrospray ionization–triple quadrupole mass spectrometry (ESI-MS/MS). Using a 100 μL injection loop and analysis time of 4 min, we obtained a detection limit of 77 ppt (parts per trillion by mass) and an analytical precision of ±10%. Measurements of vanillic acid in Arctic ice core samples from the Siberian Akademii Nauk core are shown as an example application of the method.

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