Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 43 for “"ice cores"”.
-
Climate significance of stable isotope records from Alpine ice cores
Tiefenprofile der stabilen Wasserisotopomere (d18O und dD) dreier tiefer Eisbohrkerne vom Monte Rosa Massiv (Schweizer Alpen) wurden im Hinblick auf möglicherweise aufgezeichnete Temperatursignale ausgewertet. Durch eine neuartige Methode der Wasserreduktion sind On-line dD Messungen mit einer …
-
Advances in understanding melt-affected firn and ice cores from the polar regions
Rising temperatures are an increasing issue for ice core science around the world, even in the polar regions where near-surface melt and rain-on-snow events are occurring more frequently, more extensively, and adversely affect the preservation of numerous ice-core climate proxies. The age scale …
-
‘Organics in ice’: Novel organic compounds in ice cores for use in palaeoclimate reconstruction
The majority of current ice core studies focus on analysing the inorganic component of atmospheric aerosol, trapped and preserved in the ice as a record of past atmosphere. However, this does not fully represent the make-up of atmospheric aerosol, which can be up to 50% organic. This thesis aims to …
-
Analysis of microbes in Greenland ice cores from periods of high and low atmospheric carbon dioxide levels
Glacial ice entraps microbial cells and nucleic acids that have been deposited from the atmosphere by precipitation or on dust particles carried by the wind. The ice is deposited in sequential layers representing distinct past periods of time. Metagenomics and metatranscriptomics offer means to …
-
Uncovering the Potential of Utilising Terrestrial Biogenic Markers in Ice Cores as Proxies to Past Environmental Conditions
Ice cores provide an un-matched high-resolution archive into paleoclimate reconstruction that other environmental archives (e.g. coral, sediment cores, and tree rings) do not. Limited research has focussed on terrestrial organic matter within ice cores. However, given the known relationships …
-
Implementing a new method to measure δ³⁴SSO₄ in ice cores to assess sulfate sources in West Antarctica
… However, δ³⁴SSO₄ measurements in Antarctic ice cores are scarce and have poor temporal resolution due to the large sample volume required for isotopic analysis. For this thesis, I established a new method to measure δ³⁴SSO₄ in ice cores via multicollector inductively coupled mass …
-
Diatoms in Antarctic ice cores, a novel proxy for reconstructing past wind variability in the Pacific sector of the Southern Hemisphere Westerly Wind belt
… in West Antarctica, threatening the stability of ice shelves, and ultimately contributing to global sea level rise. Over the last decades, it has been widely believed these atmospheric changes have occurred in response to recently increased greenhouse gas (GHG) concentrations and ozone depletion. …
-
Glaciochemical records from the Saint Elias Mountains, Yukon, Canada
… of the paleo-atmosphere in this region. Three ice cores from Eclipse Icefield provide a high-resolution record of precipitation chemistry in the remote northwestern North America mid-troposphere and allow investigation of spatial and temporal variability in glaciochemical signals. Greater …
-
Laser-based method for black carbon determination in lake sediment cores and black carbon deposition in Greenland since 300 CE
… deposited on bright surfaces, such as snow and ice, and during atmospheric transport. Historical records of BC, such as those measured in ice cores, can be used to reconstruct forest fire history over past millennia. Thus, quantifying BC's role in the climate system is important for …
-
Dielectric Properties of lce
… the dielectric behaviour of single crystals of ice from a temperate glacier and ice cores from the Greenland ice cap is described. A field investigation of the properties of snow on Axel Heiberg Island (Arctic Canada) is discussed. The permittivity of ice in the HF and VHF range is deduced to be …
-
Design and construction of a motor-actuated sea ice compression testing machine
… investigates the mechanical properties of sea ice in the Southern Ocean's Marginal Ice Zone, with the main emphasis on developing a specialized sea ice compression testing machine. The machine, designed for harsh sub-zero and saline conditions, would facilitate the immediate testing of ice …
-
New ice core records from West Antarctica and their spatial context: from 1000 to 100,000 years
The West Antarctic Ice Sheet (WAIS) is vulnerable to warming as a result of anthropogenic climate change, with the potential to contribute several metres to global sea level rise over the coming centuries. The Thwaites and Pine Island glaciers are already undergoing acceleration due to climate …
-
Three Hundred Year Record of Part Per Trillion (PPT)-level Perchlorate Measured with Ion Chromatography with Tandem Mass Spectrometry (IC - MS/MS)
… minimal. Therefore, a perchlorate record from ice cores will be valuable to our decision to reduce perchlorate from human activities. To measure ultra-trace perchlorate concentrations in ice cores, a method has been developed using IC-MS/MS with a detection limit of 0.1 ppt. The method (run …
-
Assessing glacier retreat and landform production at the ‘debris-charged’ snout of Kvíárjökull, Iceland
Iceland is a critical location for the study of glacier fluctuations and landform production in response to climate change due to its diverse glacial legacy and its archive of aerial photographs that provide accurately dated records of glacier retreat and landform evolution from 1945. This study …
-
Innovative water tracers and water isotopes enhance Antarctic research with climate models
… impacts from natural variability, Antarctic ice cores preserve valuable information about past climate evolution. As the interpretation of ice core records is confounded by many influencing factors, climate models are instrumental in elucidating relevant processes. Here I aim to leverage …
-
Aerosol chemistry and air-snow transfer in coastal Antarctica
… to the snow surface and inclusion into the ice.<br></br><br></br>Daily collections of aerosol particles and surface snow samples were made from British Antarctic Survey base, Halley. Aerosol and snow sea salt were found to have maximum concentrations during the austral winter and non sea …
-
Antarctic sea ice phytoplankton growth rates and survival mechanisms
… phytoplankton survive at the bottom of sea ice where there is very little irradiance for up to 6 months. Sea ice phytoplankton are understudied. This is mainly because in situ studies on sea ice are not only expensive but logistically difficult. Some researchers have elected to bring sea ice …
-
Black magnetic spherules from the glacial and sea ice of Fletcher's Ice Island (T-3)
… cosmic sources. Spherules from both the glacial ice and sea ice of Fletcher's Ice Island (T-3) were studied to determine their size distribution, sedimentation rates, and other parameters. The results were examined and shown to be similar to those of other researchers' work elsewhere. …
Page 1 of 3