Deep Ice Drilling on Law Dome
This dataset includes records from ANARE Research Notes 76; The scientific plan for the deep ice drilling on Law Dome. Per the abstract of the ANARE 76 report: Information on the past climatic and environmental conditions which existed on the surface of the earth and in its oceans, atmosphere and cr...
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| Format: | Dataset |
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Australian Antarctic Data Centre
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| Online Access: | https://researchdata.ands.org.au/deep-ice-drilling-law-dome/699716 https://data.aad.gov.au/metadata/records/ASAC_15 http://nla.gov.au/nla.party-617536 |
| Summary: | This dataset includes records from ANARE Research Notes 76; The scientific plan for the deep ice drilling on Law Dome. Per the abstract of the ANARE 76 report: Information on the past climatic and environmental conditions which existed on the surface of the earth and in its oceans, atmosphere and cryosphere can be gained by analysis of the solids, gases, water and dissolved matter contained in the Antarctic ice sheet. The Australian Antarctic Division will undertake a deep drilling program in the summer seasons 1989-90, 1990-91 and 1991-92 near the summit of Law Dome, Antarctica, to extract a 1240m ice core using an electromechanical drill in a fluid-filled borehole. The drill site has been selected to give optimum conditions for a detailed study of climatic and other changes. The snow accumulation rate at the site is 530 kg m^-2 a^-1, the surface temperature is -22 degrees C; and there is no evidence of the occurrence of surface melting in the summer months. It will be possible to determine an accurate age-depth scale for the core by counting annual layers, which are expected to be detectable to a depth of about 800m, equivalent to an age of 10,000 years. The age of the basal ice is expected to be of the order of 50,000 years. The report outlines the types of records it is intended to obtain from analysis of the core and surveys of the borehole, their potential applications and scientific justification. The recommended ice core analysis plan suggests the type and frequency of sampling required for the different parameters and describes the types of measurements and observations that will be made; e.g. visible features, oxygen and hydrogen isotope ratios, solid DC-conductivity, density, total gas content, gas composition, trace chemical and particulate content, radio-isotopes, crystal structure, etc. The high accumulation rate and low surface temperature at the site give excellent conditions for gas composition studies with an age resolution to as good as 20 years for the contained gases. It should also be possible to study the changes that have occurred in many parameters since the last ice age, at any temporal resolution from long term trends down to seasonal variations. Surveys of the borehole will be made to determine the vertical temperature profile and deformation rates inside the ice cap. The interrelation and interdependence of the various measurements is discussed. Experience gained from previous drilling and core analysis programs has been drawn upon to design a core processing and analysis plan. The schedule of activities has been arranged to optimise core conservation and the efficiency of the scheme. Available analysis facilities are reviewed and opportunities for collaboration with institutes in Australia and from other nations are highlighted. An outline of the logistic support required for the efficient running of the field program is included. A full environmental impact evaluation has been carried out elsewhere. A summary of the points addressed in the evaluation is included for information. They are specified in accordance with the Australian Antarctic Division guidelines. The fields in this dataset are: Year drilled Location Drilling method Depth of drilling Age at hole bottom Total thickness Mean annual surface temperature Annual accumulation This project was rolled into ASAC project 757 (ASAC_757). |
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