| Title | Downhole measurements in the AND-1B Borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica |
| Author | Morin, R.; Williams, T.; Henrys, S.; Crosby, T.; Hansaraj, D.; ANtarctic geological DRILLing-McMurdo Ice Shelf (ANDRILL-MIS) Science Team |
| Author Affil | Morin, R., U. S. Geological Survey, Denver, CO. Other: Northern Illinois University; University of Nebraska-Lincoln; Lamont-Doherty Earth Observatory; GNS Science, New Zealand; University of Utah; Victoria University of Wellington, New Zealand |
| Source | Studies from the ANDRILL, McMurdo Ice Shelf Project, Antarctica; initial science report on AND-1B, edited by T.R. Naish, R. Powell and R. Levy. Terra Antartica, 14(3), p.167-174, . Publisher: Universita degli Studi di Siena, Sezione Scienze della Terra, Siena, Italy. ISSN: 1122- 8628 |
| Publication Date | 2007 |
| Notes | In English. 14 refs. GeoRef Acc. No: 284750. CRREL Acc. No: 62005077 |
| Index Terms | boreholes; density (mass/volume); magnetic properties; marine deposits; physical properties; electrical resistivity; sediments; spectra; Antarctica--McMurdo Ice Shelf; Southern Ocean--McMurdo Sound; Southern Ocean--Victoria Land Basin; AND-1B Core; Antarctica; Cenozoic; cores; density; downhole methods; gamma-ray spectra; geophysical methods; lithostratigraphy; magnetic susceptibility; marine sediments; McMurdo Ice Shelf; McMurdo Sound; paleomagnetism; resistivity; Ross Ice Shelf; Ross Sea; seismograms; Southern Ocean; spatial variations; Victoria Land Basin; well logs |
| Abstract | A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientific programme defined for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fluid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profiles (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 meters below seafloor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullification of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat flux and fluid flow, and structure and stress. When integrated with physical properties and fractures measured on the core, this information should play a significant role in addressing many of the scientific objectives of the ANDRILL program. |
| Publication Type | journal article |
| Record ID | 84151 |