Compacted snow runway technology on the Ross Ice Shelf near McMurdo, Antarctica

Blaisdell, George L.; Klokov, Valeri; Diemand, Deborah

doi:10.1029/ar067p0153

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…Though similar to the ram in operation, the RSP (Figure 9), was designed for testing compacted snow (Blaisdell et al 1995). The RSP has a 30° cone tip with a maximum diameter of 1.15 cm (0.45 in.)…”

Section: Russian Snow Penetrometermentioning

confidence: 99%

Assessment of field methods for measuring mechanical properties of snow

Shoop¹,

Wieder²,

Elder³

et al. 2019

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Winter climates present a variety of surfaces that challenge vehicle mobility. Surfaces range from soft, virgin snow, to groomed snow and ice. This study evaluated the capabilities of various testing devices to measure the mechanical properties of winter surfaces. Concurrent satellite imagery supplemented in situ physical testing. The goals were (1) to find tests that most practically evaluate these winter surfaces for vehicle mobility and (2) to determine if imagery analysis correlates with mechanical properties, thus potentially allowing remote assessment of snow physical and mechanical characteristics.The test methods were typically useful for either virgin snow or groomed snow; no method worked well on all surfaces. Correlations between test devices were generally poor, but there were some important trends identified between (1) tests that measure the near-surface snow strength, (2) tests best suited for stronger snow, (3) the Clegg Impact Hammers and California Bearing Ratio, and (4) the optical imagery and surface drop cones. This study provides a rich dataset for assessing the current state of the art and future research needs for measurement and remote assessment of snow mechanical properties for vehicle mobility prediction.

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Section: Russian Snow Penetrometermentioning

confidence: 99%

Assessment of field methods for measuring mechanical properties of snow

Shoop¹,

Wieder²,

Elder³

et al. 2019

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“…These data were collected aboard the Twin Otter during the 2009/10 Antarctic season. We assumed an average surface density of 0.7 kg m −3 (Blaisdell and others, 1992; Arcone, 1996) and an ice/water basal interface. We found the average attenuation rate to be 16.4 dB km −1 .…”

Section: Radio-wave Attenuation Ratesmentioning

confidence: 99%

Airborne fine-resolution UHF radar: an approach to the study of englacial reflections, firn compaction and ice attenuation rates

et al. 2015

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ABSTRACT. We have built and operated an ultra-wideband UHF pulsed-chirp radar for measuring firn stratigraphy from airborne platforms over the ice sheets of Greenland and West Antarctica. Our analysis found a wide range of capabilities, including imaging of post firn-ice transition horizons and sounding of shallow glaciers and ice shelves. Imaging of horizons to depths exceeding 600 m was possible in the colder interior regions of the ice sheet, where scattering from the ice surface and inclusions was minimal. The radar's high sensitivity and large dynamic range point to loss tangent variations as the dominant mechanism for these englacial reflective horizons. The radar is capable of mapping interfaces with reflection coefficients as low as -80 dB near the firn-ice transition and as low as -64 dB at depths of 600 m. We found that firn horizon reflectivity strongly mirrored density variance, a result of the near-unity interfacial transmission coefficients. Zones with differing compaction mechanisms were also apparent in the data. We were able to sound many ice shelves and areas of shallow ice. We estimated ice attenuation rates for a few locations, and our attenuation estimates for the Ross Ice Shelf, West Antarctica, appear to agree well with earlier reported results.

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“…Historical accounts of the area are also available (Mellor and Swithinbank, 1989). The runway is situated in a transition zone between regions of accumulation and ablation (Blaisdell and others, 1995). It was carefully sited in this zone to assure that a thin, but permanent and complete, snow cover was present.…”

Section: Evidence Supporting Meltwater Occurrencementioning

confidence: 99%

“…Our experience at this site indicates that naturally triggered surface melt is rare, only occurring during very “hot” summers, or where concentrations of pollutants (mineral dust, oil, fuel or coolants) are located. Free surface water in the transition zone generally does not flow far, often only to ponding areas or areas with snow cover where it refreezes (Blaisdell and others, 1995). Sub-surface melt water, however, persists until the solar intensity and ambient temperatures begin to fall.…”

Section: Evidence Supporting Meltwater Occurrencementioning

confidence: 99%

Localized surface-ice weakness on a glacial ice runway

Lang

Blaisdell

1996

J. Glaciol.

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ABSTRACT. Following con stru ction of a g lacial ice runwa y o n th e R oss Ice Shelf, Antarcti ca, and prior to fli g ht operations, th e runway was proof-rolled. Th e proof exercise was d es igned to simulate typica l heavy aircraft. Initia l tes ting produ ced num erous brittle surface failures in the runway ice. Thin sectio ns of ice co res taken from th e fail ed a reas showed large crystals (c ax is ve rti ca l) of cl ear , blu e ice with lon g, verti ca l bubbl es, indicative of ic e form ed direc tl y from meltwater. Uniaxialunconfined compression tes ts on core sample. were used to compare runway ice strength with published data for polyc rys talline la bora tory ice. Since the freq u e n t failure of surface ice had not bee n expec ted , it was criti cal to und e rsta nd the form a tion and mechani ca l properti es of th e weak ice to pre\'e nt its occ urrence in the future a nd to strengthen th e existing problem a reas. We discuss th e likely sce narios for devel o pment of weak ice o n the airstrip and the physical properti es of this typ e of ice. Also, the procedure used LO repa ir success full y th e runway surface is desc ribed , whi ch culminated in tes t fli ghts, followed by full fli ght opera tions. INTRODUCTIONa n a lternating ta ll-a nd short-tooth pattern to assist In cleaning the surface of all debris. Th e includ ed a ng le of the cutting tee th w as 42° and sid e-relief a ngles were 41°. A laser-gu id ance sys tem assisted in producing a n acc ura te g rade even when th e g rader operator had great dif1icu lty seeing well enou g h to drive in a stra ig ht lin e. Snow and ice debris were r emoved from th e runway surface with a Rolb a rota ry sn ow -blo\\·er. (For a more co mpl e te

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Compacted snow runway technology on the Ross Ice Shelf near McMurdo, Antarctica

Cited by 6 publications

References 2 publications

Assessment of field methods for measuring mechanical properties of snow

Assessment of field methods for measuring mechanical properties of snow

Airborne fine-resolution UHF radar: an approach to the study of englacial reflections, firn compaction and ice attenuation rates

Localized surface-ice weakness on a glacial ice runway

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