scholarly journals Inland Ice Crystal Measurements at Eqe, West Greenland

1954 ◽  
Vol 2 (15) ◽  
pp. 324-330
Author(s):  
M. Boyé ◽  
A. Cailleux
Keyword(s):  
Ice Crystals ◽  
Ice Crystal ◽  
West Greenland ◽  
Ice Cap ◽  
Mean Diameter ◽  
Western Border ◽  
Crystal Diameter ◽  
Ice Velocity ◽  
Inland Ice

AbstractAt Eqe, on the western border of the Greenland Ice Cap, measurements of the crystals by Seligman’s method give a mean crystal diameter of 2.16 cm. at a place where the ice velocity is ceto m.fday. The “heterometry index” measured from granulometric curves by Cailleux’s method shows that melting, active ice crystals have reasonably homogeneous dimensions, with a mean diameter from 2 to 2.4 cm.

scholarly journals Inland Ice Crystal Measurements at Eqe, West Greenland

1954 ◽  
Vol 2 (15) ◽  
pp. 324-330 ◽  
Author(s):  
M. Boyé ◽  
A. Cailleux
Keyword(s):  
Ice Crystals ◽  
Ice Crystal ◽  
West Greenland ◽  
Ice Cap ◽  
Mean Diameter ◽  
Western Border ◽  
Crystal Diameter ◽  
Ice Velocity ◽  
Inland Ice

Abstract At Eqe, on the western border of the Greenland Ice Cap, measurements of the crystals by Seligman’s method give a mean crystal diameter of 2.16 cm. at a place where the ice velocity is ceto m.fday. The “heterometry index” measured from granulometric curves by Cailleux’s method shows that melting, active ice crystals have reasonably homogeneous dimensions, with a mean diameter from 2 to 2.4 cm.

scholarly journals Mass balance, ice velocity and ice temperature at the Inland Ice margin north-east of Jakobshavn, central West Greenland

1988 ◽  
Vol 140 ◽  
pp. 111-114
Author(s):  
H.H Thomsen
Keyword(s):  
Mass Balance ◽  
Drainage Basin ◽  
Hydropower Project ◽  
West Greenland ◽  
North East ◽  
Field Investigations ◽  
Ice Velocity ◽  
Inland Ice

Glaciological field investigations were made on the Inland Ice north-east of Jakobshavn. The work is part of the hydropower investigations at Pâkitsoq in a drainage basin proposed for a local hydropower project. Brief reports of the work have been given by Thomsen (1983, 1984, 1985, 1986).

scholarly journals Measurements of ice thickness on glaciers at Isortuarssûp tasia, southern West Greenland and Pâkitsoq, central West Greenland

1989 ◽  
Vol 145 ◽  
pp. 59-63
Author(s):  
L Thorning ◽  
E Hansen
Keyword(s):  
Short Distance ◽  
Ice Thickness ◽  
West Greenland ◽  
Ice Cap ◽  
North East ◽  
The North ◽  
Electromagnetic Resonance ◽  
Area North ◽  
Inland Ice ◽  
Ice Radar

Two separate geophysical projects were carried out in 1988 as part of glacier-hydrological investigations of the margin of the Inland Ice. We made a reconnaissance electromagnetic resonance survey over the ice margin adjacent to Sermilik and Isortuarssup tasia, south-east of Nuuk/Godthåb and measured ice thickness along some lines in the area of Qamanârssûp serrnia, Kangiata nunâta sermia and Kangaussarssup sermia a short distance to the north, as well as a few profiles over a local ice cap just east of Isortuarssup tasia. In the Pâkitsoq area, north east of Ilulissat/Jakobshavn, we finished the mono-pulse ice radar work started last year (Thorning & Hansen, 1988a).

scholarly journals Ice Crystal Coarsening in Ice Cream during Cooling: A Comparison of Theory and Experiment

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 321 ◽  
Author(s):  
Jingyi Mo ◽  
Robert D. Groot ◽  
Graham McCartney ◽  
Enyu Guo ◽  
Julian Bent ◽  
...  
Keyword(s):  
Ostwald Ripening ◽  
Ice Cream ◽  
Weight Fraction ◽  
Ice Crystals ◽  
Ice Crystal ◽  
Temperature Dependent ◽  
X Ray ◽  
Crystal Diameter ◽  
Multi Phase ◽  
The Relationship

Ice cream is a complex multi-phase structure and its perceived quality is closely related to the small size of ice crystals in the product. Understanding the quantitative coarsening behaviour of ice crystals will help manufacturers optimise ice cream formulations and processing. Using synchrotron X-ray tomography, we measured the time-dependent coarsening (Ostwald ripening) of ice crystals in ice cream during cooling at 0.05 °C/min. The results show ice crystal coarsening is highly temperature dependent, being rapid from ca. −6 to −12 °C but significantly slower at lower temperatures. We developed a numerical model, based on established coarsening theory, to calculate the relationship between crystal diameter, cooling rate and the weight fraction of sucrose in solution. The ice crystal diameters predicted by the model are found to agree well with the measured values if matrix diffusion is assumed to be slowed by a factor of 1.2 due to the presence of stabilizers or high molecular weight sugars in the ice cream formulation.

scholarly journals Historical fluctuations of calving glaciers in South and West Greenland

1994 ◽  
Vol 161 ◽  
pp. 73-79
Author(s):  
A Weidick
Keyword(s):  
Ice Streams ◽  
Tidewater Glaciers ◽  
West Greenland ◽  
Ice Cap ◽  
Fast Running ◽  
Behavioural Patterns ◽  
Long Term Trends ◽  
Climatic Cooling ◽  
Inland Ice

Fluctuations of calf-ice producing outlets of the Julianehåb ice cap and other local glaciers in South Greenland, and outlets of the Inland Ice in South and West Greenland between latitudes 60° and 73°N from c. A.D. 1850 to the present time are reviewed. Seasonal variations of the fast running tidewater glaciers (ice streams) may veil long term trends, but in general it is concluded that the mode of activity (advance or retreat) is nearly synchronous for the outlets and their neighbouring land-based segments, whereas amplitude differs; topographical control is important for short-term fluctuations but should not be over-emphasised. The situation around 1990 is one of spreading readvance and the observed behavioural patterns fit with Huybrechts' model for the present dynamic situation of the ice cover. This model indicates that the ice sheet generally is expanding as a consequence of the climatic cooling since the Holocene climatic optimum but also locates areas with present thinning of the ice margin.

The “KIMWIPE” Effect in Ultra-Thin Cryosections

1985 ◽  
Vol 43 ◽  
pp. 458-459
Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Fibers ◽  
Ice Crystals ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Thin Sections ◽  
Skeletal Muscle Fibers ◽  
Freeze Dried ◽  
Ice Crystal Formation

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).

Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland

2002 ◽  
pp. 133-143
Author(s):  
Bjørn Thomassen ◽  
Peter R. Dawes ◽  
Agnete Steenfelt ◽  
Johan Ditlev Krebs
Keyword(s):  
Mineral Exploration ◽  
Mining Industry ◽  
Field Work ◽  
Original Series ◽  
West Greenland ◽  
North West ◽  
Ice Caps ◽  
High Plateau ◽  
Set Up ◽  
Inland Ice

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Dawes, P. R., Steenfelt, A., & Krebs, J. D. (2002). Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland. Geology of Greenland Survey Bulletin, 191, 133-143. https://doi.org/10.34194/ggub.v191.5141 _______________ Project Qaanaaq 2001, involving one season’s field work, was set up to investigate the mineral occurrences and potential of North-West Greenland between Olrik Fjord and Kap Alexander (77°10´N – 78°10´N; Fig. 1). Organised by the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, the project is mainly funded by the latter and has the overall goal of attracting the interest of the mining industry to the region. The investigated region – herein referred to as the Qaanaaq region – comprises 4300 km2 of ice-free land centred on Qaanaaq, the administrative capital of Qaanaap (Thule) municipality. Much of the region is characterised by a 500–800 m high plateau capped by local ice caps and intersected by fjords and glaciers. High dissected terrain occurs in Northumberland Ø and in the hinterland of Prudhoe Land where nunataks are common along the margin of the Inland Ice.

scholarly journals Microstructural Characteristics of Frazil Particles and the Physical Properties of Frazil Ice in the Yellow River, China

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 617
Author(s):  
Yaodan Zhang ◽  
Zhijun Li ◽  
Yuanren Xiu ◽  
Chunjiang Li ◽  
Baosen Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Yellow River ◽  
The Yellow River ◽  
Ice Crystal ◽  
Microstructural Characteristics ◽  
Air Bubble ◽  
Frazil Ice ◽  
Sediment Content ◽  
Crystal Diameter

Frazil particles, ice crystals or slushy granules that form in turbulent water, change the freezing properties of ice to create “frazil ice”. To understand the microstructural characteristics of these particles and the physical properties of frazil ice in greater depth, an in situ sampler was designed to collect frazil particles in the Yellow River. The ice crystal microstructural characteristics of the frazil particles (morphology, size, air bubble, and sediment) were observed under a microscope, and their nucleation mechanism was analyzed according to its microstructure. The physical properties of frazil ice (ice crystal microstructure, air bubble, ice density, and sediment content) were also observed. The results showed that these microstructures of frazil particles can be divided into four types: granular, dendritic, needle-like, and serrated. The size of the measured frazil particles ranged from 0.1 to 25 mm. Compared with columnar ice, the crystal microstructure of frazil ice is irregular, with a mean crystal diameter less than 5 mm extending in all directions. The crystal grain size and ice density of frazil ice are smaller than columnar ice, but the bubble and sediment content are larger.

The Mystery of Ice Crystal Multiplication in a Laboratory Experiment

2013 ◽  
Vol 71 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Gianni Santachiara ◽  
Franco Belosi ◽  
Franco Prodi
Keyword(s):  
Laboratory Experiment ◽  
Supercooled Liquid ◽  
Ice Crystals ◽  
Formation Processes ◽  
Ice Crystal ◽  
Droplet Vaporization ◽  
Ice Nuclei ◽  
Cold Room ◽  
The Mean ◽  
Ice Multiplication

Abstract This paper addresses the problem of the large discrepancies between ice crystal concentrations in clouds and the number of ice nuclei in nearby clear air reported in published papers. Such discrepancies cannot always be explained, even by taking into account both primary and secondary ice formation processes. A laboratory experiment was performed in a cylindrical column placed in a cold room at atmospheric pressure and temperature in the −12° to −14°C range. Supercooled droplets were nucleated in the column, in the absence of aerosol ice nuclei, by injecting ice crystals generated outside in a small syringe. A rapid increase in the ice crystal concentration was observed in the absence of any known ice multiplication. The ratio between the mean number of ice crystals in the column, after complete droplet vaporization, and the number of ice crystals introduced in the column was about 10:1. The presence of small ice crystals (introduced at the top of the column) in the unstable system (supercooled droplets) appears to trigger the transformation in the whole supercooled liquid cloud. A possible explanation could be that the rapidly evaporating droplets cool sufficiently to determine a homogeneous nucleation.

scholarly journals Site information and initial results from deep ice drilling on Law Dome, Antarctica

1997 ◽  
Vol 43 (143) ◽  
pp. 3-10 ◽  
Author(s):  
V.I. Morgan ◽  
C.W. Wookey ◽  
J. Li ◽  
T.D. van Ommen ◽  
W. Skinner ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
High Accumulation ◽  
Ice Flow ◽  
Ice Cap ◽  
Basal Ice ◽  
Inland Ice ◽  
The Last Glacial Maximum ◽  
Initial Results ◽  
The Last Glacial

AbstractThe aim of deep ice drilling on Law Dome, Antarctica, has been to exploit the special characteristics of Law Dome summit, i.e. low temperature and high accumulation near an ice divide, to obtain a high-resolution ice core for climatic/environmental studies of the Holocene and the Last Glacial Maximum (LGM). Drilling was completed in February 1993, when basal ice containing small fragments of rock was reached at a depth of 1196 m. Accurate ice dating, obtained by counting annual layers revealed by fine-detail δ18О, peroxide and electrical-conductivity measurements, is continuous down to 399 m, corresponding to a date of AD 1304. Sulphate concentration measurements, made around depths where conductivity tracing indicates volcanic fallout, allow confirmation of the dating (for Agung in 1963 and Tambora in 1815) or estimates of the eruption date from the ice dating (for the Kuwae, Vanuatu, eruption ~1457). The lower part of the core is dated by extrapolating the layer-counting using a simple model of the ice flow. At the LGM, ice-fabric measurements show a large decrease (250 to 14 mm2) in crystal size and a narrow maximum in c-axis vertically. The main zone of strong single-pole fabrics however, is located higher up in a broad zone around 900 m. Oxygen-isotope (δ18O) measurements show Holocene ice down to 1113 m, the LGM at 1133 m and warm (δ18O) about the same as Holocene) ice near the base of the ice sheet. The LGM/Holocene δ18O shift of 7.0‰, only ~1‰ larger than for Vostok, indicates that Law Dome remained an independent ice cap and was not overridden by the inland ice sheet in the Glacial.

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