Large rotating ice discs on ice‐covered rivers

Nordell, Bo; Westerström, Göran

doi:10.1002/j.1477-8696.1997.tb06244.x

Cited by 7 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Large floating ice blocks have been observed on frozen rivers [1][2][3][4]. This pretty rare phenomenon is shown during winter news broadcasts on TV as the disks surprisingly rotate [5].…”

Section: Introductionmentioning

confidence: 99%

“…This pretty rare phenomenon is shown during winter news broadcasts on TV as the disks surprisingly rotate [5]. In a paper of 1997, Nordell et al reported several events of rotating ice disks [1]. The diameter D of the disks has been observed to range over two orders of magnitude from 1 to 100 m. On the other hand, the rotation speeds do not seem to depend on the size of the disk.…”

Section: Introductionmentioning

confidence: 99%

“…The mechanism of the disk formation is still to be discovered in detail. Nowadays, two hypotheses are discussed: either the disk is created by the aggregation of frazil ice in a vortex generated by the river or an ice block is formed before being rounded [1]. As the natural ice disks float on a river, the rotation is probably driven by the flow, the disk working like a water turbine.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Rotation of melting ice disks due to melt fluid flow

et al. 2016

View full text Add to dashboard Cite

We report experiments concerning the melting of ice disks (85 mm in diameter and 14 mm in height) at the surface of a thermalized water bath. During the melting, the ice disks undergo translational and rotational motions. In particular, the disks rotate. The rotation speed has been found to increase with the bath temperature. We investigated the flow under the bottom face of the ice disks by a particle image velocimetry technique. We find that the flow goes downwards and also rotates horizontally, so that a vertical vortex is generated under the ice disk. The proposed mechanism is the following. In the vicinity of the bottom face of the disk, the water eventually reaches the temperature of 4 • C for which the water density is maximum. The 4 • C water sinks and generates a downwards plume. The observed vertical vorticity results from the flow in the plume. Finally, by viscous entrainment, the horizontal rotation of the flow induces the solid rotation of the ice block. This mechanism seems generic: any vertical flow that generates a vortex will induce the rotation of a floating object.

show abstract

“…Large floating ice blocks have been observed on frozen rivers [1][2][3][4]. This pretty rare phenomenon is shown during winter news broadcasts on TV as the disks surprisingly rotate [5].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rotation of melting ice disks due to melt fluid flow

et al. 2016

View full text Add to dashboard Cite

show abstract

“…This pretty rare phenomenon can be observed during winter news broadcast as the discs surprisingly rotate. In a paper of 1993, Nordell et al reported several events of rotating ice discs [1]. The Table I presents the diameters D, the rotating speed w expressed in degrees per second for different observations (place, date and references are indicated).…”

Section: Introductionmentioning

confidence: 99%

Rotation of a melting ice at the surface of a pool

Dorbolo,

Adami,

Dubois

et al. 2015

Preprint

View full text Add to dashboard Cite

Large circular ice blocks up to 80 m of diameter have been observed on frozen river around the world. This rare event has been reported in a publication in 1993. This fascinating self-fashioned object slowly rotates at about 1 o per second. In this paper, we report a model experiment consisting in a 85 mm of diameter ice disc at the surface of a thermalised pool. The rotation speed has been found to increase with the bath temperature. Using particle image velocimetry technique, we evidence the presence of a vortex below the ice block. This vortex results from the descending flow of high density water at 4 o C. The vorticity of the vortex induces the rotation of the ice block. This mechanism is generic of any vertical flow that generates a vortex which induces the rotation of a floating object.

show abstract

“…A rare natural phenomenon, a large circular rotating ice disc in a slightly larger hole in the ice cover, occurs infrequently in some rivers in cold regions. An illustration of a revolving ice cake on the Mianus River, USA, was published in 1995(Scientific Amen'can 1995. Photographs of such discs, on the Nidelva River in Norway and Rancho Nuevo Creek in the USA, were published in La HoudZe Blanche (1971) and EOS (1983) respectively.…”

mentioning

confidence: 99%