Bergy bit and growler melt deterioration

Citation
Sb. Savage et al., Bergy bit and growler melt deterioration, J GEO RES-O, 106(C6), 2001, pp. 11493-11504
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
ISSN journal
2169-9275 → ACNP
Volume
106
Issue
C6
Year of publication
2001
Pages
11493 - 11504
Database
ISI
SICI code
0148-0227(20010615)106:C6<11493:BBAGMD>2.0.ZU;2-A
Abstract
The Canadian Ice Service, Environment Canada, is currently developing an op erational iceberg forecasting model; the present work forms part of that ef fort. While existing models predict iceberg drift and deterioration, the ne w model will account for calving that produces smaller ice pieces and subse quently track the drift and melt of the calved pieces. Bergy bits and growl ers, which we consider here to be ice pieces in the size range from 3 to 20 m, can cause large forces upon impact with offshore structures. The probab ility of encountering these bergy bits and growlers is of significant inter est to marine transportation and offshore resource development. Calving due to wave-induced erosion at the waterline of a floating iceberg can produce many thousands of small ice pieces having a wide distribution of sizes. Th ese small ice pieces then melt as individual entities and eventually disapp ear. Since the calving events occur periodically, there is a continual supp ly of small ice pieces in the neighborhood of the parent iceberg. The focus of the present paper is on the evolution of the size-frequency distributio n function for the calved ice pieces. It makes use of the initial distribut ion function following the calving event discussed by Savage et al. (2000). Dimensional analysis, laboratory tests, and field observations are applied to obtain simple correlations and devise a melt law for the smaller ice pi eces. This melt law is then used to determine the temporal evolution of the small ice piece size-frequency distribution function.