scholarly journals STRENGTH CHARACTERISTICS OF THE ICE SHEET (FIRST-YEAR SEA ICE) IN FIELD INDENTATION TESTS

1999 ◽  
Vol 15 ◽  
pp. 629-633
Author(s):  
Masafumi SAKAI ◽  
Hisao MATSUSHITA ◽  
Toru TAKAWAKI ◽  
Muneo KAWAMURA ◽  
Takashi TERASHIMA ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Sheet ◽  
Strength Characteristics ◽  
First Year ◽  
Indentation Tests

scholarly journals The tensile strength of first-year sea ice

1993 ◽  
Vol 39 (133) ◽  
pp. 609-618 ◽  
Author(s):  
J. A. Richter Menge ◽  
K. F. Jones
Keyword(s):  
Tensile Strength ◽  
Sea Ice ◽  
Maximum Stress ◽  
Ice Sheet ◽  
Tensile Load ◽  
Growth Direction ◽  
First Year ◽  
Strain Rates ◽  
Temperature Dependent

AbstractWe present the results of tests done to determine the tensile behavior of first-year columnar sea ice over a range of temperatures from −20° to −3°C and strain rates of 10−5and 10−3s−1. The temperature of a test specimen was dictated by its in-situ location within the sea-ice sheet; samples located near the top of the sea-ice sheet were tested at the lower temperatures. A tensile load was applied along the cylindrical axes of the test specimens, which were perpendicular to the growth direction of the ice. Results showed that the maximum stress reached during a test was most strongly influenced by temperature, while the failure strain and the modulus were principally affected by the loading rate. A model relating the tensile strength of the ice to its porosity based on temperature-dependent variations in the brine-pocket geometry is evaluated.

ON THE FACTORS AFFECTING THE RATE OF ABLATION OF SEA ICE

1966 ◽  
Vol 3 (4) ◽  
pp. 431-439 ◽  
Author(s):  
M. P. Langleben
Keyword(s):  
Sea Ice ◽  
Heat Budget ◽  
Ice Sheet ◽  
Ablation Rate ◽  
Shortwave Radiation ◽  
Dominant Factor ◽  
Wave Radiation ◽  
First Year ◽  
Factors Affecting ◽  
Thermal Content

A study has been made of the heat budget just before and during the season of ablation, of first year sea ice near the head of Tanquary Fiord. Ablation started as the air temperature approached 0 °C, producing a decrease in albedo from approximately 0.6 to 0.2 in less than a week. Typical values of incident shortwave radiation were 800 cal cm−2 day−1 on clear days and 400 cal cm−2 day−1 during heavy overcast. The net influx of all-wave radiation was about 350 cal cm−2 day−1 during the ablation period, and resulted in a rate of ablation of ice of approximately 4 cm day−1.It is shown that the flux of radiative heat is the dominant factor determining the ablation rate and the change in thermal content of the ice sheet. Upward conduction from the sea is small, except when surface melt runoff occurs and collects in a stable layer immediately under the ice sheet. Even partial refreezing in this layer may release large quantities of latent heat to increase the rate of bottom conduction appreciably.

scholarly journals The tensile strength of first-year sea ice

1993 ◽  
Vol 39 (133) ◽  
pp. 609-618 ◽  
Author(s):  
J. A. Richter Menge ◽  
K. F. Jones
Keyword(s):  
Tensile Strength ◽  
Sea Ice ◽  
Maximum Stress ◽  
Ice Sheet ◽  
Tensile Load ◽  
Growth Direction ◽  
First Year ◽  
Strain Rates ◽  
Temperature Dependent

AbstractWe present the results of tests done to determine the tensile behavior of first-year columnar sea ice over a range of temperatures from −20° to −3°C and strain rates of 10−5 and 10−3s−1. The temperature of a test specimen was dictated by its in-situ location within the sea-ice sheet; samples located near the top of the sea-ice sheet were tested at the lower temperatures. A tensile load was applied along the cylindrical axes of the test specimens, which were perpendicular to the growth direction of the ice. Results showed that the maximum stress reached during a test was most strongly influenced by temperature, while the failure strain and the modulus were principally affected by the loading rate. A model relating the tensile strength of the ice to its porosity based on temperature-dependent variations in the brine-pocket geometry is evaluated.

scholarly journals Dynamics of the Ice-Crushing Process

1988 ◽  
Vol 34 (118) ◽  
pp. 318-326 ◽  
Author(s):  
Ian J. Jordaan ◽  
Garry W. Timco
Keyword(s):  
Ice Sheet ◽  
Load Cycle ◽  
Stored Energy ◽  
Indentation Process ◽  
Ice Particles ◽  
Mode Of Failure ◽  
Indentation Tests ◽  
Energy Exchanges ◽  
The Mean ◽  
Crushed Ice

Abstract During fast indentation tests on ice sheets at constant rates, crushing is commonly observed at appropriate combinations of speed and aspect ratio. An analysis is made of this mode of failure, using as a basis a recently conducted test on an ice sheet under controlled conditions. The variation of load with time is given special attention, and cyclic variation of load is associated with periodic crushing (pulverization) events, followed by clearing of the crushed ice particles. An analysis of the clearing process is summarized in the paper, treating the crushed ice as a viscous material. A detailed analysis of the energy exchanges during the indentation process is given. Elastic variations of stored energy in the indenter and in the ice sheet are calculated; these are relatively minor. The dissipation of energy during a typical load cycle (3 mm movement during 0.05 s) is about 8 J. The energy required to create surfaces of the crushed ice particles is small (0.006 J), as is the work of crushing based on mechanical testing (0.09 J). It is concluded that the process of viscous extrusion of crushed ice is the main seat of energy dissipation, basically as a frictional process. A relationship for the mean thickness of the crushed ice layer is developed, based on energy-balance considerations.

Subglacial sediment pathways and deglacial chronology of the northern Barents Sea Ice Sheet

Boreas ◽  
2017 ◽  
Vol 46 (4) ◽  
pp. 750-771 ◽  
Author(s):  
Kelly A. Hogan ◽  
Julian A. Dowdeswell ◽  
Claus-Dieter Hillenbrand ◽  
Werner Ehrmann ◽  
Riko Noormets ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Ice Sheet

scholarly journals The North Sea Ice Sheet

Nature ◽  
1894 ◽  
Vol 50 (1282) ◽  
pp. 79-79
Author(s):  
HENRY H. HOWORTH
Keyword(s):  
Sea Ice ◽  
North Sea ◽  
Ice Sheet ◽  
The North ◽  
The North Sea
Sign in / Sign up

Export Citation Format

Share Document