An empirical relatives ranging from overload tension and you will firn occurrence
A couple of empirical equations having firn densification were received,offered firn porosity due to the fact a function of excess stress. In the step 1st formula, thereduction proportion away from porosity for the firn is assumed becoming proportional towards the broadening ratioof excess stress additionally the mth strength away from the fresh new porosity. The porosity exponent meters is going to be alongside -dos, to https://datingranking.net/sugar-daddies-usa/pa/philadelphia/ possess a sole-fit with fourteen depth-thickness users fromGreenland and you may Antarctica. On second picture, the fresh new prevention proportion regarding porosity wasassumed to improve proportionally on increment regarding excess pressure and thenth electricity of one’s porosity. The most high enough beliefs of the exponent may include -step 1 to at least one. It has been advised one to firn thickness, determined mainly by overburdenpressure and you may firn heat, sign up to a diminished training.
step 1 Addition
This new conversion means of firn to help you freeze is among the very simple sufferers during the polar frost-sheet training. Plenty of ideas regarding your dry densification out-of firn enjoys already been proposed ( Resource Robin Robin, 1958 Resource Schytt Schytt, 1958 Site Bader Bader, 1960, 1962 Resource Benson Benson, 1962 Anderson and Source Benson Benson, 1963 Resource Kojima Kojima, 1964 Source Gow Gow, 1975). Although not, a thorough design in addition to cereals-settling, sublimation/condensation, volume/ facial skin diffusion, freeze distortion and you can recrystallization processes was not firmly founded. Brand new densification procedure have also learned empirically ( Site Robin Robin, 1958 Resource Schytt Schytt, 1958 Reference Herron and you may Langway Herron and Langway, 1980 Source Ling Ling, 1985 Source Langway, Shoji, Mitani and you may Clausen Langway although some, 1993). (tovább…)