yft Lublin, June 1999

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Teodor Leśniak
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Waldemar STAROŃ Janusz MIELNIK Henryk GURGUL Department of Sea Physics Chair of Physics Szczecin University Wielkopolska 15,70-451 Szczecin POLAND POLISH POLAR STUDIES XXVI Polar Symposium yft

1 Waldemar STAROŃ Janusz MIELNIK Henryk GURGUL Department of Sea Physics Chair of Physics Szczecin University Wielkopolska 15, Szczecin POLAND POLISH POLAR STUDIES XXVI Polar Symposium yft Lublin, June 1999 PARAMETERS OF MINERAL ADMIXTURES IN ICE FROM HANS GLACIER* PARAMETRY ZAWIESIN MINERALNYCH W LODZIE LODOWCA HANSA INTRODUCTION The structure of ice from a glacier is very compound. It consists of different components. One of them is mineral suspension, which particles have different sizes and structure. Concentration of suspension in ice depends on many factors such as the geographical position of a glacier or geological constitution of the area where a glacier is situated and the area around a glacier. It also depends on the configuration of the glacier area and weather conditions. Considering Hans Glacier, adjacency to the area free of ice and snow at sides of the glacier and weather conditions, especially wind power and direction and precipitation, have a big influence on the concentration and size of particles. Mineral suspension in ice from a glacier influences physico-chemical phenomena inside the ice. The phenomena may be classified into two groups. One includes all the phenomena directly influenced by suspension.they are all optical processes such as transmission, absorption and diffusion of light, etc. (Gurgul, Staroń, Mielnik 1998; Jania 1993; Stochmal et al. 1996). The other group includes phenomena indirectly influenced by suspension. Among them there are thermal, physico-chemical or molecular processes (Gurgul 1996). The most characteristic parameters describing suspension are: an average diameter, cross-section area and volume of a particle. * The work was realised as a part of the research programme 6P04E01610 funded by the Scientific Research Committee.

2 Waldemar Staroń, Janusz Mielnik, Henryk Gurgul 276 Measurements of suspension were taken in summer 1997 in selected points of Hans Glacier. METHODOLOGY OF THE RESEARCH Samples of ice were collected from selected points designated by the letters: A, B, C, D, E and F (Fig. 1). The ice was melted and then it was subjected to microscoping with the aid of a projection microscope with a magnification of 1,000 times. The method was described by H. Gurgul in 1988 (Gurgul 1988). Particles of suspension were measured with the aid of the Feret method (Dera 1983) and 1S 32' 33' 34' 3S' 36' 37' 38' 39' 40' 00' 00' 01' 1S 32' 01' 33' 34' 3S' 36' 37 38' 39' 40' Fig. I.Hans Glacier (Spitsbergen) (Jania etal. 1990); Measuring points: A, B, C, D, E, F; A - N 00'862", E 15 35'802"; В - N 00'885", E 15 35"736"; С - N 00'925", E 15 36'217"; D - N 01'116", E 15 36"142"; E - N 01'400", E 15 35"840"; F - N 01'533", E 15 35'750"

Parameters of mineral admixtures in ice from Hans Glacier 277 counted. The counted particles were divided into classes differing one from another by 1 ц т in diameter size.

3 Parameters of mineral admixtures in ice from Hans Glacier 277 counted. The counted particles were divided into classes differing one from another by 1 ц т in diameter size. The result of measurements served as a base for the count of the parameters of particles. RESULTS OF MEASUREMENT Investigations were carried out in six selected points the designated by the letters A, B, C, D, E and F (Fig. 1). After microscoping, it was found that the highest concentration is in point A. Moving parallel to the head of the glacier, concentration decreases in points В and C. In the same way the concentration of suspension decreases while moving upglacier (Fig. 2). The highest concentration units was observed in point A on 25 August 1997, while the smallest one - 10 units was recorded on 24 August 1997 in point F. Such a big difference of concentration between point A and for points С or F,results from the localization of point A. It is situated at the edge of Hans Glacier. Around point A there is an open area, free of snow and ice, from where wind brings particles of suspension to the glacier. As suspension influences optical processes, it is important to determine its concentration and the sizes of particles. Based on results of measurement, an average diameter of particles in particular points was determined. An average diameter of a particle in a particular measuring DATE OF MEASUREMENT Fig. 2. Concentration in measuring points А, С and F at all measuring times

4 Waldemar Staroń, Janusz Mielnik, Henryk Gurgul 278 4,50 g- 4,00 ji LU 3,50 _J O 0 3,00 2,50 2,00 1,50 1,00 ULI 0,50 3: < 0,00 D MEASURING FIELD Fig. 3. An average diameter of a particle in measuring points A, B, C, D, E and F on 26 August 1997 E jt у 5 Field: А g *< Field: F 4 U. 3 Q Ш $ DATE OF MEASUREMENT Fig. 4. An average diameter of a particle in measuring points A and F at all measuring times

Parameters of mineral admixtures in ice from Hans Glacier 279 30 Т 25 w i I Field: А 2 0 - Field: С Щ Field: F 15 z 10 'Z. 'Z. 13.08.97 22.08.97 24.08.97 25.08.97 26.08.97 DATE OF MEASUREMENT Fig. 5.

5 Parameters of mineral admixtures in ice from Hans Glacier Т 25 w i I Field: А Field: С Щ Field: F 15 z 10 'Z. 'Z DATE OF MEASUREMENT Fig. 5. Concentration of particles of a diameter 10 ц т < D < 20 ц т in measuring points A, C, F at all measuring times Fig. 6. An average cross-section field of a particle in measuring time А, В, C, D, E and F on 26 August 1997

6 Waldemar Staroń, Janusz Mielnik, Henryk Gurgul 280 point depends on the situation of a point on the glacier. The farther from the edge and the head of the glacier a point is situated, the smaller the average diameter of a particle is noticed (Fig. 3). The relation was observed during all the time of measurement (Fig. 4). Concentration of large particles (of a diameter bigger than 10 im) influences the value of an average diameter of a particle in measuring points A, B, C, D, E and F. It was observed that the concentration of large particles increases towards the edge of the glacier (Fig. 5). A cross-section field and volume of a particle are very important parameters when considering optical processes. An average cross-section field and an average volume of a particle indicate the same relation to a measuring point as an average diameter, only the difference between particular points is much bigger. But it results from the simple mathematical relationship between the quantities (Fig. 6, 7). 600 T F < J* 400 u- ł- Й 300 O Z > cc gl Ш А В С D Е F MEASURING FIELD Fig. 7. An average volume of a particle in measuring points А, В, C, D, E and F on 26 August 1997 The smallest value of an average cross-section field of a particle was recorded on 26 August 1997 in measuring point F and it was x 10"12 m 2. The smallest average volume of a particle x 10~18 m 3 was also recorded on 26 August 1997 in measuring point F. The biggest average cross-section field x 10"12 m 2 and volume x 10"18 m 3 w e r e recorded on 25 August 1997.

Parameters of mineral admixtures in ice from Hans Glacier 281 CONCLUSIONS While the m e a s u r e m e n t s were being taken, it was observed as follows: - the value of an average diameter of a

7 Parameters of mineral admixtures in ice from Hans Glacier 281 CONCLUSIONS While the m e a s u r e m e n t s were being taken, it was observed as follows: - the value of an average diameter of a particle ranges from to p.m, - the value of a n average cross-section field of a particle ranges from to x 10" 12 m 2, - the value of an average volume of a particle ranges from to x 10_18m3. Parameters of suspension are different in particular m e a s u r i n g points.this results from the situation of the point on the glacier. Concentration increases towards the edge of t h e glacier (Fig. 2). A m o u n t of bigger particles in suspension shows the same relation. Particles of large diameter have considerable influence on a n average diameter, an average cross-section field a n d a n average volume of a particle. Changes of parameters of suspension in one measuring point relate to w e a t h e r conditions on t h a t area. Especially power and direction of wind a n d precipitation have a big influence on them. Determined parameters of suspension m a y be useful to analyse the optical processes in ice from Hans Glacier. REFERENCES J. 1983: Fizyka Morza. PWN, Warszawa: pp Н. 1996: Molekularna fizyka morza z elementami ochrony środowiska. Wyd. Nauk. Uniw. Szczecińskiego: pp GURGUL H : Występowanie układów dyspersyjnych w poiudniowej części Morza Bałtyckiego. Studia i Materiały Oceanologiczne PAN, 5 3 : GURGUL H STAROŃ W., MIELNIK J : Domieszki mineralne w lodzie Lodowca Hansa (Spitsbergen). Acta Physica US, Nr 9, Wyd. Nauk. Uniw. Szczecińskiego: JANIA J. i inni 1990: Hans Glacier - topographic map. Uniwersytet Śląski, Katowice. JANIA J. 1993; Glacjologia, PWN, Warszawa: pp STOCHMAL W., STAROŃ W., MIELNIK J GĄSOWSKI R., GŁOWACKI P : Wstępne porównanie wpływu domieszek na osłabianie światła w wodzie z lodu Lodowca Ekologii (King George Island) i z Lodowca Hansa (Spitsbergen). XXIII Sympozjum Polarne, Sosnowiec, Uniw. Śląski: DERA GURGUL STRESZCZENIE Praca dotyczy zawiesin występujących w lodzie Lodowca Hansa (Spitsbergen). Badania przeprowadzono w okresie lata 1997 roku. Z sześciu wybranych punktów pomiarowych oznaczonych literami: A, B, C, D, E i F (fig. 1) pobierano lód, topiono go i następnie poddawano mikroskopowaniu - mierzono wielkości średnic cząsteczek i zliczano je. Na podstawie wyników pomiarów średnic zawiesin obliczono parametry zawiesin: średnią średnicę cząsteczki, średnie pole przekroju cząsteczki i średnią objętość cząsteczki. W oparciu o wyniki obliczeń wykonano wykresy parametrów zawiesin w zależności od położenia punktu pomiarowego na Lodowcu Hansa (fig. 3, 6, 7) oraz czasu pomiaru (fig. 2, 4, 5).

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