Kenzo Fujiwara

National Institute of Polar Research Repository

Outline of Scientific Program and Its Results Kenzo FUJIWARA* 1. Planning of Scientific Program The straight line drawn from Syowa Station to the South Pole, across the inland of Queen Maud Land, is adequate to grasp an entire picture of East Antarctica in location and length. In 1962, when the Japanese Antarctic Research Expedition (JARE) began to make a plan on the traverse along this line, the inland of Queen Maud Land was the largest and the last unexplored area of the Antarctica. Therefore, it was expected that this plan of traverse would be worth as much as the U.S.S.R. traverse along the Mirny-Vostok­South Pole route. Shortly, the plan of traverse lost a little of its scientific and adventurous freshness, owing to the beginning of traverse activities on this area by U.S.S.R. and U.S.A. parties, but made it possible to study this area widely because of convergence of our and their routes. Therefore, our traverse route to the South Pole was carefully planned so as not to overlap and also to make a well-con­nected network with their routes. Scientific program of our traverse, shown in Table 1, was drafted on the basis of the following aims. l) Studies on the Antarctic ice sheet, and the subglacial relief and crustal structures. For these, there are necessity for working together with various kinds of geodetic and geophysical investigations, and for concerted analysis of their results syn the ti call y. 2) Meteorological and glaciological studies on ice and snow. For studies on the ice-mass budget of Antarctica, it is necessary to investigate the detailed distribution of snow accumulation on the interior of the continent, and to study some factors contributing to snow accumulation, for example, the general atmospheric circulation transporting water-mass to the interior, the loss of water­mass by sublimation and abrasion, the formation process of ice from snow, and so on. 3) Observations on geomagnetism and VLF emissions for the studies of their latitudinal variations. At the early stage of planning, it had been expected that these observations would be made in the range between 69"S and 80 v s in geomagnetic latitude along the geomagnetic meridian of the Syowa Station, but * College of General Education, Hiroshima University, Hiroshima. Member of the JARE South Pole Traverse 1968-69. 23 24 Kenzo FUJIWARA Table 1. The scientific program of the ]ARE South Pole Traverse 1968-69. Item of observation Navigation Orientation Position Elevation Meteorological Geomorphologic and geologic Glaciological Snow surface Pit of 2 m  deep Hole of 20 m deep Snow stake Strain gauge lee thickness Seismic method Radio echo method Gravity method Geomagnetic VLF emissions Medical Snow vehicle Interval At any time Every noon 4 km 00, 06 , 12 and I8GMT On occasion 4 to 16 km Within 100 km 2 and 4 km At 4 stations Within 100 km 8or l6 km 8 km 2•1 km Hourly On occasion I Tin1e required Remarks · (h-r_n_in_) __ . _ _ _ _ _ _   2-30 5 IO 30 2-30 2-00 2 l-00 2-30 l-00 5 45 Gyro-compass and sun compass Solar observation Interval method Preference of observations taken at 00 and l 2GMT Only in the ice-free areas Hardness , density , sastrugi, etc. Annual snow accumulation Snow temperature and snow sample Snow accumulation Ice flow Reflection and refraction methods Declination, inclination and total intensity Combined with the health control of members Collection of samples for studies of giant sea-salt particles and geochemistry were added to this program just before the beginning of the traverse. this plan had been left as a subject for further research owmg to a change of our traverse route. 4) Some medical studies on the traverse members, who are exposed to severe conditions of environment, for example, an extremely cold temperature and a low pressure, unstable conditions of life, and so on. 2. Progress of Investigations The formation of traverse party and its daily operation was described by MURAYAMA (197 1). Daily operation and the scientific work of the party are summarized in Table 2. Detailes of each observation will be described fully in respective report. As a whole, the scientific program was carried out satisfactorily, although some were obliged to be modified or interrupted at the beginning of the traverse. Some observations changed are as follows: Outlme of Scientific Program and Its Results Table 2. The schedule of observations during the traverse. Observations on the way 1st group (vehicle Nos. 604, 603): Two vehicles, 4 km apart from each other, progress continuously At intervals of 4 km Elevation, snow surface At 06, 12, and I8GMT: Meteorological observation At 09GMT Rdio communication to Syowa On occasion Medical study 2nd group (vehicle Nos. 605, 606): They move discontinuous! y after the first group, proceeding with the observation schedule. At intervals of 2 km: Snow stake .,_, B km: Gravity .,_, 16 km: Geomagnetism, surface snow, radio echo sounding Hourly(evry 50 min): VLF emissions At noon Astra-fix Observations at camp stations at intervals of 100 km Seismic sounding, glaciological studies by 2 m pit and :Wm hole 25 I) Field study on physics of snow and ice was removed from the scientific program because of the injury of Y. ENDO, the glaciologist. Other glaciological works were continuously carried out by other members of the party. 2) Since the earth auger had been left at St. 122, snow holes for measurements of temperature and for seismic shooting were dug by a hand auger. Their depth was about 10 m which is one-half of the planned depth. It is assumed that this is the reason for poor records of reflection. 3) The radio echo sounder set in the scientific caboose, which was damaged and left at St. 170, was not used during the way to the South Pole except at the beginning of the traverse. The sounder also developed a trouble by being exposed to an extremely low temperature. 4) At the early stage of the traverse, observation of VLF emissions was not necessarily satisfactory due to a trouble caused by rapid temperature varia­tions inside the snow vehicle, and by disconnection of the antenna. 5) The radio communication between the leader vehicle 604 and the succeeding 603 was sometimes interrupted owing to a radio trouble by low temperature. On such occasion, measurement of elevation could not be made by the interval method, and it was carried out by the single point method. Getting out of these difficulties at the early stage of the traverse, our party had gradually rearranged its setup and all observations was carried out favora­bly before the party reached 75 ° S, at which we were expected to succeed the scientific work of the JARE 1967-68 party. When our party started from the Plateau Station to the South Pole, it was getting to be such a mild weather that the vehicles could make better progress and all the scientific work proceeded very smoothly. We started the operation schedule as follows on the route south of the Plateau Station. A range of I degree in latitude, which is about l 10 km distance, was covered in three days. On the first day, we went 24 km and on 26 Kenzo FUJIWARA the second and third, 48 km each. Pit study was made on the first and second nights, and seismic and astro-fix observations from the third night till the fore­noon of the next day. On the return trip from the South Pole, our party laid emphasis on com­pleting some observations deficient on the outward trip, to solve few doubtful problems found on the outward course, and to compare the results of observa­tions on the outward and return trips. For example, there are the relationship between undulation topography and conditions of snow surface, the distinct transformations of ice surface topography near the Fuji Divide (tentative) and St. 380, modifications of surface snow in summer, and so on. Gravity and geomagnetism were measured as often as on the outward trip. Further, pit studies of 0.5 m depth and collection of snow samples for the study of geochemistry were newly carried out during the return trip. 3. Summary of Results The numbers of observations made during the traverse are given in Table 3. Data obtained are now being analysed and will soon been published in the form of a detailed article. In the next chapter and subsequent articles, it was mainly endeavored to present all the data. '5 l�IT"1""----,-------,-------,---------l-------,.Q.4J· r: J 10W--�g����-;;.- ...;·.:_�, ------t--------::;;;-;;;::--:::1;,,:;;:::---:;;;:::-----1  ,,... .. _____ .:::::: ... - -Hard�;�.',. n ......... .-----·-----'--------_._ .......... __ .;_ ______ ...__ ______ _ - 40 ___ -_ ==r= ____  _'.)now ternpe1 aturc --'-�t_i_o,_n _Ll·2-cp-----1---------., Fig. 1. The longitudinal variation of ice surface elevation, gravity, geomagnetism and surface conditions of snow along the traverse route. Section - --- -Distance (km) Days Weather Operation Position Elevation Weather Surface sno\\· Cf) Pit of 2 m .::: 0. 5 m  .§ 9 (,:j Hole of 10 m > Snow stake ... � Sea-salt particles ...a Snow samples for 0 '- geochemistry 0 Strain gauge ... Q,) Seismic ..c. Radio echo s ::i Gravity z Geomagnetics 3 components Total force only VLF emissions :'.\Iedical Table 3. Results of observations. Way to the South Pole Way from the South Pole Syowa-75°S 75 °S-Plateau Plateau-South Pole South Pole-Plateau Plateau-St. 16 _  , _ __ 836 30 Severe snow storm in the first half of October. Tempera-ture dropped below -50 °C late in October. ----498/1334 19/49 \Veather was fine every day. The lowest temperature, -59.2cc, was re-corded on Kovember 8. 1277/2611 39/88 Temper a ture rose sudden Iv in mid­Novem ber, showing signs of summer. ENDO, glaciologist, Vehicle 603 was ;Sleds ran smoothly broke his left arm abandoned because \on the snow and with the earth auger. of the engine trou- .the party reached This auger, scientifi ble. Progress'of other the South Pole safely. caboose, and all o vehicles was also steel sledges were obstructed by deep left behind. soft snow. I 199 124 Routine � 56 30 5 8 0 0 4 5 224 124 16 8 4 0 0 0 6 5 8 0 100 73 2 7 39 58 44 days 13 days 0 11 persons ------ --29 319 9 150 21 0 11 319 21 0 0 11 0 181 42 2 30 davs 11 pe�sons --- �--- -1277/3888 1294/5182 26/114 27 /141 Snow surface soften- Diurnal variation of ed by sublimation. temperature increased Occasional falls of day by day. It snow-ice crystals were ed early in Febru-observed. ary. Parts of radio echo .Some detailed ob­sounder could not 'servations were carri­be replaced. Vehi- ed out at Fuji Divide, cles had few trou- 75 °S. and other bles. 'spot;. 6 tons of fuel :were deposited for :JARE 1969-70. 0 0 319 353 9 9 79 81 0 IO 189 81 0 6 319 647 0 0 21 22 0 4 0 8 0 0 245 254 44 52 282 613 90 hours 144 hours 11 perso�J 11 persons 0 E. 5· (I) 0 ...... (Fl n rii" ::, ...... 5-i n '"C "I 0 aq "I � a I)) ::, 0... ::;:' "' � (I) C: -...... "' t-::> -.....J 28 Kenzo FUJIWARA With reference to the General map inside of the back cover, and to Figs. 1 and 2, outline of regional and seasonal aspects in the traverse area will be described. The general map presents the topography of ice sheet and directions of prevailing wind on the traverse area. Fig. I shows the longitudinal variations on the values of ice surface elevation, gravity, geomagnetism and surface conditions of snow. Fig. 2 shows daily variations of weather and some phenomena relating to it. By looking at these map and graphs in relation to one another, it will probably be possible to understand the general aspects of this area. Ice surface topography of the traverse area is divided into f-ive areas on the borders of 7 1  ° S, 74 °25'S, 8l 0S, and 87 ° S. That is, there are the marginal slope, katabatic slope, central core, interior slope, and interior basin. The marginal slope is a part of Enderby Land separated from East Antarctica proper by the subglacial through running east to west near 71 ° S. In this area, weather varies periodically and snow falls more than in the interior by the influence of coastal depressions. The surface temperatures from the start of traverse till the late October made such a periodic variation and at the same time steadily dropped to the level of -50 ° C because the party was progressing into the high land of the interior. Since the ice surface of the marginal and katabatic slopes is fairly steep, katabatic winds blow in the !:::-20+---+---c-----+------+------<l------+---1----'----l------t----+----:::d--V-"' J-30f-->,nH�lt---:-+-----+----l----r�-r--1:-�<--C:.--f--�f---l-----'C',d'-t>.,;;j--\ t-401"--t----"!o,f,->r''-.>..,---+-.------,f-.L.---+---1------1-------f----=---�---++-40 .... -50 _ __._ _______ .....,...__,_ __ �.__ __ __._ ___ ....._ ___ ....._ __ ...._ ___ ...._ __ ............ _50 J' .. ,· - --- - ·--- .. -·- ....... -·--_-__ - _  -_+s-�-,;--ait--;u--,;-;--;i"+f;h--.--� .. -0�--n--.• -....... ____  -______  -__ +_-__ -__ -__ -__ -_ -+----/_-.. >--1-'_-_.-._._... ________ + 30 Date 28 Sept. 1 Oct. 1968 St. No. Syowa L.,t ,tirdr· ( ', .) 70 15 1 Nov. 1� 225 ,1 /0 Pl.it (•.1u 71 7'.1 J.1 /·1 /r, /i, JI /,1, /'! ;.;o ;.;1 1 Dec H1 RC::; 15 1 Jan.,1969 South Polr i::V, 11. :'.'1 «Jo qo g11 15 1 Feb !', Fig. 2. Daily variations of weather and some phenomena concerning them .. Temperature and wind are values at 09 GMT. 15 Outline of Scientific Program an<l Its Results 29 speed of 7-15 m/s there. Such an extremely low temperature and high wind, which present coldness index in the ranges from 2,200 to 2,400 cal/m2 ·h meant worst conditions for activities of our traverse members. In the katabatic slope, snow accumulation was distributed sporadically in accordance with ice surface showing a stair-like topography. Ice surface topography transforms distinctly at the neighborhood of 74 ° 25'S and of Fuji Divide. This transformation gives a conspicuous boundary on areal variation of meteorological and glaciological phenomena, for example, surface wind, snow accumulation, and snow hardness, but it is not clear whether the transformation is reflected from relief of subglacial topography or not. Fuji Divide is a broad divide of the East Antarctic ice sheet, located at 77 ° 26'S and 41 °32'E, and is 3717 m above sea level, and its annual mean temperature was -57.1 °C by measurement of snow temperature at 10 m depth, and an­nual water accumulation in the ranges of 3.9 to 4.2 cm was measured by pit study. Since surface winds are very weak and show various directions near the divide, there are the softest area of snow and the originating area of katabatic winds. Surface temperature rose suddenly in the middle of November. Such a rise in temperature was recorded at the Plateau Station and also at the upper free atmosphere of Syowa Station, where the pressure is the same level as that of the traverse party. In the interior slope, there is regular undulation of ice sheet. Though glaciological phenomena vary locally in accordance with regular undulation, there are no large variations over the whole area. For example, annual mean temperature is in the small range of -49.0 ° to -51.5°C, direction of the pre­vailing wind is concentrated in the narrow sector of NNW to NNE, and snow hardness show similar values of 3 or 4 kg/cm2 over the whole area. The weather from the late November to the middle of January of the following year, when the party was operating in the area south of 81 °S, showed a well­regulated variation having a cycle of 10 to 13 days and this variation became conspicuous as the party approached the South Pole. In the same period, the sun moved around a circle higher than 10° above the horizon all day, and the snow surface was remarkably modified by sublimation by solar radiation. Getting into the interior basin, wind direction shifted to NNW only and snow hardness became very soft. These are clear differences to those of the interior slope, and, in this basin, there was no regularity on surface undulation such as seen in the interior slope. Therefore, it can be said that the interior basin is a definite unit of East Antactica. Reference MuRAYAMA, M. (197 1) : General Statement: JARE South Pole Traverse 1968-69. JARE Scient. Rep., Special Issue, No. 2, 1-22. 

Outline of Scientific Program and Its Results

https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=111&item_no=1&attribute_id=18&file_no=1

Outline of Scientific Program and Its Results

Abstract

Similar works

Full text

Available Versions

National Institute of Polar Research Repository