Search

1. Introduction The expedition ship "SOYA" was manned by three meterologists, who were in charge of weather forecasting for the operation as well as of regular ship surface observations and occasional radio-sonde observations. The weather analysis was made twice a day on the basis of the synoptic charts, 0600Z and 1800Z, which cover the whole southern hemisphere. This paper briefly reports the results of the analysis with respect to the area limitted between 40°W and 80°E. 2. Distinctive features of the synoptic pattern of this season a) A superior southward extension of subtropical anticylone was seen in January. b) The influence of the Antarctic continental anticyclone was predominant in middle December and in February. c) The change of weather phenomena in the vicinity of Lutzow-Holm Bay was considerably regular. d) There were two periods of conservative stable weather in the Antarctic coastal region, late December and early February. The former was caused by the southerly extension of subtropical anticyclone. 3. Cyclones The trajectories of major cyclones are shown in Figs. 1 and 2. Among these cyclones, two, which had developed in the area near Bouvet Island, approached Lutzow-Holm Bay, causing storms which attacked "SOYA" on Jan. 9 and 21. The relief operation was interrupted for a week or more before and after the storms. Another small depression, associated with the Antarctic front along the coast, hit Syowa Base on Jan. 31 giving minor effect on our operation. 4. Anticyclones a) Subtropical anticyclone. The quasistationary subtropical anticyclones, which are usually situated in the area between 20°S-45°S and 20°W-40°E, were developed so remarkably in middle January that their influence extended as far as to the Antarctic coast including Syowa Base, until the general pattern was changed by the approach of a deep trough at the end of middle January. b) Antarctic continental anticyclone. In middle December, Syowa Base and Lutzow-Holm Bay were under the control of the superior Antarctic continental anticyclone. But in middle January it rapidly retired to the south in early January, having been replaced by the high pressure ridge of the extended subtropical anticyclone. The continental anticyclone recovered its power again at the end of January. Then the Antarctic coastal region, from Queen Maud Land to Enderby Land, again went under the influence of the continental anticyclone, which reflected the movement of circum-polar cyclones to ENE, and Lutzow-Holm Bay remained out of the cyclone path. Thus, the stable weather lasted for about ten days in early February. 5. Antarctic front The so-called Antarctic front is a stationary one formed along the coast line of Antarctica. The physical aspect of the Antarctic front is quite complicated as has been revealed in our previous report. The remarkable Antarctic front, which was seen in middle January of this season, seemed to be of the occlude type. The daily position of the front for the period from Jan. 12 to 24 is shown in Fig. 3. An interesting relation was noticed between the movement of the cyclones along the front and the contact point of the front to the coast line, the details of which will be discussed in a latter paper. The sequence chart for Syowa Base was compared with that for Razarev Base, and a close similarity was found between them with respect to the weather change associated with the activity of the front.

The first series of the Japanese Antarctic Research Expeditions was completed in 1962, and the second series started in 1965 This is a critical review of all papers on marine geology so far published by Japanese scientists, and also of some papers by American and Soviet scientists related to the Japanese works It is the writer's desire that the review, pointing out the problems to be solved, might be of some use for the second series of the expeditions Conflicting interpretations of the results among the scientists are discussed They are, (1) origin of very deep continental shelf (What is the cause of very deep continental shelf around the Antarctica ? Fault or isostatic subsidence due to very thick continental ice cap, or else?), (2) glacial basins or submarine canyons (Are the depressions in Amundsen and Lutzow-Holm Bays glacial basins or submarine canyons formed by subaerial erosion or faulting?), (3) Tertiary ice-rafted gravels (If the gravels are Tertiary in age, they are very important to the geological history of Antarctica), (4) Quaternary marine sediments on the East Ongul Island (Are they really raised beach deposits or sediments deposited at depth of about 100m?) The other topics here included are (1) grain size, heavy mineral, clay mineral, and organic material distributions of the sediments, (2) total carbonate and organic production, and (3) oceanographic interpretation of Foraminifera distribution

Navicula gibbula var psraustralis was found in the materials collected by Dr. Hiroshi FUKUSHIMA, assistant professor of Yokohama Municipal University, at Shinnan Rocks on the Prince Olav Coast of Antarctica in 1961 and by Mr. David T. MASON of California University at Cape Barne of Ross Island. The writer, after cleaning the specimens with acid and mounting them with pleurax on slides, took microphotographs at random and enlarged them 2,000 times as large. Then the writer investigated 117 leaves of the former material and 68 leaves of the latter meterial. In external shape structure, and measured values of the shell, this diatom resembles Navicula gibbula CLEVE, except that both margins are protruded and ends are sometimes expanded in a capitate shape. However, individuals in distinguishable from Navicula gibbula are also found though rarely. They are similar to Navicula bachmanii HUST. in the point that both ends were expanded in a capitate shape, but expansion of the central part of the shell is quite different and the number of striae in 10μ is also different. This diatom closely resembles the new species (Navicula peraustralis) collected by J. MURRAY during the British Antarctic Expedition, 1907 to 1909, from the recent geological deposit containing subfossil diatoms at Cape Royds near Cape Barne, one of the stations the writer investigated this time, but the structure of striae was a little different from the original drawing of WEST. As the writer pointed out in the previous paper, in consideration of inaccurate drawing or incomplete observation on Navicula muticopsis, Pinnularia cymatopleura and Tropidoneis laevissima in WEST'S paper, it would be better to identify the diatom which was found this time as Navicula peraustralis. Judging from the characteristics of the shell as mentioned before, it would be better to regard this diatom not as a species but as a variety of Navicula gibbula CLEVE. Thus the writer proposes the following name : Navicula gibbula CLEVE var. peraustralis (W. & G. S. WEST) KO-BAYASHI Comb. Nov. Synonym Navicula peraustralis W. & G. S. WEST.

Narrow-band receivers developed for receiving exclusively the JJY signal in the presence of interferences by the other standard frequency waves with an identical carrier frequency are used since 1967 for the observation of HF radio wave absorption on board the ship of the Japanese Antarctic Research Expedition. This paper summarizes the technicality of the receiver, and presents the results of measurements obtained in the 10th JARE (Nov., 1968-Apr., 1969) by means of the receiver. Dependence of the ionospheric absorption in the nighttime on the solar activity was confirmed quantitatively by the same analysis as that given in Part I (1971) of this paper.

This paper describes the results of meteorological surface and aerological observations at Syowa Station from February 10, 1973 to January 31, 1974. The main subjects of observations, the method, and the equipments are the same as the previous year. Observed results were regularly sent to World Meteorological Centre in Melbourne via Mawson Station. Some meteorological characteristics of this year are as follows: 1) A long spell of blizzard in the first decade of April had daily maximum wind speeds exceeding 20 m/s recorded every day for 10 consecutive days. 2) On the early morning of 12 May, air temperature rose up to 1.4℃. This was the highest record for May since observation started at Syowa Station. 3) Gold weather in July and August brought monthly mean temperatures for July and August to the lowest ever observed at Syowa Station. 4) The rate of actual sunshine duration to the possible sunshine in November was 71%. This value was the largest number for this month at Syowa Station. 5) Sudden warming in the lower stratosphere was observed quasiperiodicaly from early September. A temperature rise in the warming period from 30 October to 6 November was about 30℃ at 30 mb pressure level.

This paper reports the summary of the data of the surface meteorological observations carried out during the period from June to December in 1972 at Mizuho Camp, East Antarctica. Obtained results are as follows: The differences of the pressures at Mizuho Camp and Syowa Station averaged over ten days and those of the temperatures were 240-265 mb and 13-23℃. The wind speed averaged over ten days was strongest in June and decreased almost linearly from June to December. The frequency distribution of wind speed was of roughly the Gaussian distribution with the peak at about 11 m/s. The prevailing wind direction was ESE and almost the same as the direction of the sastrugi and the slope in the vicinity of Mizuho Camp. The frequency of the prevailing wind direction was about 60% regardless of month. When the wind direction changed counterclockwise from ESE to N, the wind speed decreased and the temperature became higher. The diurnal variation of wind speed was similar to that at Syowa Station.

This paper describes the results of meteorological surface and aerological observations at Syowa Station from February 1, 1972 to February 10, 1973. The main subjects of observations, the method, and the equipments are the same as the previous year. Observed results (surface observation at 00, 06, 09, 12, 15, 18 GMT and aerological observation at 00 GMT) were sent to World Meteorological Centre in Melbourne via Mawson Station based on the WMO code, and were recorded according to the WMO regulations. Meteorological characters observed this year are as follows: 1) Temperature in the first half of this year was a little lower than the average but was unusualy high in August and September. 2) Snow accumulation in August and September was larger than in normal years, 3) The sunshine duration in the latter half was extremely shorter than in normal years, arid consequently, the thawing of snow was very slow. 4) Sudden warming in the lowci stratosphere was observed clearly since October 8. For instance, the isotherm of -50℃ was found to shift downward periodically, with a period of 11 or 12 days. 5) A rainbow was observed on the early moring of December 17. 1972. This was the first recoid ever since Syowa Station was opened. Moreover, we carried out observations of drifting snow, total amount of ozone, amount of evaporation, katabatic wind as well as atmospheric ozone, electricity and long wave radiation using a specially desinged radiosonde.

This paper describes the results of surface and aerological weather observations at Syowa Station between 1 February 1971 and 5 February 1972. Most of the methods and instruments are the same as in 1970; a meteorological satellite tracking system to receive the pictures was installed. Some meteorological characters of this period were: Temperature and solar radiation were lower than the average; Bad weather were experienced from February to April and from August to November; Snow accumulation was greater than the average; Temperatures of all the upper layers in winter were lower than the average. Total amount of ozone was observed on every suitable day except the polar night season.

In this paper are reported 15 taxa of diatom. Among these taxa, Amphora holsatica HUST., Amphora veneta KUTZ., Gomphonema angustatum (KUTZ.) RABENH., Navicula mutica KUTZ. Var. goeppertiana (BLEISCH) GRUNOW, Navicula muticopsis van HEURCK var. muticopsis f. murrayi (W. & G. S. WEST) KO-BAYASHI, Navicula simplex KRASSKE, Navicula sp., Nitzschia dubia W. SM. Var. australis M. PERAGALLO, Pinnularia cymatopleura W. & G. S. WEST and Stauroneis perminuta GRUNOW were observed on Ongul Island for the first time.

In this paper are reported 18 taxa of diatom. Among these taxa, Achnanthes brevipes var. intermedia, Cyclotella stelligera, Cymbella tumida, Diatoma hiemale var. mesodon, Frustulia rhomboides, Gomphonema acuminatum var. coronata, Navicula muticopsis f. murrayi, Nav. radiosa var. tenella, Pinnularia gibba, P. g. var. parva, Stauroneis anceps, Synedra acus and S. ulna var. oxyrhynchus are newly recorded from East Ongul Island

1967年4月から1968年1月まで,昭和基地(地磁気緯度69.7°S)において,VLF帯電磁放射の観測を行なった 受信アンテナは,直交枠形アンテナと垂直アンテナを用いた ここではVLF放射の発生の性格と,他の超高層物理現象との相関について報告する 12kHz帯のVLFの放射は,12月,1月の夏を除いたすべての季節において,夜1800から0100UTに発生した 放射の継続時間は平均して10分から20分が多く,概して地磁気嵐,オーロラ出現,電離層における電波吸収現象と複雑な相関を持っている 一方750Hz帯のVLF放射は,その発生頻度は少ないが,主に昼間に生じた 放射の継続時間は,12kHz帯の放射のそれより長く,大きな地磁気嵐時には,数時間に及ぶものもあった 750kHz帯放射の占有帯域幅の上限はせいぜい4kHz程度であった The observation of VLF emissions has been carried out at Syowa Station (geomagnetic lat. 69.7°S) in the Antarctic from April 1967 to January 1968, using a crossed loop antenna of triangle type and a vertical antenna. In this paper, the occurrence of emissions and their correlation with other geophysical phenomena are discussed. VLF emissions at 12kHz occurred almost always from 1800 to 0100U T in all seasons except for December and January, and the duration of the emissions was 10-20 minutes on the average. VLF emissions at 12kHz showed complicated dependence on geomagnetic disturbances, auroral displays and radio absorptions in the ionosphere. On the other hand, VLF emissions at 750Hz seldom occurred in the daytime, and their duration was longer than that at 12kHz. The occupied highest frequency of such emissions was found to be about 4kHz at most.

1. Introduction J.A.R.E. III had to perform the operation to reopen Syowa Base which had been left unoccupied since Feb. 1958. According to the unfavourable ice condition in the vicinity of Lutzow-Holm Bay, the operation was forced to rely mainly upon the air-transportation, which is seriously affected by meteorological condition. Thus, the weather analysis and forecast became most important to gain success in the operation. The works were carried out by three meteorologists who were on board the expedition ship "SOYA". This paper brief by reports the results of the weather analysis for the area limitted between long. 40°W and 80°E. 2. General features of the synoptic pattern and the weather In early summer, from late December to middle January, the Antarctic continental anticyclone had retired to south, and the stationary front between the continental anticyclone and subtropical anticyclone was apt to be formed along the Antarctic coast. Under such a pattern, the "SOYA", hanging around Lutzow-Holm Bay, experienced unstable weather with variable wind, much lower cloud, and poor visibility. Sometimes she met moderate storm caused by the approach of developed cyclone. The transport operation, therefore, made little progress though every opportunity of short intermittent fine weather was utilized to enforce the air transportation. In late summer, the continental anticyclone became strengthened controlling over Lutzow-Holm Bay, and the weather both at the base and at the ship site was generally stable. The transport operation was performed during the succeeding fair weather from 1st to 4th February. 3. Cyclones The "SOYA" encountered three cyclones during the period from Jan. 2 to Feb. 11. Their trajectories are shown in Fig. 3, in which we can notice the retrogressive motion of two cyclones in the area south of lat. 60°S. This was caused by the existence of the superior high pressure ridge over Enderby Land, which prevented the cyclones to move east, associated with the general pattern of meridional circulation. The trajectories of the major cyclones of this season are also shown in Figs. 2 and 3. It is pointed out that the originating position of the cyclones deflects farther south in the latter half period of summer than in the first half period. 4. Anticyclones a) Subtropical anticyclone. Quasi-stationary anticyclone, which usually extends from east to west at about lat. 20°S-45°S, was developed unusually southward in middle January. Then the activity of the front between the subtropical anticyclone and the continental one was intensified. Moreover, since the general synoptic pattern had a tendency to strengthen the meridional circulation, a high pressure ridge was formed over Enderby Land, connecting both anticyclones. The retrogression of cyclones, mentioned before, was induced by the above pattern. In late January the subtropical anticyclone gradually retired northward to its normal position. b) Antarctic continental anticyclone. The decay of the Antarctic continental anticyclone began in late December, culminated in middle January, and then showed a gradual development. At the end of January, the anticyclone became well developed, controlling over the Antarctic coastal region. c) Anticyclone, separated from the continental one. The isolated anticyclone is often formed around the waters off the Antarctic coast, having been separated from the continental anticyclone. It consists of the transitional polar airmass or polar maritime airmass. There seem to be the following three specific areas where such separations are apt to take place. 1) West part of Weddel Sea near Parma Peninsula 2) The water off the coast near 0° meridean 3) The water off Enderby Land The movement of such an anticyclone of the case 1) is illustrated in Fig. 4.

This paper describes the result of the , field intensity measurement of HF waves which was carried out at night on the way from Tokyo to Cape Town on board the "SOYA". Field intensities measured were lower than those of the so-called "unabsorbed field intensity" and the lower the frequency, the more rapidly the field intensity decreases with the distance of transmission. Hence, it is suggested that the non-deviative absorption must be taken into consideration. From the measurement on 2.5Mc/s wave, it was derived that the nondeviative absorption converted into the vertical incidence was equal to 1.0db. On the other hand, the weighted mean value for all frequencies measured was 2.5db. The difference between these values is examined herein

The ecological observation was made on the vegetative growth of shoots of Ceratodon purpureus and Bryum inconnexum. The number of green leaves and the production of rhizoids of the mosses were investigated. The community of the mosses stunted by blue green algae was observed (Figs. 9-a, -b, -c) and the growth lines in the cushion formed by Ceratodon purpureus were shown (Fig. 8). In Bryum inconnexum, the rhizoid and 14-17 leaves appear alternately on the stem (Fig. 13), and thus the rhizoidal parts of the stem of each individual are seen as the rhizoidal belts in the cross section of the cushion formed by Bryum inconnexum (Fig. 14). Therefore, it may be considered that the rhizoidal belts show the periodicity of the growth of Bryum inconnexum community. In the present paper, two types of the growth form of the cushion of Antarctic mosses have been discussed.

Computations of the ray path and absorption of radio waves by means of the ray-tracing technique are applied to the oblique propagation of MF and HF waves passing through model ionospheres in the nighttime under different conditions. The field intensity deduced from those computed results is discussed in comparison with that measured on board the ship of the Japanese Antarctic Research Expeditions as already reported in Parts I and II of this paper. It is confirmed quantitatively to a certain degree that the ionization in the nighttime E region is responsible for the absorption of MF and lower HF waves.

This paper describes the results of meteorological observations (surface and aerological) at Syowa Station between 1 February, 1970 and 20 February, 1971. Method and instruments of observation are the same as in 1969. Observed results were regularly sent to Mawson Station. Some meteorological characters of this year are as follows ; 1) Temperature in the winter season was lower than the average. 2) Continuation of bad weather was experienced in April, May and July. 3) Snow accumulation was larger than that of the preceding year. 4) Strato-warming at 50mb (20km) level was one week later than the preceding year. The observations of total amount of ozone were carried out on every suitable day through the year except the polar night intervals. A specialy designed long-term meteorograph was installed at Mizuho Camp (70°42.1'S, 44°17.5'E) on 21 July, 1970.

The observation of aurora by the radar method was carried out at Syowa Station in Antarctica during a period from April 1966 to December 1967. Instrumental outline and characteristics of the radio aurora are discussed in this paper. Results of this analysis are as follows : 1. The diurnal variation of the auroral echo occurrence takes a pronounced maximum in the morning (0300-0900L. T.) and a small maximum in the evening (1800-2200L. T.). 2. The seasonal variations of the echo activities were not distinct, but the minimum of the echo occurrence can be found only in the summertime in Antatctica. 3. On the oblique auroral reflections, the azimuthal distribution of the auroral echo occurrences showed that more auroral echoes are received from the region between 120° and 240°. 4. The occurrence time of the auroral echoes in all directions was about 0330L. T. in June, 0630L. T. in September and 0830L. T. in December. 5. The range of a maximum reception of the auroral echoes was about 300km, and the echoes from the outside region of 200km-1000km were not obtained.

Three snow vehicles, type KD60, were successfully used by the traverse party of the 9th JARE (Japanese Antarctic Research Expedition) which made a round trip along 43°E in longitude from Syowa Station to the South Pole (direct distance : 5,180 km) during a period from September 1968 to February 1969 (141 days). This paper deals with one of the vehicles, KD605, which has an overall cab, 7.2 ton in weight, and is equipped with a super-charged diesel engine. It is also provided with a navigation system, several berths for the crew and cooking space, snow melter, and some racks built in for installing observation and radio equipments. In addition, to endure the severe environment of low temperature (-60℃) and high altitude of 4,000 meters, special care was taken in selecting the materials and in making the inhabitants comfortable. The vehicle covered 5,353 km within 110 days for driving and 31 days for camping, consuming 12,068 litres in total of diesel fuel. The snow surface was relatively hard from Syowa Station to 75°S. On the upward slope, drifting and blowing snow caused by katabatic wind was intense. In some areas the snow vehicle and sleds were stuck into soft snow accumulated by wind or due to the surface configuration. The highest area along the route was a plateau more than 3,500 meters between 75°S and 80°S. Soft snow covers this plateau where the wind was very weak and the air temperature was below -50℃. Snow vehicle tracks sank as deep as 30 cm into the snow and the fuel consumption rate rose as high as 3.5 l/km. Stopping longer than 5 minutes caused the runner of sled to stick to the snow surface, so that starting without help became impossible. Sticking was more pronounced with the decrease of air temperature. On the high plateau, more than 3,700 meteis in altitude, the exhausted gas became dark due to the shortage of air and the increasing resistance. As a result, apparent output lowering was accompanied by knocking sounds while the engine was driven at low to medium speed. In the terrain south of 80°S, (except the soft snow-covered area near the pole), the air temperature was about -30℃ and the snow condition was getting better. As the terrain was downward slope, all these conditions helped the party to have pleasant driving. On the return trip, the snow surface had crust due to the effect of solar radiation and wind packing. Since the pulling-load became smaller and the air temperature became higher, the party experienced remarkable trouble to drive.

Wind velocity and temperature fluctuations were observed at Syowa Station by means of an ultra sonic anemometer thermometer during JARE 12 (1971-72). In this paper the power spectra and the probability density distribution are mainly studied. The behaviour of the power spectra in changing stability is consistent with the precedent observations. The power spectra pattern of vertical wind component is not always similar to the temperature spectra. Especially in the high frequency range the decrease of power density with frequency in vertical wind spectra is steeper than that in temperature spectra. Moreover, some peaks are seen at the frequency higher than the Brunt-Vaisala frequency. The cause of this phenomenon has not been ascertained yet. The probability density distributions of the wind and temperature fluctuations are similar to the Gaussian distribution, and the joint distributions of them also may be approximated by the Gaussian distribution. The presumed semi-normal joint probability distribution, which is used for the closed system of the correlation tensor equations, has been verified.

Diatoms of South Georgia were reported in four papers up to the present, one by P. F. REINSCH (1890), one by G. W. F. CARLSON (1913) and the remaining two by KO-BAYASHI (1963 and 1965). REINSCH recorded 19 kinds (including verieties and species) and CARLSON recorded 45 kinds (also including varieties and species). KO-BAYASHI investigated 3 kinds of diatoms (1 in 1963 and 2 in 1965) in the study of variations of Antarctic diatoms. As the Antarctic Research Expedition of the Tokyo University of Fisheries, headed by the late Professor Takeharu KUMAGORI, gave the writer the materials collected at South Georgia during the research from 1961 to 1962, the writer reports the results of investigation on 3 specimens (Nos. 1, 2 and 7). The materials are the same as those investigated by KO-BAYASHI. As a result of this investigation, the writer found 49 kinds of diatoms. Therefore, the total number of kinds in the existing record and the writer's record of South Georgia diatoms becomes 93. Among these diatoms, species of South Georgia were Achnanthes mulleri and Navicula megacuspidata, that of the Antarctic inland water was Navicula muticopsis, and that of the Antarctic ocean was Cocconeis inperatrix. Even when the endemic species of South Georgia were regarded as Antarctic species, Antarctic diatoms were only 4 species, that is less than 10% of all. Judging from this fact, diatoms of South Georgia are almost cosmopolitan species and not characteristic to the Antarctic waters. Besides, some species that are known to be abundant in northern Europe were found though in a small quantity ; thay are Achnanthes plonensis, Eunotia robusta var. tetraodon, Navicula cocconeiformis and Navicula pseudoscutiformis.

Based on the data obtained by the UMITAKA-MARU (Tokyo Univ. of Fisheries, 1453) during the period from Dec. 1961 to Feb. 1962, the general oceanographic conditions are discussed in this paper. During this expedition the temperature, salinity, dissolved oxygen, PH, Phosphate-P and Silicate-Si are investigated at all stations. As a result the followings are summarized; (1) along the oceanographic sections off Australia and Africa the Antarctic Convergences are clearly distinguished, (2) in the Indian Antarctic waters the south-going warm deep water affects to the higher latitudes zone than in the Atlantic region, (3) in the Weddell cold water region where the northerly and southerly oceanographic sections are investigated the upwelling of Warm Deep Water is critically observed, (4) by the chart of dynamical topography the meandering of west-wind drift current around the Weddell cold water region is estimated.

Observations of the nighttime ionospheric absorption have been carried out since 1958 on board the ship for the Japanese antarctic research. Field intensities of the HF standard frequency signals at different frequencies were measured during hours around midnight. In this paper, techniques of the measurement for extracting a relatively small quantity of the nighttime absorption are described. Existence of the absorption is confirmed from the fact that the rate of decrease of field intensities against the ground range at a lower frequency is much larger than that at a higher frequency. Moreover, the dependence of absorption upon the solar activity is found out from the measurement over nine years in the declining epoch of the last solar cycle. A provisional expression for estimating the nighttime absorption is proposed.

The continuous seismic reflection profiling was made in 1965-1966 during the 7th Japanese Antarctic Research Expedition This paper reports on the structure of sediments on the continental slope along the west coast of the Australian continent, as a part of the results The pneumatic gun of Lament Geological Observatory type was used as the sound source The ship's track is given in Fig 1 Photographic records are presented in Figs 3, 4, 6 and 8. Line drawings from these photographic records are presented in Figs 5, 7, 9 and 10 In these pictures, horizontal distances are given in terms of the ship's navigation time One hour navigation of the ship gives approximately 22km of distance, as the ship ran at a rate of 12 kt during the observation Depths of the sea bottom and each reflector are given in two way reflection travel time in seconds. The whole area of observation is divided into three regions depending on the character of structure of sediments Each region is numbered from the north to the south. Schematic illustrations of Fig. 11 show the character of structure of sediments in each region This division may not have practically any geological significance, since there is only one profile running parallel to the continental slope of the Australian continent

The observation of geomagnetic micropulsations with period from 300 to 0.5 seconds has been carried out by the JARE wintering party at Syowa Station from April, 1966. Geomagnetic signals are registered on a paper chart and a magnetic tape, using a slow speed tape recorder. In this report, characteristics of the recording system are briefly described and the preliminary results mainly for micropulsations of the pc-1 category, observed in 1966, are presented. Pc-1 pulsations are predominantly observed in the daytime at Syowa Station, and about one half of micropulsations with frequency of 0.2-2 Hz show a recurrent structure in f-t display. It is found that pc-1 pulsations are often associated with sudden commencements of magnetic storms which occur around local noon, and that most of ssc pulsations do not have a recurrent structure, although rising frequency of structural elements is noted in f-t display. Some spectral characteristics of pi and pc-2, 3 are also discussed.

This paper reports on the occurrence frequency of aurora derived from ascaplots, observed at Syowa Station in 1959 and 1960. Aurora was frequently in the south and after midnight. The correlation between K index at Syowa Station (K_s) and auroral activity was also discussed.

The geomagnetic total force observations along the navigation route from Japan to the Antarctic Ocean via Singapore and Cape Town were carried out using the Proton Precession Magnetometer which was used in the second (1957-58) and the third (1958-59) expeditions for the same purpose. We got nearly the same results at the Indian Ocean as on former observations. In this paper, the results of observation from Cape Town to the Antarctic Ocean are chiefly reported. 1. We discovered about 10 discrepancy between the total force of our measurement by Proton Magnetometer and that of Hermanus Observatory, Cape Province, South Africa obtain from Variometers. Fig. 1. 2. The iso-total force lines diagram deduced from the results of observation at the second and fourth expedition are illustrated in Fig. 2. 3. The annual changes of the total force between Cape Town and the Antarctic Ocean deduced from the results at the second, third and fourth expeditions are shown in Fig. 3, where no corrections for diurnal variation are applied. 4. The tso-total force lines diagram in the Lutzow-Holm Bay deduced from the results at the second and fourth expeditions are illustrated in Fig. 4. 5. Anomaly changes of about 400 were observed which are presumed to be caused by the submarine relief. Two examples are illustrated in Fig. 5.

This paper briefly reports the result of the weather analysis carried out on m/s SOYA during the relief operation of J.A.R.E. V in the Antarctic in the summer of 1960-1961. The synoptic data were collected through the interception of the wireless weather transmission listed in Table 1 and Fig. 1. The meteorological condition in the vicinity of Lutzow-Holm Bay in this season was quite favourable and was the best of the five summers from 1957 to 1961. The maximum wind velocity did not exceed 15 m/s and the amount of lower cloud was extremely small. The weather recorded on m/s SOYA is summarized in Tables 2 and 3. The frequencies of wind velocity and of the amount of lower cloud for this summer are compared with those for the previous summers, as shown in Figs. 2 and 3. The data in these figures are based on the observations at Syowa Base with respect to the common period for the five summers. The synoptic meteorological pattern, relating to the extraordinary good weather of this summer, was analysed through the weather maps prepared on m/s SOYA; and it was concluded as follows: a) In middle summer, from early January to middle February, the polar cap anticyclone was not powerful enough to control over the Antarctic coastal waters. The anticyclonic ridge, however, was apt to stagnate over the area of Queen Maudland with the meridional axis connecting the polar cap anticyclone with the meridional one. This ridge prevented developement of cyclones which ordinarily tend to appear over the waters around Bouvet Island and move southeastward to attack Lutzow-Holm Bay. Trajectories of the major cyclones in this summer are plotted in Fig. 4. It is noticed that the characteristic features of the trajectories resemble those in the summer of 1957 (Fig. 5a), when we experienced another favourable weather in the area concerned. On the contrary, the trajectories in the summer of 1958, when the worst weather was experienced, revel a different character as the well-developed cyclones frequently crossed the line of latitude 65°S approaching Lutzow-Holm Bay. The existence of the above mentioned anticyclonic ridge in this summer can be ascertained also through the five-day mean pressure distribution along the Antarctic coast from S.A.N.A.E. Base to Mirny Base, as shown in Fig. 6. b) In late summer of 1961, the polar cap anticyclone increased its intensity, expanding so widely that the coastal region of the Indian Ocean sector was completely covered with the fresh Antarctic continental air mass. At the same time, the hemi-spherical circulation showed a tendency of "High Index" type, which means a superior zonal circulation. The circum-polar cyclones were then accerelated to move along latitude line, having few southerly components. On account of this pattern, Lutzow-Holm Bay was protected from the cyclone path. Thus, throughout the whole period of the operation from 6th January to 3rd March, SOYA encountered with no severe storm in the vicinity of Lutzow-Holm Bay.

VLF emissions were observed at Syowa Station by the 11th wintering party of the Japanese Antarctic Research Expedition in 1970-1971. The present paper deals particularly with the records of auroral hiss emissions, which are believed to be emitted by precipitating electrons in the aurora. It is shown that the power spectrum of the hiss emissions is confined in the low-frequency range between 4-32kHz if the auroral arcs lie near the poleward horizon of Syowa Station, while it is extended to frequencies as high as 128kHz if the active auroral arcs appear near the zenith. This can be explained by differences in the height of the emission region and in the propagation path of the hiss in the ionosphere : the high-frequency (～64kHz) hiss is emitted at low altitudes of 1000-1500km, its propagation path being limited to a narrow region near the location of the auroral arcs, while the low-frequency (～8kHz) hiss is emitted at higher altitudes of 3000-3500km, its propagation path spreading widely due to the refraction effect in the ionosphere.

Some entrails and an embryo of a crab-eating seal captured in Antarctica (69°01'S, 30°41'E) were examined from the standpoint of morphology. This paper describes the characteristics observed with the naked eye. The dissection was performed after the material was melted indoors, as it had been frozen, and the features of entrails, weight, colour, and so on were chiefly examined. The dissected parts were kept in a 10 per-cent formalin liquid and were examined again later.