• Ocean and Polar Research
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• v.24 no.3
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• pp.249-253
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• 2002

There is a great deal evidence concerning crustal uplift, after deglaciation, in the vicinity of Syowa Station $(69^{\circ}S,\;39^{\circ}E)$ from tide gauge data, seismic evidence, raised beaches, marine terraces, etc. The geomorphological and tide gauge data show that the crustal uplift is going on around Syowa Station. Seismic observations at Syowa Station started in 1959. Phase readings of the earthquakes have been published by National Institute of Polar Research once a year since 1968, as one of the Data Report Series. Eighteen local earthquakes were detected on short period seismograms at Syowa Station in 1990-2000. The seismicity during the period from 1990 to 2000 was lower than that from 1987 to 1989 when epicenters of local earthquakes were determined by tripartite seismic array. Local earthquake activity corroborates the crustal uplif4 which is an intermittent phenomenon. Sea level falling of 4.5 mm/y was found using data in 1975-1992. This felling rate is consistent with the geomorphological data. A route for repeat leveling survey was established in East Ongul Island. No appreciable change of sea level was observed for the last 14 years. A dynamics of the crustal uplift around Syowa Station has been discussed using geomorphological data, ocean tide, and seismic and leveling data, which is estimated to be an intermittent phenomenon. When local seismic activity is high, the crustal uplift is estimated to be going on. On the contrary, the crustal uplift is in dormancy when the local seismicity is low. Repeated leveling measurements suggest no significant changes, which further supports the idea that the crustal uplift in offshore is not a tilt trend movement but a block movement.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.55-62
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• 1999

Four species of Paraphysomonas collected from the fast- ice covered area Syowa Station, East Ongul Island ($69^{\circ}00'S,\;39^{\circ}35'$) ,Antarctica occurred in the seawater throughout the year and occasionally in the sea ice. P.. antarctica is distributed to a water depth of 35m at 51.3 during the period from August 1983 to January 1984 and also down to 600m St. 5 in September 1983 at cell concentrations of 300-350 cells/ml. The Paraphysomonas spp. were dominant during the period from July to November 1983 in the area studied. The mode of the occurrence and vertical distribution of Paraphysomonas apparently coresponds to those of the bacteria and orgarnic debris-like matter in the seawater. The main components of the plankton population in the area studied, under ice-covered conditions, are Paraphysomonas, Choanoflagellates and bacteria. This work clarified that Paraphysomonas is one o f the most important bacterivores in the microbial loop of the Antarctic marine ecosystem.

• Ocean and Polar Research
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• v.26 no.3
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• pp.523-529
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• 2004

The seismic monitoring at Syowa Station$(69^{\circ}S,\;39^{\circ}E: SYO)$, located on the continental margin of the Eastern Dronning Maud Land, East Antarctica, began in 1959. Phase readings of the earthquakes have been reported since 1967 and have been annually published as part of the Data Report Series of the National Institute of Polar Research since 1968. An observation of a tripartite seismic network was carried out at SYO for a period of three years from 1987 to 1990. Epicenters of local earthquakes were determined for the first time by using the array network for the three-year period. Many different types of earthquakes, such as the mainshock-aftershock type, twin earthquake, earthquake swarms, etc., were detected during the period. After this, local events around SYO have been detected empirically from their waveforms recorded on seismograms. The seismic activity for the period of 1987-1990 was higher than that of the following decade. Earthquake epicenters, occurring during that period, were highly localized along the coast and in the central part of the $L\"{u}tzow-Holm$ Bay (LHB). Nine local earthquakes, recorded during the period of 1990-1996, showed many different types of events. The seismicity for the period of 1990-1996 was very low and the magnitudes ranged from 0.1 to 1.4. The locations of some events were determined by using the single station method for SYO, i.e., using the particle motions of the initial phase and S-P time. Two local events were detected in 1998 and one event in 2001. It would be estimated that the stress concentration was related to the glacial rebound around the LHB. Afterwards, we will be able to eventually examine the relationship between the seismicity around Antarctica and deglacial phenomena such as crustal uplift, and sea level change within the earth environmental system.