Satellite imagery, synoptic-scale analyses and automatic weather station data were used to study a subsynoptic-scale cyclone that developed over the Ross Sea and Ross Ice Shelf areas of Antarctica. A pre-existing subsynoptic-scale midtropospheric cyclone descended from southern Victoria Land into the semi-permanent baroclinic environment over the south-western corner of the Ross Sea. The subsynoptic-scale cyclone then developed into a frontal system travelling south-eastward over the Ross Ice Shelf and decayed five days later over Marie Byrd Land. It is concluded that stretching of the subsynoptic-scale low, while descending over 2000 m from the high plateau down to sea level, increased its cyclonic vorticity via conservation of potential vorticity. This, along with a cold katabatic outbreak into the northern part of the circulation, provided the mechanisms for its initial development. Subsequently, cold boundary-layer air over the Ross Ice Shelf spiralled into the subsynoptic-scale cyclone supporting its further development. An upper-level synoptic-scale cyclone that approached the area provided the upper-level support for its ESE displacement and development.

Between 18 January 1988 and 3 June 1989, an automatic weather station recorded 13 different weather parameters every 3 h on a blue-ice area located in Scharffenbergbotnen, a large cirque in central Heimefrontfjella 300 km from the Weddell Sea coast. The first part of the paper reports on annual and monthly data regarding air temperature, air pressure, wind speed and wind direction, and a comparison is also made with corresponding data from the Neumayer and Halley stations. The second part deals mainly with winter (i.e. April–September) conditions in Scharffenbergbotnen. They seem, at least during 1988–89, to have been characterized by a large-scale (30–40 days) and, superimposed on the large-scale, a small-scale (3–4 days) co-variation of air temperature, air pressure and wind speed. The large-scale variation was earlier found to be synoptically forced. This paper shows that synoptic forcing exists also on smaller time scales. Pools of cold, stagnant air are regularly formed in the cirque only to be blown away by katabatic winds triggered by small variations in the synoptic pressure field. When this happens the air temperature increases by more than 20°C and the wind direction swings from east towards south-east. When low pressures dominate in the eastern part of the Weddell Sea, the katabatic winds become very strong, but weaker wind pulses also take place when the synoptic pressure gradient is directed towards the north-east. It therefore seems as if these very regular katabatic events are forced both by synoptic-scale pressure gradients and gradients due to the sloped inversion.

The Devonian, Pivot Coal Measures in southern Victoria Land are non-carbonaceous. The sequence contains bedding parallel, titaniferous ironstones up to 50 cm thick, but no coal or carbonaceous shale, the unit is consequently renamed Pivot Member of the Arena Sandstone. The more Fe-Ti oxide-rich (up to 40 modal %) beds appear black and coal-like with conchoidal fracture and closely spaced cleat-like fractures. The coal-like beds grade laterally and vertically into less altered sedimentary rocks in which fine bedding-parallel concentrations of Fe-Ti oxide pick-out parting surfaces on ripples and other sedimentary structures. Thin section petrography shows that the Fe-Ti oxide is replacive, and outcrop relationships show that the replacement was related to dolerite intrusion 200 million years after the sedimentary host was deposited. Replacement of muscovite, biotite and chlorite by Fe-Ti-oxide occurred at 179 ± 3 Ma, at pressures of 0.3–0.4 kbar and at temperatures as low as 380°C.

At Terra Cotta Mountain, in the Taylor Glacier region of south Victoria Land, a 237 m thick Ferrar Dolerite sill is intruded along the unconformity between basement granitoids and overlying Beacon Supergroup sedimentary rocks. Numerous Ferrar Dolerite dykes intrude the Beacon Supergroup and represent later phases of intrusion. Major and trace element data indicate variation both within and between the separate intrusions. Crystal fractionation accounts for much of the geochemical variation between the intrusive events. However, poor correlations between many trace elements require the additional involvement of open system processes. Chromium is decoupled from highly incompatible elements consistent with behaviour predicted for a periodically replenished, tapped and fractionating magma chamber. Large ion lithophile element-enrichment and depletion in Nb, Sr, P and Ti suggests the addition of a crustal component or an enriched mantle source. The trace element characteristics of the Dolerites from Terra Cotta Mountain are similar to those of other Ferrar Group rocks from the central Transantarctic Mountains and north Victoria Land, as well as with the Tasmanian Dolerites. This supports current ideas that the trace element signature of the Ferrar Group is inherited from a uniformly enriched mantle source region.

Two days of the Antarctic winter (20 and 21 June 1986) were chosen to study some turbulent parameters in this particular boundary-layer. Richardson number, Monin-Obukhov length, eddy transfer coefficients, turbulent kinetic energy, turbulent intensities, friction velocities and sensible heat flux at three levels (5, 17 and 32 m) were considered. The results show how the stability at 17 and 32 m influences the turbulent transfer at 5 m. The shear of wind is the main mechanism to produce mixing in the lower atmosphere at Antarctica, and thermal inversions associated to surface cooling develop with winds < 10 ms−1 at 5 m. The possible influence of internal gravity-waves on the atmospheric boundary-layer during strong stable stratification is studied.

Recently Ricci et al. (1993) proposed a series of general guidelines for the naming of igneous and metamorphic rocks in Antarctica, based on discussions held by the SCAR Working Group on Geology. Ricci et al. (1993) suggested that names for igneous and metamorphic rock units should comprise an appropriate geographic name and simple lithological field term. However, they also suggest that names should not include terms that indicate the form or structure of a rock unit, such as dyke, pluton or batholith.

The Ahlmannryggen-Borgmassivet area of western Dronning Maud Land comprises a relatively undeformed, unmetamorphosed sequence of sedimentary-volcanogenic rocks, the Ritscherflya Supergroup, intruded by a suite of continental tholeiites, the Borgmassivet Intrusions. New Rb-Sr and Sm-Nd whole rock data from the Högfonna Formation at Grunehogna indicate a depositional age of ≈1080 Ma, the first reported direct dating of any member of the Ritscherflya Supergroup. These rocks are interpreted as a molasse-type deposit following the Kibaran orogeny at 1200–1100 Ma, and correlation is made with the Umkondo and Koras groups of southern Africa. The Ritscherflya Supergroup is intruded by the Grunehogna and Kullen sills; the ≈1000 Ma Grunehogna sill intruded unconsolidated sediments, causing partial melting of the sediments. Rb-Sr data from the Kullen sill yield an age of 1429 Ma, clearly inconsistent with these data. Combined Sr and Nd data are compatible with crustal contamination of this sill, producing a Rb-Sr pseudo-isochron with no geological age significance. By comparison with other outcrops of the Borgmassivet Intrusions at Robertskollen and Annandagstoppane, it is concluded that contamination and pseudo-isochrons may be responsible for the wide range in reported ages older than 1000 Ma. Thus the intrusive age of the Borgmassivet Intrusions is concluded to be ≈1000 Ma old. Nd model age data indicate that all rock types were ultimately derived from material separated from a depleted mantle source at ≈2200 Ma.

Infrared satellite images of the coastal area off Adélie Land were examined together with two wind data sets, one from the manned French station, Dumont d'Urville, the other one from an Automatic Weather Station (AWS) during the 1986 austral winter. A correlation between the development of open water areas (polynyas) and the appearance of extremely strong offshore winds can be drawn. The wind direction tended to be more perpendicular to the coastline during these extreme ‘events’, suggesting a katabatic origin of the increase in wind strength. In the study area the influence of the katabatic wind on the sea ice extends 20–100 km offshore. Sea ice motion further off the coast seems to be more dominated by synoptic scale weather systems. Broader scale atmospheric influences may create large polynya structures which influence the development of coastal winds, as the temperature contrast between open water and the cold continent generates its own circulation. Strong wind events can have a weakening effect on the coastal sea ice which can lead to a much more sensitive reaction of the sea ice in response to following anomalous wind events.

Livingston Island contains several, distinctive sedimentary and volcanic sequences, which document the history and evolution of an important part of the South Shetland Islands magmatic arc. The turbiditic, late Palaeozoic–early Mesozoic Miers Bluff Formation (MBF) is divided into the Johnsons Dock and Napier Peak members, which may represent sedimentation in upper and lower mid-fan settings, respectively, prior to pre-late Jurassic polyphase deformation (dominated by open folding). The Moores Peak breccias are formed largely of coarse clasts reworked from the MBF. The breccias may be part of the MBF, a separate unit, or part of the Mount Bowles Formation. The structural position is similar to the terrigenous Lower Jurassic Botany Bay Group in the northern Antarctic Peninsula, but the precise stratigraphical relationships and age are unknown. The (?) Cretaceous Mount Bowles Formation is largely volcanic. Detritus in the volcaniclastic rocks was formed mainly during phreatomagmatic eruptions and redeposited by debris flows (lahars), whereas rare sandstone interbeds are arkosic and reflect a local provenance rooted in the MBF. The Pleistocene–Recent Inott Point Formation is dominated by multiple, basaltic tuff cone relicts in which distinctive vent and flank sequences are recognized. The geographical distribution of the Edinburgh Hill Formation is closely associated with faults, which may have been reactivated as dip-slip structures during Late Cenozoic extension (arc splitting).

Meteorological measurements performed during the austral summer of 1990–91 are used to evaluate the surface energy balance and ablation at an elevation of 100 m asl on the Ecology Glacier, which is an outlet glacier of the main ice cap of King George Island, Antarctica. Strong, gusty westerly winds prevail, although occasional south-easterly winds from the Weddell Sea reach the island. Generally, the climate can be characterized as relatively warm and humid with mean summer temperatures well above 0°C. As a result, considerable ablation (0.75 m water equivalent per month) takes place in the lower parts of the Ecology Glacier. The surface energy balance and ablation are calculated using a model with input from meteorological data. In spite of the large amount of cloud (0.83), solar radiation provided most of the energy used for melting (70.3 W m−2). The longwave radiation, sensible heat flux and latent heat flux contributed −9.5, 27.4 and 7.4 W m−2 respectively. Calculations show that a temperature rise of 1°C increases the ablation by almost 15%. This indicates that the ice caps and glaciers currently present on the subantarctic islands and the Antarctic Peninsula may be quite sensitive to climate change.

Considerable controversy surrounds the biostratigraphic and palaeoclimatic interpretation of Antarctic marine Pliocene sequences (Webb & Harwood 1991). The object of this note is to document and reassess a marine Pliocene diatom assemblage from the Larsemann Hills and to discuss its significance with respect to other Antarctic Neogene deposits.

The synoptic origins of precipitation on the western side of the Antarctic Peninsula over the one year period March 1992 to February 1993 are investigated using meteorological observations, satellite imagery and analyses produced by the UK Meteorological Office. Precipitation at Rothera Station was found to occur at 30% of the synoptic reporting time with 80% of precipitation reports being associated with cyclonic disturbances. Although three quarters of all precipitation reports were for snow, the proximity of Rothera to the zone of maximum cyclonic activity meant that incursions of mild air produced rain in all seasons. During the year 95% of all precipitation was classed as slight. Variability of precipitation on the intraseasonal timescale was highly dependent on the synoptic-scale circulation. The most common synoptic situation for precipitation was a frontal cyclone over the Bellingshausen Sea which accounted for 38% of all precipitation events and 62% of the moderate and heavy precipitation reports. Of the extra-tropical cyclones that gave precipitation 49% were found to have developed south of 60°S. None of the precipitation at Rothera was attributable to mesocyclones. Snow stake measurements from Rothera were a poor indicator of precipitation as a result of blowing snow.