(Table 1) Characteristics of Klebsormidium (filamentous green algae) strains from the Antarctic, Arctic and Slovakia

The freezing and desiccation tolerance of 12 Klebsormidium strains, isolated from various habitats (aero-terrestrial, terrestrial, and hydro-terrestrial) from distinct geographical regions (Antarctic - South Shetlands, King George Island, Arctic - Ellesmere Island, Svalbard, Central Europe - Slovakia) were studied. Each strain was exposed to several freezing (-4°C, -40°C, -196°C) and desiccation (+4°C and +20°C) regimes, simulating both natural and semi-natural freeze-thaw and desiccation cycles. The level of resistance (or the survival capacity) was evaluated by chlorophyll a content, viability, and chlorophyll fluorescence evaluations. No statistical differences (Kruskal-Wallis tests) between strains originating from different regions were observed. All strains tested were highly resistant to both freezing and desiccation injuries. Freezing down to -196°C was the most harmful regime for all studied strains. Freezing at -4°C did not influence the survival of studied strains. Further, freezing down to -40°C (at a speed of 4°C/min) was not fatal for most of the strains. RDA analysis showed that certain Antarctic and Arctic strains did not survive desiccation at +4°C; however, freezing at -40°C, as well as desiccation at +20 °C was not fatal to them. On the other hand, other strains from the Antarctic, the Arctic, and Central Europe (Slovakia) survived desiccation at temperatures of +4°C, and freezing down to -40°C. It appears that species of Klebsormidium which occupy an environment where both seasonal and diurnal variations of water availability prevail, are well adapted to freezing and desiccation injuries. Freezing and desiccation tolerance is not species-specific nor is the resilience only found in polar strains as it is also a feature of temperate strains.

Deep drilling of glaciers: Russian projects in the Arctic (1975-1995)

The data collection "Deep Drilling of Glaciers: Soviet-Russian projects in Arctic, 1975-1995" was collected by the following basic considerations: - compilation of deep (>100 m) drilling projects on Arctic glaciers, using data of (a) publications; (b) archives of IGRAN; (c) personal communication of project participants; - documentation of parameters, references. Accuracy of data and techniques applied to determine different parameters are not evaluated. The accuracy of some geochemical parameters (up to 1984 and heavy metalls) is uncertain. Most reconstructions of ice core age and of annual layer thickness are discussed; - digitizing of published diagrams (in case, when original numerical data were lost) and subsequent data conversion to equal range series and adjustment to the common units. Therefore, the equal-range series were calculated from original data or converted from digitized chart values as indicated in the metadata. For the methodological purpose, the equal-range series obtained from original and reconstructed data were compared repeatedly; the systematic difference was less then 5-7%. Special attention should be given to the fact, that the data for individual ice core parameters varies, because some parameters were originally measured or registered. Parameters were converted in equal-range series using 2 m steps; - two or more parameter values were determined, then the mean-weighted (i.e. accounting the sample length) value is assigned to the entire interval; - one parameter value was determined, measured or registered independently from the parameter values in depth intervals which over- and underlie it, then the value is assigned to the entire interval; - one parameter value was determined, measured or registered for two adjoining depth intervals, then the specific value is assigned to the depth interval, which represents >75% of sample length ; if each of adjoining depth intervals represents <75% of sample length, then the correspondent parameter value is assigned to both intervals of depth. This collection of ice core data (version 2000) was made available through the EU funded QUEEN project by S.M. Arkhipov, Moscow.

Isotope geochemistry of Ninetyeast Ridge basalts

The Ninetyeast Ridge lavas have Sr and Nd isotopic ratios intermediate between those of Indian Ocean MORBs and those of the very enriched Kerguelen hot spot. In an Nd-Sr isotope diagram, they also plot close to the fields of St. Paul Island lavas and of the early magmatism on Kerguelen Archipelago. The Ninetyeast Ridge lavas were generated by mixing among at least three components: a depleted, MORB-type component, such as the one erupted today on the Southeast Indian Ridge; a very enriched, high- Sr/ Sr, low-epsilon-Nd, OIB-type component (the Kerguelen hot spot); and an OIB-type component comparable to that sampled from the St. Paul (and Amsterdam) lavas. The Ninetyeast Ridge lavas show a typical Dupal anomaly signature and Pb, Sr, and Nd isotopic systematics indicate that the Kerguelen hot spot was involved in the ridge's formation as the Indian plate moved northward. The different sites cored during ODP Leg 121 show a trend in their isotopic compositions, from less radiogenic Pb/ Pb ratios and intermediate 87Sr/86Sr and 143Nd/**Nd ratios in the oldest lavas (Site 758) toward more radiogenic 206Pb/204Pb, higher epsilon-Nd, and lower 87Sr/86Sr values in the youngest lavas (Site 756). The lavas from Site 757 have 206Pb/204Pb ratios intermediate between those of the lavas from Sites 756 and 758 and higher 87Sr/86Sr and lower epsilon-Nd values. The relative proportions of the hot spot(s) and MORB component have evolved with time, reflecting differences of tectonic setting: the relative proportion of the Kerguelen hot spot component appears lower in the younger Site 756 lavas than in the older lavas from Sites 757 and 758. Site 756 coincides with the beginning of rifting at the Southeast Indian Ridge, about 43 Ma ago. The formation of the early Kerguelen Archipelago lavas may have drained most of the plume-derived material toward the Antarctic plate. Alternatively, the proximity of the spreading-ridge axis may account for the isotopic similarity of the Site 756 lavas to young lavas erupted on the Southeast Indian Ridge, from 33? to 37?S. The older lavas of Ninetyeast Ridge may have formed when the hot spot and ridge axis did not exactly coincide. The involvement of the third component, a St. Paul hot spot, in the genesis of the Ninetyeast Ridge lavas, especially for the Site 756 lavas, is clearly indicated by Sr, Pb, and Nd isotope systematics and also by trace element ratios. These data, together with those from the Kerguelen Plateau, indicate that the Kerguelen hot spot has been active more or less continuously in the South Indian Ocean for at least 115 Ma. This could indicate that the plume, and by inference the Dupal anomaly, is deep seated in origin.

Investigation of knot nests on Ellesmere Island

Knots arrive on Ellesmere Island in late May or early June. At Hazen Camp small flocks were present on 3 June 1966, but the main influx occurred 5 June when many flocks were seen ranging in size from 6 to 60 individuals. The sexes appeared to arrive together, but the manner of pair-formation was not determined. By 7 June pairs were distributed over the tundra with large feeding flocks forming at snowfree wet marshy areas. Most nests were on Dryas-hummocked slopes and tundra, either dry or moist, with some on clay plains and summits in a mixed Dryas and Salix vegetation. A census area of 240 ha supported at least 3 breeding pairs, and possibly 5; the total number of pairs breeding in the Hazen Camp study area was estimated to be about 25 (1.09 pairs/km**2). Egg-laying (4 nests) extended from 15 to 28 June, with 3 of the 4 sets completed between 20 and 23 June. Both sexes incubated, one of the pair more regularly than the other. The song-flight display of the male was performed most frequently during egglaying and incubation. The incubation period of the last egg in one clutch was established as being between 21.5 and 22.4 days. Four nests hatched between 12 and 20 July, and the hatching period of the entire clutch was less than 24 hours. Four of 7 nests (57 %) survived and egg survival (53 %) was low. Families left the nesting area so on after hatching, concentrating at ponds where food was readily available for the young. Both adults attended the young during the pre-fledging period, but the females apparently departed before the young had hedged. Males left once the young could fly and the adult fall migration was complete by early August. Most 01 the young departed belore mid-August. Fall migration is complete by late August or early September. The breeding season appears to be timed to peak load supply for the young. Adult Chironomidae emergence was highest between 3 and 17 July, the period during which most successful nests hatched. The increasing scarcity of adult insects for the young after mid-July was offset by family movements over the tundra and the early departure of half the adult population. Food also seemed to influence the distribution of breeding pairs aver the tundra, restricting them to the general vicinity of marshes, streams, and ponds where food is most available when the young hatch. Territoriality in the Knot appears to be closely associated with the protection of the nest against predators and has at least a local effect in regulating the number of breeding pairs. Plant material was important in the diet of adult Knots throughout the summer and the primary food from the time of arrival until mid-June. After mid-June the percentage of animal matter increased as dipterous insects became available (especially adult Chironomidae), but plant materials continued to constitute a large part of the diet, usually more than 50 %. The food of the young before fledging consisted principally of adult chironomids.

First record of Antipathella subpinnata in the Azores

The first record of Antipathella subpinnata ( Ellis and Solander, 1786) for the Azores archipelago is presented based on bottom longline by-catch analysis and ROV seafloor surveys, extending the species western-most boundary of distribution in the NE Atlantic. The species was determined using classic taxonomy and molecular analysis targeting nuclear DNA. Although maximum spine height on Azorean colonies branchlets is slightly smaller than that reported from Mediterranean colonies (0.12 vs 0.16 mm), the analysis of partial 18S rDNA, complete ITS1, 5.8S, ITS2 and partial 28S rDNA suggests that the Azorean and Mediterranean specimens belong to the same species. Video surveys of an A. subpinnata garden detected near Pico Island are used to provide the first in situ description of the species habitat in the region and the first detailed description of a black coral garden in the NE Atlantic. With A. subpinnata being the only coral found between 150 and 196 m depths, this is the deepest black coral garden recorded in the NE Atlantic and the first one to be monospecific. The species exhibited a maximum density of 2.64 colonies/m**2 and occurred across a surface area estimated at 67,333 m**2, yielding a local population estimate of 50,500 colonies.

Baseline surface radiation during the International Polar Year 2007-2009

Downwelling and upwelling shortwave and longwave radiation components from six active polar sites, taking part of the Baseline Surface Radiation Network (BSRN), were selected for the period of the last International Polar Year (March 2007 to March 2009), and included in the BSRN-IPY dataset, along with metadata and supplementary data for some of the stations. Two sites, located at Svalbard archipelago (Ny Ålesund) and Alaska (Barrow), represent Arctic sea-level conditions. Four Antarctic stations represent both sea-level (Dronning Maud Land and Cosmonaut Sea) and high-elevation conditions (South Pole and East Antarctic Plateau). The BSRN-IPY dataset content and quality are discussed.

Geochemistry of picrite basalts from the Liohi Volcano

Research of the ocean floor using the Mir submersibles carried out south of the Hawaiian Archipelago allowed to recover flows of recent picrite basalts. Lava vents are confined to a field of development of open fractures of a gjar type. Basalts represent initial lava flows in the structure of the Hawaiian volcanic archipelago. Considering contents of alkali and rare-earth elements in them, the picrite basalts of the bottom could be assigned to a series of island tholeiites. They are products of high level melting of asthenospheric matter at depth about 75-80 km as a result of decompression near a deep fracture that occurred in the lithosphere and asthenosphere. Similar picrite basalts were found in the base of the youngest volcano of the Hawaiian chain the Loihi Volcano. With respect to contents of alkali metals, these rocks are assigned to the subalkaline series of rocks formed during melting of garnet lherzolites. This could probably be explained by supply of melts from deeper levels of the asthenosphere after partial packing of an initial magma effluent fracture.

Flower and seed biomass, and germination rate of arctic tundra plants in response to long term experimental warming

We provide new information on changes in tundra plant sexual reproduction in response to long-term (12 years) experimental warming in the High Arctic. Open-top chambers (OTCs) were used to increase growing season temperatures by 1-2 °C across a range of vascular plant communities. The warming enhanced reproductive effort and success in most species; shrubs and graminoids appeared to be more responsive than forbs. We found that the measured effects of warming on sexual reproduction were more consistently positive and to a greater degree in polar oasis compared with polar semidesert vascular plant communities. Our findings support predictions that long-term warming in the High Arctic will likely enhance sexual reproduction in tundra plants, which could lead to an increase in plant cover. Greater abundance of vegetation has implications for primary consumers - via increased forage availability, and the global carbon budget - as a function of changes in permafrost and vegetation acting as a carbon sink. Enhanced sexual reproduction in Arctic vascular plants may lead to increased genetic variability of offspring, and consequently improved chances of survival in a changing environment. Our findings also indicate that with future warming, polar oases may play an important role as a seed source to the surrounding polar desert landscape.

Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes

The Neogene and Quaternary sedimentary record of Leg 71 and previously drilled sequences from the Southern Ocean reveal evidence of a major late Miocene change of oceanic and glacial conditions in the southern high latitudes during paleomagnetic Chron 9. The characteristics of late Miocene sedimentation and in particular the study of erosional patterns and ice-rafted debris suggest the following conclusions. 1) In the late Miocene, the Polar Front first migrated to the northern latitudes of the Southern Ocean and surface water temperatures became similar to those of today. 2) Extensive ice shelves or ice tongues were not present along the Antarctic margin until late Chron 9 (about 9.0 Ma). 3) Before Chron 9, West Antarctica was occupied by an archipelago and the West Antarctic Sea. 4) Extensive ice shelves formed in the West Antarctic region, eventually coalescing and thickening to form the grounded West Antarctic ice sheet by Chron 9. 5) The newly formed West Antarctic ice sheet was probably unstable and frequently became an ungrounded ice shelf, thus accounting for the scarcity of late Miocene ice-rafted debris. 6) Extensive erosion or nondeposition of sediment was probably the result of increased Antarctic Bottom Water (AABW) formation in the West Antarctic region during the initial formation of extensive West Antarctic ice shelves and during periods when the West Antarctic ice sheet was ungrounded. 7) In the Southwest Atlantic, AABW velocity waned during the latest Miocene. During the late Gilbert Chron a major and permanent change occurred in the pattern of ice-rafting to the South Atlantic, and after 4.35 Ma the increased IRD accumulation rate and frequency of major episodes of IRD accumulation suggest increased stability of the West Antarctic ice sheet. In addition, radiolarian faunas of Hole 514 record at least eight migrations of the Polar Front to the north of the site during the past 4.07 m.y. An apparent increase in the frequency of Polar Front migrations occurred about 2.7-2.6 Ma, possibly in response to oceanic change induced by fluctuations in glacial conditions of the Northern Hemisphere.

Mineralogy and pyrolysis at DSDP Hole 62-463

A 15-meter sequence of early Aptian organic-matter-rich sediments, cored at Deep Sea Drilling Project Site 463 (western Mid-Pacific Mountains) has been submitted for detailed mineralogical studies (XRD, SEM) and organiccarbon characterization. Although intense diagenesis has obscured the sedimentary record of depositional conditions, the history has been tentatively reconstructed. Through sustained volcanic activity and alteration processes on the archipelago, large amounts of silica were released into the sea water, resulting in a "bloom" of radiolarians. Hard parts settled in large amounts, yielding a hypersiliceous sediment; amorphous silica was diagenetically transformed into chalcedony, opal-CT and clinoptilolite through dissolution and recrystallization. Oxidization of part of the radiolarian soft parts (1) depleted the sea water in dissolved oxygen, allowing the burial of organic matter, and (2) generated carbon dioxide which led to dissolution of most of the calcareous tests. Moderate depositional depth and a high sedimentation rate are though to have prevailed during this episode. An immature stage of evolution is assigned to the studied organic matter, which is of two origins: autochthonous marine material, and allochthonous humic compounds and plant debris. Rhythmic sedimentation characterizes the distribution of the organic matter; each sequence shows (1) an upward progressive increase in organic-carbon content, and (2) an upward enrichment in marine organic matter.

Chemical and isotopic compositions of lavas from the Broken Ridge and Southern Kerguelen Plateau

Lavas from several major bathymetric highs in the eastern Indian Ocean that are likely to have formed as Early to Middle Cretaceous manifestations of the Kerguelen hotspot are predominantly tholeiitic; so too are glass shards from Eocene to Paleocene volcanic ash layers on Broken Ridge, which are believed to have come from eruptions on the Ninetyeast Ridge. The early dominance of tholeiitic compositions contrasts with the more recent intraplate, alkalic volcanism of the Kerguelen Archipelago. Isotopic and incompatible-element ratios of the plateau lavas are distinct from those of Indian mid-ocean ridge basalts; their Nd, Sr, 207Pb/204Pb and 2078b/204Pb isotopic ratios overlap with but cover a much wider range than measured for more recent oceanic products of the Kerguelen hotspot (including the Ninetyeast Ridge) or, indeed, oceanic lavas from any other hotspot in the world. Samples from the Naturaliste Plateau and ODP Site 738 on the southern tip of the Kerguelen Plateau are particularly noteworthy, with e-Nd(T) = -13 to -7, (87Sr/86Sr)T=0.7090 to 0.7130 and high 207Pb/204Pb relative to 206Pb/204Pb. In addition, the low-e-Nd(T) Naturaliste Plateau samples are elevated in SiO2 (>54 wt%). In contrast to "DUPAL" oceanic islands such as the Kerguelen Archipelago, Pitcairn and Tristan da Cunha, the plateau lavas with extreme isotopic characteristics also have relative depletions in Nb and Ta (e.g., Th/Ta, La Nb > primitive mantle values); the lowest e-Nd(T) and highest Th/Ta and La Nb values occur at sites located closest to rifted continental margins. Accepting a Kerguelen plume origin for the plateau lavas, these characteristics probably reflect the shallow-level incorporation of continental lithosphere in either the head of the early Kerguelen plume or in plume-derived magmas, and suggest that the influence of such material diminished after the period of plateau construction. Contamination of asthenosphere with the type of material affecting Naturaliste Plateau and Site 738 magmatism appears unlikely to be the cause of low-206Pb/204Pb Indian mid-ocean ridge basalts. Finally, because isotopic data for the plateaus do not cluster or form converging arrays in isotope-ratio plots, they provide no evidence for either a quickly evolving, positive ?Nd, relatively high-206Pb/204Pb plume composition, or a plume source dominated by mantle with e-Nd of -3 to ~0.

List of plant species found on Victoria Island

While engaged in geoecological field work on Victoria Island, 277 new plants could be recorded for the vicinities of Holman, Cambridge Bay, Wellington Bay, Mt. Pelly, Richardson Islands, Hadley Bay, and Minto lnlet; 8 of them were new for Victoria Island, 6 for the western Canadian arctic archipelago.