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Petroleum resource assessment of the East Greenland Basin
Get PDFThe onshore and offshore parts of the East Greenland Basin are important areas for petroleum exploration at the North Pole. Although assessments by the US Geological Survey suggest a substantial petroleum potential in this area, their estimates carry a high risk because of uncertainties in the exploration data. This paper compares the reservoir-forming conditions based on data from the East Greenland Basin and the North Sea Basin. The petroleum resources of the East Greenland Basin were assessed by geochemical and analogy methods. The East Greenland Basin was a rift basin in the late Paleozoic–Mesozoic. Its basement is metamorphic rock formed by the Caledonian Orogeny in the Archean to Late Ordovician. In the basin, Devonian–Paleogene strata were deposited on the basement. Lacustrine source rock formed in the late Paleozoic and marine source rocks in the Late Jurassic. Shallow-marine sandstone reservoirs formed in the Middle Jurassic and deep-marine turbiditic sandstone reservoirs formed in the Cretaceous. The trap types are structure traps, horst and fault-block traps, salt structure traps, and stratigraphic traps. The East Greenland Basin possesses superior reservoir-forming conditions, favorable petroleum potential and preferable exploration prospects. Because of the lack of exploration data, further evaluation of the favorable types of traps, essential amount of source rock, petroleum-generation conditions and appropriate burial histories in the East Greenland Basin are required
Impacts of global climate change on birds and marine mammals in Antarctica
Get PDFBirds and marine mammals in Antarctica, especially penguins and seals, are top consumers and critical elements of the Southern Ocean ecosystem. As a region undergoing rapid global change, new challenges will be posed to the survival of these vertebrates species. Global climate change causes many alterations, such as ocean temperature rise, altered sea ice distribution, and abnormal climate events along with effects of intensive human activities, such as fishing. These not only directly affect the spatiotemporal distributions and population dynamics of Antarctic birds and marine mammals but also indirectly influence them via modification of their food resources. At present, the impact of climate change on birds and marine mammals in the Antarctica is focusing on a number of species in a few areas. Response mechanisms of these species are still very limited and therefore require further long-term and continuous monitoring and research
Review of CHINARE chemical oceanographic research in the Southern Ocean during 1984–2016
Get PDFBetween 1984 and 2016, China executed 33 Antarctic cruises with the icebreaker R/V Xuelong, which have provided opportunities for Chinese scientists to investigate the status and changes of the Southern Ocean. Research in chemical oceanography constitutes one of the primary missions of the Chinese National Antarctic Research Expedition (CHINARE). This paper reviews nearly 30 years of Chinese Antarctic expeditions, focusing on the major progress achieved in chemical oceanographic research. Specifically, the sea-surface distributions and air–sea fluxes of CO2 and N2O are considered, and the transport, flux, and budget of organic matter are investigated based on isotopes in the Southern Ocean, especially in Prydz Bay. In addition, the nutrient distribution and deep-water particle export in Prydz Bay and the study of aerosol heavy metal characteristics are considered. Finally, the prospects for future Chinese Antarctic chemical oceanographic research are outlined
Mass change of the Antarctic ice sheet inferred from ICESat and CryoSat-2
Get PDFThis study examined the mass change of the Antarctic ice sheet (AIS) based on ICESat and CryoSat-2 observations. We estimated the AIS exhibited mass losses of −101±15 Gt·a−1 during the ICESat period (Sept–Nov 2003 to Sept–Oct 2009) and −186±55 Gt·a−1 during the CryoSat-2 period (Jan 2011 to Dec 2015). Mass losses occurred mainly in the sectors of the Amundsen and Bellingshausen seas. Benefitting from the 30-d subcycle of CryoSat-2, we obtained monthly estimates of mass evolution. Considerable annual variations were observed in the mass evolution sequences and the climatological monthly mass evolution. Seasonal mass evolutions in the sectors of the Bellingshausen and Amundsen seas were found most representative of the annual variation. The geographical distribution characteristics of interannual AIS mass evolution were revealed by the annual average mass evolution sequences. During Jan 2011 to Dec 2015, the ice sheets in the sectors of the Bellingshausen and Amundsen seas, and the Totten Glacier, experienced increasingly rapid areal mass loss. An area of mass gain with a moderate rate of increase was found between Dronning Maud Land and Enderby Land. Rapid mass accumulation has occurred in a limited area of the Kamb Ice Stream
Nucleotide differences in the mbf1 gene of the lichenized fungus Umbilicaria decussata collected in polar and non-polar regions
Get PDFMultiprotein bridging factor 1 (MBF1) is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbf1 gene in the lichen-forming fungus Umbilicaria decussata collected from polar (i.e., Antarctica and the Arctic) and non-polar (i.e., Armenia) regions. The 552-bp Udmbf1 genes isolated from eight samples contained numerous sequence variations, including single nucleotide polymorphisms as well as insertions and deletions. The frequency of nucleotide changes was higher in the intron than in the coding sequence. The nucleotide polymorphism levels (π=0.01792, θ=0.01792) and haplotype diversity (Hd=1) in the Udmbf1 gene from Antarctic samples were relatively high. Additionally, of the 19 detected nucleotide sequence variation sites, 15 were observed only in Antarctic samples. The resulting amino acid changes occurred in the N-terminal, whose function remains unknown. Although these DNA polymorphisms and amino acid changes have been verified in Antarctic samples of U. decussata, there is still little evidence indicating that different environmental conditions affected the functional evolution of Udmbf1. Additional studies involving more U. decussata samples from representative ecotypes will be necessary to uncover the relationships among DNA polymorphisms, functional gene evolution, and lichen habitats
Overview of China’s Antarctic research progress 1984–2016
Get PDFIt is more than 30 years since the first Chinese National Antarctic Research Expedition (CHINARE) landed in Antarctica in 1984, representing China’s initiation in polar research. This review briefly summarizes the Chinese Antarctic scientific research and output accomplished over the past 30 years. The developments and progress in Antarctic research and the enhancement of international scientific cooperation achieved through the implementation of the CHINARE program have been remarkable. Since the 1980s, four permanent Chinese Antarctic research stations have been established successively and 33 CHINAREs have been completed. The research results have been derived from a series of spatiotemporal observations in association with various projects and multidisciplinary studies in the fields of oceanography, glaciology, geology, geophysics, geochemistry, atmospheric science, upper atmospheric physics, Antarctic astronomy, biology and ecology, human medicine, polar environment observation, and polar engineering
Advances in Chinese and international biogeochemistry research in the western Arctic Ocean: a review
Get PDFOver the past decades, the Arctic Ocean has experienced rapid warming under climate change, which has dramatically altered its physical and biogeochemical properties. Reduction in the sea-ice cover is one of the most important driving forces of biogeochemical changes in the Arctic Ocean. Between 1999 and 2016, seven Chinese National Arctic Research Expeditions have taken place in the Bering and Chukchi seas, allowing assessment of the biogeochemical response of the western Arctic Ocean to global warming. Herein, we summarize advances in Chinese and international marine biogeochemistry research in the western Arctic Ocean, reviewing results from the Chinese expeditions and highlighting future trends of biogeochemistry in the Pacific Arctic region. The findings reported in this paper contribute towards a better understanding of water masses, greenhouse gases, nutrients, ocean acidification, and organic carbon export and burial processes in this region
Summertime CO2 fluxes from tundra of Ny-Ålesund in the High Arctic
Get PDFThe Arctic ecosystem, especially High Arctic tundra, plays a unique role in the global carbon cycle because of amplified warming in the region. However, relatively little research has been conducted in High Arctic tundra compared with other global ecosystems. In the present work, summertime net ecosystem exchange (NEE), ecosystem respiration (ER), and photosynthesis were investigated at six tundra sites (DM1–DM6) on Ny-Ålesund in the High Arctic. NEE at the tundra sites varied between a weak sink and strong source (−3.3 to 19.0 mg CO2·m−2·h−1). ER and gross photosynthesis were 42.8 to 92.9 mg CO2·m−2·h−1 and 54.7 to 108.7 mg CO2·m−2·h−1, respectively. The NEE variations showed a significant correlation with photosynthesis rates, whereas no significant correlation was found with ecosystem respiration, indicating that NEE variations across the region were controlled by differences in net uptake of CO2 owing to photosynthesis, rather than by variations in ER. A Q10 value of 1.80 indicated weak temperature sensitivity of tundra ER and its response to future global warming. NEE and gross photosynthesis also showed relatively strong correlations with C/N ratio. The tundra ER, NEE, and gross photosynthesis showed variations over slightly waterlogged wetland tundra, mesic and dry tundra. Overall, soil temperature, nutrients and moisture can be key effects on CO2 fluxes, ecosystem respiration, and NEE in the High Arctic
Progress of Chinese zooplankton ecology research in Prydz Bay, Antarctica
Get PDFZooplankton are considered an important trophic link between primary producers and higher trophic level species in the Southern Ocean ecosystem. Since 1989, when the Chinese Antarctic Zhongshan Station was built, zooplankton have regularly been sampled and investigated in Prydz Bay through oceanographic surveys of each Chinese National Antarctic Research Expedition. This review summarizes the main results from zooplankton ecology studies conducted in Prydz Bay by Chinese researchers. Major topics covered in this review are: (1) a description of the biology and ecology of Antarctic krill (Euphausia superba), the key zooplankton species of the Southern Ocean ecosystem; (2) zooplankton community structure, including the horizontal distribution in the epipelagic region and vertical distribution between 0−1500 m; (3) feeding ecology of dominant species such as Antarctic krill, salps and copepods; (4) a short introduction to the molecular research; and (5) prospects for future research