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Canada ratified the United Nations Convention on the Law of the Sea (UNCLOS) in 2003. With that ratification is an obligation to submit data and information to the U.N. pertaining to the limits of the country's extended continental shelf (ECS); the portion of the juridical continental shelf that extends beyond 200 nautical miles. A team of Canadian scientists, managers, and legal experts that included representation from three Federal Departments (Natural Resources Canada, Fisheries and Oceans Canada, and Global Affairs Canada) with additional support from other departments, spent 13 years compiling and acquiring data to provide the scientific evidence to support delineation of Canada's seaward most maritime limit. The submission has the potential to provide Canada with 2.4 million km (2) of additional submarine landmass in the Atlantic and the Arctic oceans over which Canada exercises sovereign rights for the purpose of exploring and exploiting its natural resources. Specific information such as the tectonic framework of the continental margin, the geomorphology of the margin and in particular the continental slope, the geologic nature of adjoined ridges, rises, and plateaux, and sediment thickness within adjacent basins are examples of fundamental pieces of geoscientific information needed to substantiate Canada's outermost maritime limits. This paper highlights a number of segments of Canada's continental margins to showcase this scientific evidence and how it is applied in the UNCLOS context. In doing so, the paper demonstrates the geologic complexity of Canada's margins as illustrated in scientific publications that have resulted from these new data collections, while at the same time presenting new scientific evidence and interpretations. This collection of data and information provides a wealth of new knowledge in Canada's offshore regions. The massive data compilation in the Atlantic led to conception of continental margins, in a source-to-sink scenario, as having an equilibrium base level or graded form, comparable to river systems. Departures from this shape relate to the interplay of sedimentary processes and in particular to those processes that do not fit the source-to-sink paradigm. For example, a significant part of the Atlantic margin is shown to be heavily influenced by along-slope geostrophic currents that generated massive contourite drift deposits. These deposits reflect lateral transport of sediment that had a significant impact on the morphology of the margin. The role of mass transport processes in shaping continental margins is also highlighted, and in particular the collapses of entire segments of the margin were observed. The prominent role mass failure processes play in delivering sediment to the adjacent abyssal plain is also critical in the ECS context. These observations challenge the entrenched notion of a continental margin comprising a shelf, slope, and rise and in particular the concept of the "continental rise". Prior to 2006, regions of the Arctic Ocean seaward of the Canadian landmass had fewer than 5000 km of seismic reflection data. The massive efforts of Arctic coastal States to map their margins for ECS purposes have led to a leap in technological advances to acquire data in ice-covered seas and have led to a wealth of new geoscientific knowledge. Perhaps foremost amongst this knowledge is demonstration that Canada Basin is indeed a fully developed ocean basin, albeit significantly infilled with sediment. Based on this knowledge and identification of related structures, new realistic tectonic scenarios for opening of the Amerasia Basin are proposed that include a significant component of transform or strike-slip motions. With seismic velocity and rock sample information, the continental nature of Alpha and Mendeleev ridges has been substantiated. Even bathymetric data were lacking in the Arctic and new editions of seafloor maps now support grids of 500 m spacing; although some regions remain sparse. Once thought to be relatively stagnant, sedimentary processes such as found in many ocean basins were discovered in the Arctic Ocean. Evidence of geostrophic currents, sediment mass failures, and deep-sea turbidity current channels were found to be ubiquitous, even in the deepest parts of the Arctic's basins. Key words: United Nations Convention on the Law of the Sea, extended continental shelf, continental margin, Atlantic Ocean, Arctic Ocean, 1. Introduction It is a common adage that we know more about the Moon and Mars than we do about the oceans on Earth. As an example, according to the [...]

Bathymetry (seafloor depth), is a critical parameter providing the geospatial context for a multitude of marine scientific studies. Since 1997, the International Bathymetric Chart of the Arctic Ocean (IBCAO) has been the authoritative source of bathymetry for the Arctic Ocean. IBCAO has merged its efforts with the Nippon Foundation-GEBCO-Seabed 2030 Project, with the goal of mapping all of the oceans by 2030. Here we present the latest version (IBCAO Ver. 4.0), with more than twice the resolution (200 × 200 m versus 500 × 500 m) and with individual depth soundings constraining three times more area of the Arctic Ocean (∼19.8% versus 6.7%), than the previous IBCAO Ver. 3.0 released in 2012. Modern multibeam bathymetry comprises ∼14.3% in Ver. 4.0 compared to ∼5.4% in Ver. 3.0. Thus, the new IBCAO Ver. 4.0 has substantially more seafloor morphological information that offers new insights into a range of submarine features and processes; for example, the improved portrayal of Greenland fjords better serves predictive modelling of the fate of the Greenland Ice Sheet.

We present a synthesis of the rates of gross, new, net and primary production along with particulate organic carbon (POC) flux at 100 m from four cruises along 170°W in the Southern Ocean. Concurrent satellite pigment data, a primary productivity model, and a nitrate mass balance are used to extrapolate daily production estimates in space and time to seasonal and annual rates. From this analysis, we gain a better understanding of the timing, magnitude and impact of the phytoplankton blooms in this region. One of the dominant features with respect to plankton biomass is the association of high chlorophyll levels with the retreat of the sea ice which begins in October just south of the Polar Front. Our primary production model and satellite pigment data suggest higher production and flux levels characterize the marginal ice zone than previous estimates. Elevated rates of new production in ice impacted regions are restricted to relatively short periods following retreat of the ice edge. Export is found to lag the onset of production by up to 1 month. The ratio of POC flux at 100 m to primary production when averaged over the entire season is quite high, increasing from 15% to 25% in the Subantarctic zones to 35-40% near the Polar Front and as high as 50-65% in the southernmost stations, just north of the Ross Sea gyre. Comparisons of phytoplankton community structure and Fe stress indicators suggest that blooms at the Polar Front are initially dominated by large centric diatoms, but are replaced by smaller pennate diatom and non-diatom species as Fe levels decrease. Further south, where Fe levels are never as high and large diatoms are not found, we still observe relatively high biomass and elevated production rates and POC fluxes during the short growing season. © 2003 Elsevier Science Ltd. All rights reserved.

A high-resolution chronology obtained upon correlating oxygen isotope data for trapped O2 in the GISP2 and Vostok cores helps determine climate correlations between Greenland and Antarctica during the last glaciation. Interstadials lasting for longer than 2,000 years in Greenland led to the occurrence of interstadials in east Antarctica. Climate correlation between Greenland and Antarctica can be partially attributed to partial deglaciation and changes in ocean circulation.

In vitro measurements of gross and net oxygen production, which were done during the 1992 JGOFS Equatorial Pacific study were scaled to net and gross carbon (C) production. Results were then compared to (super 14)C production and new/export production. Analysis of the compiled data show that (super 14)C production rates are almost the same as net carbon production rates in the upper half of the euphotic zone. It was also observed that C productivities in samples incubated for 24 hours are approximately 45% of gross carbon production rates computed from oxygen production.

Nutrient uptake ratios and the Si:C:N composition ratios of particulate matter were measured within a diatom bloom located between the Antarctic Polar Front and the edge of the receding pack ice in the Pacific sector of the Southern Ocean along 170°W from 2 December 1997 to 3 January 1998. Rates of silicic acid, nitrate, ammonium and urea uptake were measured along with simultaneous estimates of net and gross carbon uptake derived from net oxygen production and 18O gross production rates. Concurrent measures of silica dissolution rates allowed net silicic acid uptake to be estimated. Comparison of integrated rates of gross silicic acid uptake, gross carbon uptake, and total nitrogen (nitrate+ammonium+urea) uptake revealed that gross uptake ratios within the bloom closely matched Redfield proportions. The mole ratio of gross Si uptake to total N uptake averaged 0.96±0.08, indistinguishable from the mean value of 0.90 characteristic of nutrient-replete diatoms in culture. The mean gross Si uptake: gross C mole uptake ratio, 0.20±0.02, was 50% higher than the typical diatom Si:C ratio of 0.13. Gross C:total N uptake mole ratios averaged 5.2±0.4, reasonably close to the Redfield value of 6.6. In contrast, average net uptake ratios were significantly higher than Redfield (C:NO3−=9.1±1.5, Si:C=0.52±0.12, Si:NO3−=3.7±0.4) and exceeded their corresponding gross uptake ratios by 180–380%. On average, net uptake was somewhat enriched in C, and greatly enriched in Si, over gross uptake; ratios of net uptake exceeded corresponding Redfield (C:N) or typical diatom (Si:C, Si:N) ratios by 38% for C:N, by a factor of 4.0 for Si:C and by a factor of 4.1 for Si:N. Thus, there was a transition from the plankton taking up nutrients in nearly Redfield proportions, to particles becoming slightly enriched in C over N and highly enriched in silica relative to organic matter through the combined effects of metabolic losses and food web processes. These results point to the operation of an efficient silicate pump that enriches particles in silica relative to organic matter prior to their export. We hypothesize that low [Fe] accentuated the decoupling between the cycling of silica and organic matter in the bloom. The average [Fe] in the mixed layer (0.13–0.29 nM) falls in a range that has been shown experimentally to dramatically increase Si(OH)4:NO3− uptake ratios by plankton assemblages in our study area. That result, together with the observation that gross uptake ratios of Si(OH)4 to total N were nearly in Redfield proportions, suggests that the main effect of low [Fe] was to increase reliance on regenerated nitrogen sources by inhibiting nitrate uptake. More efficient recycling of particulate nitrogen in surface waters compared to biogenic silica led to the selective depletion of silicic acid over nitrate, creating a positive feedback between [Fe] and the silicate pump, where low [Fe] accelerates the onset of Si limitation and diminishes the export of organic matter relative to silica. [Copyright &y& Elsevier]

Determines gross and net oxygen production and dark community respiration rates measured during austral spring and summer across the Antarctic Polar Front. In vitro oxygen production and respiration rates; Carbon production and respiration rates across the region; Net biological oxygen production estimated from mixed-layer oxygen saturation.

Focuses on a study which examined the relationships among oxygen, carbon and nitrogen production and respiration rate measurements made in the Arabian Sea during the 1995 Northeast and Southwest Monsoons. Information on atmospheric and climatic conditions at the Arabian Sea; Methods; Results of the study.

Deals with a study which investigated the bacterial and phytoplankton dynamics in the Ross Sea, Antarctica over four Austral summers in 1996 to 1997. Materials and methods; Results; Discussion.

Presents information on a study which reported the net and gross production rates for samples from three Joint Global Ocean Flux Study cruises to the Ross Sea, Antarctica during spring-autumn 1996 to 1997. Experimental methods; Results and Discussion; Conclusion.

We present a synthesis of the rates of gross, new, net and primary production along with particulate organic carbon (POC) flux at 100 m from four cruises along 170°W in the Southern Ocean. Concurrent satellite pigment data, a primary productivity model, and a nitrate mass balance are used to extrapolate daily production estimates in space and time to seasonal and annual rates. From this analysis, we gain a better understanding of the timing, magnitude and impact of the phytoplankton blooms in this region. One of the dominant features with respect to plankton biomass is the association of high chlorophyll levels with the retreat of the sea ice which begins in October just south of the Polar Front. Our primary production model and satellite pigment data suggest higher production and flux levels characterize the marginal ice zone than previous estimates. Elevated rates of new production in ice impacted regions are restricted to relatively short periods following retreat of the ice edge. Export is found to lag the onset of production by up to 1 month. The ratio of POC flux at 100 m to primary production when averaged over the entire season is quite high, increasing from 15% to 25% in the Subantarctic zones to 35–40% near the Polar Front and as high as 50–65% in the southernmost stations, just north of the Ross Sea gyre. Comparisons of phytoplankton community structure and Fe stress indicators suggest that blooms at the Polar Front are initially dominated by large centric diatoms, but are replaced by smaller pennate diatom and non-diatom species as Fe levels decrease. Further south, where Fe levels are never as high and large diatoms are not found, we still observe relatively high biomass and elevated production rates and POC fluxes during the short growing season. [Copyright &y& Elsevier]

Provides information on a study that reported on the estimated annual carbon (C) and silicon (Si) fluxes, use them to construct vertical budgets for particulate organic carbon and biogenic silica and evaluates the quantitative relationships between the C and Si cycles throughout the water column and upper sediments. Methodology of the study; Results and discussion on the study.