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In the 2010s Canada was a world leader in creating interactive documentaries. By the 2020s many of these celebrated i-docs were rendered inaccessible by obsolete technology. This collection examines the short-lived past and the imagined future of the i-doc and emphasizes its impact on the contemporary film and media landscape in Canada and beyond.

Based on the results of the expedition works during the 55th and 57th cruises of the R/V Akademik Nikolai Strakhov in the area of the King’s Trough mesostructural complex (the eastern flank of the MAR), seismoacoustic profiling data of the upper part of the sedimentary cover are obtained. Reference reflectors, which were correlated with the DSDP 608 and IODP U1312 deep-sea drilling holes, are identified from the seismoacoustic sections. The sections cover the entire Quaternary sediment record (glacial cycles) and a part of the Upper Pliocene sediment record. Sedimentation rates within the different structures of the King’s Trough are calculated as a result of the works. During the past 1.5 Ma, sedimentation rates have been slightly different across the study area from background sedimentation rates, while earlier sedimentation rates were recorded to exceed the background ones by several times. There is a period of sharply increased sedimentation rates (up to 180 m/My) at ca. 1.5 Ma, which may be due to abrupt climate changes and ocean level fluctuations. Prior to the onset of the Mid-Pleistocene Transition ~1.5 Ma ago, a bottom current might have flowed along the bottom of the western part of the King’s Trough, which caused high sedimentation rates in the bottom of the trough. The current stopped after the onset of the transition, which could be due to regional restructuring of the Atlantic Meridional Overturning Circulation. These conclusions are correlated with sedimentation rates and changes in ocean surface temperature based on the data from IODP U1313.

The data analyses and results presented here are based on the field measurement campaign of the Reliable Data Acquisition Platform for Tidal (ReDAPT) project (Energy Technologies Institute (ETI), U.K. 2010–2015). During ReDAPT, a 1 MW commercial prototype tidal turbine was deployed and operated at the Fall of Warness tidal test site within the European Marine Energy Centre (EMEC), Orkney, U.K. Mean flow speeds and Turbulence Intensity (TI) at multiple positions proximal to the machine are considered. Through the implemented wave identification techniques, the dataset can be filtered into conditions where the effects of waves are present or absent. Due to the volume of results, only flow conditions in the absence of waves are reported here. The analysis shows that TI and mean flows are found to vary considerably between flood and ebb tides whilst exhibiting sensitivity to the tidal phase and to the specification of spatial averaging and velocity binning. The principal measurement technique was acoustic Doppler profiling provided by seabed-mounted Diverging-beam Acoustic Doppler Profilers (D-ADP) together with remotely-operable Single-Beam Acoustic Doppler Profilers (SB-ADP) installed at mid-depth on the tidal turbine. This novel configuration allows inter-instrument comparisons, which were conducted. Turbulence intensity averaged over the rotor extents of the ReDAPT turbine for flood tides vary between 16.7% at flow speeds above 0.3 m/s and 11.7% when considering only flow speeds in the turbine operating speed range, which reduces to 10.9% (6.8% relative reduction) following the implementation of noise correction techniques. Equivalent values for ebb tides are 14.7%, 10.1% and 9.3% (7.9% relative reduction). For flood and ebb tides, TI values resulting from noise correction are reduced in absolute terms by 3% and 2% respectively across a wide velocity range and approximately 1% for turbine operating speeds. Through comparison with SB-ADP-derived mid-depth TI values, this correction is shown to be conservative since uncorrected SB-ADP results remain, in relative terms, between 10% and 21% below corrected D-ADP values depending on tidal direction and the range of velocities considered. Results derived from other regions of the water column, those important to floating turbine devices for example, are reported for comparison.

Various forms of shallow gas have been observed in seafloor strata, on the seabed and in the water column during acoustic profiling investigations in 2007–2009 in Xiamen Bay and adjacent areas. Acoustically transparent zones, acoustic turbidity and gas seepage can be seen in seabed strata, pockmarks and accumulation bodies have been found on the seafloor, and hummocky features and mushroom shaped gas signatures can be identified in the water column. This evidence shows that shallow gas is widely distributed in and around Xiamen Bay, due to degradation of the organic matter transported by the Jiulong River. The area covered by such features is roughly estimated at 150 km2, and methane flux is estimated to be 150 × 106 m3 assuming the thickness of gas bearing formations to be 1 m. This study shows that even small rivers flowing out onto a continent shelf contribute to recognizable methane flux and are linked to identifiable gas reservoirs in the shallow seabed. More detailed studies are required to understand the role of such systems as a component of the global carbon cycle. Key Points Propose using chemical sampling methods to evaluate methane flux is deficiencies Revealed the methane flux in a small estuary in the upper 30 m of the seabed Small rivers in methane escape processes play a significant role

Harnessing the energy of tidal currents has huge potential as a source of clean renewable energy. To do so in a reliable and cost effective way, it is critical to understand the interaction between tidal turbines, waves, and turbulent currents in the ocean. Scaled testing in a tank test provides a controlled, realistic, and highly reproducible down-scaled open ocean environment, and it is a key step in gaining this understanding. Knowledge of the hydrodynamic conditions during tests is critical and measurements at multiple locations are required to accurately characterise spatially varying flow in test tank facilities. The paper presents a laboratory technique using an acoustic velocimetry instrument, the range over-which measurements are acquired being more akin to open water applications. This enables almost simultaneous multi-point measurements of uni-directional velocity along a horizontal profile. Velocity measurements have been obtained from a horizontally mounted Single Beam Acoustic Doppler (SB-ADP) profiler deployed in the FloWave Ocean Energy Research Facility at the University of Edinburgh. These measurements have been statistically compared with point measurements obtained while using a co-located Acoustic Doppler Velocimeter (ADV). Measurements were made with both instruments under flow velocities varying from 0.6 ms−1 to 1.2 ms−1, showing that flow higher than 1 ms−1 was more suitable. Using a SB-ADP has shown the advantage of gaining 54 simultaneous measurement points of uni-directional velocity, covering a significant area with a total distance of 10 m of the test-tank, at a measurement frequency of 16 Hz. Of those measurement points, 41 were compared with co-located ADV measurements covering 8 m of the profile for a tank nominal flow velocity of 0.8 ms−1, and four distributed locations were chosen to to carry out the study at 0.6 ms−1, 1.0 ms−1, and 1.2 ms−1. The comparison with the ADV measurement showed a 2% relative bias on average.

The paper deals with results of geological and geophysical study of the East Siberian Sea coastal areas are reported. Research activities started in 2018 in the frame of the State Geological Mapping Project (GK-1000/3) and continued in 2022 under support of the Russian Science Foundation. A seismo-stratigraphic scheme of the Quaternary sediment sequence has been compiled, and a conception of the paleogeographical evolution in the Late Pleistocene–Holocene has been proposed.

Nonstationary convection forced by distributed buoyancy sources is a fundamental environmental fluid mechanics process, particularly in ice-covered freshwater waterbodies. In this paper, we present novel field-based results that characterise the diurnal evolution of the main energetics of radiatively-driven convection in ice-covered lakes that is the radiatively-induced buoyancy flux, B, and the kinetic energy dissipation rate, \\[\\varepsilon\\]. To estimate the spatiotemporal distribution of \\[\\varepsilon\\], we applied scale similarity of the velocity structure functions to identify the fine turbulence scales from high-frequency velocity measurements. The field study was carried out at Lake Vendyurskoe, Russia, in April 2016. Small-scale velocity fluctuations were measured using acoustic Doppler current profiler in a 2 m layer beneath the ice cover. The method was proven to be valid for low-energy convection without mean shear. The inertial subrange, covering order of magnitude in the spatial domain, was identified by fitting the \\[^2/_3\\] scaling power law to the structure function method, thus confirming the regime of fully developed turbulence. The calculated rate of dissipation of turbulent kinetic energy \\[\\varepsilon\\] reaches values up to \\[3 \\times 10^{-9} \\hbox { m}^{2}\\hbox {s}^{-3}\\]. Although a strong correlation between \\[\\varepsilon\\] and B was observed, \\[\\varepsilon\\] picks up about 1 h later after the onset of the heating-phase. This delay roughly corresponds to the turnover time of the energy containing eddies. We finally observed a decay of \\[\\varepsilon\\] at night, during the relaxation-phase, but, interestingly, the level remained above the statistical error.

Paddy fields irrigated using water from the Shinkawa River in Niigata, Japan, are subject to adverse effects associated with the occurrence of saltwater wedges in the river. The extent of saltwater intrusion in the river varies, depending on river discharge and tidal amplitude. In this study, field observations and numerical simulation of the Shinkawa River estuary were applied to ascertain the influence of saltwater wedges on paddy cultivation during the irrigation period. The saltwater wedge was surveyed using an echo-sounding profiling system (SC-3); results indicated that the longitudinal profiles of the saltwater wedge were 4.7 and 2.2 km from the river mouth sluice gate at the high water mark of spring tide and at the low water mark of neap tide, respectively. According to the vertical profiling using electrical conductivity (EC) meters at bridges crossing the river, there was a rigid interface between freshwater and saltwater with a thin halocline zone of approximately 0.25 m. These profiles were well reproduced by the one-dimensional, two-layer, unsteady flow model. The results of the model simulation and EC observation indicate that when the vertical position of the halocline rises to 1.2 m below the inlet of the water intake pumping station, the EC value rises sharply to 1,500 μs/cm, which is an unsuitable level for irrigation water. It is estimated that for about 23 % of the total irrigation period, pump operation is halted as a result of this mechanism.

Acoustic Doppler Profilers (ADPs) are routinely used to measure flow velocity in the ocean, enabling multi-points measurement along a profile while Acoustic Doppler Velocimeters (ADVs) are laboratory instruments that provide very precise point velocity measurement. The experimental set-up allows laboratory comparison of measurement from these two instruments. Simultaneous multi-point measurements of velocity along the horizontal tank profile from Single-Beam Acoustic Doppler Profiler (SB-ADP) were compared against multiple co-located point measurements from an ADV. Measurements were performed in the FloWave Ocean Energy Research Facility at the University of Edinburgh at flow velocities between 0.6 ms − 1 and 1.2 ms − 1 . This paper describes the data; the analysis of the inter-instrument comparison is presented in an associated Sensors paper by the same authors. This data-set contains (a) time series of raw SB-ADP uni-directional velocity measurements along a 10 m tank profile binned into 54 measurements cells and (b) ADV point measurements of three-directional velocity time series recorded in beam coordinates at selected locations along the profile. Associated with the data are instrument generated quality data, metadata and user-derived quality flags. An analysis of the quality of SB-ADP data along the profile is presented. This data-set provides multiple contemporaneous velocity measurements along the tank profile, relevant for correlation statistics, length-scale calculations and validation of numerical models simulating flow hydrodynamics in circular test facilities.

In 2017, a detailed study of the Eastern Gulf of Finland (the Baltic Sea) seafloor was performed to identify and map submerged glacial and postglacial geomorphologic features and collect data pertinent to the understanding of sedimentation in postglacial basins. Two key areas within the Gulf were investigate using a multibeam echosounder, SeaBat 8111 and an EdgeTech 3300-HM acoustic sub-bottom profiling system. High-resolution multibeam bathymetric data (3-m resolution) were used to calculate aspect, slope, terrain ruggedness and bathymetric position index using ArcGIS Spatial Analyst and the Benthic Terrain Modeler toolbox. These data and resultant thematic maps revealed, for the first time, such features as streamlined till ridges, end-moraine ridges, and De Geer moraines that are being used for the reconstruction of the deglaciation in the Eastern Gulf of Finland. This deglaciation occurred between 13.8 and 13.3 ka BP (Pandivere–Neva stage) and 12.25 ka BP (Salpausselkä I stage). Interpretations of the seismic-reflection profiles and 3D models showing the surfaces of till, and the identification of the Late Pleistocene sediment and modern bottom relief, indicate deep relative water-level fall in the Early Holocene and, most likely, several water-level fluctuations during this time.