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[1] The NEPTUNE Canada cabled observatory network enables non-destructive, controlled experiments and timeseries observations with mobile robots on gas hydrates and benthic community structure on a small plateau of about 1 km 2 at a water depth of 870 m in Barkley Canyon, about 100 km offshore Vancouver Island, British Columbia. A mobile Internet operated vehicle was used as an instrument platform to monitor and study up to 2000 m 2 of sediment surface in real-time. In 2010 the first mission of the robot was to investigate the importance of oscillatory deep ocean currents on methane release at continental margins. Previously, other experimental studies have indicated that methane release from gas hydrate outcrops is diffusion-controlled and should be much higher than seepage from buried hydrate in semipermeable sediments. Our results show that periods of enhanced bottom currents associated with diurnal shelf waves, internal semidiurnal tides, and also wind-generated near-inertial motions can modulate methane seepage. Flow dependent destruction of gas hydrates within the hydrate stability field is possible from enhanced bottom currents when hydrates are not covered by either seafloor biota or sediments. The calculated seepage varied between 40-400 mmol CH 4 m À2 s À1 . This is 1-3 orders of magnitude higher than dissolution rates of buried hydrates through permeable sediments and well within the experimentally derived range for exposed gas hydrates under different hydrodynamic boundary conditions. We conclude that submarine canyons which display high hydrodynamic activity can become key areas of enhanced seepage as a result of emerging weather patterns due to climate change. Citation: Thomsen, L., C. Barnes, M. Best, R. Chapman, B. Pirenne, R. Thomson, and J. Vogt (2012), Ocean circulation promotes methane release from gas hydrate outcrops at the NEPTUNE Canada Barkley

The instrumentation for a pathfinder mission towards a possible large scale neutrino telescope named "STRings for Absorption length in Water" (STRAW) is presented in terms of design and performance. In June 2018 STRAW was deployed at the Cascadia Basin site operated by Ocean Networks Canada and has been collecting data since then. At a depth of about 2600 meters, the two STRAW 120 meters tall mooring lines are instrumented by three "Precision Optical Calibration Modules" (POCAM) and five Digital Optical Sensors (sDOM). The main objectives of STRAW are the measurement of light extinction in different wavelength bands and bioluminescence at Cascadia Basin. We describe the instrumentation deployed in the Pacific Ocean and show some data from the first measurements.

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ABSTRACT. We review methods which are widely used for compression of astronomical images. These include multiresolution approaches. We use such an approach, a pyramidal median transform, which is followed by noise suppression at each resolution scale. To preserve photometric and astrometric fidelity to the input image, a multiresolution astronomical-object support is used. We discuss the common astronomical noise models (additive Poisson, Gaussian, and Poisson plus Gaussian). A range of examples on digitized plate, and on CCD, image data is used to show the effectiveness of this approach.

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