The Solid Carbon initiative aims to inject carbon dioxide (CO2) into the upper ocean crust, utilizing mineralization as a means for permanent carbon dioxide removal to mitigate climate change. After seven years of pre-feasibility and feasibility studies, we have demonstrated that the Cascadia Basin, located in the Northeast Pacific offshore Vancouver Island, is an ideal site for a deep-ocean CO2 injection test. This site has been the focus of decades of intensive scientific investigations, including a hydrogeological injection test. Additionally, the presence of Ocean Networks Canada's NEPTUNE cabled observatory, which provides power and communication to seafloor sensors and instrumented boreholes, further supports its suitability for this demonstration. Our efforts confirm that conducting a CO2 injection test at this location is both viable and promising, warranting field demonstration. We also investigated regulatory, public, and engineering aspects for taking Solid Carbon to a full-scale negative emissions technology and identified the legislative needs, public concerns, benefits, and realistic implementation scenarios that would involve floating platforms to generate wind power for direct air or ocean capture of CO2 and facilitate injection for decades to come. Advantages of deep ocean settings for basalt injection are the massive capacities (up to 750 Gt in the Cascadia Basin alone, and over 30,000 Gt of CO2 globally), huge unused wind energy resources far away from human activities, short injection holes that can be drilled robotically, and several natural safety mechanisms that prevent accidentally lost CO2 to escape back into the atmosphere including a CO2-depleted deep ocean.

Cabled ocean observatories enable permanent continuous observations in situ in addition to regular sampling during observatory maintenance expeditions, which allow for some of the most comprehensive monitoring to understand the fate of methane all the way from below the seafloor (with instrumented boreholes), through the seafloor (with bottom sensors, cameras or cabled vehicles) into the water column (with sonars). Ocean Networks Canada is operating the NEPTUNE observatory off the coast of Vancouver Island since 2009 with two of its instrument nodes at gas hydrate sites. The first site, Clayoquot Slope, is at around 1200 m water depth and is a site of high fluid expulsion including large amounts of methane gas seepage, which has been observed for over a decade with permanent sonar scanning. The second site, Barkley Canyon, is at about 900 m water depth and has hydrate mounds with exposed gas hydrate on the seafloor, and is unique for its thermogenic methane and also oil seepage, and the most important observations have been made by a remotely-operated cabled and instrumented a seafloor crawler called Wally. This presentation will provide a few highlights on gas hydrate observations and invites the research community for new ideas how to expand the use of the permanent and continuous data flow opportunities that stem from the 24/7 presence of power and communication availability at the two different hydrate sights.

Data time series covering extended periods of time in support of long-term environmental studies are particularly difficult and expensive to collect, especially at offshore locations. Ocean Networks Canada’s (ONC) undersea cabled observatories in the Northeast Pacific ocean have been collecting an extensive array of oceanographic, seismic, geophysical, biological and acoustical data over periods that, in some cases, extend beyond sixteen years. With regard to soundscape studies, ONC currently owns and operates 22 hydrophones (including four 4-element, three-dimensional arrays) between the VENUS coastal observatory in the Salish Sea and the NEPTUNE offshore deep-sea observatory in the Northeast Pacific Ocean. The data, streamed in quasi-real-time to ONC’s web data portal, offer a window on a number of different environments, from the busy, shallow waters of the Salish Sea to the 2200 m of depth of the Endeavour hydrothermal-vent field. This presentation gathers highlights from the latest research utilizing ONC’s acoustic infrastructure and data, ranging from ambient noise to hydrothermal-vent soundscapes, seismic events, bioacoustics, and signal processing applications such as source localization.

<p>Long time series observations in the ocean are rare. In the Northeast Pacific, Ocean Networks Canada (ONC) of the University of Victoria operates a number of permanent cabled ocean observatories. The first was installed in 2006, and they have successfully produced many interdisciplinary high-resolution time series over the years, the longest being over 16 years in duration. The cabled observatories operated by ONC include the VENUS coastal observatory and the NEPTUNE off-shore deep-sea observatory. Each observatory has several sites where an observatory node provides continuous power and high bandwidth communications to a wide range of ocean and geophysical sensors. Various long high-resolution time series will be presented and the assessment of climate, decadal, inter-seasonal, annual, and even daily cycles, variations, and signals will be discussed. Such long time series, including environmental baselines, are key for evaluating physicochemical and biological change in the oceans in response to natural variations and climate change. In this way, recent efforts to leverage our time series data in robust monitoring, measurement, reporting, and verification (M2RV) frameworks in the context of different marine carbon dioxide removal (mCDR) approaches, will also be presented.</p>

Offshore basalts, most commonly found as oceanic crust formed at mid-ocean ridges, are estimated to offer an almost unlimited reservoir for CO2 sequestration and are regarded as one of the most durable locations for carbon sequestration since injected CO2 will mineralize, forming carbonate rock. As part of the Solid Carbon project, the potential of the Cascadia Basin, about 200 km off the west coast of Vancouver Island, Canada, is investigated as a site for geological CO2 sequestration. In anticipation of a demonstration proposed to take place, it is essential to assess the tendency of geologic faults in the area to slip in the presence of CO2 injection, potentially causing seismic events. To understand the viability of the reservoir, a quantitative risk assessment of the proposed site area was conducted. This involved a detailed characterization of the proposed injection site to understand baseline stress and pressure conditions and identify individual faults or fault zones with the potential to slip and thereby generate seismicity. The results indicate that fault slip potential is minimal (less than 1%) for a constant injection of up to ~2.5 MT/yr. This is in part due to the thickness of the basalt aquifer and its permeability. The results provide a reference for assessing the potential earthquake risk from CO2 injection in similar ocean basalt basins.

<p>Oceanic crustal basalt rock has been identified to be the most abundant CO2 sequestration reservoir on earth with a total capacity of up to 250,000 Gt of CO2 and the added advantage of the CO2 mineralizing into carbonate rock in the safest and most durable way. Experiments and pilot projects have established geologic carbon storage in basalt on land (e.g. Carbfix in Iceland) but have not been carried out offshore and are therefore required to demonstrate and prove this form of carbon storage offshore. We are presenting the ongoing Solid Carbon project, which is currently in the feasibility stage of demonstrating this concept in the Cascadia Basin offshore Vancouver Island where Ocean Networks Canada operates a cabled ocean observatory, which will be utilized to monitor and verify this form of geologic carbon storage. The demonstration site is at about 2700 m water depth, where the ocean crust is overlain by 200-600 m of sediment acting as a cap for the porous and permeable crustal basalt aquifer (300-500 m thick), underlain by a thick conductive basement. From previous seafloor drilling campaigns, the subsurface and hydrogeology in this area are well known, feeding both into sequestration modelling and also planning the required monitoring. In addition to planning the offshore demonstration experiment, the Solid Carbon project further includes research on social, regulatory and social acceptance as well as adding offshore energy and direct carbon capture to transform the concept into a negative emission technology. We will present the past, present and potential future of this form of geologic carbon storage.</p>

<p>Since 2012 Ocean Networks Canada (ONC) has acquired high-quality long-term multibeam sonar data from the seafloor at Clayoquot Slope off Vancouver Island which is one of the most active methane vent regions of the Cascadia Margin, and where ONC has one of its nodes of the NEPTUNE cabled seafloor observatory. The sonar was first deployed at a vent field of irregular activity (near Bubbly Gulch), and since 2014 it is located at an extremely active field (Gastown Alley). The data that have been analyzed so far exhibit the strong dependence of gas bubble emissions with tidal pressure, although the tides alone cannot explain all the observed dynamics such as onset cessation of ebullition or periods of strong versus absence of seepage, and other factors need to be considered and ideally monitored to predict future seepage.</p><p>Seafloor cabled observatories are ideal to acquire high-resolution data of many ocean and seafloor parameters, including those from high-bandwidth data or power-intensive instruments. This presentation is an opportunity to explore possibilities to modify the existing seepage observatory, adding to the already installed instruments at Clayoquot Slope, or change focus to Barkley Canyon, another ONC node location, where hydrate mounts and outcrops occur and methane vents also exist.</p>

Barkley Canyon is one of the few known sites worldwide with the occurrence of thermogenic gas seepage and formation of structure-II and structure-H gas hydrate mounds on the seafloor. This site is the location of continuous seafloor monitoring as part of the Ocean Networks Canada (ONC) cabled observatory off the west coast off Vancouver Island, British Columbia, Canada. We combine repeat remotely operated vehicle (ROV) seafloor video observations, mapping with an autonomous underwater vehicle (AUV), ship-, ROV-, and AUV-based identification of gas flares, as well as seismic and Chirp data to investigate the distribution of fluid migration pathways. Geologically, the site with the prominent gas hydrate mounds and associated fluid seepage is covering an area of ∼0.15 km 2 and is situated on a remnant of a rotated fault block that had slipped off the steep flanks of the north-east facing canyon wall. The gas hydrate mounds, nearly constant in dimension over the entire observation period, are associated with gas and oil seepage and surrounded by debris of chemosynthetic communities and authigenic carbonate. The formation of gas hydrate at and near the seafloor requires additional accommodation space created by forming blisters at the seafloor that displace the regular sediments. An additional zone located centrally on the rotated fault block with more diffuse seepage (∼0.02 km 2 in extent) has been identified with no visible mounds, but with bacterial mats, small carbonate concretions, and clam beds. Gas venting is seen acoustically in the water column up to a depth of ∼300 m. However, acoustic water-column imaging during coring and ROV dives showed rising gas bubbles to much shallower depth, even <50 m, likely a result of degassing of rising oil droplets, which themselves cannot be seen acoustically. Combining all observations, the location of the gas hydrate mounds is controlled by a combination of fault-focused fluid migration from a deeper reservoir and fluid seepage along more permeable strata within the rotated slope block. Fluids must be provided continuously to allow the sustained presence of the gas hydrate mounds at the seafloor.

Pockmarks are crater-like depressions of erosive nature in marine or lacustrine sediments. They are often interpreted as the surface manifestation of hydrocarbon venting but may also result from freshwater flow in coastal regions, compaction induced sediment dewatering, or bottom scouring around natural or anthropogenic objects. Hence, they can be of relevance for the global carbon cycle, offshore infrastructure, benthic life, and slope stability. New bathymetric data from offshore Vancouver Island, Canada, indicate the presence of a huge pockmark field that had escaped attention in previous studies. The pockmarks are located between 100 and 200 mt depth around the head of Barkley Canyon. Owing to the presence of a large cabled underwater observatory related to the canyon, a wealth of multi-resolution and multi-disciplinary seafloor data is available from the pockmark field. Available data include multibeam surveys, seafloor video footage, seismic and EK60 echo-sounder profiles, and multibeam water-column information. First results from seafloor mapping indicate that the pockmark field consists of several thousands of pockmarks. By applying workflows that automatically map the pockmarks in digital elevation models, we are able to quantitatively investigate their morphology and spatial distribution. The pockmarks range in size between 100 - 500 m², with some exceptions as large as 900 m². Their mean depth varies between 0.5 - 2 m. Seepage of gas from the seafloor is well known from the area but could not yet been directly associated with the pockmark depressions. Instead, limited video footage from the seafloor indicate that at least some depressions host meter-sized boulders within their craters. We will next investigate possible temporal changes in pockmark morphology and seep activity by individual analysis of datasets that have been repeatedly collected between 2010-2020. By resolving pockmark morphologies and seep activities on an annual time-scale over a decade, the results will hopefully add a level of detail to our understanding of pockmark formation and seep activity within one of North Americas largest pockmark fields.

Seabed methane gas emissions occur worldwide at cold seeps located along most continental margins. Fluxes of methane gas released from the seabed in the form of bubbles can be extremely variable even over short time intervals. Some factors controlling the variability are still poorly understood. Here, we report on the results of continuous long-term sonar monitoring of bubble emissions at a depth of 1,260 m on the Clayoquot Slope, northern Cascadia margin. With a total monitoring duration of 4 years and a sampling period of 1 h, this is by far the longest high temporal resolution monitoring of seabed methane gas release ever conducted. Our results provide evidence that the diurnal and semi-diurnal tides influence the timing of the onset and cessation of bubble emissions. However, gas emissions within the monitoring area are active more than 84% of the time, indicating that tides alone are not sufficient to make venting pause. We hypothesize that the gas fluxes are transient but generally sufficiently high to maintain ebullition independently of the tidally-induced bottom pressure variations. Results also show that the tides do not seem to modulate the vigor of active gas emissions.

The advent of large-scale cabled ocean observatories brought about the need to handle large amounts of ocean-based data, continuously recorded at a high sampling rate over many years and made accessible in near-real time to the ocean science community and the public. Ocean Networks Canada (ONC) commenced installing and operating two regional cabled observatories on Canada’s Pacific Coast, VENUS inshore and NEPTUNE offshore in the 2000s, and later expanded to include observatories in the Atlantic and Arctic in the 2010s. The first data streams from the cabled instrument nodes started flowing in February 2006. This paper describes Oceans 2.0 and Oceans 3.0, the comprehensive Data Management and Archival System that ONC developed to capture all data and associated metadata into an ever-expanding dynamic database. Oceans 2.0 was the name for this software system from 2006–2021; in 2022, ONC revised this name to Oceans 3.0, reflecting the system’s many new and planned capabilities aligning with Web 3.0 concepts. Oceans 3.0 comprises both tools to manage the data acquisition and archival of all instrumental assets managed by ONC as well as end-user tools to discover, process, visualize and download the data. Oceans 3.0 rests upon ten foundational pillars: (1) A robust and stable system architecture to serve as the backbone within a context of constant technological progress and evolving needs of the operators and end users; (2) a data acquisition and archival framework for infrastructure management and data recording, including instrument drivers and parsers to capture all data and observatory actions, alongside task management options and support for data versioning; (3) a metadata system tracking all the details necessary to archive Findable, Accessible, Interoperable and Reproducible (FAIR) data from all scientific and non-scientific sensors; (4) a data Quality Assurance and Quality Control lifecycle with a consistent workflow and automated testing to detect instrument, data and network issues; (5) a data product pipeline ensuring the data are served in a wide variety of standard formats; (6) data discovery and access tools, both generalized and use-specific, allowing users to find and access data of interest; (7) an Application Programming Interface that enables scripted data discovery and access; (8) capabilities for customized and interactive data handling such as annotating videos or ingesting individual campaign-based data sets; (9) a system for generating persistent data identifiers and data citations, which supports interoperability with external data repositories; (10) capabilities to automatically detect and react to emergent events such as earthquakes. With a growing database and advancing technological capabilities, Oceans 3.0 is evolving toward a future in which the old paradigm of downloading packaged data files transitions to the new paradigm of cloud-based environments for data discovery, processing, analysis, and exchange.

EDITORIAL article Front. Earth Sci., 27 April 2022Sec. Biogeoscience https://doi.org/10.3389/feart.2022.868609

Extreme events have long been underestimated in the extent to which they shape the surface of our planet, our environment, its ecological integrity, and the sustainability of human society. Extreme events are by definition rarely observed, of significant impact and, as a result of their spatiotemporal range, not always easily predicted. Extremes may be short-term catastrophic events such as tsunamis, or long-term evolving events such as those linked to climate change; both modify the environment, producing irreversible changes or regime shifts. Whatever the driver that triggers the extreme event, the damages are often due to a combination of several processes and their impacts can affect large areas with secondary events (domino effect), whose effects in turn may persist well beyond the duration of the trigger event itself. Early studies of extreme events were limited to opportunistic approaches: observations were made within the context of naturally occurring events with high societal impact. Given that climate change is now moving us out of a relatively static climate regime during the development of human civilization, extreme events are now a function of underlying climate shifts overlain by catastrophic processes. Their impacts are often due to synergistic factors, all relevant in understanding process dynamics; therefore, an integrated methodology has become essential to enhance the reliability of new assessments and to develop strategies to mitigate societal impacts. Here we summarize the current state of extreme event monitoring in the marine system, highlighting the advantages of a multidisciplinary approach using Research Infrastructures for providing the temporal and spatial resolution required to monitor Earth processes and enhance assessment of associated impacts.

Deep-sea environmental datasets are ever-increasing in size and diversity, as technological advances lead monitoring studies towards long-term, high-frequency data acquisition protocols. This study presents examples of pre-analysis data treatment steps applied to the environmental time series collected by the Internet Operated Deep-sea Crawler “Wally” during a 7-year deployment (2009–2016) in the Barkley Canyon methane hydrates site, off Vancouver Island (BC, Canada). Pressure, temperature, electrical conductivity, flow, turbidity, and chlorophyll data were subjected to different standardizing, normalizing, and de-trending methods on a case-by-case basis, depending on the nature of the treated variable and the range and scale of the values provided by each of the different sensors. The final pressure, temperature, and electrical conductivity (transformed to practical salinity) datasets are ready for use. On the other hand, in the cases of flow, turbidity, and chlorophyll, further in-depth processing, in tandem with data describing the movement and position of the crawler, will be needed in order to filter out all possible effects of the latter. Our work evidences challenges and solutions in multiparametric data acquisition and quality control and ensures that a big step is taken so that the available environmental data meet high quality standards and facilitate the production of reliable scientific results.

Extract There are many challenges facing submarine mass movement researchers and engineers. This book comes at a time when, in the past five years, a number of high-profile submarine landslide disasters have reached the world's attention. In September of 2018 a magnitude 7.5 strike-slip-type earthquake in Palu, Indonesia, generated a short-wavelength tsunami of height over 2 m and run-up on shore of over 8 m. The waves took the lives of hundreds of people, yet uncounted, many of whom were gathered for a festival on the beach. The combination of these wave dimensions with observations of the wave timing and directions indicate strongly that a submarine landslide was the source of this devastation (Arikawa et al. 2018; Heidarzadeh et al. 2018; Muhari et al. 2018; Carvajal et al. 2019). Sadly, barely 3 months later the same nation suffered a tsunami formed by the underwater collapse of the Anak Krakatau volcano, which killed at least 500 people. On the other side of the globe, in June 2017, many houses in the village of Nuugaatsiaq, West Greenland, were destroyed and some lives were lost from a coastal landslide-generated tsunami (Gauthier et al. 2018). Another event in 2014 saw the small village of Nord–Statland, Norway badly damaged by a submarine landslide (Sylfest et al. 2016).

There is presently insufficient information to accurately assess the hazard posed by a tsunamigenic megathrust earthquake rupturing the Cascadia Subduction Zone in the Pacific Northwest. We report our plans to deploy a Northern Cascadia Subduction Zone Observatory (NCSZO) offshore Vancouver Island, Canada, which will comprise a seafloor network of seven new Global Positioning System sites to measure deformation caused by the subduction of the oceanic Juan de Fuca Plate beneath the continental North America Plate, and a Deformation Front Laboratory at the oceanic trench to monitor aseismic creep events on the shallow part of the plate interface. The NCSZO will make effective and sustainable use of the Ocean Networks Canada NEPTUNE observatory, and be complemented by the highest density of land-based seismic and high-rate geodetic stations in Canada. We expect the NCSZO will enable significant improvements of tsunami and earthquake risks assessments after only a few years of measurements.