• NEANIAS Underwater Research Community

The ocean and the marine parts of the cryosphere interact directly with, and are affected by, the seafloor and its primary properties of depth (bathymetry) and shape (morphology) in many ways. Bottom currents are largely constrained by undersea terrain with consequences for both regional and global heat transport. Deep ocean mixing is controlled by seafloor roughness, and the bathymetry directly influences where marine outlet glaciers are susceptible to the inflow relatively warm subsurface waters - an issue of great importance for ice-sheet discharge, i.e., the loss of mass from calving and undersea melting. Mass loss from glaciers and the Greenland and Antarctic ice sheets, is among the primary drivers of global sea-level rise, together now contributing more to sea-level rise than the thermal expansion of the ocean. Recent research suggests that the upper bounds of predicted sea-level rise by the year 2100 under the scenarios presented in IPCC’s Special Report on the Ocean and Cryosphere in a Changing Climate (SROCCC) likely are conservative because of the many unknowns regarding ice dynamics. In this paper we highlight the poorly mapped seafloor in the Polar regions as a critical knowledge gap that needs to be filled to move marine cryosphere science forward and produce improved understanding of the factors impacting ice-discharge and, with that, improved predictions of, among other things, global sea-level.We analyze the bathymetric data coverage in the Arctic Ocean specifically and use the results to discuss challenges that must be overcome to map the most remotely located areas in the Polar regions in general Refereed 14.a Sea surface height 2022-01-17 Reports with methodological relevance

The importance of the marine environment to human existence makes it imperative that information models represent the multidimensional nature of reality as closely as possible in order to facilitate good governance. Information for a jurisdiction, on the effects of its formal law and community interests on the marine environment (e.g. nature and spatial extents and the rights, responsibilities, and restrictions etc.) would be stored in a marine cadastre. Other information on the physical, biological, socio-cultural and economic nature of the environment may be linked to the cadastre to give it a multipurpose function. This paper has the following objectives: 1. To highlight new spatial information technologies that facilitate the retrieval of various marine datasets; 2. To outline how emerging technology can be used to visualise the complexity of issues in a marine environment; 3. To outline some of the issues encountered in Canadian research in designing a marine cadastre.

An increasing number of underwater structures require regular, highly accurate inspections to maintain a safe and sustainable operation. Conventional sonar systems often lack the necessary resolution and precision, and camera-based systems are easily disturbed by turbid water. A technology which can bridge this gap is pulsed time-of-flight ranging. It provides higher resolution and precision compared to acoustic methods and tolerates turbid water. In this paper, we present a specialized underwater LiDAR (light detection and ranging) system which is capable of recording camera-like planar scenes using a two-dimensional beam-deflection unit. This is achieved using a combination of two rotating wedge-prisms mounted into custom-build motor modules which allows configurable linear, circular, and planar scan-patterns. Its compact design, paired with a large 33° deflection angle and 45 mm clear aperture makes it ideal for challenging underwater conditions.

In this invited seminar as part of the NOAA Integrated Ocean and Coastal Mapping Seminar Series (and in association with the multi-agency and White House National Ocean Mapping, Exploration, and Characterization (NOMEC) Council), the author briefly lays out the case for a “geographic approach” for bringing the importance of the ocean front-and-center in the minds of policy-makers and the public, for making the critical intersection between ocean mapping and climate, and all within the context of the very-important UN Decade of Ocean Science for Sustainable Development. Included are descriptions of new geospatial applications with end-to-end capability, from creating content to high-end modeling and novel analytics to effective science communication back to communities. This is especially the communities who truly understand that the ocean is not too big to fail or fix. Our very future depends upon it.

Two seminal advances in the late 1970s in science and technology spurred the establishment of the National Oceanic and Atmospheric Administration (NOAA) Vents Program: the unexpected discovery of seafloor vents and chemosynthetic ecosystems on the Galápagos Spreading Center (GSC), and civilian access to a previously classified multibeam mapping sonar system. A small team of NOAA scientists immediately embarked on an effort to apply the new mapping technology to the discovery of vents, animal communities, and polymetallic sulfide deposits on spreading ridges in the Northeast Pacific Ocean. The addition of interdisciplinary colleagues from NOAA’s cooperative institutes at Oregon State University and the University of Washington led to the creation of the Vents Program in 1983 at NOAA’s Pacific Marine Environmental Laboratory. Within a decade, Vents surveyed the entire Juan de Fuca and Gorda Ridges for hydrothermal activity, discovered the first “megaplume,” established multiyear time series of hydrothermal fluid measurements, and, for the first time, acoustically detected and responded to a deep-sea volcanic eruption. With this experience, and partnering with researchers from around the globe, Vents expanded to exploration along the East Pacific and GSC divergent plate boundaries. In 1999, the Vents Program embarked on systematic surveys along volcanic arcs and back-arc basins of the Mariana and Kermadec-Tonga subduction zones. For three decades, the Vents Program focused on understanding the physical, chemical, and biological environmental consequences of global-scale processes that regulate the transfer of heat and mass from Earth’s hot interior into the ocean. As the fourth decade began, the Vents Program was restructured into two new programs, Earth-Ocean Interactions and Acoustics, that together continue, and broaden, the scope of Vents’ pioneering ocean exploration and research.

The ocean and the marine parts of the cryosphere interact directly with, and are affected by, the seafloor and its primary properties of depth (bathymetry) and shape (morphology) in many ways. Bottom currents are largely constrained by undersea terrain with consequences for both regional and global heat transport. Deep ocean mixing is controlled by seafloor roughness, and the bathymetry directly influences where marine outlet glaciers are susceptible to the inflow relatively warm subsurface waters - an issue of great importance for ice-sheet discharge, i.e., the loss of mass from calving and undersea melting. Mass loss from glaciers and the Greenland and Antarctic ice sheets, is among the primary drivers of global sea-level rise, together now contributing more to sea-level rise than the thermal expansion of the ocean. Recent research suggests that the upper bounds of predicted sea-level rise by the year 2100 under the scenarios presented in IPCC’s Special Report on the Ocean and Cryosphere in a Changing Climate (SROCCC) likely are conservative because of the many unknowns regarding ice dynamics. In this paper we highlight the poorly mapped seafloor in the Polar regions as a critical knowledge gap that needs to be filled to move marine cryosphere science forward and produce improved understanding of the factors impacting ice-discharge and, with that, improved predictions of, among other things, global sea-level. We analyze the bathymetric data coverage in the Arctic Ocean specifically and use the results to discuss challenges that must be overcome to map the most remotely located areas in the Polar regions in general.

Aujourd’hui, seuls 15% des fonds des océans du globe sont cartographiés à haute résolution, d’environ 100 mètres. L’Institut Français de Recherche pour l’Exploitation de la Mer (Ifremer) participe à la collecte de données de profondeur des fonds marins haute résolution, les « données bathymétriques », en déployant ses navires océanographiques équipés de sondeurs-multifaisceaux. Le stage au sein du service de cartographie marine de l’Ifremer a permis dans un premier temps de traiter des données bathymétriques brutes acquises sur la dorsale de l’océan Atlantique Nord central entre 1991 et 2018, et de les compiler pour créer des modèles numériques de terrain. Ces modèles constituent de véritables supports de recherche en géosciences. Ils sont diffusés aux chercheurs en interne et en externe de l’Ifremer, alimentent des projets de recherche internationaux. Dans un second temps, c’est un travail d’analyse qui a été effectué en collaboration avec les chercheurs : l’étude des structures abyssales de la dorsale Atlantique entre 14°N et 35°N pour mieux comprendre la tectonique des plaques, ainsi que la cartographie structurale d’une zone d’exploration de sulfures polymétalliques. Today, only 15% of the global ocean floor has been mapped at a high resolution of around 100 meters. The French Research Institute for the Exploitation of the Sea (Ifremer) participates in the acquisition of high-resolution seafloor depth data called "bathymetric data", by deploying its oceanographic vessels equipped with multibeam echo sounders. This internship within the ocean mapping service of Ifremer allowed, firstly, the processing of raw bathymetric data, acquired between 1991 and 2018 over the central North Atlantic mid-ocean ridge, and to compile them in digital terrain models. These models are necessary to improve geologic investigations, and they are available to scientists in Ifremer and elsewhere. The models also contribute to international bathymetric models and research projects. In a second step, data analyses were carried out in collaboration with Ifremer researchers : a study of the abyssal hill structures of the mid-Atlantic ridge between 14°N and 35°N was carried out in order to better understand the plate tectonic movements and a structural geology map was created for a polymetallic sulphides exploration zone.

Timely and accurate identification of change detection for areas depicted on nautical charts constitutes a key task for marine cartographic agencies in supporting maritime safety. Such a task is usually achieved through manual or semi-automated processes, based on best practices developed over the years requiring a substantial level of human commitment (i.e., to visually compare the chart with the new collected data or to analyze the result of intermediate products). This work describes an algorithm that aims to largely automate the change identification process as well as to reduce its subjective component. Through the selective derivation of a set of depth points from a nautical chart, a triangulated irregular network is created to apply a preliminary tilted-triangle test to all the input survey soundings. Given the complexity of a modern nautical chart, a set of feature-specific, point-in-polygon tests are then performed. As output, the algorithm provides danger-to-navigation candidates, chart discrepancies, and a subset of features that requires human evaluation. The algorithm has been successfully tested with real-world electronic navigational charts and survey datasets. In parallel to the research development, a prototype application implementing the algorithm was created and made publicly available.

Despite recent technological advances in seafloor mapping systems, the resulting products and the overall operational efficiency of surveys are often affected by poor awareness of the oceanographic environment in which the surveys are conducted. Increasingly reliable ocean nowcast and forecast model predictions of key environmental variables – from local to global scales – are publicly available, but they are often not used by ocean mappers. With the intention of rectifying this situation, this work evaluates some possible ocean mapping applications for commonly available oceanographic predictions by focusing on one of the available regional models: NOAA’s Gulf of Maine Operational Forecast System. The study explores two main use cases: the use of predicted oceanographic variability in the water column to enhance and extend (or even substitute) the data collected on-site by sound speed profilers during survey data acquisition; and, the uncertainty estimation of oceanographic variability as a meaningful input to estimate the optimal time between sound speed casts. After having described the techniques adopted for each use case and their implementation as an extension of publicly-available ocean mapping tools, this work provides evidence that the adoption of these techniques has the potential to improve efficiency in survey operations as well as the quality of the resulting ocean mapping products.