scholarly journals MARINE GEOLOGY IN ATLANTIC CANADA - A GOVERNMENT PERSPECTIVE

2006 ◽  
Vol 43 (2) ◽  
Author(s):  
Richard A. Pickrill ◽  
David J.W. Piper
Keyword(s):  
Coastal Zone ◽  
Autonomous Vehicles ◽  
Numerical Models ◽  
Global Climate ◽  
Sustainable Use ◽  
Digital Data ◽  
Marine Geology ◽  
Anthropogenic Pressures ◽  
Positioning Systems ◽  
Ocean Management

The two priorities for government marine geoscience over the next decades are: (1) seabed mapping for ocean management, including safe and sustainable use of natural resources; and (2) societal responses in the coastal zone to natural hazards, global climate change and anthropogenic pressures including environmental degradation. Meeting these priorities will require scientific study of the history of past glaciations; erosion, transport and flocculation processes of sea-floor sediments, particularly of muds; and sediment transport and deposition and their interaction with environmental quality in estuarine systems, including the role of ice and storms. Numerical models are required to predict the consequences of natural rise in sea level and human interference in coastal systems and for predictive decision making in ocean management. Threerecent revolutionary developments in technology will influence how science is done: these are the development of Global Positioning Systems (GPS), of multibeam sonar, and of digital data collection, storage and dissemination. However, other capital acquisitions and technological developments are necessary. These include new ships, expanded multibeam capability, and underwater autonomous vehicles. New photographic/video systems will provide resolution higher than that of multibeam bathymetry. In the coastal zone, remote sensing tools such as Light Detection And Ranging (Lidar) and kinematicGPS will accelerate monitoring of coastal change. Cabled seabed observatories will provide time series and real-time information on extreme events. Research boreholes are essential to understand geological framework.Les deux priorités du programme gouvernemental de géologie marine au cours des 20 prochaines années sont les suivantes : (1) cartographie des fonds marins pour la gestion des océans, et notamment l’utilisation sécuritaire et durable des ressources naturelles; et (2) les réponses sociétales, dans la zone côtière, aux risques naturels, aux changements climatiques planétaires et aux pressions anthropogéniques, notamment la dégradation de l’environnement. Pour réaliser ces priorités, il faudra procéder à des études scientifiques sur l’histoire des glaciations passées; l’érosion, le transport et la floculation des sédiments des fonds marins, en particulier des boues; le transport et le dépôt des sédiments ainsi que leurs relations avec la qualité environnementale dans les systèmes estuariens, notamment le rôle de la glace et des tempêtes. Des modèlesnumériques sont nécessaires pour prévoir les conséquences de l’élévation naturelle des niveaux marins et des interférences humaines dans les systèmes côtiers, de même que pour prendre des décisions prévisionnelles en gestion marine. Trois progrès révolutionnaires récents de la technologie vont avoir une influence sur les modes d’exécution des activités scientifiques : le développement du GPS, le développement du sonar multifaisceau ainsi que la collecte, le stockage et la diffusion des données numériques. Cependant, il faudra d’autres équipements et innovations technologiques, comme de nouveaux navires, d’autres dispositifs de sondage multifaisceau ainsi que des véhicules sous-marins autonomes. De nouveaux systèmes photographiques et vidéo offriront une résolution supérieure à celle de la bathymétrie multifaisceau. Dansla zone côtière, certains outils de télédétection (comme le Lidar) et le GPS en mode cinématique vont accélérer l’observation des variations côtières. Des observatoires de fonds marins câblés fourniront des séries chronologiques et des données en temps réel sur les événements extrêmes. Des sondages de prospection seront essentiels à la compréhension du cadre géologique.

Antarctic Climate History and Global Climate Changes

2017 ◽  
Author(s):  
Pontus Lurcock ◽  
Fabio Florindo
Keyword(s):  
Ocean Circulation ◽  
Climate Changes ◽  
Numerical Models ◽  
Global Climate ◽  
Sediment Cores ◽  
Ice Sheets ◽  
Global Ocean ◽  
Climate History ◽  
Global Climate Changes ◽  
Planetary Albedo

Antarctic climate changes have been reconstructed from ice and sediment cores and numerical models (which also predict future changes). Major ice sheets first appeared 34 million years ago (Ma) and fluctuated throughout the Oligocene, with an overall cooling trend. Ice volume more than doubled at the Oligocene-Miocene boundary. Fluctuating Miocene temperatures peaked at 17–14 Ma, followed by dramatic cooling. Cooling continued through the Pliocene and Pleistocene, with another major glacial expansion at 3–2 Ma. Several interacting drivers control Antarctic climate. On timescales of 10,000–100,000 years, insolation varies with orbital cycles, causing periodic climate variations. Opening of Southern Ocean gateways produced a circumpolar current that thermally isolated Antarctica. Declining atmospheric CO2 triggered Cenozoic glaciation. Antarctic glaciations affect global climate by lowering sea level, intensifying atmospheric circulation, and increasing planetary albedo. Ice sheets interact with ocean water, forming water masses that play a key role in global ocean circulation.

scholarly journals East Antarctic sea ice: observations and modelling

1998 ◽  
Vol 27 ◽  
pp. 427-432 ◽  
Author(s):  
Anthony P. Worby ◽  
Xingren Wu
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Numerical Models ◽  
Global Climate ◽  
Thickness Distribution ◽  
Ice Thickness ◽  
Antarctic Sea Ice ◽  
Pack Ice ◽  
Concentration Sensitivity ◽  
Sensitivity Studies

The importance of monitoring sea ice for studies of global climate has been well noted for several decades. Observations have shown that sea ice exhibits large seasonal variability in extent, concentration and thickness. These changes have a significant impact on climate, and the potential nature of many of these connections has been revealed in studies with numerical models. An accurate representation of the sea-ice distribution (including ice extent, concentration and thickness) in climate models is therefore important for modelling global climate change. This work presents an overview of the observed sea-ice characteristics in the East Antarctic pack ice (60-150° E) and outlines possible improvements to the simulation of sea ice over this region by modifying the ice-thickness parameterisation in a coupled sea-ice-atmosphere model, using observational data of ice thickness and concentration. Sensitivity studies indicate that the simulation of East Antarctic sea ice can be improved by modifying both the “lead parameterisation” and “rafting scheme” to be ice-thickness dependent. The modelled results are currently out of phase with the observed data, and the addition of a multilevel ice-thickness distribution would improve the simulation significantly.

scholarly journals Διαχρονική παρατήρηση των μεταβολών της ακτογραμμής τμήματος της παράκτιας ζώνης του νόμου Πιερίας και εκτίμηση των επιπτώσεων από την μελλοντική άνοδο της θαλάσσιας στάθμης

2005 ◽  
Vol 38 ◽  
pp. 182
Author(s):  
Κ. ΤΣΑΝΑΚΑΣ ◽  
Ε. ΚΑΡΥΜΠΑΛΗΣ ◽  
Ι. ΠΑΡΧΑΡΙΔΗΣ
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Global Climate ◽  
Aerial Photographs ◽  
Qualitative Assessment ◽  
Gis And Remote Sensing ◽  
Socioeconomic Environment ◽  
Area North ◽  
Remote Sensing Techniques

The aim of this study is to detect shoreline changes along part of the coastal zone of Piena during the time period between 1969 and 2000 using aerial photographs and satellite images. Additionally, a quantitative and qualitative assessment of the future sea-level rise (triggered by the global climate change) implications to the physical and socioeconomic environment of the area is attempted taking into account various sea-level rise scenarios. Retreating as well as prograding regions along the study area were defined and retreating/prograding rates for the time periods 1969-1987 and 1987-2000 were estimated using GIS and Remote Sensing techniques. Building activity rates for the coastal area of Paralia Katerinis were also estimated for the same periods. The coastline of the study area is retreating^ except than the area north of torrent Mavroneri where a progradation rate of 48 cm/year was estimated between 1969 and 1987. Retreating rate of the coast for the northern part of the area (Saltworks) is estimated to be 25 cm/year and 19 cm/yrear for the periods of 1969-1987 and 1987-2000 respectively. The broader study area is particularly vulnerable to a potential future sealevel rise due to the low-lying topography of the coastal zone and intensive socioeconomic activities such as tourism and commerce.

scholarly journals The impact of economic activity on the ecological state of the water reservoirs of Ishim

2018 ◽  
Vol 7 (3) ◽  
pp. 98-103
Author(s):  
Natalia Evgenievna Suppes
Keyword(s):  
Private Sector ◽  
Coastal Zone ◽  
Visual Assessment ◽  
Organic Pollution ◽  
The State ◽  
Water Bodies ◽  
Economic Activities ◽  
Water Reservoirs ◽  
Anthropogenic Pressures ◽  
The Impact

This article analyzes the problem of the state of the water bodies in Ishim by anthropogenic pressures. The study shows that the water reservoirs are negatively influenced by the economic activities of the population. The author defines their main directions: industrial wastewater discharge to the city water bodies, construction and operation of engineering constructions, activity in the private sector. To assess the state of the water bodies the author uses the results of the visual assessment of the state of the riverbeds and their coastal zone, the organoleptic water indicators (turbidity, color and smell), the analysis of the hydrobiological studies (determination of the degree of saprobity of the water bodies as indicators ciliated infusoria). The study showed the satisfactory condition of all the water reservoirs and the non-critical impact. As the enterprises for light manufacturing and food industries in Ishim are not sources of chemical, organic and other pollution the visual assessment didn't reveal significant deformations of the riverbeds and any changes in the coastal zone. The impact of the private sector is local and not the significant cause of organic pollution.

scholarly journals A river system modelling platform for Murray-Darling Basin, Australia

2012 ◽  
Vol 15 (4) ◽  
pp. 1109-1120 ◽  
Author(s):  
Ang Yang ◽  
Geoff Podger ◽  
Shane Seaton ◽  
Robert Power
Keyword(s):  
Time Series Data ◽  
Local Development ◽  
Global Climate ◽  
Sustainable Use ◽  
River System ◽  
Series Data ◽  
System Modelling ◽  
Hydrological Simulation ◽  
Modelling Framework ◽  
Murray Darling Basin

Global climate change and local development make water supply one of the most vulnerable sectors in Australia. The Australian government has therefore commissioned a series of projects to evaluate water availability and the sustainable use of water resources in Australia. This paper discusses a river system modelling platform that has been used in some of these nationally significant projects. The platform consists of three components: provenance, modelling engine and reporting database. The core component is the modelling engine, an agent-based hydrological simulation system called the Integrated River System Modelling Framework (IRSMF). All configuration information and inputs to IRSMF are recorded in the provenance component so that modelling processes can be reproduced and results audited. The reporting database is used to store key statistics and raw output time series data for selected key parameters. This river system modelling platform has for the first time modelled a river system at the basin level in Australia. It provides practitioners with a unique understanding of the characteristics and emergent behaviours of river systems at the basin level. Although the platform is purpose-built for the Murray-Darling Basin, it would be easy to apply it to other basins by using different river models to model agent behaviours.

scholarly journals Summary of Discussions

1986 ◽  
Vol 8 ◽  
pp. 210
Author(s):  
Mark F. Meier
Keyword(s):  
Ice Sheet ◽  
Digital Data ◽  
Hard Copy ◽  
Data Bases ◽  
Positioning Systems ◽  
The World ◽  
The Future ◽  
Radio Echo Sounding ◽  
Glacier Mapping ◽  
Echo Sounding

In 1965, the first International Symposium on Glacier Mapping was held in Ottawa. This was convened at the beginning of the International Hydrological Decade, at a time of great expansion in glaciological research around the world. The purpose and scope of glacier mapping were well defined, perhaps for the first time, by the late Valter Schytt and others at the Symposium, It must be remembered that this symposium took place at a time when much of the technology we now take for granted did not exist. In some respects the symposium was prophetic: Gordon Robin suggested that the topography of the ice sheet might be measurable with an altimeter mounted in a satellite, and A.H. Waite, Jr. discussed the beginning attempts to sound glaciers using radio waves. Now in 1985 a Symposium on the same subject has been concluded in Reykjavik. It is apparent that the interest generated in the first Symposium has had a real effect, and some dreams have come true. Jay Zwally reported that repeated satellite altimetry has measured growth of part of the Greenland Ice Sheet, and sophisticated radio echo-sounding programs are adding the third dimension to glacier mapping. And glacier mapping has progressed in many other new and exciting directions. However, problems remain. For instance, only 20% of the Antarctic continent has been mapped at a scale of 1:250 000 or larger and what maps do exist of Antarctica were compiled over long periods of time and cannot be precisely dated. There are still few maps of remote areas in the world and these often lack geographic coordinates and captions in a language of common international use. The navigation or positioning systems used in many large-scale mapping programs have not been as highly developed as they should be. Much glacier mapping data now exists in digital form, but many of the digital data bases can not be accessed internationally. What are the needs for the future? First, we need wider application of digital data bases, including digital terrain models and geographic information systems. These should be set up so that the data can be retrieved by scientists from different countries, a difficult problem for parochial, technical, and political reasons. Attention needs to be given to long-term storage of digital data to insure against degradation with time. Once a good digital data base is established, the appropriate hard copy maps can be produced to whatever specifications are appropriate. But computers will not solve everyone’s needs. We certainly will need, far into the future, classical paper maps, the so-called “hard copy” that displays all of the information the field glaciologist or traveller requires. Public display maps that show the topography in an artistic way that is clear to the inexperienced viewer will always be needed. Of course, all maps should have geographic coordinates and a legend in an international language, such as English, to meet the needs of the international community. The quality of mapping will have to improve to meet tomorrow’s needs, This will include such things as improved definition of ice sheet surfaces, especially along ice divides so that flow patterns can be discerned. We need to integrate accurate positioning systems with the radio echo-sounding or other mapping systems. Repeated mapping of certain glaciers or ice mass areas, using similar mapping specifications, will be needed to detect change in these ice masses; such maps will have to be very precise in the measurement of surface ice elevation, We will certainly need “snapshot” maps of the large ice sheets, a task that can probably be accomplished only through the use of satellite technology. The field has come a long way in the last twenty years but it will probably progress far more in the next twenty. I wish to thank all of the speakers and the participants and those who so superbly organized the Symposium for a most challenging and productive meeting. Thank you all very much.

scholarly journals Kinematic and Dynamic Vehicle Model-Assisted Global Positioning Method for Autonomous Vehicles with Low-Cost GPS/Camera/In-Vehicle Sensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5430 ◽  
Author(s):  
Haigen Min ◽  
Xia Wu ◽  
Chaoyi Cheng ◽  
Xiangmo Zhao
Keyword(s):  
Coordinate System ◽  
Autonomous Vehicles ◽  
Low Cost ◽  
Positioning System ◽  
Visual Slam ◽  
Multiple Model ◽  
Positioning Systems ◽  
Local Accuracy ◽  
Global Positioning ◽  
Vehicle Sensors

Real-time, precise and low-cost vehicular positioning systems associated with global continuous coordinates are needed for path planning and motion control in autonomous vehicles. However, existing positioning systems do not perform well in urban canyons, tunnels and indoor parking lots. To address this issue, this paper proposes a multi-sensor positioning system that combines a global positioning system (GPS), a camera and in-vehicle sensors assisted by kinematic and dynamic vehicle models. First, the system eliminates image blurring and removes false feature correspondences to ensure the local accuracy and stability of the visual simultaneous localisation and mapping (SLAM) algorithm. Next, the global GPS coordinates are transferred to a local coordinate system that is consistent with the visual SLAM process, and the GPS and visual SLAM tracks are calibrated with the improved weighted iterative closest point and least absolute deviation methods. Finally, an inverse coordinate system conversion is conducted to obtain the position in the global coordinate system. To improve the positioning accuracy, information from the in-vehicle sensors is fused with the interacting multiple-model extended Kalman filter based on kinematic and dynamic vehicle models. The developed algorithm was verified via intensive simulations and evaluated through experiments using KITTI benchmarks (A project of Karlsruhe Institute of Technology and Toyota Technological Institute at Chicago) and data captured using our autonomous vehicle platform. The results show that the proposed positioning system improves the accuracy and reliability of positioning in environments in which the Global Navigation Satellite System is not available. The developed system is suitable for the positioning and navigation of autonomous vehicles.

scholarly journals The Zrmanja River Estuary (Adriatic Coast, Croatia) – the Need for Interdisciplinary Approach to Protection of Coastal Areas

2018 ◽  
Vol 55 (1) ◽  
pp. 9-32
Author(s):  
Željka Fiket ◽  
Goran Kniewald
Keyword(s):  
Sustainable Use ◽  
River Estuary ◽  
Interdisciplinary Approach ◽  
Karst Area ◽  
Geochemical Data ◽  
Anthropogenic Factors ◽  
Anthropogenic Pressures ◽  
Adriatic Coast ◽  
Enclosed Bay ◽  
Sedimentation Processes

The Zrmanja River estuary is a semi-enclosed bay immersed in a karstic landscape of the eastern Adriatic coast. It represents a highly indented system which includes part of the Zrmanja River, downstream from the Jankovića Buk, the Novigrad and the Karin Seas, and the strait connecting the Novigrad Sea with the Velebit Channel. The very fact that the estuary of the Zrmanja River is located in the karst area makes this system highly vulnerable and susceptible to possible anthropogenic pressures. Preservation of such and similar water systems relies on the knowledge of the main factors that govern its physical, chemical, biological and geochemical features. Due to the lack of geochemical data for the Zrmanja River estuary, a comprehensive study was carried out to explain sedimentation processes and the origin of the material within this estuary and provide additional knowledge necessary for its sustainable use and preservation. This paper, therefore, attempts to summarize the obtained data, focusing on the main natural and anthropogenic factors that define the geochemistry of the Zrmanja River estuary.

scholarly journals Assessing the Hydrodynamic Response of the Mar Menor Lagoon to Dredging Inlets Interventions through Numerical Modelling

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 959 ◽  
Author(s):  
Miriam García-Oliva ◽  
Ángel Pérez-Ruzafa ◽  
Georg Umgiesser ◽  
William McKiver ◽  
Michol Ghezzo ◽  
...  
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Agricultural Practices ◽  
Mitigation Measures ◽  
Negative Effects ◽  
Anthropogenic Pressures ◽  
Water Renewal ◽  
Mar Menor ◽  
Mar Menor Lagoon

The Mar Menor lagoon has been subjected to high anthropogenic pressures. Among them, in the early 1970s, dredging and enlargement of one of the inlets to make a navigable channel has had strong consequences on the hydrology, ecology, and fisheries of the lagoon. In recent years, changes in agricultural practices have induced an eutrophication process, leading to loss of water quality. As a solution, some management proposals have included dredging of the inlets in order to increase the water renewal. However, these proposals did not take into account the negative effects of previous experiences nor the consequences on environmental conditions of the lagoon and therefore on biological processes. The purpose of this work is to assess the effect that proposed mitigation measures, could have on the hydrodynamic conditions and discuss its possible ecological consequences. A three-dimensional (3D) numerical model has been used to simulate the lagoon under different dredging scenarios, covering different dredging depths and extensions. The simulated current fields and fluxes through the inlets, as well as water renewal times have been compared for the different scenarios. It is found that some of the considered scenarios take the system beyond the threshold of sustainability, where the modified current dynamics could affect sediment transport, beach dynamics and fishing capacities in a significant way. Water exchange with the Mediterranean is also strongly affected, with consequences for species connectivity, and a homogenization of the water renewal times that could lead to loss of ecosystem heterogeneity and structural complexity. The study demonstrates the utility of numerical models as effective tools for the management of coastal areas.

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