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2018 Geological Survey of Canada (GSC) Atlantic Science Hour

Who: Kristopher L. Kendell

Canada-Nova Scotia Offshore Petroleum Board
Halifax, Nova Scotia

What: Anthropic impacts on coastal systems, submarine geohazards and continental margins evolution

Carboniferous strata of the Sydney Basin outcrop onshore Cape Breton Island and extend offshore beneath the Laurentian Channel and Burin Platform. The offshore portion of the basin, between Nova Scotia and Newfoundland, is the predominant focus of this study. Subsurface maps were generated using an extensive suite of 2D seismic surveys that vary significantly in vintage and quality across the basin. Exploration wells intersecting the seismic data are shallow and only provide calibration of the Late Carboniferous seismic stratigraphy for the western and nearshore regions. To enhance interpretation of these variable quality surveys with limited well control, additional data sets were integrated into the workstation environment; including modern topography, surface geology, gravity, magnetics and research seismic.

Many of the seismic surveys were collected in the 1980's or earlier and imaging artefacts such as conventional seafloor and peg-leg multiples present a significant interpretation challenge. A recent seismic survey collected on the eastern side of the basin has substantially improved imaging, providing a higher degree of interpretation confidence that was used to guide interpretation on neighbouring poorer-quality surveys. In some areas, shallow, high-resolution research seismic profiles were vectorized and incorporated into the database. These shallow penetrating profiles helped to clearly distinguish higher amplitude flat-lying artefacts on the industry profiles, from folded dipping, and erosionally truncated Carboniferous and/or Permian strata. Significant efforts were also made to ensure that the shallow offshore geological interpretations were consistent with the stratigraphy exposed on Cape Breton Island. Likewise, exposed basement terranes in onshore areas were correlated with a moderate degree of confidence into offshore areas, with interpretations bolstered by the integrated gravity and magnetics data sets.

The integration and analysis of multiple data sets has reduced the many uncertainties that impeded an accurate subsurface interpretation of the Sydney Basin. Despite the remaining uncertainties, two significant observations can be made. (1) Pre-Carboniferous basement rocks are conceivably much shallower in the northern extent of the basin, consequently the overlying Carboniferous section thins to less than 1 km in some areas. (2) Horton Group rocks, and to a lesser degree the Windsor Group, may be localised and restricted to narrow grabens in the central Sydney Basin, thus occupying a less extensive area than previously interpreted.

When: 10:30 am, Wednesday, October 24, 2018

Where: AGC Boardroom, 5th Floor Murray, Bedford Institute of Oceanography, Dartmouth, Nova Scotia


Who: Dr. Thomas James

GSC-Pacific (Sidney)

What: Projected Sea-Level Rise in Canada

Recent scientific findings on projected global sea-level rise, especially those related to stability of the Antarctic ice sheet, will be discussed in the context of recent work on updating relative sea-level projections for Canada.

When: 11:00 am, Wednesday, October 18, 2018

Where: AGC Boardroom, 5th Floor Murray, Bedford Institute of Oceanography, Dartmouth, Nova Scotia


Who: Vittorio Maselli

School of Geosciences
University of Aberdeen

What: Anthropic impacts on coastal systems, submarine geohazards and continental margins evolution

This talk is aimed to present a brief overview of my experience in three particular research subjects and its potential application to the study of the Eastern Canada margin, in the light of my future position at the Department of Earth Sciences at Dalhousie University.

In the first part, I concentrate on coastal environments, probably the most complex, fragile and densely populated landscapes on Earth. Focusing on the largest southern European deltas, I will show how enhanced, and unaware, anthropic pressures on the landscape controlled their formation and retreat during the last few thousands of years. In the second part, I will outline research results associated with the study of marine geohazards, in particular tsunamis and landslides. I will present the results of a series of field campaigns along the coastline of Tanzania and the discovery of a 1000-yr old event that appears to have devastated a Swahili settlement. Tsunamis can be generated by earthquakes or by large submarine landslides, and it is often difficult to disentangle the role of different processes in promoting continental margin instability. Here, I will show how sediment supply, halokinesis and deep ocean circulation promoted margin instability along the Sigsbee Escarpment in the deep water Gulf of Mexico during the Late Quaternary. Continental margins form and evolve in response to allogenic and autogenic processes. The East Africa margin is one of the few places in the world where it is possible to observe the effect of continental rifting on the evolution of both continental and marine landscapes. In this last section of the talk, I will show how the East African Rift System (EARS) led to a physiographic change of the western Somali basin, promoting a reorganization of the deepwater drainage system and a shift in ocean bottom circulation.

When: 10:30 am, Wednesday, September 12, 2018

Where: AGC Boardroom, 5th Floor Murray, Bedford Institute of Oceanography, Dartmouth, Nova Scotia


Who: Valentina Yanko

Head of the Department of Physical and Marine Geology
Head of the Laboratory of Marine Geology and Geochemistry
Head of the Scientific and Educational Center of Geoarchaeology
Marine and Environmental Geology (SECGMEG)
Odessa I. I. Mechnikov National University, Ukraine

What: Degassing of the Black Sea Bottom under global climate change: significance for environment, geological exploration and navigation

The Black Sea basin contains great resources of methane gas stored in form of gas hydrates beneath sea floor, the amount of which is believed higher than in any other known gas reservoir on Earth. Gas related features e.g. submarine volcanoes, gas seeps, and gas bogs release methane to water column. The project is focussed on mapping these features on the Black Sea shelf and slope and on understanding energy resources and related geohazards in the world's largest (428,000 km2) meromictic basin. This research is relevant to energy policy makers and coastal managers who deal with environmental hazards and sustainable development in the region under the Global Climate Change. The presentation will address the current knowledge of the methane resources and seep-related features in the Black Sea, and discuss approaches, significance and benefits of the research into methane degassing.

When: 10:30 am, Wednesday, August 1, 2018

Where: AGC Boardroom, 5th Floor Murray, Bedford Institute of Oceanography, Dartmouth, Nova Scotia


Last Modified: 2018-10-18