Who: Josué J. Jautzy

What: Clumped isotope geochemistry: a new frontier in exploring our environment

The observation of stable isotopes at the beginning of the last century led to a series of technical and scientific developments that triggered the onset of a new way of exploring our environment. These scientific advances have led to the development of geochemical tools that allows us to understand physico-chemical processes encoded in natural archives, perform source differentiation, determine formation temperatures and study reaction mechanisms. In the last couple of decades, further technological advancement in mass spectrometry has allowed us to dive into intramolecular isotopic measurements. In this presentation, we will illustrate this new way of probing environmental processes through research applied to the thermometry of methane and carbonates in various environments, as well as the study of life in the deep subsurface. We will conclude with an outlook of the future of this field, which will likely revolutionize isotope geochemistry in the coming decades.

When: POSTPONED

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

Who: Alex Normandeau

What: Marine geohazards on glaciated margins: new insights from recent GSC cruises

Marine geohazards, including submarine landslides and turbidity currents are common in glaciated environments and are known to be quite active. However, their exact recurrence and the external controls responsible for their recurrence and triggers are still poorly understood. Recent Geological Survey of Canada (Atlantic) cruises (2018041, 2018042, 2019804 and 2019Nuliajuk) have allowed the collection of new multibeam bathymetry data and sediment cores. The recent analysis of these data have allowed an improved understanding of marine geohazards in glaciated regions, from the role the retreat pattern of glaciers plays on turbidity current activity to the identification of new triggers for submarine landslides. This presentation will show recent results from Baffin Bay and the Scotian Slope with the overall goal of revealing new insights on how marine geohazards are triggered on glaciated margins.

When: 11:00 am, Wednesday, November 27, 2019

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

Who: David Didier

What: Morphodynamic behavior of beaches in the Estuary and Gulf of St. Lawrence (EGSL): exploring nearshore morphological controls on coastal water levels and hazards

Coasts are complex dynamic systems shaped by high waves in conjunction with high tides and storm surges – and multiple processes occurring at various scales. Canada's coastline is also highly affected by cryogenic and glacial processes. One of the greatest concern for climate adaptation strategies is the varying exposure to incident wave energy combined with changing sea ice cover. Storms (and sea level) are the main threats to coastal infrastructures, and therefore the geographical and geological characteristics need to be considered when studying coastal hazards and impacts. Although sheltered from ocean and long waves, beaches in the EGSL suffer from a shrinking and fragile nearshore ice complex during winter months when storm impacts increase significantly. This talk presents recent works on coastal morphodynamic in the EGSL, introducing studies on flooding and erosion, and discussing the role of the coastal morphology on total water levels. New results on swash-related processes inducing coastline retreat will be revealed and ongoing works will be presented.

When: 11:00 am, Wednesday, November 20, 2019

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

Who: Melissa Grey

What: Digesting the Late Carboniferous: using fish coprolites to reconstruct the aquatic paleoecosystem of the Joggins Formation, Nova Scotia, Canada

Coprolites (fossilized feces) preserve the diets of the animals that produce them and therefore can provide valuable insights into paleoenvironments and paleoecosystems. Coprolites are abundant in the limestones throughout the Joggins Fossil Cliffs UNESCO World Heritage Site and are used, along with what is already known from body fossils, to reconstruct the Late Carboniferous food web of this estuarine environment. The host rock (limestones), abundance, and content of the coprolites indicate that the majority of the Joggins Formation coprolites originate from fish. Specimens were studied in hand sample and with standard transmitted-light microscopy in order to classify the morphology of the coprolites (e.g., large, spiral, cylindrical, irregular, conical, or small/equant) and determine their contents. This enabled the creation of a hypothetical trophic pyramid with rhizodonts at the apex producing the largest coprolites, and smaller fish species, such as haplolepids, responsible for the small/equant-shaped coprolites at the secondary consumer level. Energy Dispersive X-Ray Spectroscopy (EDS) will be used in conjunction with scanning electron microscopy (SEM) to test our hypothesis that coprolites from different trophic levels will have dissimilar elemental compositions because of dietary differences. Preliminary results on ten samples of various morphotypes/hypothesized trophic levels indicate that there are elemental differences, supporting our hypothesis. Small/equant coprolites exhibit enrichment primarily with respect to barite along with some pyrite and one sample with minor zinc sulphide. Cylindrical, irregular, spiral and conical coprolites tend to contain pyrite and zinc sulphide with minimal barite. The single large coprolite analyzed contained only barite. Further EDS analysis on additional samples (particularly small/equant and large morphotypes) is required to validate whether these elemental discrepancies are indeed the result of different diets and can therefore be related to trophic level.

When: 2:00 pm, Thursday, November 14, 2019

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

Who: Blair Greenan

What: Canada's Changing Climate Report

This report is about how and why Canada's climate has changed and what changes are projected for the future. This report is the first of a series to be released as part of Canada in a Changing Climate: Advancing our Knowledge for Action. It documents changes across Canada in temperature, precipitation, snow, ice, permafrost and freshwater availability as well as in Canada's three oceans. This first document of the series provides the climate-science foundation for upcoming reports, which will address the impacts of climate change on our communities, environment and economy, and how we are adapting.

When: 11:00 am, Wednesday, November 6, 2019

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

Who: Jonathan Beaudoin ¹ and Craig Brown ²

What: Recent advances in multispectral backscatter and water column imaging from multibeam echosounders

Acoustic remote sensing of the seabed provides essential information for geological and habitat mapping. The typical products of interest are bathymetry, slope, rugosity and acoustic backscattering strength, with multibeam echosounders (MBES) generally being the tool of choice to acquire these data sets. The combined acoustic response of the seabed and the subsurface can vary with MBES operating frequency. At worst, this can make for difficulties in merging results from different mapping systems or mapping campaigns. At best, however, having observations of the same seafloor at different acoustic wavelengths allows for increased discriminatory power in seabed classification and characterization efforts. The varying response of materials to different wavelengths of electromagnetic energy has been used to great success in the field of satellite remote sensing where the term multi-spectral is used to describe sensors that provide these type of data and also to techniques that take advantage of it.

Early research in this field shows promising results from mapping platforms that offer multiple MBES, this typically being done to allow a single platform to provide mapping capabilities over a wide range of depths (e.g. high frequency for shallow water and low frequency for deeper water). With care, the multiple MBES systems on a single platform can be operated simultaneously so as not to interfere with each other and the acquisition of multi-spectral data sets is possible on these platforms. In the past few years, MBES manufacturers have introduced systems with broadband capabilities, allowing users much more choice in terms of selecting the frequency of operation. In some systems, the frequency can be modified on a ping-by-ping basis, allowing for frequency hopping ping configurations that can provide multi-spectral acoustic measurements with a single pass and a single system.

In this talk, we will discuss early collaborative field efforts in the Bedford Basin that led to the transition from a prototype hardware and corresponding software processing workflow to a working system that was ready for use in the field. We will touch on some examples of early multispectral work, specifically we will explore findings and various acquisition and post-processing hurdles that were discovered, followed by a brief discussion of potential applications. We will also introduce how we have made improvements to FMGT, the QPS seabed backscatter processing software, to set the stage for researchers to begin exploring, developing and refining applications for multi-spectral acoustic observations of the seabed. Finally, we will cap off by exploring how the same techniques used for imaging the seafloor can also be used to image the water column and we will showcase some early results from separate field trials in Bedford Basin.

When: 11:00 am, Wednesday, October 30, 2019

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

Who: Gavin Manson

What: CanCoast 2.0: Data and Indices to Describe the Sensitivity of Canada's Marine Coasts to Changing Climate

Baseline mapping of coastal characteristics and understanding of the dynamic response of coastal sensitivity to environmental changes provide a strong foundation for climate change adaptation in Canada's coastal regions. CanCoast is a collection of datasets that describe the physical characteristics of Canada's marine coasts. It includes datasets that are not expected to change through time (such as coastal materials and backshore slope), and some that are projected to change as climate changes (such as wave height and mean sea level). CanCoast includes: sea-level change (early and late 21st century); wave-heights including the effects of sea ice (early and late 21st century); ground ice content; coastal materials; tidal range; and backshore slope. These are mapped to a common high-resolution shoreline and each shoreline segment is assigned a score of 1 to 5 for each characteristic. From the scores, a novel technique, known as mu-statics, is used to calculate indices that show the generalised coastal sensitivity of Canada's marine coasts in early and late 21st century climates and the spatially-variable change in sensitivity between the early and the late 21st century. Because of the scales of the input data, the generalised indices are best used to identify regions that differ in sensitivity to changing climate, rather than local properties or coastal infrastructure with specific characteristics that cannot be resolved in this national-scale approach.

NOTE SPECIAL TIME: 2:00 pm, Wednesday, October 16, 2019

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

Who: David Eaton

What: Crustal Fluids, Friction and Faults: What can we learn from injection-induced earthquakes?

Induced earthquakes - seismic events that are triggered by human activities - have been linked to various anthropogenic processes including deep underground mining, impoundment of a large surface water reservoir behind a dam, and subsurface injection or withdrawal of fluids. Several energy technologies, such as shale-gas development and enhanced geothermal systems, rely on subsurface fluid-injection processes that mimic certain naturally occurring phenomena. The deployment of these energy technologies has led to felt seismicity in some areas where certain necessary conditions are met, notably the presence of a pre-existing fault network and a hydraulic pathway connecting it to the injection source. Passive-seismic monitoring is a rapidly developing geophysical technique used to characterize fracture growth, fluid diffusion and fault activation across a range of temporal and spatial scales. Recent investigations of induced seismicity are yielding surprising new insights about fluid transport, ground motion, and the frictional behaviour of faults. Examination of induced events could therefore aid in understanding natural earthquakes in intraplate regions and, more generally, fluid-driven processes in the Earth's crust.

When: 11:00 am, Wednesday, October 9, 2019

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