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Alex Normandeau

@sedialex.bsky.social
1.1K followers 303 following 12 posts

Marine geoscientist at the Geological Survey of Canada (Atlantic)

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Alex Normandeau @sedialex.bsky.social · 29/10/2025
We have a new paper in Science Advances on seasonal movements of the sub-Arctic seafloor. Using sub-annual bathymetry, porewater data, and moored sensors, we observed the seabed expanding and contracting through freeze–thaw cycles, forming seasonal frost blisters. doi.org/10.1126/scia...
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Reposted by Alex Normandeau
Canadian Journal of Earth Sciences @canjearthsci.bsky.social · 07/05/2025
📣The May issue of CJES is now LIVE. 📃Featuring: "Holocene earthquake-triggered submarine landslides and turbidites in western Baffin Bay" by @sedialex.bsky.social et al. cdnsciencepub.com/doi/full/10.... 📸Fig 1. Study sites in western Baffin Bay. #marine #landslide #geosky #earthquake #geoscience
Map showing the location of the two study sites in western Baffin Bay (Scott Trough and Home Bay) along with earthquake epicenters (between 1985 and 2023) and their magnitudes
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Alex Normandeau @sedialex.bsky.social · 10/04/2025
Our new study out in G-cubed, wrapping up 8 years of repeat seafloor mapping, flow monitoring, and sediment coring in a glacierized fjord. We made some interesting discoveries about how glaciers, turbidity currents, and submarine landslides interact in these dynamic environments tinyurl.com/49xms8hr
Figure from the scientific study illustrating the many processes operating in a glacierized floor and the sediments that are left behind on the seafloor
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Reposted by Alex Normandeau
Dr Dan Shugar 🇨🇦 @watershedlab.bsky.social · 10/04/2025
Ooooh new paper from @sedialex.bsky.social that is going to go right to the top of my pile of papers to read! 🧪⚒️ "Processes and Products of Turbidity Currents and Submarine Landslides in a Glacierized Fjord (Southwind Fjord, Baffin Island)" agupubs.onlinelibrary.wiley.com/doi/full/10....
agupubs.onlinelibrary.wiley.com
Processes and Products of Turbidity Currents and Submarine Landslides in a Glacierized Fjord (Southwind Fjord, Baffin Island)
Overview of 8 years of seabed mapping, flow monitoring and sediment coring in a dynamic glacierized fjord Turbidity currents occur every year and confine sand to the fjord basin floor with little...
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Alex Normandeau @sedialex.bsky.social · 03/12/2024
Elisabeth Steel (Queen's U.) and I invite you to submit abstracts on clastic marine sedimentology. Our session aims to connect marine sedimentologists working on modern, experimental, and ancient depositional systems, bridging the gap between these fields. Deadline for abstract submission: Feb. 16!
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Alex Normandeau @sedialex.bsky.social · 21/11/2024
Just like the 1929 earthquake was recorded in marine sediments offshore Atlantic Canada, the 1933 earthquake triggered a turbidite in Baffin Bay. Sediment cores from the region suggest other large earthquakes occurred during the late Holocene. Stay tuned for our upcoming paper on the subject
Left: image of a sediment core showing a turbidite near the bottom. Right: Remotely-operated vehicle collecting a sediment core in Baffin Bay
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Alex Normandeau @sedialex.bsky.social · 19/11/2024
The earthquake triggered a submarine landslide and turbidite recorded in marine sediments offshore Atlantic Canada. We know other very large landslides occurred during the last 4,000 years thanks to marine sediment cores collected in the deep waters of eastern Canada
Image showing on the left, a sediment core with submarine landslide deposits, and on the right, a map of the source of 2 large landslides that occurred in 1929 and 450 CE.
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Alex Normandeau @sedialex.bsky.social · 18/11/2024
These same sediment cores being analyzed through a CT-Scan and a μCT-Scan to reconstruct the past history of the region
Sediment core analyzed through a CT-ScanShort sediment core being analyzed through a micro CT-Scan
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Alex Normandeau @sedialex.bsky.social · 02/10/2024
How is marine geoscience conducted at the Geological Survey of Canada? Here are some of the tools we use to characterize the seafloor and monitor seabed processes, in collaboration with our partners from academia and other government departments.
Illustration showcasing the various tools deployed from a scientific vessel, including multibeam echosounders, piston coring, autonomous underwater vehicles, remotely operated vehicles and moorings.
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Alex Normandeau @sedialex.bsky.social · 24/09/2024
We deployed an autonomous underwater vehicle and 3 moorings in Shortland Canyon, eastern Canada, from the RRS Discovery. Sediment cores were also recovered from the canyon bottom. These data will allow us to understand the physical oceanography and seabed processes in eastern Canadian canyons.
ADCPs in a float deployed from a shipA sediment trap floating in the oceanAn autonomous underwater vehicle deployed from a ship
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Alex Normandeau @sedialex.bsky.social · 07/09/2024
A few years ago, I created animations to illustrate how geological sampling and surveys are conducted at sea. Here are two examples: 1) piston coring to collect long sediment cores 2) multibeam surveys to create maps of the seafloor. Animations are available here: sites.google.com/view/normand...
Image illustrating piston coring operationsImage illustrating multibeam echosounder operations
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