Patrick Lajeunesse

Patrick Lajeunesse
Laval University | ULAVAL · Department of Geography

Ph.D.

About

168
Publications
30,138
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2,039
Citations
Citations since 2017
60 Research Items
1302 Citations
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250

Publications

Publications (168)
Presentation
The transition between marine- and terrestrial-based ice front corresponds to a key moment of deglaciation where stabilizations or readvances can occur. In West Greenland, a morainic system called the Fjord Stade is defined by two major stabilization periods associated with climatic events: the Marrait moraine (ca. 9.3 ka) and the Tasiussaq moraine...
Article
Full-text available
The Green Edge project was designed to investigate the onset, life, and fate of a phytoplankton spring bloom (PSB) in the Arctic Ocean. The lengthening of the ice-free period and the warming of seawater, amongst other factors, have induced major changes in Arctic Ocean biology over the last decades. Because the PSB is at the base of the Arctic Ocea...
Article
Full-text available
The glaciological significance of ice shelves is relatively well established for the stability of modern ice sheets of Antarctica. Past ice shelves of the Arctic, however, are poorly documented while their role for the stability of former ice sheets remains mostly unknown. Here we present swath bathymetry data and seismostratigraphic profiles that...
Article
In eastern Canada, the Charlevoix-Kamouraska/Bas-Saint-Laurent (CKBSL) seismic zone presents a seismic hazard almost as high as that of the active Pacific zone. The major event of February 5, 1663 CE, with an estimated magnitude of ≥7, highlights the importance of this seismic hazard. The numerous submarine landslides mapped in the St. Lawrence Est...
Article
Deltas are at the transition between fluvial and marine sedimentary environments where sediment density flows are often triggered during high river discharge events, forming submarine channels and sediment waves. On wave‐influenced deltas, longshore currents are particularly efficient at transporting sediment alongshore, reducing the likelihood of...
Article
Full-text available
High‐resolution imagery of the morphological character of modern active turbidite systems are critical for understanding the complexity of turbidity current processes occurring on the seafloor. Here, we describe a 30 cm‐resolution autonomous underwater vehicle repeat bathymetric dataset that allows to significantly increase the geomorphological det...
Preprint
The Green Edge project was designed to investigate the onset, life and fate of a phytoplankton spring bloom (PSB) in the Arctic Ocean. The lengthening of the ice-free period and the warming of seawater, amongst other factors, have induced major changes in arctic ocean biology over the last decades. Because the PSB is at the base of the Arctic Ocean...
Article
Full-text available
This paper presents a new annually laminated record (varves) from Lake Walker, Québec North Shore (eastern Canada) spanning the period from ~ 3230 to 2320 ± 20 cal BP. A ~ 3.5-m-long composite sequence was established with the best regular and continuous laminated intervals using computed tomography and high-resolution photographs. The varve chrono...
Article
Full-text available
Over the past decades, riparian land-use changes coupled to the multiplication of river infrastructures have enhanced vulnerability issues for societies and ecosystems located along large rivers. Exposure to geohazards is also changing due to the ongoing climate change, underlining the need for flexible management strategies for riparian environmen...
Article
Full-text available
Analysis of short sediment cores collected in Grand Lake, Labrador, revealed that this lake is an excellent candidate for the preservation of a laminated sediment record. The great depth of Grand Lake, the availability of fine sediments along its tributaries and its important seasonal river inflow have favoured the formation of a 160-year-long clas...
Article
Fjords can transition from marine embayments to lacustrine waterbodies under glacio-isostatic change following their deglaciation. However, little is known on how a transition from fjord to lake is influenced by glacial dynamics and how it influences sedimentation in and around the basin. Here, we analyse bathymetry imagery and subbottom imagery in...
Article
Climate change is impacting surficial geomorphic processes, especially in sensitive areas such as the sub-Arctic. One of the most common examples involves landslides, which often develop in glacio-isostatically raised marine clays in northeastern Canada. One of these sites, an expansive area of complex landslide terrain located at the mouth of the...
Article
Full-text available
Cyclic‐step bedforms typifying a Froude‐supercritical flow regime are a recurrent component of depositional/erosional turbiditic systems. Over modern delta slopes, cyclic steps have been inferred from observations of upslope‐migrating crescent‐shaped bedforms. However, the recognition in the sedimentary record of the resulting stratal pattern and d...
Preprint
Full-text available
Analysis of short sediment cores collected in Grand Lake, Labrador, revealed that this lake is an excellent candidate for the preservation of laminated sediments record. The great depth of Grand Lake, the availability of fine sediments along its tributaries, and its important seasonal river inflow have favored the formation of a 160 years-long clas...
Article
This review article deals with bank erosion from the perspective of rivers affected by seasonal ice formation. These rivers drain half of the terrestrial land surface globally, and are mainly located in both periglacial and cold, non-periglacial environments across the Northern Hemisphere. This review is based on a literature survey of 124 publicat...
Chapter
The Quaternary heritage and landscape of the Témiscouata–Madawaska Valley consists of an assemblage of landforms and deposits associated with former stabilizations of glacial margins during the Late Pleistocene development of an ice-free corridor in the Notre-Dame Ice Cap (NDIC), through which Glacial Lake Madawaska developed. This lake occupied an...
Article
The Lake Saint-Jean lowland is a particular area in eastern Canada as it constitutes an important Late Quaternary depocenter compared with other surrounding onshore regions. Here, the recent literature about the Late Quaternary history of the Lake Saint-Jean depocenter from the glaciated period to present-day is summarized; subsequently, we present...
Article
One of the most particular morphological features of the Québec North Shore (North Shore of the Estuary and Gulf of the St. Lawrence, eastern Canada) is the occurrence of deltaic complexes that form thick and extensive sediment bodies (gravel, sand and mud) along the modern coastline. The deltaic complexes were emplaced during the retreat of the La...
Article
High‐resolution multibeam bathymetric data and acoustic sub‐bottom profiles were recently collected in Grand Lake (Labrador), one of the deepest lake basins in eastern North America, to reconstruct: (1) the retreat of the Laurentide Ice Sheet (LIS) west of Lake Melville, and (2) the history of sedimentation since deglaciation in this 54‐km long, 3‐...
Article
Three sediment cores recovered on the lower slope of the continental shelf in western Baffin Bay (Arctic Canada) as well as swath bathymetry and subbottom profiler data collected on the shelf and slope of the region were analysed to investigate whether the Laurentide Ice Sheet (LIS) reached the shelf edge offshore Home Bay during the Last Glacial M...
Article
Full-text available
Three sediment cores recovered on the lower slope of the continental shelf in western Baffin Bay (Arctic Canada) as well as swath bathymetry and subbottom profiler data collected on the shelf and slope of the region were analysed to investigate whether the Laurentide Ice Sheet (LIS) reached the shelf edge offshore Home Bay during the Last Glacial M...
Article
The monitoring of turbidity currents enables accurate internal structure and timing of these flows to be understood. Without monitoring, triggers of turbidity currents often remain hypothetical and are inferred from sedimentary structures of deposits and their age. In this study, the bottom currents within 20 m of the seabed in one of the Pointe‐de...
Article
Full-text available
This paper presents a series of 50 geomorphological maps of the seabed of northeastern Baffin Island fiords and cross-shelf troughs, in eastern Arctic Canada. The mapping was produced using swath bathymetry imagery from multiple bathymetry datasets. A total of 24 types of landform were systematically mapped (>55,000 landforms) and reflect processes...
Article
Full-text available
This Data in Brief article presents sedimentological and geochemical parameters from a set of sedimentary samples collected in the Saint-Charles River, a tributary of the Saint-Lawrence River flowing in Québec City (QC, Canada). It details the experimental design, methods, materials and results of destructive analyses related to a multi-proxy study...
Article
Full-text available
Glacier and ice sheet mass loss as a result of climate change is driving important coastal changes in Arctic fjords. Yet, limited information exists for Arctic coasts regarding the influence of glacial erosion and ice mass loss on the occurrence and character of turbidity currents in fjords, which themselves affect delta dynamics. Here, we show how...
Article
Fiord morphology plays a fundamental role in glacier flow dynamics and on ice-margin stability. As most of the present-day margins of the Greenland Ice Sheet lays in fiords, there is a need for understanding short- and long-term glacial dynamics in fiord settings. We investigate ice-sheet retreat patterns in previously glaciated submarine terrain o...
Article
Québec City (QC, Canada) is an important urban center developed along the Saint-Charles River, at the confluence with the Saint-Lawrence River. Here, environmental issues related to pollution have been recently raised for sediments trapped upstream a dam built in the early 1970s. The major concern is about downstream transport of sediments and cont...
Article
Full-text available
Ice-stream networks constitute the arteries of ice sheets through which large volumes of glacial ice are rapidly delivered from the continent to the ocean. Modifications in ice-stream networks have a major impact on ice sheet mass balance and global sea level. Reorganizations in the drainage network of ice streams have been reported in both modern...
Article
Full-text available
A radiocarbon-dated marine sediment core retrieved in Kane Basin, central Nares Strait, was analysed to constrain the timing of the postglacial opening of this Arctic gateway and its Holocene evolution. This study is based on a set of sedimentological and geochemical proxies of changing sedimentary processes and sources that provide new insight int...
Preprint
Glacier and ice sheet mass loss as a result of climate change is driving important coastal changes in Arctic fjords. Yet, limited information exists for Arctic coasts regarding the influence of glacial erosion and ice mass loss on the occurrence and character of turbidity currents in fjords which themselves affect delta dynamics. Here, we show how...
Article
Full-text available
Ice stream networks constitute the arteries of ice sheets through which large volumes of glacial ice are rapidly delivered from the continent to the ocean. Modifications in ice stream networks have major impact on ice sheet mass balance and global sea level. However, the mechanisms controlling ice stream switching remain poorly understood. Here, we...
Article
Investigation of seismic activity in eastern Canada is important for natural hazard management as two major active seismic zones with many historical records are located in the region: the Western Québec seismic zone (WQSZ) and the Charlevoix–Kamouraska seismic zone (CKSZ), with the latter being the most active in northeastern America. This paper d...
Poster
The coupling of unmanned aerial systems (UAS) with Structure-from-Motion (SfM) photogrammetry allows rapid and inexpensive 3D field imagery. This method was used to quantify sediment transport in an urban river flowing in downtown Quebec City (Saint-Charles River). The aim was to evaluate the impact of dam management operations at the outlet (i.e.,...
Conference Paper
Full-text available
The objective of this 4-days excursion is to study different aspects of the Quaternary last deglaciation which relates to the recession and final disappearance of the Laurentide Ice Sheet during the latest Wisconsinan and Holocene along the Québec North Shore (North Shore of the Estuary of the St. Lawrence, Québec, Canada). A particular emphasis wi...
Article
Full-text available
A radiocarbon dated marine sediment core retrieved in Kane Basin, central Nares Strait, was analysed to constrain the timing of the postglacial opening of this Arctic gateway and its Holocene evolution. This study is based on a set of sedimentological and geochemical proxies of changing sedimentary processes and sources that translate into ice shee...
Article
Swath bathymetry data and seismic profiles collected in the NW Gulf of St Lawrence reveal a series of wedge-shaped depositional systems interpreted as grounding zone wedges (GZWs). Some segments of the GZWs change locally to form frontal moraines, or morainal banks, and subaqueous ice-contact fans, reflecting changes in either the nature of the ice...
Article
Deglacial sedimentary sequences recording the decay and final demise of ice sheets result from intricate interactions between the pattern of ice margin retreat, inherited basin physiography and relative sea-level (RSL) changes. A specific emphasis is here given to the glacio-isostatic adjustment (GIA), which may force postglacial local RSL fall in...
Conference Paper
Lake Melville and the Gulf of St. Lawrence are estuarine environments that are influenced by the freshwater run-off from eastern Canada and, in addition, are sensitive to broad scale oceanographic changes via the subsurface inflowing Labrador Current (LC) and the Laurentian Bottom Current, an offshoot of the Gulfstream, respectively. Paleoenvironme...
Article
Full-text available
This paper analyzes short gravity cores sampled along transects in three adjacent deep fjord-lakes (lakes Pentecôte, Walker, and Pasteur) on the Québec North Shore, eastern Canada, to evaluate the distribution of laminated sediments and potential for varve formation. Facies analysis based on lithological description, digital photos, CT-scan images,...
Poster
Full-text available
These expanded records allow paleomagnetic secular variation (PSV) from the Baffin Bay to be studied in high-resolution and will thus make it possible to reconstitute the variations of the magnetic field in order to establish a chronostratigraphy of the sedimentary sequences and to deduce the advances and glacial retreats.
Presentation
A glacial landsystem approach has been used to investigate ice-sheet retreats in previously englaciated terrain in order to provide analogues for modern ice-sheet response to climate change and sea-level rise. Although some sectors of palaeo-ice sheets have been the focused of numerous landsystem studies, none has focused on the Laurentide Ice Shee...
Conference Paper
Full-text available
Ice-streaming is one the most efficient mechanism through which ice can be exported from the interior of ice sheets to the ocean. The stability of ice sheet is therefore intrinsically linked to the activity of their ice stream networks. Inferred in modern and palaeo-ice sheets, changes in the drainage network of ice streams usually results into ice...
Poster
Full-text available
Late Quaternary patterns of deglaciation in Clyde Inlet, eastern Baffin Island
Article
Full-text available
The paleogeographic reconstruction of the successive inland positions of a retreating ice sheet is generally constrained by mapping moraines. However, deltaic complexes constructed by sediment-charged meltwater can also provide a record of the retreating ice-margin positions. Here, we examine a serie of ice-contact, ice-distal glaciofluvial and par...
Article
Full-text available
Reconstructing the extent, flow and decay of the Laurentide Ice Sheet (LIS) on the continental shelves of North America during the last glaciation provides paleoglaciological analogues that are essential for understanding and predicting how modern marine-based ice-sheets will respond to future climate change and sea level fluctuations. The geometry...
Article
The Magdalen Islands (Québec, Canada) in the centre of the Gulf of St. Lawrence are located in a strategic position for providing an overview of the relative sea-level (RSL) history of the Maritime Provinces of eastern Canada. Although data are available for the coastal terrestrial areas of the Maritimes, data from the Gulf are very scarce and both...
Article
Full-text available
The nature of glaciomarine sediments deposited during ice margin retreat can vary according to physiographic setting and relative sea level fluctuations. To understand the effects of these two parameters on sedimentation, we analyzed the sediment records of four lakes located within former isolated glaciomarine embayments of the northern Champlain...
Article
The evolution of deltas and submarine fans is often envisioned as largely controlled by relative sea-level variations. However, in some cases, relative sea level can have less effect on delta and submarine fan activity than sediment supply and shelf geomorphology. In order to document the relative importance of these three factors on deltaic and su...
Poster
Full-text available
Late Wisconsinan glacial dynamics in Broughton and Merchant’s Bay troughs, eastern Baffin Island
Poster
Full-text available
These results and paleomagnetic data indicate that the chronostratigraphy is similar both inside and outside the crater and that sediments possibly deposited before the last glaciation could not be sampled.
Conference Paper
Full-text available
Post-LGM (LastGlacialMaximum) deglacial sequences are dominated by backstepping grounding zone wedges (GZWs) and ensuing deltaic and coastal successions. While the grounding line position governs sediment entry points in the early deglacial epoch characterized by glaciomarine environment, the relative sea level (RSL) fall forced by the glacio-isost...
Conference Paper
Full-text available
Recent multibeam bathymetry and subbottom profiler data were collected during the 2015 and 2016 ArcticNet cruises aboard the CCGS Amundsen to investigate the pattern and dynamics of former ice-flow on the northeastern Baffin Shelf and in the Baffin Island fjords. Merged with data from previous ArcticNet cruises (2003-2014), the new dataset reveals...
Chapter
Full-text available
In the recent years, Lake Pavin sedimentary basin has been intensively studied by several acoustic surveys (high resolution seismic reflection profiling, multibeam bathymetry) and gravity coring campaigns. This new data set combining acoustic images and multidisciplinary study of sediment cores allows characterizing contrasted subaquatic sedimentar...
Chapter
Full-text available
In this chapter we present an up-to-date database of sedimentary sequences retrieved from Lake Pavin during the last 50 years in both oxic and anoxic waters. The detailed history of this mid Holocene crater lake can be reconstructed from the correlation of radiocarbon dated sedimentary sequences retrieved from the deep central basin, a subaquatic p...
Article
Deglacial sequences typically include backstepping grounding zone wedges and prevailing glaciomarine depositional facies. However, in coastal domains, deglacial sequences are dominated by depositional systems ranging from turbiditic to fluvial facies. Such deglacial sequences are strongly impacted by glacio-isostatic rebound, the rate and amplitude...
Article
Two gravity cores (778 and 780) sampled at the Nelson River mouth and one (776) at the Churchill River mouth in western Hudson Bay, Canada, were analyzed in order to identify the impact of dam construction on hydrology and sedimentary regime of both rivers. Another core (772) was sampled offshore and used as a reference core without a direct river...
Conference Paper
Full-text available
Deglacial episodes form specific and intricate sedimentary sequences characterized by stratigraphic architectures and stacking pattern not only dependent on the usual A/S ratio but also on glacial advance/retreat cycles. Deglacial sedimentary successions are either subdivided according to the ice margin dynamic, RSL changes, or a combination of bot...
Article
High Arctic lakes are commonly used for paleoclimatic reconstructions because they are particularly sensitive to climate variability. However, the processes leading to sediment deposition and distribution in these lakes are often poorly understood. Here, for the first time in the Canadian High Arctic, we present original data resulting from swath b...
Article
High-resolution swath bathymetry data collected in fjord-lakes Pentecôte, Walker and Pasteur (eastern Québec, Canada) allowed imaging in great detail the deltas of four rivers in order to understand the factors controlling the formation and downslope evolution of bedforms present on their slopes. The morphometry and morphology of 199 bedforms refle...
Article
The Charlevoix region, in southeastern Québec, is characterized by a dramatic landscape formed by the junction of the Laurentian Highlands, the Charlevoix Astrobleme and the St Lawrence Estuary. At the Last Glacial Maximum (LGM), the region was completely covered by the Laurentide Ice Sheet (LIS). The complex topography of the region was the stage...
Conference Paper
Full-text available
Deltaic landforms and related stratigraphic architectures are frequently used as proxy for reconstruction of past continental or marine environmental evolutions. Indeed, in addition to autocyclic processes, emplacement of deltaic systems is primarily controlled by changes in sediment supply and relative sea-level (RSL). In our study, we investigate...
Article
Disturbed lacustrine deposits of eastern Canada have been associated with past seismic events in the intraplate Western Québec Seismic Zone (WQZ) and the Charlevoix–Kamouraska Seismic Zone (CKSZ). With five major earthquakes that occurred during historical times and hundreds of minor earthquakes, the CKSZ is the most active seismic zone in eastern...
Article
Lake sediments are relevant natural seismographs over long time scale. However, because tectonicevents are not systematically recorded in lake sediments, one forthcoming challenge forpaleoseismology is to better assess lake sensitivity to earthquakes. To this end, a limnogeologicalinvestigation, including hydroacoustic mapping techniques, cores sam...