scholarly journals Widespread glacial erosion on the Scandinavian passive margin

Geology ◽  
2021 ◽  
Author(s):  
Vivi K. Pedersen ◽  
Åsne Rosseland Knutsen ◽  
Gustav Pallisgaard-Olesen ◽  
Jane Lund Andersen ◽  
Robert Moucha ◽  
...  
Keyword(s):  
High Elevation ◽  
Passive Margin ◽  
Inner Shelf ◽  
Glacial Erosion ◽  
Late Pliocene ◽  
Source To Sink

The topography in Scandinavia features enigmatic high-elevation low-relief plateau regions dissected by deep valleys and fjords. These plateau regions have long been interpreted as relict landforms of a preglacial origin, whereas recent studies suggest they have been modified significantly by glacial and periglacial denudation. We used late Pliocene–Quaternary source-to-sink analyses to untangle this scientific conundrum. We compared glacier-derived offshore sediment volumes with estimates of erosion in onshore valleys and fjords and on the inner shelf. Our results suggest that onshore valley and fjord erosion falls 61%–66% short of the offshore sink volume. Erosion on the inner shelf cannot accommodate this mismatch, implying that the entire Scandinavian landscape and adjacent shelf have experienced significant glacial erosion.

scholarly journals Supplemental Material: Widespread glacial erosion on the Scandinavian passive margin

2021 ◽  
Author(s):  
Vivi Pedersen ◽  
et al.
Keyword(s):  
Sea Level ◽  
Passive Margin ◽  
Dynamic Topography ◽  
Glacial Erosion ◽  
Source To Sink ◽  
Effective Elastic Thickness ◽  
Wedge Volume

Table S1 (source to sink analysis), and the influence of dynamic topography (Fig. S1), effective elastic thickness (Fig. S2), and paleo sea level Fig. S3) on shelf wedge volume and bedrock deflection.<br>

scholarly journals Supplemental Material: Widespread glacial erosion on the Scandinavian passive margin

2021 ◽  
Author(s):  
Vivi Pedersen ◽  
et al.
Keyword(s):  
Sea Level ◽  
Passive Margin ◽  
Dynamic Topography ◽  
Glacial Erosion ◽  
Source To Sink ◽  
Effective Elastic Thickness ◽  
Wedge Volume

Table S1 (source to sink analysis), and the influence of dynamic topography (Fig. S1), effective elastic thickness (Fig. S2), and paleo sea level Fig. S3) on shelf wedge volume and bedrock deflection.<br>

Sea level response to Quartenary erosion and deposition in Scandinavia 

2021 ◽  
Author(s):  
Gustav Pallisgaard-Olesen ◽  
Vivi Kathrine Pedersen ◽  
Natalya Gomez
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Glacial Cycles ◽  
Glacial Erosion ◽  
Erosion And Deposition ◽  
Late Pliocene ◽  
Glacial Origin ◽  
Sediment Deposits ◽  
Mass Redistribution ◽  
Global Sea Level

&lt;div&gt; &lt;p&gt;The landscape in western Scandinavia has undergone dramatic changes through numerous glaciations during the Quaternary. These changes in topography and in the volumes of offshore sediment deposits, have caused significant isostatic adjustments and local sea level changes, owing to erosional unloading and depositional loading of the lithosphere. Mass redistribution from erosion and deposition also has the potential to cause significant pertubations of the geoid, resulting in additional sea-level changes. The combined sea-level response from these processes, is yet to be investigated in detail for Scandinavia.&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;In this study we estimate the total sea level change from late-Pliocene- Quaternary glacial erosion and deposition in the Scandinavian region, using a gravitationally self-consistent global sea level model that includes the full viscoelastic response of the solid Earth to surface loading and unloading. In addition to the total late Pliocene-Quaternary mass redistribution, we &lt;span&gt;also &lt;/span&gt;estimate transient sea level changes related specifically to the two latest glacial cycles.&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;We utilize existing observations of offshore sediment thicknesses of glacial origin, and combine these with estimates of onshore glacial erosion and estimates of erosion on the inner shelf. Based on these estimates, we can define mass redistribution and construct a preglacial landscape setting.&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;Our preliminary results show &lt;span&gt;perturbations of&lt;/span&gt; the local sea level up to &amp;#8764; 200 m since&lt;span&gt; the&lt;/span&gt; late-Pliocene in the Norwegian Sea, suggesting that erosion and deposition ha&lt;span&gt;ve&lt;/span&gt; influenced the local paleo sea level history in Scandinavia significantly.&lt;/p&gt; &lt;/div&gt;

scholarly journals Glacial erosion dynamics in a small mountainous watershed (Southern French Alps): A source-to-sink approach

2017 ◽  
Vol 458 ◽  
pp. 366-379 ◽  
Author(s):  
Lucile Bonneau ◽  
Samuel Toucanne ◽  
Germain Bayon ◽  
Stéphan J. Jorry ◽  
Laurent Emmanuel ◽  
...  
Keyword(s):  
Glacial Erosion ◽  
French Alps ◽  
Source To Sink ◽  
Mountainous Watershed

scholarly journals Quantitative stratigraphic analysis in a source-to-sink numerical framework

2018 ◽  
Author(s):  
Xuesong Ding ◽  
Tristan Salles ◽  
Nicolas Flament ◽  
Patrice Rey
Keyword(s):  
Sea Level ◽  
Trajectory Analysis ◽  
Rate Of Change ◽  
Sediment Supply ◽  
Passive Margin ◽  
Shelf Edge ◽  
Analysis Method ◽  
Source To Sink ◽  
Sedimentary Architecture ◽  
Thermal Subsidence

Abstract. The sedimentary architecture at continental margins reflects the interplay between the rate of change of accommodation creation (δA) and the rate of change of sediment supply (δS). As a result, stratigraphic interpretation increasingly focuses on understanding the link between deposition patterns and changes in δA/δS. Here, we use the landscape modelling framework pyBadlands to assess the respective performance of two well-established stratigraphic interpretation techniques: the trajectory analysis method and the accommodation succession method. In contrast to most Stratigraphic Forward Models (SFMs), pyBadlands provides self-consistent sediment supply to basin margins as it simulates erosion, sediment transport and deposition in a source-to-sink context. We present a landscape evolution that takes into account periodic sea level variations and passive margin thermal subsidence over 30 million years, under uniform rainfall. We implement the two aforementioned approaches to interpret the resulting depositional cycles at the continental margin. We first apply both the trajectory analysis and the accommodation succession methods to manually map key stratigraphic surfaces and define stratigraphic units from shelf-edge (or offlap break) trajectories, stratal terminations and stratal geometries. We then design a set of post-processing numerical tools to calculate shoreline and shelf-edge trajectories, the temporal evolution of changes in accommodation and sedimentation, and automatically produce stratigraphic interpretations. Comparing manual and automatic stratigraphic interpretations reveals that the results of the trajectory analysis method depend on time-dependent processes such as thermal subsidence whereas the accommodation succession method does not. In addition to reconstructing stratal stacking patterns, the tools we introduce here make it possible to quickly extract Wheeler diagrams and synthetic cores at any location within the simulated domain. Our work provides an efficient and flexible quantitative sequence stratigraphic framework to evaluate the main drivers (climate, sea level and tectonics) controlling sedimentary architectures and investigate their respective roles in sedimentary basins development.

scholarly journals Glacial Erosion Rates Determined at Vorab Glacier: Implications for the Evolution of Limestone Plateaus

Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 356
Author(s):  
Olivia Steinemann ◽  
Alicia Martinez ◽  
Vincenzo Picotti ◽  
Christof Vockenhuber ◽  
Susan Ivy-Ochs
Keyword(s):  
Eastern Alps ◽  
Crystalline Rock ◽  
High Elevation ◽  
Glacial Erosion ◽  
Mountain Ranges ◽  
Glacier Forefield ◽  
Erosion Rates ◽  
Cosmogenic Nuclide ◽  
Crystalline Bedrock ◽  
The Relationship

Understanding how fast glaciers erode their bedrock substrate is one of the key elements in reconstructing how the action of glaciers gives mountain ranges their shape. By combining cosmogenic nuclide concentrations determined in glacially abraded bedrock with a numerical model, we quantify glacial erosion rates over the last 15 ka. We measured cosmogenic 36Cl in fourteen samples from the limestone forefield of the Vorab glacier (Eastern Alps, Switzerland). Determined glacial erosion rates range from 0.01 mm a−1 to 0.16 mm a−1. These glacial abrasion rates differ quite markedly from rates measured on crystalline bedrock (>1 mm a−1), but are similarly low to the rates determined on the only examined limestone plateau so far, the Tsanfleuron glacier forefield. Our data, congruent with field observations, suggest that the Vorab glacier planed off crystalline rock (Permian Verrucano) overlying the Glarus thrust. Upon reaching the underlying strongly karstified limestone the glacier virtually stopped eroding its bed. We attribute this to immediate drainage of meltwater into the karst passages below the glacier, which inhibits sliding. The determined glacial erosion rates underscore the relationship between geology and the resulting landscape that evolves, whether high elevation plateaus in limestone terrains or steep-walled valleys in granitic/gneissic areas.

Spatial variation of erosion rates and passive margin escarpment embayment from New England, NSW and Bellenden Ker, Queensland, Australia: an analysis using GIS and in-situ 10Be basin-wide cosmogenic nuclides

2020 ◽  
Author(s):  
Jamie Glass ◽  
Alexandru Codilean ◽  
Reka Fülöp ◽  
Klaus Wilcken ◽  
Tim Cohen ◽  
...  
Keyword(s):  
New England ◽  
Spatial Variation ◽  
Erosion Rate ◽  
Soil Depth ◽  
High Elevation ◽  
Passive Margin ◽  
Annual Rainfall ◽  
Main Trunk ◽  
Erosion Rates ◽  
Great Escarpment

&lt;p&gt;The eastern seaboard of Australia is characterized by a passive margin and a continental divide that separates the inland-draining rivers from those that drain to the Coral and Tasman seas. Seaward of this divide lies the Great Escarpment (GE) of Australia that separates a moderate relief coastal plain from a low relief, high elevation plateau. Quantifying the spatial variation of erosion rates from temperate New England (NE), NSW and tropical Bellenden Ker (BK), Queensland, two regions with distinctly different climates and escarpment embayment, could help constrain erosional controls that contribute to escarpment form. In this study, we compared forty detrital 10Be samples collected from sediments in the main trunk and tributaries of five major rivers: the Macleay, Bellinger, and Clarence in NE and the Russel-Mulgrave and North Johnstone in BK. We then traced the escarpment position in ARCGIS and calculated a sinuosity ratio to better compare the degree of embayment in each region. Across both datasets we found that for NE, which has deep gorges cutting into the plateau, the degree of embayment was twice that of BK, where the escarpment position is significantly less embayed and erosion rates significantly more variable (ratio of .18 vs .38). Erosion rates in low slope areas, such as on the plateau, were universally low with no other significant controlling factors. There was no correlation between erosion rates and catchment area, and that our data echo previous studies that find that once mean rainfall passes an approximate threshold (around 2000mm/yr) basin characteristics that are known to control erosion rates, such as slope and lithology, are subdued.&lt;/p&gt;&lt;p&gt;&amp;#160;In temperate NE, where rainfall ranges from approximately 800-1200mm/yr, there was a moderate linear correlation with mean catchment rainfall and erosion rates (R&lt;sup&gt;2&lt;/sup&gt; .50), which is likely due to a strong orographic effect due to the escarpment. Erosion rates from tributaries below the plateau were highly variable and ranged from 5m/Ma up to 60m/Ma and correlated strongly with mean catchment slope (R&lt;sup&gt;2&lt;/sup&gt; .86). In addition, there were moderate inverse linear correlations between erosion rate and the catchment total percent granite and sedimentary rock (R&lt;sup&gt;2&lt;/sup&gt; .53 and .63 respectively) and a moderate correlation between erosion rate and catchment total percent metamorphic rock (R&lt;sup&gt;2&lt;/sup&gt; .57). Similar to previous studies, these data suggest that in temperate climates with moderate amounts of annual rainfall, individual basin characteristics play a significant role in controlling basin wide erosion rates.&lt;/p&gt;&lt;p&gt;In contrast, data from tropical BK, where mean rainfall amounts are in excess of 2000mm/yr, erosion rates from tributaries below the plateau were significantly less variable than NE. Rates had a mean of 37m/Ma &amp;#177; 9 (standard deviation 5m/Ma, N=10) and were not significantly correlated with mean catchment slope nor catchment lithology. The mean erosion rate of BK is similar to that of other studies in the region, though with slightly less variability, and possibly reinforces the hypothesis from other researchers that in tropical climates with significant mean rainfall, soil depth effectively armors hillslopes and prevents bedrock erosion from occurring.&lt;/p&gt;

Recent crustal movements on the Labrador Shelf

1970 ◽  
Vol 7 (2) ◽  
pp. 571-575 ◽  
Author(s):  
A. C. Grant
Keyword(s):  
Sedimentary Rocks ◽  
Outer Shelf ◽  
Inner Shelf ◽  
Glacial Erosion ◽  
Precambrian Rocks ◽  
Crustal Movements ◽  
Channel One ◽  
Seaward Side ◽  
Isostatic Adjustment ◽  
Structural Disturbance

Seismic profiler investigations have confirmed that the marginal channel that occurs on the Labrador Shelf separates crystalline Precambrian rocks underlying the inner shelf from sedimentary rocks on the outer shelf. The relief of the channel is thought to be mainly the result of glacial erosion, but there is also evidence of structural disturbance associated with this feature. Most seismic profiler transects show pronounced upwarping of the sedimentary strata underlying the seaward side of the marginal channel. One explanation offered for this upwarping is that it may possibly be due to isostatic adjustment following removal of material by glacial erosion.

Selective glacial erosion on the Norwegian passive margin

Geology ◽  
2013 ◽  
Vol 41 (12) ◽  
pp. 1203-1206 ◽  
Author(s):  
Adrian M. Hall ◽  
Karin Ebert ◽  
Johan Kleman ◽  
Atle Nesje ◽  
Dag Ottesen
Keyword(s):  
Passive Margin ◽  
Glacial Erosion
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