scholarly journals An assessment of the influence of orbital forcing on Late Pliocene global sea-level using a shallow-marine sedimentary record from the Wanganui Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Juliet Perry Sefton
Keyword(s):  
New Zealand ◽  
Sea Level ◽  
Benthic Foraminifera ◽  
Volume Changes ◽  
Shallow Marine ◽  
Late Pliocene ◽  
Ice Volume ◽  
Global Ice Volume ◽  
Global Sea Level ◽  
Water Depths

<p>Classical Milankovitch Theory suggests variance in the orbital cycles of precession (21,000 year) modulated by eccentricity (~100,000 year) and obliquity (41,000 year) should have a profound influence on polar insolation and ice volume. However, the globally-integrated ice volume proxy record (benthic δ¹⁸O) during the Late Pliocene (3.0-2.6 Ma) is dominated by obliquity-paced cycles, and lacks a significant precession component. A number of conceptual hypotheses have been proposed to explain this “41,000 year problem”, but palaeoclimate records independent of the benthic δ¹⁸O record are required to test these hypotheses.  The Wanganui Basin, New Zealand, contains a well-dated, shallow-marine Neogene sedimentary succession that is widely recognised as an important site for examining sea-level/ice volume changes at orbital frequencies. In this study, the shallow-marine Late Pliocene Mangaweka Mudstone is examined at an orbital-scale resolution (~3-5 kyr sampling) along a continuous 672 metre thick (true thickness) outcropping road section on Watershed Road between the Rangitikei and Turakina River valleys.  Two modern analogue-calibrated water depth proxies were used to evaluate palaeobathymetric changes: (i) sediment texture and (ii) benthic foraminifera census data. An overall trend of shallowing to inner-shelf water depths occurs up-section, but is superimposed by higher frequency fluctuations. For the lowermost ~400 metres of the section, in situ benthic foraminifera assemblages indicate water depths >100 metres. As wave-induced sand transport does not occur on the modern Manawatu-Wanganui outer-shelf, and modern wave climates are assumed to be analogous to the Pliocene, it is concluded that the sediment grainsize approach is not an appropriate proxy for reconstruction water depth changes in the lower ~400 metres of section.  An integrated magneto-, bio- and tephrostratigraphy was developed that constrains the outcrop succession to between ~3.0 Ma and 2.58 Ma. Nine distinct cycles spanning ~400,000 years are identified in the grainsize and benthic foraminifera assemblages. Within the uncertainty of the age model, the Mangaweka Mudstone grainsize cycles can be matched one-for-one to the δ¹⁸O glacial-interglacial cycles, as they display a similar pattern in terms of frequency and amplitude. The frequency of the Mangaweka Mudstone cycles (and the corresponding interval in the benthic δ¹⁸O record) are dominated by the ~40,000 year obliquity cycle, but with a subordinate eccentricity component. Therefore, the fluctuations in the grainsize and benthic foraminifera proxies likely represent an indirect response to global sea-level fluctuations via their effect on continental shelf sediment transport mechanisms (non-wave) with the orbitally-paced transgression and regression of the shoreline on a restricted palaeo- continental shelf.  The implications for the orbital theory of the ice ages are that during the Late Pliocene, global ice volume changes responded primarily to obliquity, and the precession influences were either: (i) too low in amplitude to have influenced the grainsize and benthic foraminifera assemblages in the Mangaweka Mudstone depositional environment, or (ii) cancelled-out in global ice volume and sea-level changes because precession forcing is anti-phased between the hemispheres.</p>

scholarly journals An assessment of the influence of orbital forcing on Late Pliocene global sea-level using a shallow-marine sedimentary record from the Wanganui Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Juliet Perry Sefton
Keyword(s):  
New Zealand ◽  
Sea Level ◽  
Benthic Foraminifera ◽  
Volume Changes ◽  
Shallow Marine ◽  
Late Pliocene ◽  
Ice Volume ◽  
Global Ice Volume ◽  
Global Sea Level ◽  
Water Depths

<p>Classical Milankovitch Theory suggests variance in the orbital cycles of precession (21,000 year) modulated by eccentricity (~100,000 year) and obliquity (41,000 year) should have a profound influence on polar insolation and ice volume. However, the globally-integrated ice volume proxy record (benthic δ¹⁸O) during the Late Pliocene (3.0-2.6 Ma) is dominated by obliquity-paced cycles, and lacks a significant precession component. A number of conceptual hypotheses have been proposed to explain this “41,000 year problem”, but palaeoclimate records independent of the benthic δ¹⁸O record are required to test these hypotheses.  The Wanganui Basin, New Zealand, contains a well-dated, shallow-marine Neogene sedimentary succession that is widely recognised as an important site for examining sea-level/ice volume changes at orbital frequencies. In this study, the shallow-marine Late Pliocene Mangaweka Mudstone is examined at an orbital-scale resolution (~3-5 kyr sampling) along a continuous 672 metre thick (true thickness) outcropping road section on Watershed Road between the Rangitikei and Turakina River valleys.  Two modern analogue-calibrated water depth proxies were used to evaluate palaeobathymetric changes: (i) sediment texture and (ii) benthic foraminifera census data. An overall trend of shallowing to inner-shelf water depths occurs up-section, but is superimposed by higher frequency fluctuations. For the lowermost ~400 metres of the section, in situ benthic foraminifera assemblages indicate water depths >100 metres. As wave-induced sand transport does not occur on the modern Manawatu-Wanganui outer-shelf, and modern wave climates are assumed to be analogous to the Pliocene, it is concluded that the sediment grainsize approach is not an appropriate proxy for reconstruction water depth changes in the lower ~400 metres of section.  An integrated magneto-, bio- and tephrostratigraphy was developed that constrains the outcrop succession to between ~3.0 Ma and 2.58 Ma. Nine distinct cycles spanning ~400,000 years are identified in the grainsize and benthic foraminifera assemblages. Within the uncertainty of the age model, the Mangaweka Mudstone grainsize cycles can be matched one-for-one to the δ¹⁸O glacial-interglacial cycles, as they display a similar pattern in terms of frequency and amplitude. The frequency of the Mangaweka Mudstone cycles (and the corresponding interval in the benthic δ¹⁸O record) are dominated by the ~40,000 year obliquity cycle, but with a subordinate eccentricity component. Therefore, the fluctuations in the grainsize and benthic foraminifera proxies likely represent an indirect response to global sea-level fluctuations via their effect on continental shelf sediment transport mechanisms (non-wave) with the orbitally-paced transgression and regression of the shoreline on a restricted palaeo- continental shelf.  The implications for the orbital theory of the ice ages are that during the Late Pliocene, global ice volume changes responded primarily to obliquity, and the precession influences were either: (i) too low in amplitude to have influenced the grainsize and benthic foraminifera assemblages in the Mangaweka Mudstone depositional environment, or (ii) cancelled-out in global ice volume and sea-level changes because precession forcing is anti-phased between the hemispheres.</p>

scholarly journals Nonlinear response of the Antarctic Ice Sheet to late Quaternary sea level and climate forcing

2019 ◽  
Vol 13 (10) ◽  
pp. 2615-2631 ◽  
Author(s):  
Michelle Tigchelaar ◽  
Axel Timmermann ◽  
Tobias Friedrich ◽  
Malte Heinemann ◽  
David Pollard
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Volume Changes ◽  
Antarctic Ice Sheet ◽  
Glacial Ice ◽  
Ice Volume ◽  
Global Sea Level ◽  
The Individual ◽  
The Antarctic

Abstract. Antarctic ice volume has varied substantially during the late Quaternary, with reconstructions suggesting a glacial ice sheet extending to the continental shelf break and interglacial sea level highstands of several meters. Throughout this period, changes in the Antarctic Ice Sheet were driven by changes in atmospheric and oceanic conditions and global sea level; yet, so far modeling studies have not addressed which of these environmental forcings dominate and how they interact in the dynamical ice sheet response. Here, we force an Antarctic Ice Sheet model with global sea level reconstructions and transient, spatially explicit boundary conditions from a 408 ka climate model simulation, not only in concert with each other but, for the first time, also separately. We find that together these forcings drive glacial–interglacial ice volume changes of 12–14 ms.l.e., in line with reconstructions and previous modeling studies. None of the individual drivers – atmospheric temperature and precipitation, ocean temperatures, or sea level – single-handedly explains the full ice sheet response. In fact, the sum of the individual ice volume changes amounts to less than half of the full ice volume response, indicating the existence of strong nonlinearities and forcing synergy. Both sea level and atmospheric forcing are necessary to create full glacial ice sheet growth, whereas the contribution of ocean melt changes is found to be more a function of ice sheet geometry than climatic change. Our results highlight the importance of accurately representing the relative timing of forcings of past ice sheet simulations and underscore the need for developing coupled climate–ice sheet modeling frameworks that properly capture key feedbacks.

scholarly journals Pliocene glacial-interglacial sea-level change

2021 ◽  
Author(s):  
◽  
Georgia Grant
Keyword(s):  
Oxygen Isotope ◽  
Sea Level ◽  
Northern Hemisphere ◽  
Water Depth ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Late Pliocene ◽  
Ice Volume ◽  
Global Sea Level

<p>The mid- to late Pliocene (3.3-2.6 Ma) spans one of the most significant climatic transitions of the Cenozoic. It is characterised by global cooling from a climate with an atmospheric CO2 concentration of ~400 ppm and temperatures of 2-3°C warmer-than-present, to one marked by the progressive expansion of ice sheets on northern hemisphere. Consequently, the mid-Pliocene warm period (MPWP; 3.3-3.0 Ma) provides the most accessible and recent geological analogue for global sea-level variability relevant to future warming. Global mean sea level has been estimated at 22 ± 10 m above present-day for MPWP. However, recent re-evaluations of this estimate suggest that spatially-varying visco-elastic responses of the crust, local gravitational changes and dynamic topography from mantle processes may preclude ever being able to reconstruct peak Pliocene mean sea level. The Whanganui Basin, New Zealand, contains a ~5 km thick stratigraphic succession of Pliocene-Pleistocene (last 5 Ma), shallow-marine, cyclical sedimentary sequences demonstrated to record orbitally-paced, glacial-interglacial global sea-level fluctuations. A limitation of the Whanganui sea level record, to date, has been an inability to resolve the full amplitude of glacial-interglacial water depth change due to the occurrence of cycle bounding unconformities representing sub-aerial erosion during glacial lowstands.  This thesis analyses a new ~900 m-thick, mid- (3.3-3.0 Ma) to late Pliocene (3.0-2.6 Ma), shallow-marine, cyclical sedimentary succession from a remote and relatively understudied part of Whanganui Basin. Unlike previous studies, these shelf sediments were continuously deposited, and were not eroded during sea-level lowstands, and thus provide the potential to reconstruct the full amplitude of glacial-interglacial sea-level change. On orbital timescales the influence of mantle dynamic processes is minimal. The approach taken applies lithofacies, sequence stratigraphy, and benthic foraminiferal analyses and a novel depth-dependent sediment grain size method to reconstruct the paleowater depths for, two continuously-cored drill holes, which are integrated with studies of outcropping sections. The thesis presents a new record of the amplitude and frequency of orbitally-paced, global sea-level changes from a wave-graded continental shelf, that is independent of the benthic δ¹⁸O proxy record of global ice-volume change.  Paleobathymetric interpretations are underpinned by analysis of extant benthic foraminiferal census data and a statistical correlation with the distribution of modern taxa. In general, water depths derived from foraminiferal modern analogue technique are consistent with variability recorded by lithofacies. The inferred sea-level cycles co-vary with a qualitative climate record reconstructed from a census of extant pollen and spores, and a modern temperature relationship. A high-resolution age model is established using magnetostratigraphy constrained by biostratigraphy, and the dating and correlation of tephra. This integrated chronostratigraphy allows the recognition of 23 individual sedimentary cycles, that are correlated “one-to-one” across the paleo-shelf and are compared to the deep-ocean benthic oxygen isotope (δ ¹⁸O) record.  A grain size-water depth technique was developed to quantify the paleobathymetry with more precision than the relatively insensitive benthic foraminifera approach. The method utilises a water depth threshold relationship between wave-induced near bed velocity and the velocity required to transport sand. The resulting paleobathymetric records of the most sensitive sites, the mid-Pliocene Siberia-1 drill core and the late Pliocene Rangitikei River section, were selected to compile a composite paleobathymetry. A one-dimensional backstripping method was then applied to remove the effects of tectonic subsidence, sediment and water loading on the record, to derive a relative sea level (RSL) curve.  The contribution of glacio-hydro-isostatic (GIA) processes to the RSL record was evaluated using a process-based forward numerical solid Earth model for a range of plausible meltwater scenarios. The Whanganui Basin RSL record approximates eustatic sea level (ESL) in all scenarios when variability is dominated by Antarctic Ice Sheet meltwater source during the mid-Pliocene, but overestimates ESL once Northern Hemisphere ice sheet variability dominates in the late Pliocene.  The RSL record displays 20 kyr precession-paced sea level variability during the MPWP with an average amplitude of ~15 ± 8 m, in-phase with southern high-latitude summer insolation. These are interpreted as ~20 m Antarctic Ice Sheet contributions, offset by ~ 5 m anti-phased Greenland Ice Sheet contribution, in the absence of a significant Northern Hemisphere ice sheets. This interpretation is supported by a previously published ice-proximal precession-paced, ice-berg-rafted debris record recovered off the coast of Wilkes Land. The Whanganui RSL record is not consistent with a dominant 40 kyr pacing observed the benthic oxygen isotope stack at this time. While the deep ocean benthic δ¹⁸O stack is of varying temporal and spatial resolution, during this time interval, the Whanganui RSL record implies a more complex relationship between ice-volume and oxygen isotope composition of sea water (δ¹⁸Oseawater). The relative influences of varying composition of the polar ice sheets, marine versus land based ice, the out-of-phase behaviour of polar ice sheet growth and retreat, and a potential decoupling of ocean bottom water temperature and δ¹⁸Oseawater are explored.  The late Pliocene relative sea level record exhibits increasing ~40 kyr obliquity-paced amplitudes of ~20 ± 8 m. This is interpreted as a response to the expansion of Northern Hemisphere ice sheets after ~2.9 Ma. During this time the Antarctic proximal ice-berg rafted debris records display continuing precession-paced ice-volume fluctuations, but with decreasing amplitude suggesting cooling and stabilisation of the East Antarctic Ice Sheet. With the bipolar glaciation, the ocean δ¹⁸O signal became increasingly dominated by northern hemisphere ice-volume. However, the RSL record implies relatively limited ice-volume contributions (up to ~25 m sea level equivalent) prior to ~2.6 Ma.  The large amplitude contribution of Antarctic Ice Sheets to global sea level during the MPWP has significant implications for the sensitivity of the Antarctica Ice Sheet to global temperatures 2-3°C above preindustrial levels, and atmospheric CO₂ forecast for the coming decades.</p>

scholarly journals Pliocene glacial-interglacial sea-level change

2021 ◽  
Author(s):  
◽  
Georgia Grant
Keyword(s):  
Oxygen Isotope ◽  
Sea Level ◽  
Northern Hemisphere ◽  
Water Depth ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Late Pliocene ◽  
Ice Volume ◽  
Global Sea Level

<p>The mid- to late Pliocene (3.3-2.6 Ma) spans one of the most significant climatic transitions of the Cenozoic. It is characterised by global cooling from a climate with an atmospheric CO2 concentration of ~400 ppm and temperatures of 2-3°C warmer-than-present, to one marked by the progressive expansion of ice sheets on northern hemisphere. Consequently, the mid-Pliocene warm period (MPWP; 3.3-3.0 Ma) provides the most accessible and recent geological analogue for global sea-level variability relevant to future warming. Global mean sea level has been estimated at 22 ± 10 m above present-day for MPWP. However, recent re-evaluations of this estimate suggest that spatially-varying visco-elastic responses of the crust, local gravitational changes and dynamic topography from mantle processes may preclude ever being able to reconstruct peak Pliocene mean sea level. The Whanganui Basin, New Zealand, contains a ~5 km thick stratigraphic succession of Pliocene-Pleistocene (last 5 Ma), shallow-marine, cyclical sedimentary sequences demonstrated to record orbitally-paced, glacial-interglacial global sea-level fluctuations. A limitation of the Whanganui sea level record, to date, has been an inability to resolve the full amplitude of glacial-interglacial water depth change due to the occurrence of cycle bounding unconformities representing sub-aerial erosion during glacial lowstands.  This thesis analyses a new ~900 m-thick, mid- (3.3-3.0 Ma) to late Pliocene (3.0-2.6 Ma), shallow-marine, cyclical sedimentary succession from a remote and relatively understudied part of Whanganui Basin. Unlike previous studies, these shelf sediments were continuously deposited, and were not eroded during sea-level lowstands, and thus provide the potential to reconstruct the full amplitude of glacial-interglacial sea-level change. On orbital timescales the influence of mantle dynamic processes is minimal. The approach taken applies lithofacies, sequence stratigraphy, and benthic foraminiferal analyses and a novel depth-dependent sediment grain size method to reconstruct the paleowater depths for, two continuously-cored drill holes, which are integrated with studies of outcropping sections. The thesis presents a new record of the amplitude and frequency of orbitally-paced, global sea-level changes from a wave-graded continental shelf, that is independent of the benthic δ¹⁸O proxy record of global ice-volume change.  Paleobathymetric interpretations are underpinned by analysis of extant benthic foraminiferal census data and a statistical correlation with the distribution of modern taxa. In general, water depths derived from foraminiferal modern analogue technique are consistent with variability recorded by lithofacies. The inferred sea-level cycles co-vary with a qualitative climate record reconstructed from a census of extant pollen and spores, and a modern temperature relationship. A high-resolution age model is established using magnetostratigraphy constrained by biostratigraphy, and the dating and correlation of tephra. This integrated chronostratigraphy allows the recognition of 23 individual sedimentary cycles, that are correlated “one-to-one” across the paleo-shelf and are compared to the deep-ocean benthic oxygen isotope (δ ¹⁸O) record.  A grain size-water depth technique was developed to quantify the paleobathymetry with more precision than the relatively insensitive benthic foraminifera approach. The method utilises a water depth threshold relationship between wave-induced near bed velocity and the velocity required to transport sand. The resulting paleobathymetric records of the most sensitive sites, the mid-Pliocene Siberia-1 drill core and the late Pliocene Rangitikei River section, were selected to compile a composite paleobathymetry. A one-dimensional backstripping method was then applied to remove the effects of tectonic subsidence, sediment and water loading on the record, to derive a relative sea level (RSL) curve.  The contribution of glacio-hydro-isostatic (GIA) processes to the RSL record was evaluated using a process-based forward numerical solid Earth model for a range of plausible meltwater scenarios. The Whanganui Basin RSL record approximates eustatic sea level (ESL) in all scenarios when variability is dominated by Antarctic Ice Sheet meltwater source during the mid-Pliocene, but overestimates ESL once Northern Hemisphere ice sheet variability dominates in the late Pliocene.  The RSL record displays 20 kyr precession-paced sea level variability during the MPWP with an average amplitude of ~15 ± 8 m, in-phase with southern high-latitude summer insolation. These are interpreted as ~20 m Antarctic Ice Sheet contributions, offset by ~ 5 m anti-phased Greenland Ice Sheet contribution, in the absence of a significant Northern Hemisphere ice sheets. This interpretation is supported by a previously published ice-proximal precession-paced, ice-berg-rafted debris record recovered off the coast of Wilkes Land. The Whanganui RSL record is not consistent with a dominant 40 kyr pacing observed the benthic oxygen isotope stack at this time. While the deep ocean benthic δ¹⁸O stack is of varying temporal and spatial resolution, during this time interval, the Whanganui RSL record implies a more complex relationship between ice-volume and oxygen isotope composition of sea water (δ¹⁸Oseawater). The relative influences of varying composition of the polar ice sheets, marine versus land based ice, the out-of-phase behaviour of polar ice sheet growth and retreat, and a potential decoupling of ocean bottom water temperature and δ¹⁸Oseawater are explored.  The late Pliocene relative sea level record exhibits increasing ~40 kyr obliquity-paced amplitudes of ~20 ± 8 m. This is interpreted as a response to the expansion of Northern Hemisphere ice sheets after ~2.9 Ma. During this time the Antarctic proximal ice-berg rafted debris records display continuing precession-paced ice-volume fluctuations, but with decreasing amplitude suggesting cooling and stabilisation of the East Antarctic Ice Sheet. With the bipolar glaciation, the ocean δ¹⁸O signal became increasingly dominated by northern hemisphere ice-volume. However, the RSL record implies relatively limited ice-volume contributions (up to ~25 m sea level equivalent) prior to ~2.6 Ma.  The large amplitude contribution of Antarctic Ice Sheets to global sea level during the MPWP has significant implications for the sensitivity of the Antarctica Ice Sheet to global temperatures 2-3°C above preindustrial levels, and atmospheric CO₂ forecast for the coming decades.</p>

scholarly journals Nonlinear response of the Antarctic ice sheet to Quaternary sea level and climate forcing

2019 ◽  
Author(s):  
Michelle Tigchelaar ◽  
Axel Timmermann ◽  
Tobias Friedrich ◽  
Malte Heinemann ◽  
David Pollard
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Volume Changes ◽  
Antarctic Ice Sheet ◽  
Glacial Ice ◽  
Ice Volume ◽  
Modeling Studies ◽  
Global Sea Level ◽  
The Individual ◽  
The Antarctic

Abstract. Antarctic ice volume has varied substantially during the Quaternary, with reconstructions suggesting a glacial ice sheet extending to the continental shelf break, and interglacial sea level highstands of several meters. Throughout this period, changes in the Antarctic ice sheet were driven by changes in atmospheric and oceanic conditions and global sea level, yet so far, modeling studies have not addressed which of these environmental forcings dominate, and how they interact in the dynamical ice sheet response. Here we force an Antarctic ice sheet model with global sea level reconstructions and transient, spatially explicit boundary conditions from a 408 ka climate model simulation, not only in concert with each other but, for the first time, also separately. We find that together, these forcings drive glacial-interglacial ice volume changes of 12–14 m SLE, in line with reconstructions and previous modeling studies. None of the individual drivers – atmospheric temperature and precipitation, ocean temperatures, sea level – single-handedly explains the full ice sheet response. In fact, the sum of the individual ice volume changes amounts to less than half of the full ice volume response, indicating the existence of strong nonlinearities and forcing synergy. Both sea level and atmospheric forcing are necessary to create full glacial ice sheet growth, whereas the contribution of ocean melt changes is found to be more a function of ice sheet geometry than climatic change. Our results highlight the importance of accurately representing the relative timing of forcings of past ice sheet simulations, and underscore the need for developing coupled climate-ice sheet modeling frameworks that properly capture key feedbacks.

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;

Sign in / Sign up

Export Citation Format

Share Document