Constraint of GIA in Northern Europe with Geological RSL and VLM Data

2020 ◽  
Author(s):  
Karen Simon ◽  
Riccardo Riva
Keyword(s):  
North Sea ◽  
Tide Gauge ◽  
Northern Europe ◽  
British Isles ◽  
Additional Measure ◽  
Isostatic Adjustment ◽  
The North ◽  
Vertical Land Motion ◽  
The North Sea ◽  
Semi Empirical

<p>In this study, we focus on better constraint of the long term glacial isostatic adjustment (GIA) signal at present-day, and its role as a contributor to total present-day rates of change. The main study area extends from the coastal regions of northern Europe to Scandinavia. Both Holocene relative sea level (RSL) data as well as vertical land motion (VLM) data are incorporated as constraints in a semi-empirical GIA model. Specifically, 70 geological rates of GIA-driven RSL change are inferred from Holocene data; peak RSL fall is indicated in central Scandinavia and the northern British Isles where past ice sheets were thickest, RSL rise is indicated in the southern British Isles and along the northern European coastline. Rates of vertical land motion from GPS at 108 sites provide an additional measure of regional GIA deformation. Within the study area, the geological RSL data complement the spatial gaps of the VLM data and vice versa; both datasets are inverted in a semi-empirical GIA model to yield updated estimates of regional present-day GIA deformations. A regional validation is presented for the North Sea, where the GIA signal may be complicated by lateral variations in Earth structure and existing predictions of regional and global GIA models are discrepant. The model validation in the North Sea region indicates that geological data are needed to fit independent estimates of GIA-related RSL change inferred from tide gauge rates, suggesting that the geological rates provide an important additional constraint of present-day GIA.</p>

Constraint of GIA in Northern Europe and the North Sea with Geological RSL and GPS Data

2021 ◽  
Author(s):  
Karen Simon ◽  
Riccardo Riva ◽  
Bert Vermeersen
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Tide Gauge ◽  
Data Driven ◽  
Northern Europe ◽  
Additional Measure ◽  
The North ◽  
Vertical Land Motion ◽  
The North Sea ◽  
Semi Empirical

<p>This study focusses on improved constraint of the millennial time-scale glacial isostatic adjustment (GIA) signal at present-day, and its role as a contributor to present-day sea-level budgets. The study area extends from the coastal regions of northern Europe to Scandinavia. Both Holocene relative sea level (RSL) data as well as vertical land motion (VLM) data are incorporated as constraints in a semi-empirical GIA model. Specifically, 71 geological rates of GIA-driven RSL change are inferred from Holocene proxy data. Rates of vertical land motion from GNSS at 108 sites provide an additional measure of regional GIA deformation; within the study area, the geological RSL data complement the spatial gaps of the VLM data and vice versa. Both datasets are inverted in a semi-empirical GIA model to yield updated estimates of regional present-day GIA deformations. A regional validation is presented for the North Sea, where the GIA signal may be complicated by lateral variations in Earth structure and existing predictions of regional and global GIA models show discrepancies. The model validation in the North Sea region suggests that geological data are needed to fit independent estimates of GIA-related RSL change inferred from tide gauge rates, indicating that geological rates from Holocene data can provide an important additional constraint for data-driven approaches to GIA estimation. The geological proxy rates therefore provide a unique dataset with which to complement or validate existing data-driven approaches that use satellite era rates of change.</p>

scholarly journals North SEAL: a new dataset of sea level changes in the North Sea from satellite altimetry

2021 ◽  
Vol 13 (8) ◽  
pp. 3733-3753
Author(s):  
Denise Dettmering ◽  
Felix L. Müller ◽  
Julius Oelsmann ◽  
Marcello Passaro ◽  
Christian Schwatke ◽  
...  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Tide Gauge ◽  
Sea Level Changes ◽  
Adaptation Measures ◽  
Isostatic Adjustment ◽  
The North ◽  
Sea Level Anomalies ◽  
Vertical Land Motion ◽  
The North Sea

Abstract. Information on sea level and its temporal and spatial variability is of great importance for various scientific, societal, and economic issues. This article reports about a new sea level dataset for the North Sea (named North SEAL) of monthly sea level anomalies (SLAs), absolute sea level trends, and amplitudes of the mean annual sea level cycle over the period 1995–2019. Uncertainties and quality flags are provided together with the data. The dataset has been created from multi-mission cross-calibrated altimetry data preprocessed with coastal dedicated approaches and gridded with an innovative least-squares procedure including an advanced outlier detection to a 6–8 km wide triangular mesh. The comparison of SLAs and tide gauge time series shows good consistency, with average correlations of 0.85 and maximum correlations of 0.93. The improvement with respect to existing global gridded altimetry solutions amounts to 8 %–10 %, and it is most pronounced in complicated coastal environments such as river mouths or regions sheltered by islands. The differences in trends at tide gauge locations depend on the vertical land motion model used to correct relative sea level trends. The best consistency with a median difference of 0.04±1.15 mm yr−1 is reached by applying a recent glacial isostatic adjustment (GIA) model. With the presented sea level dataset, for the first time, a regionally optimized product for the entire North Sea is made available. It will enable further investigations of ocean processes, sea level projections, and studies on coastal adaptation measures. The North SEAL data are available at https://doi.org/10.17882/79673 (Müller et al., 2021).

scholarly journals NorthSEAL: A new Dataset of Sea Level Changes in the North Sea from Satellite Altimetry

2021 ◽  
Author(s):  
Denise Dettmering ◽  
Felix L. Müller ◽  
Julius Oelsmann ◽  
Marcello Passaro ◽  
Christian Schwatke ◽  
...  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Tide Gauge ◽  
Sea Level Changes ◽  
Adaptation Measures ◽  
Isostatic Adjustment ◽  
The North ◽  
Sea Level Anomalies ◽  
Vertical Land Motion ◽  
The North Sea

Abstract. Information on sea level and its temporal and spatial variability is of great importance for various scientific, societal and economic issues. This article reports about a new sea level dataset for the North Sea (named NorthSEAL) of monthly sea level anomalies (SLA), absolute sea level trends and sea level mean annual amplitudes over the period 1995–2019. Uncertainties and quality flags are provided together with the data. The dataset has been created from multi-mission cross-calibrated altimetry data, preprocessed 5 with coastal dedicated approaches and gridded with innovative methods to a 6–8 km wide triangular mesh. The comparison of SLA and tide gauge time series shows a good consistency with average correlations of 0.85 and maximum correlations of 0.93. The improvement with respect to existing global gridded altimetry solutions amounts to 8–10 %, and it is most pronounced in complicated coastal environments such as river mouths or regions sheltered by islands. The differences in trends at tide gauge locations depend on the vertical land motion model used to correct relative sea level trends. The best 10 consistency with a median difference of 0.04 ± 1.15 mm/year is reached by applying a recent glacial isostatic adjustment (GIA) model. With the presented sea level dataset, for the first time, a regionally optimized product for the entire North Sea is made available. It will enable further investigations of ocean processes, sea level projections and studies on coastal adaptation measures. The NorthSEAL data is available at https://doi.org/10.17882/79673 (Müller et al., 2021).

Storm Xaver over Europe in December 2013 and its energy meteorological impacts

2020 ◽  
Author(s):  
Anthony Kettle
Keyword(s):  
Storm Surge ◽  
North Sea ◽  
Tide Gauge ◽  
Offshore Wind ◽  
Northern Europe ◽  
Energy Infrastructure ◽  
The North ◽  
Short Period ◽  
The North Sea ◽  
The Uk

<p>Storm Xaver impacted the northern Europe on 5-6 December 2013.  It developed southeast of Greenland and passed north of Scotland and across southern Norway on a trajectory that led to a cold air outbreak across the North Sea and intense convection activity in northern Europe.  Strong sustained north winds led to a high storm surge that impacted all countries bordering the North Sea.  Storm Xaver was a century scale event with certain locations around the North Sea reporting their highest ever water levels since the start of modern records.  Media reports from the time of the storm chronicle the scale of the disruptions, including many cancelled flights, interrupted rail networks, closed bridges and roads, coastal building collapses, and power blackouts across northern Europe.  Much of this was due to the strong winds, but coastal storm surge flooding was important in the UK, and it led to interrupted port operations around the North Sea.</p><p>The storm was important for energy infrastructure and particularly for wind energy infrastructure.  In the northern North Sea, petroleum platforms were evacuated and operations closed ahead of the storm as a precautionary measure.  A number of onshore wind turbines were badly damaged by high winds and lightning strikes in the UK and Germany.  Over the North Sea, wind speeds exceeded the turbine shutdown threshold of 25 m/s for an extended period of time, with economic impacts from the loss of power generation.   In the German Bight, the FINO1 offshore wind energy research platform was damaged at the 15 m level by large waves.  This was the third report of storm damage to this platform after Storm Britta in 2006 and Storm Tilo in 2007.  Researchers have highlighted the need to reassess  the design criteria for offshore wind turbines based on these kinds of extreme meteorological events.  For the offshore wind industry, an important element of energy meteorology is to characterize both the evolving wind and wave fields during severe storms as both elements contribute to turbine loads and potential damage.</p><p>The present conference contribution presents a literature review of the major events during Storm Xaver and impacts on energy infrastructure.  Tide gauge records are reanalyzed to trace the progress of the storm surge wave around the North Sea.  A spectral analysis is used to separate the long period storm surge component, diurnal/semidiurnal tide, and short period components in the original water level record.  The short period component of the tide gauge record is important as it may be linked with infragravity waves that have been implicated in certain cases of offshore infrastructure damage in addition to coastal erosion.  Discussion is made of offshore wave records during the storm.  Storm Xaver is compared with two damaging offshore storms in 2006 and 2007.</p>

Sceaf, Japheth and the origins of the Anglo-Saxons

2002 ◽  
Vol 31 ◽  
pp. 13-46 ◽  
Author(s):  
Daniel Anlezark
Keyword(s):  
North Sea ◽  
Oral Tradition ◽  
Historical Record ◽  
Northern Europe ◽  
British Isles ◽  
Anglo Saxon ◽  
The North ◽  
The North Sea

The Anglo-Saxons' awareness of their cultural and racial affiliation with their continental cousins is well attested, as is their interest in the earliest migrations of their ancestors to the British Isles from the homelands of northern Europe. The founding figures who led the migrations from Europe across the North Sea had names which were preserved by oral tradition well into the Christian period, and the names of these founders of Anglo-Saxon dynasties entered the historical record when Christian missionaries introduced the technology of writing among the Anglo-Saxons.

scholarly journals Large-scale forcing of the European Slope Current and associated inflows to the North Sea

Ocean Science ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 315-335 ◽  
Author(s):  
Robert Marsh ◽  
Ivan D. Haigh ◽  
Stuart A. Cunningham ◽  
Mark E. Inall ◽  
Marie Porter ◽  
...  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Tide Gauge ◽  
Density Gradients ◽  
Current Transport ◽  
Tide Gauge Records ◽  
The North ◽  
Wide Range ◽  
The North Sea ◽  
Northern North Sea

Abstract. The European Slope Current provides a shelf-edge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988–2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely recruited from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25–50 % reductions of these density gradients over 1996–1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10–40 % of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a general decline in this percentage over 1988–2007. Salinities in the Slope Current correspondingly decreased, evidenced in ocean analysis data. Further to the north, in the Atlantic Water conveyed by the Slope Current through the Faroe–Shetland Channel (FSC), salinity is observed to increase over this period while declining in the hindcast. The observed trend may have broadly compensated for a decline in the Atlantic inflow, limiting salinity changes in the northern North Sea during this period. Proxies for both Slope Current transport and Atlantic inflow to the North Sea are sought in sea level height differences across the FSC and between Shetland and the Scottish mainland (Wick). Variability of Slope Current transport on a wide range of timescales, from seasonal to multi-decadal, is implicit in sea level differences between Lerwick (Shetland) and Tórshavn (Faroes), in both tide gauge records from 1957 and a longer model hindcast spanning 1958–2012. Wick–Lerwick sea level differences in tide gauge records from 1965 indicate considerable decadal variability in the Fair Isle Current transport that dominates Atlantic inflow to the northwest North Sea, while sea level differences in the hindcast are dominated by strong seasonal variability. Uncertainties in the Wick tide gauge record limit confidence in this proxy.

scholarly journals Coastal archaeologies: settlement on the changing North Sea littoral

Antiquity ◽  
2017 ◽  
Vol 91 (358) ◽  
pp. 1095-1097
Author(s):  
Hans Peeters
Keyword(s):  
Sea Level ◽  
North Sea ◽  
British Isles ◽  
Prehistoric Archaeology ◽  
Sea Floor ◽  
The Past ◽  
The North ◽  
The North Sea ◽  
The Many ◽  
Rising Sea Level

Over the past decade or so, the submerged prehistoric archaeology and landscapes in the area that is known to us today as the North Sea have received increasing attention from both archaeologists and earth scientists. For too long, this body of water was perceived as a socio-cultural obstacle between the prehistoric Continent and the British Isles, the rising sea level a threat to coastal settlers, and the North Sea floor itself an inaccessible submerged landscape. Notwithstanding the many pertinent and pervasive problems that the archaeology of the North Sea still needs to overcome, recent research has made clear that these rather uninspiring beliefs are misplaced.

Clay mineralogy of the Tertiary onshore and offshore strata of the British Isles

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 5-46 ◽  
Author(s):  
J. M. Huggett ◽  
R. W. O'B. Knox
Keyword(s):  
North Sea ◽  
Volcanic Ash ◽  
Middle Miocene ◽  
Clay Mineralogy ◽  
British Isles ◽  
Subsequent Increase ◽  
The North ◽  
Clay Deposits ◽  
The North Sea ◽  
Clay Formation

AbstractTertiary sediments are of restricted occurrence in the onshore British Isles but occur extensively offshore, attaining thicknesses of ~4 km in the Faroe—Shetland Basin and ~3 km in the North Sea Basin. Clay mineral stratigraphic studies of the North Sea Paleocene to Lower Miocene successions show a dominance of smectite (and smectite-rich illite-smectite) with minor illite, kaolin and chlorite. Abundant smectite in the Paleocene and Eocene reflects alteration of volcanic ash derived from pyroclastic activity associated with the opening of the North Atlantic between Greenland and Europe. However, the persistence of high smectite into the Oligocene and Middle Miocene indicates that smectite-rich soils on adjacent land areas may also have been an important source of detrital clays. An upwards change to illite-dominated assemblages in the Middle Miocene reflects higher rates of erosion and detrital clay supply, with a subsequent increase in chlorite reflecting climatic cooling. The persistence of smectite-rich assemblages to depths of >3000 m in the offshore indicates little burial-related diagenesis within the mudstone succession, possibly as a consequence of over-pressuring. Despite the importance of Paleocene and Eocene sandstones as hydrocarbon reservoirs in the North Sea and Faroe-Shetland basins, there are few published details of the authigenic clays. The principal clay cements in these sandstones are kaolin and chlorite, with only minor illite reported.The offshore successions provide a valuable background to the interpretation of the more intensively studied, but stratigraphically less complete, onshore Tertiary successions. The most extensive onshore successions occur in the London and Hampshire basins where sediments of Paleocene to earliest Oligocene age are preserved. Here clay assemblages are dominated by illite and smectite with subordinate kaolin and chlorite. The relatively large smectite content of these successions is also attributed primarily to the alteration of volcanic ash. Associated non-smectitic clays are largely detrital in origin and sourced from areas to the west, with reworking of laterites and “china clay” deposits developed over Cornish granites. Authigenic clays include glauconite (sensu lato), early diagenetic kaolin that has replaced muscovite (principally in the London Clay Formation of the London Basin) and smectite that has replaced ash. Pedogenesis has extensively modified the assemblages in the Reading Formation and Solent Group. Tertiary sediments are largely missing from onshore northern and western Britain, but clays and sands of Eocene and Oligocene age are locally preserved in small fault-bounded basins. Here, clay assemblages are dominated by kaolin with minor illite.

Long-term trends in the distribution, abundance and seasonal occurrence of larvae of mackerel (Scomber scombrus L.) around the British Isles, 1948–1978

1981 ◽  
Vol 61 (2) ◽  
pp. 343-358 ◽  
Author(s):  
S. H. Coombs ◽  
C. E. Mitchell
Keyword(s):  
Surface Temperature ◽  
North Sea ◽  
Sea Surface ◽  
Seasonal Occurrence ◽  
British Isles ◽  
Scomber Scombrus ◽  
The North ◽  
The North Sea ◽  
Long Term Trends

The distribution, abundance and seasonal occurrence of larvae of mackerel (Scomber scombrus L.) are described from routine Continuous Plankton Recorder (CPR) sampling around the British Isles over the period 1948–78, and from more intensive CPR sampling in the Celtic Sea in 1977. There were two main areas of larval concentration: in the North Sea and over and adjacent to the Celtic Plateau; subsidiary aggregations were observed to the northwest of Ireland and to the west of Norway. There were some similarities between the distribution of larvae around the British Isles and that of adult Calanus spp. In the North Sea there was a southerly shift of larval distribution over the period 1948–77; over a similar period the abundance of larvae increased to reach high numbers by the late 1950s and subsequently declined after the mid-6os. To the south-west of the British Isles numbers of larvae showed a long-term decline. The long-term trends of distribution and abundance are discussed in relation to concurrent biological and environmental change. The clearest relationship was found between the numbers of mackerel larvae in the North Sea and sea-surface temperature in the North Atlantic, which suggests a common causative agent for both sets of observations; also, there was a weak relationship with both spawning stock biomass and sea-surface temperature at the spawning areas. In the North Sea the seasonal occurrence of larvae was from May to August, the majority being taken in June and July; over the period 1948–77 the seasonal time of occurrence of highest numbers of larvae has remained relatively constant. In the Celtic Sea the seasonal occurrence of larvae was spread over a longer period, from March to August, with relatively high numbers from March to June; over the period 1950–78 the time of occurrence has been variable, possibly with a tendency towards later timing in more recent years.

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