scholarly journals Sequence stratigraphy, basin morphology and sea-level history for the Permian Kapp Starostin Formation of Svalbard, Norway

2017 ◽  
Vol 155 (5) ◽  
pp. 1023-1039 ◽  
Author(s):  
DAVID P. G. BOND ◽  
DIERK P. G. BLOMEIER ◽  
ANNA M. DUSTIRA ◽  
PAUL B. WIGNALL ◽  
DANIEL COLLINS ◽  
...  
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Depositional History ◽  
Marine Strata ◽  
The North ◽  
Sverdrup Basin ◽  
Permian Extinction ◽  
Basin Morphology ◽  
Homoclinal Ramp

AbstractBased on seven measured sections from Svalbard, the marine strata of the Permian Kapp Starostin Formation are arranged into seven transgressive–regressive sequences (TR1–TR7) ofc. 4–5 Ma average duration, each bound by a maximum regressive surface. Facies, including heterozoan-dominated limestones, spiculitic cherts, sandstones, siltstones and shales, record deposition within inner, middle and outer shelf areas. The lowermost sequence, TR1, comprises most of the basal Vøringen Member, which records a transgression across the Gipshuken Formation following a hiatus of unknown duration. Temperate to cold, storm-dominated facies established in inner to middle shelf areas between the latest Artinskian and Kungurian. Prolonged deepening during sequences TR2 and TR3 was succeeded by a long-term shallowing-upward trend that lasted until the latest Permian (TR4–TR7). A major depocentre existed in central and western Spitsbergen while to the north, Dickson Land remained a shallow platform, leading to a shallow homoclinal ramp in NE Spitsbergen and Nordaustlandet. The Middle Permian extinction (late Capitanian) is recorded near the base of TR6 in deeper parts of the basin only; elsewhere this sequence is not recorded. Likewise the youngest sequence, TR7, extending to the upper formational contact of latest Permian age, is found only in the basin depocentre. Comparison with age-equivalent strata in the Sverdrup Basin of Canada reveals a remarkably similar depositional history, with, for example, two (third-order) sea-level cycles recorded in the Late Permian of both regions, in keeping with the global record. Sequence stratigraphy may therefore be a powerful correlative tool for onshore and offshore Permian deposits across NW Pangaea.

Occurrence of Zoophycos in the Ruteh Formation, Middle Permian (Guadalupian), Central Alborz, Iran: palaeoenvironmental and sequence stratigraphy implications

2020 ◽  
Vol 298 (3) ◽  
pp. 285-309
Author(s):  
Forough Abasaghi ◽  
Asadollah Mahboubi ◽  
Mohammad Hosein Mahmoudi Gharaie ◽  
Mohammad Khanehbad
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Middle Permian ◽  
Hydrodynamic Condition ◽  
Anal Ysis ◽  
Sea Level Fluctuations ◽  
Marine Strata ◽  
System Tracts ◽  
Environmental Sequences ◽  
Homoclinal Ramp

Zoophycos is widely distributed in the marine strata of the Middle Permian Ruteh For- mation in the Alborz Mountain, Iran. The investigation of the Zoophycos, along with environmental variables is a useful tool for interpretation of the palaeoenvironmental and sequence stratigraphy anal- ysis. The petrographic observations led to the identification of ten facies in four facies belts including tidal flat, lagoon, shoal, and open marine, deposited on a homoclinal ramp. Moreover, two third- order depositional sequences were recognized in response to the sea- level fluctuations within the Ruteh For - mation. Detailed studies of the sequence stratigraphy revealed a relationship between the occurrences of Zoophycos and changes in the hydrodynamic condition in the basin. It appears that Zoophycos has been influenced by the ecological and palaeoenvironmental parameters, such as sedimentation rate, nutrient supply, oxygen, wave base, and substrate in the shallow to deep environments. Based on the sedimentological and ichnological analysis, Zoophycos has been formed with various dimensions, morphology, fillings, and densities together with rising and falling in the sea-level. The trace- maker has followed an opportunistic strategy in the unstable conditions of shallow environments, whereas it has chosen a k-selected strategy in more stable deep environments. Additionally, variability in Zoophycos illustrates, how the trace- maker adopted itself with environmental sequences. This reason, owing to optimal conditions, has caused that the abundance of Zoophycos was high in the Transgres- sive System Tracts (TST). Evidence shows that the response of Zoophycos to the ecological properties of the environment usually has deposit- feeder and chemosymbiosis behaviours.

scholarly journals Sequence stratigraphy of the ANDRILL AND-2A drillcore, Antarctica: A long-term, ice-proximal record of Early to Mid-Miocene climate, sea-level and glacial dynamism

2011 ◽  
Vol 305 (1-4) ◽  
pp. 337-351 ◽  
Author(s):  
Christopher R. Fielding ◽  
Greg H. Browne ◽  
Brad Field ◽  
Fabio Florindo ◽  
David M. Harwood ◽  
...  
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy

scholarly journals Results of sea level studies at RSHU

2020 ◽  
pp. 269-305
Author(s):  
V.N. Malinin ◽  
S.M. Gordeeva ◽  
Yu.V. Mitina ◽  
O.I. Shevchuk
Keyword(s):  
Sea Level ◽  
North Atlantic ◽  
Caspian Sea ◽  
World Ocean ◽  
Volga Basin ◽  
Cyclonic Activity ◽  
The Caspian Sea ◽  
The North ◽  
The North Atlantic

Study of sea level is being developed at RSHU in several directions: global, regional and local. The global one includes the study of the patterns of interannual fluctuations of the global sea level (GLS), identification of their genesis and development of a set of methods for its long-term forecast. Two approaches to the genesis of GLS are considered. In foreign studies, changes in GLS are determined by changes in the water mass of various cryosphere components, land water reserves and steric level fluctuations. Another approach, implemented at RSHU, is to assess contributions of various factors using the equation of the freshwater balance of the World Ocean as the sum of eustatic and steric factors. A physical-statistical method for two-decade GLS forecasting, based on delay in the GLS response to air temperature over the ocean, has been developed, as well as the GLS projections at the end of the century for climatic scenarios according to the CMIP5 project have been provided. In the regional context, the main attention is paid to identifying the genesis of the interannual variability of the Caspian Sea level with the aim of its long-term forecasting. The entire chain of cause-and-effect relationships in the North Atlantic-atmosphere-Volga basin-Caspian level system is discussed. It has been established that, as a result of the intensification of cyclonic activity in the North Atlantic, especially in the Norwegian Sea, caused by the processes of large-scale interaction between the ocean and the atmosphere, there is an increase in evaporation and in the zonal transfer of water vapour to Europe and then to the Volga basin. Therefore, more precipitation falls in the runoff-forming zone of the basin, the annual runoff of the Volga and the level of the Caspian Sea increasing. The reverse is observed with weakening of cyclonic activity in the North Atlantic. In view of this, the level of the Caspian Sea is an integral indicator of largescale moisture exchange in the ocean-atmosphere-land system. The article discusses the features of interannual sea level fluctuations in Kronstadt since 1836. A simple two-parameter model for forecasting sea level by the end of the 21st century is proposed for major climate scenarios, the predictors being the GSL and the North Atlantic Oscillation. According to the most realistic forecast, the level in Kronstadt may rise to 34-59 cm (Baltic system) by the end of the century, while according to the “pessimistic” one — to 80-90 cm (Baltic system). The estimates of the extreme storm surge at which the level rise north of the Gorskaya can reach 600 cm (Baltic system) are given. The effect of flooding from storm surges is especially strong near Sestroretsk. The total area of possible flooding of the Kurortny district at a 4-m high surge wave exceeds 1260 hectares, all the beaches being completely lost. The trajectories of flood cyclones and their role for periods of climate warming and cooling are considered

Coastal Sea Level Change from in the North Eastern Atlantic

2020 ◽  
Author(s):  
Luciana Fenoglio-Marc ◽  
Bernd Uebbing ◽  
Jürgen Kusche ◽  
Salvatore Dinardo
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Sea Level Change ◽  
Altimeter Data ◽  
Level Change ◽  
The North ◽  
North Eastern ◽  
Coastal Sea

<p>A significant part of the World population lives in the coastal zone, which is affected by coastal sea level rise and extreme events. Our hypothesis is that the most accurate sea level height measurements are derived from the Synthetic Aperture Altimetry (SAR) mode. This study analyses the output of dedicated processing and assesses their impacts on the sea level change of the North-Eastern Atlantic. </p><p>It will be shown that SAR altimetry reduces the minimum usable distance from five to three kilometres when the dedicated coastal retrackers SAMOSA+ and SAMOSA++ are applied to data processed in SAR mode. A similar performance is achieved with altimeter data processed in pseudo low resolution mode (PLRM) when the Spatio-Temporal Altimeter sub-waveform Retracker (STAR) is used. Instead the Adaptive Leading Edge Sub-waveform retracker (TALES) applied to PLRM is less performant. SAR processed altimetry can recover the sea level heights with 4 cm accuracy up to 3-4 km distance to coast. Thanks to the low noise of SAR mode data, the instantaneous SAR and in-situ data have the highest agreement, with the smallest standard deviation of differences and the highest correlation. A co-location of the altimeter data near the tide gauge is the best choice for merging in-situ and altimeter data. The r.m.s. (root mean squared) differences between altimetry and in-situ heights remain large in estuaries and in coastal zone with high tidal regimes, which are still challenging regions. The geophysical parameters derived from CryoSat-2 and Sentinel-3A measurements have similar accuracy, but the different repeat cycle of the two missions locally affects the constructed time-series.</p><p>The impact of these new SAR observations in climate change studies is assessed by evaluating regional and local time series of sea level. At distances to coast smaller than 10 Kilometers the sea level change derived from SAR and LRM data is in good agreement. The long-term sea level variability derived from monthly time-series of LRM altimetry and of land motion-corrected tide gauges agrees within 1 mm/yr for half of in-situ German stations. The long-term sea level variability derived from SAR data show a similar behaviour with increasing length of the time series.</p><p> </p>

scholarly journals The long-term variability of extreme sea levels in the German Bight

Ocean Science ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 651-668 ◽  
Author(s):  
Andreas Lang ◽  
Uwe Mikolajewicz
Keyword(s):  
Sea Level ◽  
German Bight ◽  
Large Scale ◽  
Internal Variability ◽  
Climate System ◽  
System Model ◽  
Tide Gauge Record ◽  
Sea Levels ◽  
The North

Abstract. Extreme high sea levels (ESLs) caused by storm floods constitute a major hazard for coastal regions. We here quantify their long-term variability in the southern German Bight using simulations covering the last 1000 years. To this end, global earth system model simulations from the PMIP3 past1000 project are dynamically scaled down with a regionally coupled climate system model focusing on the North Sea. This approach provides an unprecedented long high-resolution data record that can extend the knowledge of ESL variability based on observations, and allows for the identification of associated large-scale forcing mechanisms in the climate system. While the statistics of simulated ESLs compare well with observations from the tide gauge record at Cuxhaven, we find that simulated ESLs show large variations on interannual to centennial timescales without preferred oscillation periods. As a result of this high internal variability, ESL variations appear to a large extent decoupled from those of the background sea level, and mask any potential signals from solar or volcanic forcing. Comparison with large-scale climate variability shows that periods of high ESL are associated with a sea level pressure dipole between northeastern Scandinavia and the Gulf of Biscay. While this large-scale circulation regime applies to enhanced ESL in the wider region, it differs from the North Atlantic Oscillation pattern that has often been linked to periods of elevated background sea level. The high internal variability with large multidecadal to centennial variations emphasizes the inherent uncertainties related to traditional extreme value estimates based on short data subsets, which fail to account for such long-term variations. We conclude that ESL variations as well as existing estimates of future changes are likely to be dominated by internal variability rather than climate change signals. Thus, larger ensemble simulations will be required to assess future flood risks.

A modelling study of the mixing of 137 Cs in the seas of the European Continental Shelf

1984 ◽  
Vol 310 (1513) ◽  
pp. 407-436 ◽  
Keyword(s):  
Continental Shelf ◽  
Sea Level ◽  
Irish Sea ◽  
Residual Flow ◽  
The North ◽  
Shelf Seas ◽  
Modelling Studies ◽  
Flow Components ◽  
Turn Over

A two-dimensional numerical model is formulated to simulate long-term mixing in the coastal waters over the European Continental Shelf. By using both tidal and wind-driven components, the mean circulation over this region is computed and is shown to be in good agreement with earlier estimates from (i) modelling studies, (ii) observations of residual flow, and (iii) observations of mean sea level distribution. Long-term gradients of sea level in the adjacent oceanic region are found to be unimportant for shelf circulation. These residual flow components are used to develop a mixing model, observational data of the mixing of 137 Cs (released from Windscale over a 17 year period) are used to calibrate and evaluate the model. The model accurately simulates the transport routes of this material both spatially and temporally. This transport is shown to be dependent on both advection and dispersion. The model is used to determine various time constants for the shelf seas, namely: age, residence times and turn-over-times. Thus, the turn-over-time of the North Sea is calculated to be 530 d compared with a value of 328 d for the Irish Sea. The geographical distribution of turn-over-times differentiates regions of vigorous mixing from more stagnant regions and thereby indicates regions conducive to the formation of thermal fronts. The model also indicates that about one third of the material discharged from Windscale is lost to the ocean in the vicinity of the shelf edge to the north and west of Scotland.

scholarly journals New relative sea-level (RSL) indications from the Eastern Mediterranean: Middle Bronze Age to the Roman period (~3800–1800 y BP) archaeological constructions at Dor, the Carmel coast, Israel

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251870
Author(s):  
Assaf Yasur-Landau ◽  
Gilad Shtienberg ◽  
Gil Gambash ◽  
Giorgio Spada ◽  
Daniele Melini ◽  
...  
Keyword(s):  
Bronze Age ◽  
Sea Level ◽  
Iron Age ◽  
Eastern Mediterranean ◽  
Roman Period ◽  
Hellenistic Period ◽  
Relative Sea Level ◽  
The North ◽  
Middle Bronze Age

This article presents new archaeological observations and multidisciplinary research from Dor, Israel to establish a more reliable relative sea level for the Carmel Coast and Southern Levant between the Middle Bronze Age and the Roman period (ca. 3500–1800 y BP). Our record indicates a period of low relative sea level, around -2.5 m below present, from the Middle Bronze Age to the Hellenistic period (ca. 3500–2200 y BP). This was followed by a rapid rise to present levels, starting in the Hellenistic period and concluding during the Roman period (ca. 2200–1800 y BP). These Roman levels agree with other relative sea-level indications from Israel and other tectonically stable areas in the Mediterranean. Several relative sea-level reconstruction models carried out in the current study provide different predictions due to their parameters and do not model the changes observed from field data which points to a non-isostatic origin for the changes. Long-term low stable Iron Age relative sea level can be seen in Dor, where Iron Age harbor structures remain around the same elevation between ca. 3100–2700 y BP. A similar pattern occurs at Atlit, the Iron Age harbor to the north used continuously from ca. 2900 y BP to the beginning of the Hellenistic period (ca. 2200 y BP). An examination of historical and archaeological sources reveals decline and occasional disappearance of Hellenistic sites along the coast of Israel at ca. 2200 y BP (2nd century BCE), as in the case of Yavneh Yam, Ashdod Yam, Straton’s Tower, and tel Taninim. In Akko-Ptolemais, the large harbor installations built in the Hellenistic period were never replaced by a substantial Roman harbor. The conclusions of this research are thus relevant for the sea-level research community and for the historical analyses of the Israeli and South Levantine coastline.

Inter-annual and long-term mean sea level changes along the North Sea coastline

2013 ◽  
Vol 165 ◽  
pp. 1987-1992 ◽  
Author(s):  
Thomas Wahl ◽  
Ivan D. Haigh ◽  
Sönke Dangendorf ◽  
Jürgen Jensen
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
The North ◽  
The North Sea
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