'Clean' spectral analysis of long-term sea-level changes

Terra Nova ◽  
1990 ◽  
Vol 2 (2) ◽  
pp. 138-141 ◽  
Author(s):  
J.G. Negi ◽  
R.K. Tiwari ◽  
K.N.N. Rao
Keyword(s):  
Spectral Analysis ◽  
Sea Level ◽  
Sea Level Changes

A long-term trend and temporal fluctuations of the sea level at the Polish Baltic coast

2011 ◽  
Vol 40 (2) ◽  
Author(s):  
Bernard Wiśniewski ◽  
Tomasz Wolski ◽  
Stanisław Musielak
Keyword(s):  
Spectral Analysis ◽  
Sea Level ◽  
Data Series ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
Term Trend ◽  
Baltic Coast ◽  
Long Term Trend ◽  
Linear Trends

AbstractThe analysis of sea level record series along the Polish coast is presented. The main aim was to identify linear trends in the sea level changes at the coastal (Świnoujście, Kołobrzeg, Ustka, Łeba, Władysławowo, Hel, Gdynia, Gdańsk), lagoonal (Trzebież, Tokmicko) and riverine (Szczecin) gauge stations. The analysis showed individual coastal stations to differ in the rate of sea level changes. During 60 years of continuous observations (1947–2006), the differences varied from 1.0 (the western part of the coast) to 2.5 mm year−1 (the eastern part of the coast). The longest, more than 100-yr-long data series showed the sea level rise in Świnoujście and Kołobrzeg to be about 0.5 mm year−1; 1.57 mm year−1 being revealed in Gdańsk. Spectral analysis applied to the data showed numerous fluctuations and cyclicity in changes of the annual mean sea level at the Polish coast. A distinct, major 3-year cycle was revealed. In addition, three secondary cycles of 4.6, 6.7, and 8.6 years were present in the data, more or less clearly identifiable at individual stations.

scholarly journals An introduction to causes and consequences of Cretaceous sea-level changes (IGCP 609)

2019 ◽  
Vol 498 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Michael Wagreich ◽  
Benjamin Sames ◽  
Malcolm Hart ◽  
Ismail O. Yilmaz
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Short Term ◽  
Sea Level Fluctuations ◽  
Groundwater Aquifer ◽  
Sea Level Oscillations ◽  
Short And Long Term ◽  
Geological Timescale ◽  
Land Water

AbstractThe International Geoscience Programme Project IGCP 609 addressed correlation, causes and consequences of short-term sea-level fluctuations during the Cretaceous. Processes causing several ka to several Ma (third- to fourth-order) sea-level oscillations during the Cretaceous are so far poorly understood. IGCP 609 proved the existence of sea-level cycles during potential ice sheet-free greenhouse to hothouse climate phases. These sea-level fluctuations were most probably controlled by aquifer-eustasy that is altering land-water storage owing to groundwater aquifer charge and discharge. The project investigated Cretaceous sea-level cycles in detail in order to differentiate and quantify both short- and long-term records based on orbital cyclicity. High-resolution sea-level records were correlated to the geological timescale resulting in a hierarchy of sea-level cycles in the longer Milankovitch band, especially in the 100 ka, 405 ka, 1.2 Ma and 2.4 Ma range. The relation of sea-level highs and lows to palaeoclimate events, palaeoenvironments and biota was also investigated using multiproxy studies. For a hothouse Earth such as the mid-Cretaceous, humid–arid climate cycles controlling groundwater-related sea-level change were evidenced by stable isotope data, correlation to continental lake-level records and humid–arid weathering cycles.

Middle and Late Holocene Sea-Level Changes in Eastern Maine Reconstructed from Foraminiferal Saltmarsh Stratigraphy and AMS 14C Dates on Basal Peat

1999 ◽  
Vol 52 (3) ◽  
pp. 350-359 ◽  
Author(s):  
W.Roland Gehrels
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Range ◽  
Sea Level Changes ◽  
The Past ◽  
Amplitude Fluctuations ◽  
Vertical Distributions ◽  
Low Amplitude ◽  
Long Term Trend

A relative sea-level history is reconstructed for Machiasport, Maine, spanning the past 6000 calendar year and combining two different methods. The first method establishes the long-term (103 yr) trend of sea-level rise by dating the base of the Holocene saltmarsh peat overlying a Pleistocene substrate. The second method uses detailed analyses of the foraminiferal stratigraphy of two saltmarsh peat cores to quantify fluctuations superimposed on the long-term trend. The indicative meaning of the peat (the height at which the peat was deposited relative to mean tide level) is calculated by a transfer function based on vertical distributions of modern foraminiferal assemblages. The chronology is determined from AMS 14C dates on saltmarsh plant fragments embedded in the peat. The combination of the two different approaches produces a high-resolution, replicable sea-level record, which takes into account the autocompaction of the peat sequence. Long-term mean rates of sea-level rise, corrected for changes in tidal range, are 0.75 mm/yr between 6000 and 1500 cal yr B.P. and 0.43 mm/yr during the past 1500 year. The foraminiferal stratigraphy reveals several low-amplitude fluctuations during a relatively stable period between 1100 and 400 cal yr B.P., and a sea-level rise of 0.5 m during the past 300 year.

Facies and depositional sequence evolution controlled by high-frequency sea-level changes in a shallow-water carbonate ramp (late Kimmeridgian, NE Spain)

2004 ◽  
Vol 141 (6) ◽  
pp. 717-733 ◽  
Author(s):  
M. AURELL ◽  
B. BÁDENAS
Keyword(s):  
Sea Level ◽  
High Frequency ◽  
Early Stage ◽  
Local Variation ◽  
Carbonate Ramp ◽  
Sequence Evolution ◽  
Sea Level Changes ◽  
Depositional Sequence ◽  
Ne Spain

The outcrops of the Sierra de Albarracín (NE Spain) allow a precise reconstruction of the shallow sedimentary domains of a late Kimmeridgian carbonate ramp, developed in western marginal areas of the Iberian Basin. The sedimentary record shows a hierarchical sequence stratigraphic organization, which implies sea-level changes of different frequencies. The studied succession is arranged in a long-term transgressive–regressive sequence, which is likely to reflect local variation in the subsidence rates. This sequence includes four higher-order sequences A to D, which have variable thickness (from 3 to 21 m). The similar sedimentary evolution observed in distant localities suggests the existence of high-frequency sea-level fluctuations controlling the sequence development. The average amplitude of these cycles would range from 5 to 10 m. The precise estimation of their duration (some few hundreds of kyr) and their possible assignment to any of the long-term orbital cycles (the 100 or the 400 kyr eccentricity cycles) is uncertain. Sequences A and B, formed during the long-term transgressive interval, are relatively thin (from 3 to 9 m) give-up sequences that were never subaerially exposed. These sequences are locally formed by five shallowing-upward elementary sequences. Sequences C and D are catch-down sequences with evidence of emersion of subtidal facies. Sequence C, formed during the stage of maximum gain of long-term accommodation, is the thickest sequence (from 13 to 21 m) and includes coral–microbial reefs (pinnacles up to 16 m in height). The increased production rates were able to fill part of the accommodation created during the early stage of high-frequency sea-level rise and the shallow platform was eventually exposed to subaereal erosion and meteoric cementation.

scholarly journals An evaluation of climate, crustal movement and base level controls on the Middle-Late Pleistocene development of the River Severn, U.K.

2002 ◽  
Vol 81 (3-4) ◽  
pp. 329-338 ◽  
Author(s):  
D. Maddy
Keyword(s):  
Sea Level ◽  
Late Glacial ◽  
High Energy ◽  
Cold Climate ◽  
Faunal Remains ◽  
Sea Level Changes ◽  
Climate Conditions ◽  
Oxygen Isotope Stage ◽  
Base Level

AbstractThe Pleistocene development of the lower Severn valley is recorded in the fluvial sediments of the Mathon and Severn Valley Formations and their relationship to the glacigenic Wolston (Oxygen Isotope Stage 12), Ridgacre (OIS 6) and Stockport (OIS 2) Formations. The most complete stratigraphical record is that of the Severn Valley Formation, which post-dates the Anglian Wolston Formation and comprises a flight of river terraces, the highest of which is c.50 m above the present river. The terrace staircase indicates that the Severn has progressively incised its valley during the post-Anglian period. The terrace sediments are predominantly composed of fluvially deposited sands and gravels, largely the result of deposition in high-energy rivers under cold-climate conditions. Occasionally towards the base of these terrace deposits low-energy fluvial facies are preserved which contain faunal remains and yield geochronology which support their correlation with interglacial conditions. This simple stratigraphy supports a climate-driven model for the timing of terrace aggradation and incision, with the incision mode at its most effective during the cold-warm transitions and the aggradational mode at its most effective during warm-cold climate transitions. The chronology of terrace aggradation in the lower Severn seems to correspond with the Milankovitch lOOka climate cycles. The timing of incision events suggests that base level (eustatic sea-level) changes do not play a significant role i.e. incision occurs as sea-level is rising.Although climate change is significant in governing the timing of incision, the long-term incision of the River Severn appears to be driven by crustal uplift. A long-term incision rate of 0.15 m ka1, calculated using the base of the terrace deposits, is believed to closely equate with the long-term uplift rate. Superimposed on this long-term uplift are periods of complex terrace sequence development resulting from rapid incision during periods of glacio-isostatic rebound, with large incision events reflecting the rebound adjustment to late glacial stage isostatic depression. However, in no case in the Severn valley has glacial encroachment led to enhanced incision, suggesting that there has been no additional uplift resulting from isostatic compensation for glacial erosion.

scholarly journals Drilling to Decipher Long-Term Sea-Level Changes and Effects – A Joint Consortium for Ocean Leadership, ICDP, IODP, DOSECC, and Chevron Workshop

2008 ◽  
Vol 6 ◽  
pp. 19-28 ◽  
Author(s):  
C. S. Fulthorpe ◽  
K. G. Miller ◽  
A. W. Droxler ◽  
S. P. Hesselbo ◽  
G. F. Camoin ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Changes

No abstract available. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.6.02.2008" target="_blank">10.2204/iodp.sd.6.02.2008</a>

Submerged speleothem in Malta indicates tectonic stability throughout the Holocene

The Holocene ◽  
2018 ◽  
Vol 28 (10) ◽  
pp. 1588-1597 ◽  
Author(s):  
Stefano Furlani ◽  
Fabrizio Antonioli ◽  
Timmy Gambin ◽  
Sara Biolchi ◽  
Saviour Formosa ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Karst Environment ◽  
Marine Deposits ◽  
Archaeological Data ◽  
Decadal Scale ◽  
Term Data

Submerged caves represent potential archives of speleothems with continental and marine biogenic layers. In turn, these can be used to reconstruct relative sea-level changes. This study presents new data on the tectonic behaviour of the island of Malta during the Holocene. These data were obtained from a speleothem sampled, during an underwater survey, at a depth of −14.5 m, inside a recently discovered submerged cave. Since the cave was mainly formed in a subaerial karst environment, the presence of a speleothem with serpulids growing on its continental layers permitted the reconstruction of the chronology for drowning of the cave. The radiocarbon dates obtained from the penultimate and last continental layers of the speleothem, before a serpulid encrustation, were compared with synthetic aperture radar (SAR) and global positioning system (GPS) data, together with published sedimentological and archaeological data. The radiocarbon analyses provided an average age of 7.6 ka BP that perfectly aligns with the Lambeck’s model of Holocene sea level. Morevoer, long-term data agree with published archeological and sedimentological data as well as with SAR interpherometric and GPS trends on a decadal scale. We conclude that the Maltese islands were tectonically stable during the Holocene, and this tectonic behaviour still persists nowadays. On the contrary, new informations on older deposits, such as MIS5e (Maritime Isotope Stage, corresponding to 125 ka ago) were not found in the study area, confirming the lack of older Quaternary marine deposits in these islands.

scholarly journals Stratigraphy and sedimentology of a basement-onlapping shallow marine sandstone succession, the Charcot Bugt Formation, Middle–Upper Jurassic, East Greenland

2003 ◽  
Vol 1 ◽  
pp. 893-930 ◽  
Author(s):  
Michael Larsen ◽  
Stefan Piasecki ◽  
Finn Surlyk
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Upper Jurassic ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Western Basin ◽  
Shallow Marine ◽  
East Greenland ◽  
Depositional Systems

A rocky shore developed in early Middle Jurassic times by transgression of the crystalline basement in Milne Land at the western margin of the East Greenland rift basin. The basement is onlapped by shallow marine sandstones of the Charcot Bugt Formation, locally with a thin fluvial unit at the base. The topography of the onlap surface suggests that a relative sea-level rise of at least 300 m took place in Early Bathonian – Middle Oxfordian times. The sea-level rise was punctuated by relative stillstands and falls during which progradation of the shoreline took place. Palynological data tied to the Boreal ammonite stratigraphy have greatly improved time resolution within the Charcot Bugt Formation, and the Jurassic succession in Milne Land can now be understood in terms of genetically-related depositional systems with a proximal to distal decrease in grain size. The sequence stratigraphic interpretation suggests that translation of the depositional systems governed by relative sea-level changes resulted in stacking of sandstone-dominated falling stage deposits in the eastern, basinwards parts of Milne Land, whereas thick, remarkably coarsegrained transgressive systems tract deposits formed along the western basin margin. The bulk of the Charcot Bugt Formation consists of stacked sandstone-dominated shoreface units that prograded during highstands. The overall aggradational to backstepping stacking pattern recognised in the Charcot Bugt Formation is comparable to that in the contemporaneous Pelion Formation of the Jameson Land Basin and in correlative units of the mid-Norway shelf and the Northern North Sea. We suggest that the long-term evolution of the depositional systems may have been controlled by long-term eustatic rise acting in concert with relative sea-level changes reflecting regionally contemporaneous phases of rift initiation, climax and gradual cessation of rifting.

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