A paper on South Baltic Sea msl, with datasets

https://egqsj.copernicus.org/articles/59/3/2011/egqsj-59-3-2011.pdf

quoted by

https://journals.sagepub.com/doi/full/10.1177/0959683620981703 figure 4


Late Quaternary sea-level history from northwestern Europe reflects the temporally and spatially varying influence of eustatic, isostatic, tectonic and geoidal components, and, to a minor extent of local factors such as sediment compaction, halokinetics and hydrographic fluctuations. The many combinations of these factors within a rather limited area make Northwest Europe an intensively studied natural sealevel lab.

Since the last Scandinavian Ice shield started to melt at about 18,000 BC and vanished from the present southern Baltic coast at about 13,000 BC, the Baltic Sea Basin was, except for some short periods, isolated from the ocean until the Mid-Holocene. Its water level was determined by highly fluctuating lakes

Recent gauge data from coastal NE-Germany (Baltic Sea) suggest that the eustatic component of the observed sea-level record is superimposed by a spatially different non-eustatic, predominantly glacio-isostatic component. To investigate to which amount the past sea level was influenced by these two components, we traced the sea-level history back as far as the coastal sediment sequence allowed.

Only after about 7,200 BC was the basin permanently linked to the ocean, when the North Sea water table rose above the sills in the Great and the Little Belt (today 4 E&G / Vol. 59 / No. 1–2 / 2010 / 3–20 / DOI 10.3285/eg.59.1-2.01 / © Authors / Creative Commons Attribution License -24 m and -20 m msl, respectively). The resulting sea-level (sl) rise in the Baltic Basin is called the Littorina transgression.

data from different profiles located very close to each other do show differences resulting from factors like (auto-)compaction, material redeposition, differential peat accumulation or erosion and these cannot be avoided. The only small-scale sl fluctuation detected in many single profiles is related to the Little Ice Age, but the extent of the water table fall is still unknown.

they differ from each other regularly, with deviations becoming smaller with decreasing age. A shoreline diagram indicates that no significant tectonic events disturbed the relative movements between the three study areas.

In the Fischland area, isostatic movement ceased ca. 1 to 0 ka BC and was replaced by a rather stable or indifferent behaviour. For the N-Rügen/Hiddensee study area, an ongoing slow uplift is still evident. Further improvements in all rsl curves may slightly change these estimations.

we cannot finally state whether the Wismar area experiences a subsidence or the same movement when compared with the Belgian coast.

I movimenti isostatici (meglio: non eustatici) mostrano un cambiamento, una specie di stabilizzazione, attorno al 3000 BCE, per cui uso questa data come partenza per i fit lineari fino al 1500 CE per vedere se la pendenza attualmete misurata è semplicemente la continuazione dell'uscita dalla LIA.

Per i dati relativi a Wismar (l'unico tra questi di cui ho il livello dal 1857 al 2010 a sealevel.info) propongo un giochino: Dal fit tra -3000 a +1721 (anni) calcolato con 10 dati su 4721 anni: sl=-0.93+5.63E-04*anno
anno 1857 ==>0.12 m = 12 cm
anno 2010 ==>0.20 m = 20 cm
differenza 8 cm <============

Misurati (a occhio sul grafico di sealevel.info)
anno 1857 ==>6.84 m
anno 2010 ==>7.08 m
differenza 24 cm <===========

Qualcuno può dire che i due valori NON sono compatibili? E che nei 160 anni recenti la crescita del livello è diversa da quella dei quasi 5000 anni precedenti?
Io credo che la crescita recente sia compatibile con il recupero dalla LIA o anche dalla glaciazione cioè con l'andamento definito dal fit 3000 BCE e 1720 CE.

A comparison of the many rsl curves from these latter countries shows that they are similar to each other in the rapid rsl ascent before 5,000 BC. The most important differences in the curves pertain to the absolute position of sl reached at this time and to the subsequent period between 5,000 and 0 BC, during which the curves differ in the temporal order of sl highstands and the magnitude of relative variations overprinted on the main trend of sl rise. Only during the last 2,000 years do the curves become more similar again.

  • Evidently, during the Mid- to Late Holocene, the Baltic curves show a remarkably higher rsl than the North Sea curves, pointing to differential crustal movement between the two areas.

    Basal peat samples were used to extend the curves to greater depth and age or – together with archaeological finds and/or drowned tree stumps.

    Only after about 7,200 BC was the basin permanently linked to the ocean, when the North Sea water table rose above the sills in the Great and the Little Belt (today -24 m and -20 m msl, respectively).


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