The Bal tic Sea is not typ i cally con sid ered as an area af fected by tsu na mis. How ever, dur ing the Late Pleis to cene and Ho lo cene sev eral tsu nami events have been in ter preted from the sed i men tary re cord, mainly in Swe den and Es to nia. Fur ther more, on the south ern coast of the Bal tic Sea, there are his tor i cal ac counts of catastrophical ma rine floodings called "der Seebär" ("the Sea Bear"). Their de scrip tions re veal many fea tures typ i cal for tsu nami, but their gen e sis re mained un known and sed i men tary ev i dence for such events has not been found. Here we pro vide ev i dence of sandy event lay ers from the area of Rogowo, NW Po land -the area of his tor i cal cat a strophic storms as well as "der Seebär" events. The study area is a low-ly ing coastal plain with an av er age el e va tion of -0.5 to +0.5 m a.s.l., pro tected from the open sea by beach and coastal dune sys tems up to 5 m high. Sedimentological, micropalaeontological and geo chem i cal anal y ses along with AMS 14 C dat ing were ap plied to sed i mentary suc ces sions seen in 5 ma jor trenches and 198 sed i ment cores up to 1.5 m long. Two sandy lay ers were iden ti fied in the peat de pos its that de vel oped on the plain dur ing the last ~2000 years. They re veal a num ber of typ i cal fea tures of tsu nami depos its (sig nif i cant lat eral ex tent and thick ness, rip-up clasts, chem i cal and micropalaeontological ev i dence of ma rine or i gin), how ever, 14 C dat ing along with the his tor i cal ac counts re vealed that the ma jor layer, ex tend ing at least 1.2 km from the mod ern coasts, was prob a bly de pos ited by ar gu ably the larg est storm surge dur ing the last 2000 years, which took place in 1497 AD. These storm de pos its were likely formed dur ing in un da tion of the low-ly ing coastal plain af ter ma jor breach ing of coastal dunes re sult ing in tsu nami -like flow pat tern and thus sim i lar sedimentological ef fects. A dis con tin u ous sand layer of youn ger age (18th cen tury) and shar ing sim i lar prop er ties to the pre vi ous one may be re lated to "der Seebär" event or an other storm surge. The study re vealed that the south ern Bal tic Sea coast may be af fected by much greater coastal flood ing than known from more re cent ac counts and ob ser va tions. Thus, the pre sented geo log i cal re cord should be taken as an ex am ple of a worst-case scenario in coastal zone risk as sess ment from nat u ral haz ards. These events left sed i men tary de pos its that re sem ble tsu nami depos its. It is likely that, in sim i lar set tings where storm surges cause uni di rec tional in un da tion of a coastal plain, it may not be pos si ble to es tab lish whether the re sult ing de pos its were laid down from storms or tsu na mis.Key words: tsu nami de pos its, storm surge de pos its, grain size anal y sis, geo chem is try, ra dio car bon dat ing, Bal tic Sea.
The Swiss‐Norwegian training model established in 2011 has been used across Europe to infer past mean July air temperatures using Chironomidae subfossils. It combines reference sites from Norway and the Swiss Alps but lacks representative localities from the central European plains belt. This gap complicates reconstructions from temperate European latitudes, and thus, a Polish training set (TS) was developed. Data from 102 lakes, mainly from Pomerania and the Masurian Lakelands, as well as the Polish Plain, the Sudetes, and the Carpathian Mountains were included. After selecting and merging suitable chironomid taxa, the Swiss‐Norwegian‐Polish TS includes 357 lakes and 134 chironomid morphotypes, and it has a mean July air temperature range of 3.5 to 20.0 °C. The weighted averaging‐partial least squares (WA‐PLS) and artificial neural network (ANN) transfer function based on the extended TS performs well: R2jack = 0.91/0.95 and root mean squared error of prediction (RMSEP) = 1.39 °C/1.34 °C, respectively. The transfer function applied to the Żabieniec Lake sequence (central Poland) reveals higher summer temperatures (2.5–4.0 °C) for the Lateglacial and for the Holocene (1.0 °C) compared to the Swiss‐Norwegian model. The reconstruction based on the Swiss‐Norwegian TS shows an increasing trend from the Bølling‐Allerød Interstadial to the Meghalayan period, whereas the new model reconstruction shows no increasing trend when using WA‐PLS and a slightly decreasing trend when using ANN. Summer temperatures in the Lateglacial in Żabieniec inferred using the Swiss‐Norwegian TS are consistent with other temperature reconstructions for 50–55°N in Europe, while those based on the Swiss‐Norwegian‐Polish TS (SNP TS) show closer affinity to more western sites than the eastern European ones. Despite being uncommon, the application of ANN can be a good equivalent of the WA‐PLS technique especially in situations where the available database is limited to fewer than a few hundred variables.
The climate variability and related sea-level changes during the Holocene are still under discussion, especially in a regional context. Very little information comes from the southern and south-eastern Baltic coast. The aim of the paper is to gain insight on the history of regional environmental changes, particularly sea-level and storminess, and their driving forces. The investigations were located on a peatland on the coast of Puck Lagoon (Gulf of Gdańsk, southern Baltic Sea). The analysis of peat core comprised: radiocarbon dating, analysis of stable isotopes 18O and 13C and chemical components, as well as palynological and diatomic studies. Results showed the 1.0 m peat section accumulated over 1500 years, with a time resolution of 100 years per sample. The average water level in the Puck Lagoon rose by ca. 0.85 m during the last 1500 years in a cyclic mode, with a period cycle of ca. 600–550 years and an amplitude not exceeding 0.5 m. The accelerated sea level rise and frequent storminess occurred during the first half of the Dark Ages (1500−1300 years b2k) and LIA (750−450 years b2k) and since the beginning of the 20th century. Recognized environmental changes are well correlated with both temperature changes in the North Atlantic and changes in total solar irradiance, suggesting synchronous Northern Hemisphere-wide fluctuations. The solar forcing was an important constituent of natural climate variability in the past and of forcing climate warming during modern times - after the Little Ice Age.
Sea-level changes of the Baltic Sea have been in the focus since the beginning of Baltic history studies. The main goal of the study is to reconstruct Holocene sea-level changes in the eastern part of Pomeranian Bay and the Szczecin Lagoon. For this purpose, 171 radiocarbon dates were used for the eastern part of Pomeranian Bay and 131 radiocarbon dates for the Szczecin Lagoon. The data allow reconstructing sea-level changes in the last 8500 years in the eastern part of Pomeranian Bay and 7500 years in the Szczecin Lagoon. The sea level 8500 yr b2k was ca. 16 m in Pomeranian Bay, while 7500 yr b2k in the Szczecin Lagoon, it was ca. 8 m below the present sea level. Initially, the fast sea-level rise (up to 9.0 mm/yr) slowed down about 6000 yr b2k to ca. 1.0 mm/yr. In the last 5000 years, the sea level rose at a rate of 0.5 mm/yr in both sites. Analysed data allow distinguishing an extreme event (or events) that disturbed a rather regular course of sea-level rise, which occurred between 7314 and 7022 yr b2k. The history of sea-level changes was similar in the eastern part of Pomeranian Bay and the Szczecin Lagoon despite differences in the geological structure of the pre-Quaternary bedrock and potential various trends in vertical crustal movements. Similarities to some other regions of the southern Baltic and the world ocean allow assuming that sea-level changes in the study area in the last 9000 years in general were eustatic in nature.
Zarys treści. Natężenie czynników kształtujących plażę i wydmy nadbrzeżne podlega cią-głym zmianom. Analizując struktury sedymentacyjne można określić ich zmienność, a co za tym idzie -odtworzyć etapy rozwoju rzeźby. Badania prowadzone były na plaży i wydmach nadbrzeżnych na wschód od Pogorzelicy na 361 km polskiego wybrzeża. Pomiary na plaży wykazały, że ulega ona sezonowym zmianom. W górnej i dolnej części plaży zaobserwowano akumulację materiału, zaś w części środkowej -ubytek. W osadach zachowały się ślady pięciu wezbrań sztormowych, podczas których linia wody sięgała podstawy wydmy. Analiza osadów wydm wykazała zmienność tendencji rozwojowych. W przeszłości zdarzały się okresy dominacji akumulacji, w których dochodziło do tworzenia się nowych wałów wydmowych oraz odbudowywania starych, a także okresy dominacji procesów niszczenia. Obecność poziomu glebowego świadczy z kolei o okresach stabilizacji wydmy.Słowa kluczowe: rozwój rzeźby, Wybrzeże Trzebiatowskie, plaża, wydmy nadbrzeżne, struktury sedymentacyjne. WstępGłówną rolę w kształtowaniu plaży i wydm nadbrzeżnych odgrywają procesy morfolitodynamiczne i hydrodynamiczne, wywołane przede wszystkim przez wiatr, falowanie, zmiany poziomu morza, zróżnicowanie osadu oraz obecność roślinności (Leontjew i inni, 1982;Musielak, 1989). Natężenie tych procesów podlega ciągłym zmianom i ma swoje odzwierciedlenie w warstwach osadów budujących formy brzegowe. Badania struktur sedymentacyjnych pozwalają http://dx
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