Sunkiųjų mineralų įtaka paplūdimio nuolydžio susidarymui

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Baltijos jūros smėlėto kranto ritminių darinių kaita

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Possibilities of regeneration of Palanga coastal zone

An intensive abrasion of the coast of the most popular Lithuanian Palanga health‐resort necessitates consideration of the most effective ways of its stabilization. Based on the data of field investigations and literary sources, the possibilities of Palanga coastal zone regeneration using the sand dredged from the entrance channel of Klaipeda port are considered. Based on the current geodynamic trends of Palanga coastal zone and results obtained by comparative analysis of granulometric composition of sediments dredged from the entrance channel of Klaipeda Port, the optimal possibilities of using the dredged sand for coast regeneration were determined. It was established that formation of underwater sandbar (analogue of natural bar) in the surf zone of coastal sector between the Palanga Pier and Birute Mount at a depth of 3 m would be the best solution for coast regeneration under the current conditions. Palangos kranto zonos rekultivavimo galimybių tyrimai Santrauka. Intensyvi populiariausio Lietuvoje Palangos kurorto jūros kranto arda verčia ieškoti efektyvių kranto stabilizavimo metodų. Pastaruoju metu (2003–2008 m.) atlikti apsauginio paplūdimio kopagūbrio tvirtinimo bei paplūdimio sąnašu atsargų papildymo Palangos rekreacinėje zonoje darbai lėmė tik trumpalaikį kranto apsaugos efektą. Straipsnyje, remiantis natūrinių tyrimų bei literatūros duomenimis, įvertintos smėlio, iškasamo iš Klaipėdos įplaukos kanalo, naudojimo Palangos kranto zonai regeneruoti galimybės. Atsižvelgus į dabartines Palangos kranto zonos geodinamines tendencijas bei atlikus šio ruožo ir iškasamo iš Klaipedos uosto įplaukos kanalo birių sąnašų sudėties lyginamają analizę, nustatytos optimalios iškasamo smėlio panaudojimo kranto zonai regeneruoti galimybės. Esant dabartinei situacijai efektyviausias kranto zonos regeneravimo būdas – povandeninio volo (gamtinio sekliaus analogo) 3 m gylyje kranto ruožo tarp Palangos tilto ir Birutės kalno gožos zonoje formavimas. Reikšminiai žodžiai: kranto zonos sąnašų papildymas, dirbtinis sėklius, sąnašų granuliometrinė sudėtis. Исследование возможностей рекультивации береговой зоны Паланги Резюме. Интенсивный размыв морского берега в рекреационной зоне самого популярного курорта Литвы – Палангe вынуждает искать эффективные способы его стабилизации. Выполненные за последнее время (2003–2008 гг.) работы по укреплению дюнного вала и попытка пополнить пляж наносами в береговой зоне г. Паланги дали лишь кратковременный берегозащитный эффект. На основе натурных данных в статье оценены возможности использования для регенерации береговой зоны Паланги песка, выкапываемого из подвходного канала порта Клайпеды. Учитывая полученные результаты исследований современных геодинамических тенденций береговой зоны г. Паланги, состав наносов подвходного канала порта г. Клайпеды и изучаемого участка, установлены оптимальные возможности использования добываемого песка для стабилизации береговой зоны г. Паланги. Установлено, что при нынешней ситуации самым эффективным способом регенерации береговой зоны является формирование подводного вала (аналог природного) в прибойной зоне на глубине 3 метров на участке между Палангским мостом и мысом горы Бируте. Ключевые слова: подпитка береговой зоны, искусственный подводный вал, гранулометрический состав наносов. First Publish Online: 21 Jun 201

Stipriausios vėjo audros Baltijos jūros Lietuvos pakrantėje

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Impact of Šventoji port jetties on coastal dynamics of the Baltic sea

As the safe depth for navigation is no longer ensured due to intense accumulation of sediments in the avanport of the old port, which was constructed in 1923–1940, reconstruction of Šventoji port jetties was planned, which should commence in 2013. The assessment of impact of Šventoji port jetties was done on the nearby coasts, based on analysis of the 20th and 21st century cartographic material as well as monitoring data on coastal dynamics. The old port construction caused the formation of the accumulative cape; the area of which has grown to 44.90 ha. The coastline erosion processes have become especially intense northwards from the formed cape to the Latvian border. Approx. 38.41 ha area of land has been washed-out in the section. During the last 17 years, the southern jetty has become more and more pervious to sediments. Sediment volume stabilization occurred on the northern side of the jetty, and accumulation tendency was in the southern part of the port. Results of sediment transport modelling with MIKE 21 confirm that the reconstruction of Šventoji port according to alternative “1” (length of jetties – 400 m) answers the minimal requirements of port and makes the least impact for the hydrodynamic and lithodynamic processes in the Baltic Sea nearshore. The reconstruction of port according to alternative “2” (length of jetties – 800 m) will cause the intensive changes of the Baltic Sea coastline dynamics in adjacent regions. First published online: 14 Dec 201

Kuršių nerijos jūros kranto paplūdimio sąnašų smėlio dalelių kaita 1993–2018 metais

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Lithological anomalies in a relict coastal dune : geophysical and paleoenvironmental markers

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 34 (2007): L09707, doi:10.1029/2007GL029767.Ground exposures of migration surfaces (slipfaces) of a relict Holocene coastal dune along the southeastern Baltic Sea coast provide an ideal opportunity for establishing the causes of prominent reflections on geophysical profiles. High-amplitude reflections on high-resolution ground-penetrating radar (GPR) images correlate well with two major lithological anomalies: 1) paleosols developed on dune slipfaces, and 2) slipfaces consisting of heavy-mineral concentrations (HMCs). Paleosols serve as indicators of dune stability, represent datable chronostratigraphic surfaces, and help reconstruct dune paleo-morphology. HMCs have substantially higher magnetic susceptibility values than background quartz-rich sands and, where they are well-developed, can be also used for spatial correlation. Based on their occurrence at the study site, these enriched horizons likely represent periods of increased wind activity (storminess). Multiple HMCs upwind of paleosol P1 (800–670 cal years BP) likely reflect periods of intensified wind activity along the southeast Baltic region during the Medieval Warm Period.This research was funded by the Ocean and Climate Change Institute and The J. Lamar Worzel Assistant Scientist Fund of the Woods Hole Oceanographic Institution