Mid and late Holocene multiproxy analysis of environmental changes linked to sea-level fluctuation and climate variability of the Río de la Plata estuary

Studi sejarah fluktuasi muka air laut dan perubahan lingkungan di Paparan Sunda masih sedikit dilakukan. Ada dua isu yang saling terkait yang menjadi permasalahan utama terkait dengan perubahan muka air laut di wilayah ini yaitu kurangnya rekaman data fluktuasi muka air laut dan perubahan lingkungan selama kurun waktu mid-late Holosen dengan kualitas yang bagus. Hal itu memiliki konsekwensi terhadap munculnya isu kedua yaitu tidak terdefinisikannya secara jelas dan tepat baik waktu maupun besaran posisi muka air laut pada saat mid-Holosen. Penelitian ini dilakukan untuk merekonstruksi perubahan lingkungan selama Holosen Akhir di wilayah Paparan Sunda menggunakan rekaman polen endapan mangrove. Pemboran tangan dilakukan guna pengamatan stratigrafi dan pengambilan sampel untuk analisis-analisis sedimentologi dan mikropaleontologi di laboratorium. Hasil studi ini menunjukkan bahwa perubahan lingkungan terjadi di Pulau Belitung selama setidaknya 1500 tahun terakhir sebagai akibat dari proses progradasi. Proses ini menyebabkan garis pantai terus maju hingga mencapai posisi saat ini. Endapan mangrove di lokasi penelitian juga merekam kejadian insidentil yang secara hipotetis diduga sebagai peristiwa tsunami akibat letusan Krakatau yang terjadi pada tahun 1883 AD dan sekitar 535-536 AD.Kata Kunci: Belitung, polen, mangrove, Mid-Holosen, Krakatau, muka laut, perubahan lingkungan.There is only minor study on sea-level fluctuation and environmental change in Sunda Shelf. The main isues in this area are lacking good quality of sea-level fluctuation and environmental change record during mid-late Holocene in which accordingly the onset time and sea-level height of the Mid-Holocene Maximum Transgression event have not been well defined. This study aims to reconstruct environmental changes during late Holocene in the Sunda Shelf area based on mangrove pollen record. Hand-auger was applied to make stratigraphic observation and sampling for sedimentological and micropaleontological analyses in the laboratory. Result of this study shows environmental changes occured within the last ca.1500 years due to coastal progradation in Belitung. This progradation shifted the coastal line seaward to attain the present position. The pollen record also reflects rapid and brief changes that may hypothetically be interpreted as the 535-536 AD and 1883 AD Krakatau tsunamis.Keywords: Belitung, pollen, mangroves, Mid-Holocene, Krakatau, sea level, environmental changes.

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Coastal environmental changes associated with Holocene sea-level fluctuation: Southeastern Buenos Aires, Argentina

Quaternary International ◽

10.1016/1040-6182(94)00046-8 ◽

1995 ◽

Vol 26 ◽

pp. 55-60 ◽

Cited By ~ 12

Author(s):

Federico Ignacio Isla ◽

Marcela A. Espinosa

Keyword(s):

Sea Level ◽

Buenos Aires ◽

Environmental Changes ◽

Level Fluctuation ◽

Sea Level Fluctuation ◽

Holocene Sea Level

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Fishing strategies for managing climate variability and change in the estuarine front of the Río de la Plata

Climate Change and Adaptation ◽

10.4324/9781849770750-26 ◽

2012 ◽

pp. 367-384

Keyword(s):

Climate Variability ◽

Rio De La Plata ◽

Climate Variability And Change ◽

Río De La Plata ◽

La Plata ◽

Fishing Strategies

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Holocene Evolution of the Outer Lake of Hwajinpo Lagoon On the Eastern Coast of Korea; Environmental Changes with Holocene Sea-Level Fluctuation of the East Sea (Sea of Japan)

Radiocarbon ◽

10.1017/s0033822200035839 ◽

2004 ◽

Vol 46 (2) ◽

pp. 797-808 ◽

Cited By ~ 6

Author(s):

Jong-Gwon Yum ◽

Kang-Min Yu ◽

Keiji Takemura ◽

Toshiro Naruse ◽

Akihisa Kitamura ◽

...

Keyword(s):

Sea Level ◽

Environmental Changes ◽

River System ◽

Eastern Coast ◽

Estuarine System ◽

Level Fluctuation ◽

Radiocarbon Dates ◽

Sedimentary Environments ◽

Sea Level Fluctuation ◽

Low Sulfur Content

The evolution of the outer lake of Hwajinpo Lagoon in Korea has been reconstructed using environmental proxies (lithologic, geochemical, and fossil data) with a chronology established using 7 accelerator mass spectrometry (AMS) radiocarbon dates. Grain size, water content, and X-ray analyses from the core of outer coastal lakes (HJ99) were used to reconstruct sedimentary environments by using total organic carbon, C/N, S, and C/S chemical proxies. Assemblages of mollusc remains also provided paleoenvironmental information. The environmental changes of the outer lake of Hwajinpo Lagoon can be divided into 6 depositional phases. The basin of the Hwajinpo was exposed and underwent a weathering process before the Holocene period. The muddy sand layer on the weathered bedrock indicated an estuarine system about 6000 BP. The laminated layer implies that the lagoonal system was anoxic between about 5500–2800 BP. The marl layer implies a relatively oxic lagoonal condition with mollusc presence about 2500 B P. The layer of very low sulfur content indicates a freshwater lake system isolated by a sand barrier about 1700 BP. Beginning about 1000 B P, the river system deposits progress progradation on the marl layer. Two erosional landforms could be related with a high standing sea level span during Holocene. These high-stands are dated at 5700 BP and 2200 BP and are supposed to have formed erosional landforms of about 1.6 amsl and 0.8 amsl, respectively. Environmental changes of the outer lake of Hwajinpo Lagoon are considered due mainly to the lake- and sea-level fluctuation during Holocene.

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