Reconstruction of Paleo-Temperature During the Holocene Using WA-PLS Analysis of Modern Pollen From the Surface Soil in the Southeastern Part of the Korean Peninsula

2017 ◽  
Vol 24 (4) ◽  
pp. 13-25
Author(s):  
Soon-Ock Yoon ◽  
Beomjin Hwang ◽  
Sangill Hwang
1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.


2019 ◽  
Vol 59 (2) ◽  
pp. 391-409
Author(s):  
Arghya Kumar Hait ◽  
Hermann Behling

Abstract The Sundarban Mangrove Forest in the Sundarban Biosphere Reserve, located at the mouth of the Ganga–Brahmaputra Delta in India, is the most diverse mangrove ecosystem in the world. Sediment cores were taken from two widely separated islands in that reserve: Chamta (CMT) and Sudhyanyakhali (SDK). Pollen analysis and radiocarbon dating were used to study the Holocene development and dynamics of this unique ecosystem. Modern pollen rain study reveals a strong relation between modern pollen rain and the present vegetation, as well as a high rate of Phoenix palludosa pollen production.The pollen records indicate that man-grove existed at CMT from ~5960 and at SDK from ~1520 cal yr BP. Changes in relative sea level, including the frequency and intensity of inundation as well as fluctuating precipitation, have been the major factors along with geomorphic processes that control the development and dynamics of the mangrove in the area during the Holocene. The mid Holocene mangrove at CMT declined, to be progressively replaced by successive communities, and eventually reached climax stage, while the SDK site is transitional in nature. The mangrove responds rapidly to changes in environmental conditions at both locations. Because of large-scale anthropogenic interventions, it is unlikely that similar rapid responses will occur in the future.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyunwoo Lee ◽  
Heejun Kim ◽  
Takanori Kagoshima ◽  
Jin-Oh Park ◽  
Naoto Takahata ◽  
...  

Abstract On September 12, 2016, a ML 5.8 earthquake hit Gyeongju in the southeastern part of the Korean Peninsula (SeKP), although the area is known to be far from the boundary of the active plate. A number of strike-slip faults are observed in heavily populated city areas (e.g., Busan, Ulsan, Pohang, and Gyeongju). However, dissolved gases related to the active faults have rarely been studied despite many groundwater wells and hot springs in the area. Here we report new results of gas compositions and isotope values of helium and carbon dioxide (CO2) in fault-related fluids in the region. Based on gas geochemistry, the majority of gas samples are abundant in CO2 (up to 99.91 vol.%). Measured 3He/4He ratios range from 0.07 to 5.66 Ra, showing that the mantle contribution is up to 71%. The range of carbon isotope compositions (δ13C) of CO2 is from −8.25 to −24.92‰, showing mantle-derived CO2 is observed coherently where high 3He/4He ratios appear. The weakening of faults seems to be related to enhanced pressures of fluids containing mantle-derived helium and CO2 despite the ductile lower crust underneath the region. Thus, we suggest that the SeKP strike-slip faults penetrate into the mantle through ductile shearing.


2020 ◽  
Author(s):  
Jinheum Park ◽  
Jungjae Park ◽  
Sangheon Yi ◽  
Jaesoo Lim ◽  
Jin Cheul Kim ◽  
...  

Abstract. The dynamics of the East Asian Summer Monsoon (EASM) and their link to past societies during the Holocene are topics of growing interest. In this study, we present analyses of a ca. 6,000-year pollen record, as well as X-ray fluorescence (XRF) and grain-size data from the STP18-03 core sampled from Miryang in the Korean Peninsula, which spans ca. 8.3–2.3 ka BP. In-phase relationships of these proxies revealed an imprint of the Holocene Climate Optimum (HCO) during the early to mid-Holocene and subsequent drying toward the late Holocene in accordance with decreasing solar insolation. At centennial timescales, our study indicates wet conditions during ca. 8.3–7.5, 7.1–6.4, 6.0–4.8, and 3.6–2.8 ka BP, and a drier climate during ca. 7.5–7.1, 6.4–6.0, and 4.8–3.6 ka BP. Notably, our finding for ca. 6.4–6.0 ka BP contributes further evidence of a drying event in the Korean Peninsula during this period. We suggest that the Pacific Ocean played a role in the underlying mechanism of hydroclimate change in the region. A strong Kuroshio Current (KC) and long-term El Niño–Southern Oscillation (ENSO)-like variability in the Western Tropical Pacific (WTP) were closely linked to the influence of the EASM over the Korean Peninsula. In particular, dry phases during ca. 4.8–3.6 and 2.8–2.3 ka BP, which were synchronous with a more active ENSO, closely corresponded to lower population levels according to a summed probability distribution (SPD) of archaeological records assembled in the Korean Peninsula. This finding implies that past human societies of Korea were highly vulnerable to climate deterioration caused by precipitation deficits.


Author(s):  
Anna Agatova ◽  
◽  
Roman Nepop ◽  
Igor Slyusarenko ◽  
Piotr Moska ◽  
...  

Multidisciplinary studies of various natural archives indicate contrasting changes in the human habitat in the high-mountainous southeastern part of the Russian Altai during the last 20,000 years. This period includes the final stage of the last glaciation and its degradation, the formation of the last giant ice-dammed lakes in the intermountain basins and their cataclysmic draining, considerable transformation of glacial landscapes to modern diverse and mosaic structure. Warmer and more humid climate in the first half of the Holocene was followed by cooling and repeated advances of mountain glaciers. The general trend to cooling and aridization in the second half of the Holocene is the most pronounced during the last two millennia. Deglaciation and final drying of intermountain basins boosted a renovation of the local ecosystems and established an environmental baseline of human occupation in the region. The arid climate, widespread permafrost and low population density determined a good preservation of archaeological heritage in the region, which is located at the crossroad between East and West, North and South. This paper presents the analysis of previously published and new data including newly obtained 14C and OSL dates, which allow to correlate climatically driven landscape transformations with habitat of ancient communities and cultures shifting in the region during the last 20, 000 years, as well as to assess the anthropogenic impact on the environment.


The Holocene ◽  
2021 ◽  
pp. 095968362110191
Author(s):  
Jinheum Park ◽  
Jungjae Park ◽  
Sangheon Yi ◽  
Jaesoo Lim ◽  
Jin Cheul Kim ◽  
...  

The dynamics of the East Asian Summer Monsoon (EASM) and their link to past societies during the Holocene are topics of growing interest. In this study, we present results of pollen, geochemistry, and grain-size analyses from the STP18-03 core sampled from Miryang in the Korean Peninsula, which spans ca. 8.3–2.3 ka BP. In-phase relationships of these proxies revealed an imprint of the Holocene Climate Optimum (HCO) during the early to mid-Holocene and subsequent drying toward the late-Holocene in accordance with decreasing solar insolation. At centennial timescales, our study indicates drier climate during ca. 7.5–7.1, 6.4–6.0, and 4.8–3.6 ka BP. Notably, our finding for ca. 6.4–6.0 ka BP contributes further evidence of a drying event in the Korean Peninsula during this period. We suggest that the Pacific Ocean played a role in the underlying mechanism of hydroclimate change in the region. A strong Kuroshio Current (KC) and long-term El Niño–Southern Oscillation (ENSO)-like variability in the Western Tropical Pacific (WTP) were closely linked to the influence of the EASM over the Korean Peninsula. In particular, dry phases during ca. 4.8–3.6 and 2.8–2.3 ka BP, which were synchronous with a more active ENSO, closely corresponded to lower population levels indicated by a summed probability distribution (SPD) of archaeological records previously assembled in the Korean Peninsula. This finding implies that past human societies of Korea were highly vulnerable to climate deterioration caused by precipitation deficits.


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