Hydrography of Marian Cove, King George Island, West Antarctica: implications for ice-proximal sedimentation during summer

2014 ◽  
Vol 27 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Kyu-Cheul Yoo ◽  
Min Kyung Lee ◽  
Ho Il Yoon ◽  
Yong Il Lee ◽  
Cheon Yoon Kang
Keyword(s):  
Water Structure ◽  
Suspended Particles ◽  
King George Island ◽  
West Antarctica ◽  
Short Term ◽  
Suspended Particulate ◽  
Water Layers ◽  
North Western ◽  
Proximal Zone ◽  
Main Factor

AbstractDuring the summer, from 1996–2000, vertical profiles of conductivity, temperature and transmissivity were obtained near the tidewater glacier of Marian Cove, King George Island, Antarctic Peninsula. The aims for the study were to determine the short-term variations of water structure due to hydrographic forcings and to understand sedimentation of suspended particulate matter in Antarctic fjord environments. Four distinct water layers were identified in the ice-proximal zone of the cove: i) a surface layer composed of cold and turbid meltwater, ii) a relatively warm Maxwell Bay inflow layer with characteristics of outer fjord water, iii) a turbid/cold mid-depth layer (40–70 m) originating from subglacial discharge, and iv) a deep layer comprised of the remnant winter water. The main factor influencing the characteristics of glacial meltwater layers and driving deposition of suspended particles in the cove is tidal forcing coupled with wind stress. The relatively small amount of meltwater discharge in Marian Cove yields low accumulation rates of non-biogenic sedimentary particles in the cove. The response to north-western and western winds, coupled with flood tide, may promote settling and sedimentation of suspended particles from turbid layers in the ice-proximal zone of the cove.

scholarly journals Effects of Short-Term Rice Straw Return on the Soil Microbial Community

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 561
Author(s):  
Enze Wang ◽  
Xiaolong Lin ◽  
Lei Tian ◽  
Xinguang Wang ◽  
Li Ji ◽  
...  
Keyword(s):  
Microbial Community ◽  
Rice Straw ◽  
Paddy Soil ◽  
Soil Microbial Community ◽  
Short Term ◽  
Soil Microbial ◽  
Microbial Network ◽  
Straw Return ◽  
Bacteria And Fungi ◽  
Main Factor

Rice straw is a byproduct of agricultural production and an important agricultural resource. However, rice straw has not yet been effectively used, and incorrect treatment methods (such as burning in the field) can cause serious damage to the environment. Studies have shown that straw returning is beneficial to soil, but there have been few studies focused on the effect of the amount of short-term straw returned on the soil microbial community. This study evaluates 0%, 50%, 75%, and 100% rice straw returned to the field on whether returning different amounts of straw in the short term would affect the diversity and composition of the soil microbial community and the correlation between bacteria and fungi. The results show that the amount of straw returned to the field is the main factor that triggers the changes in the abundance and composition of the microbial community in the paddy soil. A small amount of added straw (≤ 50% straw added) mainly affects the composition of the bacterial community, while a larger amount of added straw (> 50% straw added) mainly affects the composition of the fungal community. Returning a large amount of straw increases the microbial abundance related to carbon and iron cycles in the paddy soil, thus promoting the carbon and iron cycle processes to a certain extent. In addition, network analysis shows that returning a large amount of straw also increases the complexity of the microbial network, which may encourage more microbes to be niche-sharing and comprehensively improve the ecological environment of paddy soil. This study may provide some useful guidance for rice straw returning in northeast China.

A 2000-year record of mercury and ancient civilizations in seal hairs from King George Island, West Antarctica

2006 ◽  
Vol 368 (1) ◽  
pp. 236-247 ◽  
Author(s):  
Liguang Sun ◽  
Xuebin Yin ◽  
Xiaodong Liu ◽  
Renbin Zhu ◽  
Zhouqing Xie ◽  
...  
Keyword(s):  
King George Island ◽  
West Antarctica ◽  
Ancient Civilizations

scholarly journals Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

2021 ◽  
Author(s):  
Yiting Nan ◽  
Peiyong Guo ◽  
Hui Xing ◽  
Sijia Chen ◽  
Bo Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Protein Content ◽  
Suspended Particulate Matter ◽  
Soluble Protein ◽  
Suspended Particles ◽  
Dose Effect ◽  
Soluble Protein Content ◽  
Sod Activity ◽  
Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

scholarly journals Shell beds from the Low Head Member (Polonez Cove Formation, early Oligocene) at King George Island, west Antarctica: new insights on facies analysis, taphonomy and environmental significance

2014 ◽  
Vol 26 (4) ◽  
pp. 400-412 ◽  
Author(s):  
Fernanda Quaglio ◽  
Lucas Veríssimo Warren ◽  
Luiz Eduardo Anelli ◽  
Paulo Roberto Dos Santos ◽  
Antonio Carlos Rocha-Campos ◽  
...  
Keyword(s):  
King George Island ◽  
West Antarctica ◽  
Delta Front ◽  
Early Oligocene ◽  
Fan Delta ◽  
Shell Beds ◽  
The Matrix ◽  
Low Head ◽  
New Interpretation ◽  
Shell Bed

AbstractShell bed levels in the Low Head Member of the early Oligocene Polonez Cove Formation at King George Island, West Antarctica, are re-interpreted based on sedimentological and taphonomic data. The highly fossiliferous Polonez Cove Formation is characterized by basal coastal marine sandstones, overlain by conglomerates and breccias deposited in fan-delta systems. The shell beds are mainly composed of pectinid bivalve shells of Leoclunipecten gazdzickii and occur in the basal portion of the Low Head Member. Three main episodes of bioclastic deposition are recorded. Although these shell beds were previously interpreted as shelly tempestites, we present an alternative explanation: the low fragmentation rates and low size sorting of the bioclasts resulted from winnowing due to tidal currents (background or diurnal condition) in the original bivalve habitat. The final deposition (episodic condition) was associated with subaqueous gravity driven flows. This new interpretation fits with the scenario of a prograding fan-delta front, which transported shell accumulations for short distances near the depositional site, possibly between fair-weather and storm wave bases. This work raises the notion that not every shell bed with similar sedimentological and taphonomic features (such as geometry, basal contact, degree of packing and shell orientation in the matrix) is made in the same way.

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