scholarly journals LANDSCAPE-CLIMATIC CHANGES IN THE SOUTH SAKHALIN ISLAND IN THE MIDDLE-LATE ATLANTIC EPOCH OF THE HOLOCENE

Author(s):  
Yu.A. Mikishin ◽  
I.G. Gvozdeva
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
M. V. Rodkin ◽  
I. N. Tikhonov

Seismic process is usually considered as an example of occurrence of the regime of self-organizing criticality (SOC). A model of seismic regime as an assemblage of randomly developing episodes of avalanche-like relaxation, occurring at a set of metastable subsystems, can be the alternative of such consideration. The model is defined by two parameters characterizing the scaling hierarchical structure of the geophysical medium and the degree of metastability of subsystems of this medium. In the assemblage, these two parameters define a modelb-value. An advantage of such approach consists in a clear physical sense of parameters of the model. The application of the model for parameterization of the seismic regime of the south part of Sakhalin Island is considered. The models of space changeability of the scaling parameter and of temporal changeability of the parameter of metastability are constructed. The anomalous increase of the parameter of metastability was found in connection with the Gornozavodsk and Nevelsk earthquakes. At the present time, high values of this parameter occur in the area of the Poyasok Isthmus. This finding is examined in comparison with other indications of an increase in probability of occurrence of a strong earthquake in the South Sakhalin region.


The Holocene ◽  
2021 ◽  
pp. 095968362110331
Author(s):  
Matthew Adesanya Adeleye ◽  
Simon Edward Connor ◽  
Simon Graeme Haberle

Understanding long-term (centennial–millennial scale) ecosystem stability and dynamics are key to sustainable management and conservation of ecosystem processes under the currently changing climate. Fossil pollen records offer the possibility to investigate long-term changes in vegetation composition and diversity on regional and continental scales. Such studies have been conducted in temperate systems, but are underrepresented in the tropics, especially in Africa. This study attempts to synthesize pollen records from Nigeria (tropical western Africa) and nearby regions to quantitatively assess Holocene regional vegetation changes (turnover) and stability under different climatic regimes for the first time. We use the squared chord distance metric (SCD) to assess centennial-scale vegetation turnover in pollen records. Results suggest vegetation in most parts of Nigeria experienced low turnover under a wetter climatic regime (African Humid Period), especially between ~8000 and 5000 cal year BP. In contrast, vegetation turnover increased significantly under the drier climatic regime of the late-Holocene (between ~5000 cal year BP and present), reflecting the imp role of moisture changes in tropical west African vegetation dynamics during the Holocene. Our results are consistent with records of vegetation and climatic changes in other parts of Africa, suggesting the Holocene pattern of vegetation change in Nigeria is a reflection of continental-scale climatic changes.


2021 ◽  
Vol 55 (2) ◽  
pp. 405-426
Author(s):  
I. F. Skirina ◽  
N. A. Tsarenko ◽  
F. V. Skirin

This paper presents the results of the study of lichen flora in swamp complexes of Sakhalin Island, obtained during expeditionary research in 2005–2009 and 2014–2020. The revealed species composition of lichens includes 172 species. The 28 of them are new for Sakhalin and 93 are new for the island swamp complexes. Bryocaulon pseudosatoanum is included in the regional and federal Red lists. Lecidea nylanderi is new to the south of the Far East. The information about substrates, habitats and locations is given for all species. The data on the distribution in the south of the Far East and, in some cases for all Far East, are listed for selected species that are new for Sakhalin Island and the south of the Far East. For the first time, a characteristic of the distribution of lichens in oligotrophic, eutrophic and mesotrophic bogs of Sakhalin Island is given.


2017 ◽  
Vol 72 (1) ◽  
pp. 63-74
Author(s):  
T. A. Kiryukhina ◽  
S. I. Bordunov ◽  
A. A. Solov’eva

2021 ◽  
Vol 9 ◽  
Author(s):  
Shengli Yang ◽  
Xiaojing Liu ◽  
Ting Cheng ◽  
Yuanlong Luo ◽  
Qiong Li ◽  
...  

Aeolian sediments hold key information on aeolian history and past environmental changes. Aeolian desertification and extensive land degradation have seriously affected the eco-environment in the Gannan region on the eastern Tibetan Plateau. Understanding the history of aeolian activities can deepen our understanding of the impacts of climatic changes on aeolian activities in the future. This study uses a detailed chronology and multiple proxy analyses of a typical aeolian section in Maqu to reconstruct aeolian activities in the region during the Holocene. Our results showed that aeolian activities have occurred in the eastern Tibetan Plateau since the early Holocene. Magnetic susceptibility, grain size records, and paleosols formation indicated a trend of stepwise weakening in aeolian activities from the early Holocene to the present. The weakening of aeolian activities was divided into three stages: ∼10.0–8.0 ka BP, ∼8.0–4.0 ka BP, and ∼4.0 ka BP to the present. Paleosols were primarily formed after ∼8.0 ka BP, and episodically interrupted aeolian activities processes in the Gannan region. Aeolian activity may increase in the Gannan region as the climate gradually warms. Climatic changes and local hydrological conditions have jointly affected the history of aeolian activities in this region.


1997 ◽  
Vol 40 (2) ◽  
Author(s):  
G. Vargemezis ◽  
J. Zlotnicki ◽  
G. Tsokas ◽  
B. C. Papazachos ◽  
E. E. Papadimitriou

Two magnetotelluric stations have been installed in the South-Eastern Thessaly basin (Central Greece), which have recorded the geomagnetic and geoelectric fields since 1993. The aim is to detect long lasting abnormal changes of the geoelectric field which may be due to impending earthquakes. The geoelectric recordings were checked against the climatic changes such as temperature changes and precipitation and no correlation was observed. Ten anomalies were observed with characteristics similar to seismoelectric signals which have been reported in the literature and thus we can assume that these changes constitute precursory phenomena. The duration of these signals varies from several days to a few weeks. Some of them keep on developing until the occurrence of an earthquake, and others appear like transient changes several days before. The high seismicity of the area where the stations are located creates difficulties in the correlation of the signals with certain shocks.


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