Western Plateau Research Articles

Análise integrada da paisagem: perfis geoecológicos na transição Planalto Ocidental - Depressão Periférica no município de São Pedro, estado de São Paulo

O presente artigo aborda as contribuições advindas do uso de perfis geoecológicos na análise integrada da paisagem. A pesquisa foi baseada no estudo de transectos na transição do Planalto Ocidental para a Depressão Periférica em São Pedro - SP, e buscou compreender a organização e dinâmica da paisagem local, de modo a hierarquizar as forças atuantes em uma perspectiva geossistêmica. Fazendo uso de bases cartográficas, fotografias aéreas e imagem SRTM, levantaram-se características geológicas, geomorfológicas, pedológicas e hidrográficas, bem como a vegetação original e uso da terra atual. Ainda no contexto geográfico, foi possível estabelecer relações sistêmicas entre os temas escolhidos e suas respectivas escalas de atuação, verificando-se a interação dos elementos que compõem a paisagem a partir de um perfil síntese, permitindo também melhor compreensão da atuação antrópica na área de estudo. Os resultados demonstraram forte influência de caráter litoestrutural, assim como uma ocupação antrópica dependente das condições topográficas e pedológicas.

The Elbrus (Caucasus, Russia) ice core record – Part 2: history of desert dust deposition

Abstract. Ice cores are one of the most valuable paleo-archives. Records from ice cores provide information not only about the amount of dust in the atmosphere, but also about dust sources and their changes in the past. In 2009, a 182 m long ice core was recovered from the western plateau of Mt Elbrus (5115 m a.s.l.). This record was further extended after a shallow ice core was drilled in 2013. Here we analyse Ca2+ concentrations, a commonly used proxy of dust, recorded in these Elbrus ice records over the time period of 1774–2013 CE. The Ca2+ record reveals quasi-decadal variability with a generally increasing trend. Using multiple regression analysis, we found a statistically significant spatial correlation of the Elbrus Ca2+ summer concentrations with precipitation and soil moisture content in the Levant region (specifically Syria and Iraq). The Ca2+ record also correlates with drought indices in North Africa (r=0.67, p<0.001) and Middle East regions (r=0.71, p<0.001). Dust concentrations prominently increase in the ice core over the past 200 years, confirming that the recent droughts in the Fertile Crescent (1998–2012 CE) present the most severe aridity experienced in at least the past two centuries. For the most recent 33 years recorded (1979–2012 CE), significant correlations exist between Ca2+ and Pacific circulation indices (Pacific Decadal Oscillation, Southern Oscillation Index and Niño 4), which suggests that the increased frequency of extreme El Niño and La Niña events due to a warming climate has extended their influence to the Middle East. Evidence demonstrates that the increase in Ca2+ concentration in the ice core cannot be attributed to human activities, such as coal combustion and cement production.

The Traditional Knowledge of Wild Edible Leaf used by Tribal People in Chhattisgarh

Chhattisgarh, A state of rich biodiversity zone covered a wide range of forest having three climatic zones namely north and central eastern plateau zone, Eastern plateau zone, Western plateau zone supporting a rich biodiversity. Approximately, 30 tribal inhabitants depend on forest for survival and population live below the poverty line. The forest provide a significant role to provide them wild leafy vegetables, consumed by the tribal and other local inhabitants. These wild edible leaves not only provide the nutritional requirements of local population but ensure food security for the people living in and around forests areas. The role of present study was to enthuses the various wild edible leaves eaten by the local communities.

Isotopic composition of oxygen in snow-and-firn thickness on the Eastern peak of Elbrus, the Caucasus

The isotopic composition of oxygen of the snow-and-firn and snow thickness on the Eastern peak of Elbrus had been studied. In 2006-2008, a number of snow samples were taken in the near-peak area of Elbrus to analyze the isotopic composition of them. The drilling was performed at the crater of the Eastern peak in 2006 (64 samples) while in 2017 the samples were taken from snow pit (25 samples). Another core to a depth of 23.8 m was extracted at the Western Plateau (118 samples) for the purpose to compare local 5 18 О values with samples from the Eastern peak. The δ 18 О values in the snow-and-firn thickness from the crater of the Eastern peak vary from -6.8 to -19.41 %o with the average value of -12.61 %o. It was revealed that snow layers with extremely low values of δ 18 О (down to -30 %) found on the eastern slope were absent on the western plateau. The loss of part of the annual isotope precipitation signal due to the winter extra light horizons could be caused by two reasons: wind drift of the freshly deposited snow, as well as the absence of part of the winter snowfalls with isotope-light precipitation at altitudes higher 5300 m. Seasonal variations of δ 18 О values, equal to 12 % and found in the snow-and-firn thickness on the Eastern peak, indicate that formation of the isotopic characteristics of snow is determined here by the equilibrium Rayleigh condensation and this is associated with the annual amplitude of the air temperature by a coefficient of 0.6 %o/°C. In the isotopic record obtained on the Western plateau of Elbrus, the relationship of values δ 18 О with the condensation temperature may be disturbed due to the frequent change of the main moisture-bearing air masses. This leads to significantly different δ 18 О values in precipitation at the same temperatures (the connection of seasonal δ 18 О values with the annual amplitude of air temperature varies from 0.3 to 1.12 % о /° С ).

Assessment of ecosystem services of rice farms in eastern India

BackgroundRice is a major cereal crop and staple food of eastern India, and most farmers depend solely on rice for their livelihood. Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced. These benefits are provided through ecosystem services (ES) that include both marketable and non-marketable.MethodsIn this study, the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed. A stratified random sampling technique was used in this study for selection of agro-climatic zones, districts, blocks, gram panchayat, and study units (households). Soil sampling was also performed for assessing the regulating services (biocontrol of pests, carbon flow, soil erosion, nitrogen fixation), provisioning services (food and by-products), and supporting services (soil fertility, hydrological flow, nutrient cycling, and soil formation).ResultsThe results indicated that the total economic value of ecosystem services ranged from US$ 1238 to 1688 ha−1 year−1. The marketed (primary production) and non-marketed ecosystem services values ranged from 66–89 to 11–34% of the total, respectively. Valuation of some of the ecosystem services such as cultural services, biodiversity, and gas regulation, which may play a significant role in total ecosystem services, has not been made due to non-availability of data and appropriate methodology for rice ecosystem. Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India. Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services, while permitting sustainable agro-ecological intensification. The highest total economic gap between ES value and farm income was found in the north central plateau zone (US$ 1063 ha−1 year−1) and the lowest in the north western plateau zone (US$ 670 ha−1 year−1).ConclusionWe suggest various measures to reduce the economic gap, including payments for ecosystem services for rice farming for sustainability of the ecosystem and agricultural development, while ensuring reliable farm income.

Protocol for the use of legacy data and magnetic signature on soil mapping of São Paulo Central West, Brazil.

The demand for information on the soil resource to support the establishment of public policies for land use and management has grown exponentially in the last years. However, there are still difficulties to the proper use of already existing information for soil mapping. Here we aimed to establish a protocol for soil mapping using legacy data, magnetic signature and soil attributes evaluation. A total of 493 soil samples were collected at 0-0.20 m in the geological domain of Western Plateau of São Paulo State. This work has three parts: First, we performed a classification analysis using soil mapping units (SMU) extracted from conventional soil map and Support Vector Machines algorithm (SVM). As covariates, we used categorical information, such as geology, dissection and landform maps. Second, we used soil attributes to perform a cluster analysis using k-means as partitioning method. To choose the optimal number of clusters, the same number of SMU showed in the conventional soil map (e.g. 34 clusters) were used. The last step was to compare soil and clusters maps predicted by SVM with the conventional soil map. Results showed good performance of SVM for both classifications (clusters and SMU), with overall accuracy of 0.60 and 0.90 respectively. In addition, the distribution of soil attributes within each cluster was more homogeneous and well distributed than within SMU, showing that is very possible to use numerical classification for soil mapping. Future soil surveys could use cluster analysis as a preliminary evaluation for better understanding of tropical soil variations.

Aloformação Andradina: expressão do Antropoceno no Planalto Ocidental Paulista

O quadro geológico do Planalto Ocidental Paulista (220.000 km2) no estado de São Paulo é marcado pela ocorrência de depósitos sedimentares que assoreiam os fundos de vale de primeira e segunda ordem, resultantes de uma excessiva produção de sedimentos, com abrangência regional, num curto intervalo de poucas dezenas de anos. Estes sedimentos têm como origem a manifestação de intensos processos erosivos consequentes à devastação das florestas primitivas, realizada pelo processo de colonização de origem europeia no século XX. Os depósitos podem ser reconhecidos no campo pela alternância nos sedimentos de camadas mais argilosas e mais arenosas, contendo artefatos que constituem indicadores inequívocos de sua origem antrópica. Podem ser detectados em imagens de satélite e em fotografias aéreas que permitem, de uma parte, verificar a extensão de suas ocorrências nos fundos dos vales e, de outra parte, a sua dinâmica ao longo do tempo. Assim, constata-se que ocorrem em toda a rede de drenagem do Planalto Ocidental Paulista, apesar de individualmente ocuparem extensões relativamente reduzidas em cada berço de drenagem. Por apresentarem expressão regional de ocorrência, características persistentes e por representarem um epiciclo geotecnogênico de grande importância, é cientificamente relevante que estes depósitos, que marcam a colonização do Planalto Ocidental Paulista, sejam reconhecidos como uma nova formação: a aloformação Andradina, cujos critérios de definição seguiram o Léxico Estratigráfico do Brasil. A denominação Andradina, além de representar a localidade que teve o primeiro depósito a ser estudado (em 1994), constitui um dos principais locais de referência das pesquisas pioneiras realizadas por Pierre Monbeig, nos anos de 1940, e onde é possível reconhecê-la como um estratótipo, que não é resultante de um evento fortuito ou localizado, mas representa um quadro geológico configurado no Antropoceno, como vem sendo definida a nova época do Quaternário pela Comissão Estratigráfica da IUGS, marcada pela ação da humanidade como agente geológico.

Clinical research on osteoporosis and fracture risks in plateau areas in China

Osteoporosis is a chronic disease influenced by multiple factors. The fractures associated with osteoporosis are known as osteoporotic fractures. The factors associated with osteoporosis and fracture include oxygen concentration, sunshine, body mass, gender, age, trauma, dietary habits, tobacco and alcohol use, medical history and inheritance. Factors such as oxygen concentration, topography and dietary habits play a more important role in the western plateau areas in China than in the plain areas. The present study reviews the clinical research on the osteoporosis and fracture risks in the plateau areas in China and proposes prevention and treatment measurements for the risk factors to reduce the incidences of osteoporosis and fracture in the plateau areas. Key words: Osteoporosis; Fractures, bone; Plateau areas; Risks

Deciphering impacts of climate extremes on Tibetan grasslands in the last fifteen years

Climate extremes have emerged as a crucial driver of changes in terrestrial ecosystems. The Tibetan Plateau, facing a rapid climate change, tends to favor climate extremes. But we lack a clear understanding of the impacts of such extremes on alpine grasslands. Here we show that extreme events (drought, extreme wet, extreme cold and extreme hot) occurred at a frequency of 0.67–4 months decade−1 during 2001–2015, with extreme precipitation predominantly occurring in June-to-August and extreme temperatures in May. Drought and extreme wet cause opposite and asymmetric effects on grassland growth, with drought-induced reductions greater than increases due to extreme wet. Grassland responses to extreme temperatures, which predominantly occur in May, show a dipole-like spatial pattern, with extreme hot (cold) events enhanced (reduced) growth in the eastern plateau but slightly reduced (enhanced) growth in the western plateau. These opposite responses to extreme temperatures over the eastern plateau are explained by the possibility that the occurrence of extreme cold slows the preseason temperature accumulation, delaying the triggering of spring phenology, while extreme hot hastens the accumulation. In the western plateau, in contrast, positive responses to extreme cold are induced by accompanying high precipitation. Furthermore, high extremeness of climate events generally led to a much lower extremeness in growth response, implying that the Tibetan grasslands have a relatively high resistance to climate extremes. The ecosystem models tested could not accurately simulate grassland responses to drought and extreme temperatures, and require re-parameterization before trust can be placed in their output for this region.

Summer Atmospheric Heat Sources over the Western–Central Tibetan Plateau: An Integrated Analysis of Multiple Reanalysis and Satellite Datasets

Multiple bias-corrected top-quality reanalysis datasets, gauge-based observations, and selected satellite products are synthetically employed to revisit the climatology and variability of the summer atmospheric heat sources over the Tibetan Plateau (TP). Verification-based selection and ensemble-mean methods are utilized to combine various datasets. Different from previous works, this study pays special attention to estimating the total heat source (TH) and its components over the data-void western plateau (70°–85°E), including the surface sensible heat (SH), latent heat released by precipitation (LH), and net radiation flux (RD). Consistent with previous studies, the climatology of summer SH (LH) typically increases (decreases) from southeast to northwest. Generally, LH dominates TH over most of the TP. A notable new finding is a minimum TH area over the high-altitude region of the northwestern TP, where the Karakoram mountain range is located. We find that during the period of 1984–2006, TH shows insignificant trends over the eastern and central TP, whereas it exhibits an evident increasing trend over the western TP that is attributed to the rising tendency of LH before 1996 and to that of RD after 1996. The year-to-year variation of TH over the central–eastern TP is highly correlated with that of LH, but that is not the case over the western TP. It is also worth noting that the variations of TH in each summer month are not significantly correlated with each other, and hence study of the interannual variation of the TP heat sources should consider the remarkable subseasonal variations.

Comparative analysis of IgG and IgG subclasses against Plasmodium falciparum MSP-119 in children from five contrasting bioecological zones of Cameroon

BackgroundStudies reporting the natural immune responses against malaria in children from different geographical settings in endemic areas are not readily available. This study was aimed at comparing the immune responses against Plasmodium falciparum MSP-119 antigen in children from five contrasting bioecological zones in Cameroon.MethodsIn a cross-sectional survey, children between 2 and 15 years, were enrolled from five ecological strata including the south Cameroonian equatorial forest, sudano-sahelian, high inland plateau, high western plateau, and the coastal strata. The children were screened for clinical malaria (defined by malaria parasitaemia ≥ 5000 parasites/µl plus axillary temperature ≥ 37.5 °C). Their antibody responses were measured against P. falciparum MSP-119 antigen using standard ELISA technique.ResultsIn all, 415 children comprising 217 (52.3%) males participated. Total IgG and IgG1–IgG4 titres were observed to increase with age in all the strata except in the sudano-sahelian and high inland plateau strata. Total IgG and IgG1–IgG4 titres were significantly higher in the coastal strata and lowest in the high inland plateau (for IgG1 and IgG2) and sudano-sahelian strata (for IgG3 and IgG4). Titres of the cytophilic antibodies (IgG1 and IgG3) were significantly higher than the non-cytophilic antibodies (IgG2 and IgG4) in all the strata except in the sudano-sahelian and high inland plateau strata. Total IgG and IgG subclass titres were significantly higher in children positive for clinical malaria compared to negative children in all study sites except in the high western plateau and coastal (for IgG1 and IgG3), and the sudano-sahelian strata (for all antibodies). Furthermore, a significant positive correlation was observed between parasite density and IgG2 or IgG4 titres in all study sites except in the south Cameroonian equatorial forest and sudano-sahelian strata.ConclusionsThis study showed that antibody responses against MSP-119 vary considerably in children from the different bioecological strata in Cameroon and could be linked to the differential exposure to malaria in the different strata. Furthermore, the rate of antibody acquisition was not observed to increase in an age-dependent manner in low transmission settings.

A complexidade dos sistemas de assentamentos ameríndios no Planalto Ocidental Paulista vistos a partir da arqueologia: a contribuição do LAG/MAR

O Planalto Ocidental Paulista foi, outrora, densamente ocupado por povos agricultores indígenas. Apresenta-se, aqui, o levantamento dos dados arqueológicos das ocupações indígenas pesquisadas na área do Planalto Ocidental Paulista, pelo LAG (Laboratório de Arqueologia Guarani e Estudos da Paisagem) e MAR (Museu de Arqueologia Regional) da FCT/UNESP (Faculdade de Ciências e Tecnologia/Universidade Estadual Paulista). No Planalto Ocidental Paulista, encontramos as etnias Guarani e/ou Tupi; Kaingang e Kayapó. Objetiva-se trazer à luz a cultura material, a partir da caracterização dos objetos, da localização das habitações e do meio físico dessas ocupações, a partir dos quais, ainda que de forma inicial, se possa conhecer, ao menos em parte, as características desses grupos indígenas.

Impacts of snow cover duration on vegetation spring phenology over the Tibetan Plateau

Snow cover occupies large percentage of land surface in Tibetan Plateau. Snow cover duration (SCD) during non-growing seasons plays a critical role in regulating alpine vegetation’s phenology by affecting the energy budgets of land surface and soil moisture conditions. Different period’s snow cover during non-growing season may have distinct effect on the vegetation’s phenology. Start of season (SOS) has been observed advanced under the ongoing climate change in the plateau, but it still remains unclear how the SCD alters the SOS. This study attempts to answer the following questions: (i) What is the pattern of spatial and temporal variations for SCD and grassland SOS? (ii) Which period’s SCD plays a critical role in grassland’s SOS? The remote sensing datasets from the Moderate Resolution Imaging Spectroradiometer (MODIS) were utilized to compute the SOS and SCD on the Tibetan Plateau over 2003–15. The Asymmetric Gaussian function was applied to extract SOS. We also explored the spatial pattern and temporal variation of SOS and SCD. Then, by using linear correlation coefficients, we investigated the driving effects of different period’s non-growing season SCD on SOS. The non-growing season SCD slightly decreased during 2003–15, while SOS exhibited an overall advancing trend. Advanced trends in SOS were observed in the eastern plateau, and the delayed trends were mainly founded in western plateau. Snow cover area exhibited two separate peaks during autumn and late winter over the plateau. Extended SCD regions mainly distributed in middle-east of the plateau, while shrunken SCD distributed in other regions of the plateau. SCD of different seasons caused distinct effects on vegetation SOS. Lengthened autumn SCD advanced SOS over the eastern plateau. The slightly lengthened SCD postponed SOS over the western plateau. In the wet meadow regions, advanced SOS was positively associated with SCD during the entire non-growing season, whereas for the dry steppe, SCD over the preseason played a more dominant role. The SCD of previous autumn and winter also showed lag effect on SOS over meadow regions to a certain extent. This study confirmed the importance of SCD to phenological processes at the beginning of growing season and further suggested that role of SCD should be discriminated for different periods and for different heat-water conditions. With the lag effects and SCD’s distinct effect of different seasons considered, predictions on the Tibetan Plateau’s spring phenology could be improved.

Crustal thickness estimates beneath four seismic stations in Ethiopia inferred from p-wave receiver function studies

Moho depths beneath four stations of the Ethiopian Seismic Station Network (ESSN) are estimated from P-wave receiver functions (RF). We used high quality seismic data recorded at ANKE (Ankober), DILA (Dilla), HARA (Harar) and SEME (Semera) stations for earthquakes located at epicentral distances ranging from 30 to 100° with magnitude mb ≥ 5.5. We applied a frequency domain deconvolution technique to remove source and propagation path effects from the earthquakes waveforms to make the RFs dependent only on the structure beneath the seismic stations. The minimum number of teleseismic earthquakes used is 14 for HARA while the maximum is 39 for SEME station. A linearized-iterative inversion is applied on the generated radial component of the receiver functions to obtain P-wave velocity models beneath the stations. We achieved a reasonably good fit between the observed and synthetic RFs, which demonstrated the high quality of the inversion process. From the obtained models we estimated Moho depths of 26 ± 2 km for SEME, 36 ± 2 km for DILA, 38 ± 2 km for HARA and 42 ± 1.7 km for ANKE. The lowest Moho depth is observed at Semera station which implies a thinned crust while the highest crustal thickness is observed at Ankober, which lies along the North western plateau margin. Our results agree with previous observations which strengthen the hypothesis that Moho depths estimated for stations that lie within the rift and rift margins are lower than those located in the plateaus. Our RFs inversions show a low velocity gradient at about 16 km depth at Semera station, interpreted as evidence for lower crustal storage of partial melt.

Ouasel village in western Anbar plateau as a model of desert villages in Iraq

Ouasel village had been originated in western Anbar plateau before one century ago. It is located at 3km north of al-wafaa town. Its community combined from some Arabic tribes that applied agricultural practices as in Euphrates valley of Anbar province. Sheep grazing was motivator to be first establishment where some immigrants were stabilized there. Later, they were applying cultivation activity with determinant areas. They also worked in rock, sand and gravels quarries which distributed in western plateau per se. therefore, in general Ouasel village is considered as a model for desert villages in Iraq based on its nature of establishment, economic activity and social relationships among its population. Furthermore, the governorate strategy is clearly disable to provide population and services level in this village. Thus it could be recommended to find curing solutions to develop this desert village of Anbar.

Present Situation and Prospect of Flammable Ice Exploration and Development in Permafrost in China

As the world’s most promising clean and efficient energy, combustible ice has attracted more and more attention from all over the world, and the heat has increased in a geometric series. There is combustible ice in the 27% land and 90% sea areas of the world. The reserves amount to 2×10¹⁶m³, and the carbon content is more than twice of all the proven fossil fuels combined. There have been 79 countries and regions where flammable ice reservoirs have been discovered, and at least 38 permafrost zones have found flammable ice in the land region.The flammable ice in the permafrost is mainly distributed in the Qinghai-Tibet Plateau, the western plateau and the Greater Xiaoxing’an Mountains in Northeast China. The area is about 215 × 10 ⁴ km ², accounting for 22.4% of the land area, and the amount of resources is about 350 × 10⁸ tons of oil equivalent. The present situation of investigation and research on flammable ice in land area, the present situation of exploration and development in China, the identification technology, drilling technology, logging technology and development technology of flammable ice in land area are summarized. It is pointed out that commercial exploitation of flammable ice in land area is faced with problems such as Greenhouse Effect, geological hazard, environmental effect, laws and regulations, etc. The prospect of exploration and development of flammable ice in land area of China is prospected.

Finger millet and horsegram intercropping systems in replacement series for advantages and weed smothering

The land use efficiency and weed suppression through intercropping plays a pivotal role. A field experiment was carried out on finger millet (Eleusine indica L. Gaertn) –horsegram (Macrotyloma uniflorum (Lam.) Verdc.) mono- and intercropping with various weeding (0, 1, or 2 hand-weeding operations) and row spacing (20 and 30 cm) treatments in the Bastar plateau region of India over consecutive five Kharif seasons (2010/2014). The experimental design was a randomized complete block with eighteen treatments replicated thrice. Five percent significant differences were observed in yield and its economics with and without weeding treatments. Horsegram yield was significantly reduced by Finger millet when intercropped. However, total productivity and land use efficiency were higher under the intercropping system as compared to monocrops of either species. There was a significant reduction in weed density and biomass for the intercropping system over both monocrops. Finger millet facilitated an increase in nodule number and dry weight in horsegram under intercropping over monocrops, moreover, root length of horsegram was greater when intercropped. These findings suggest that intercropping Finger millet and horsegram increase total productivity per unit area improve land use efficiency and suppress weeds. Focussing the experimental findings, Finger millet–horsegram (30 cm) with two weedings may be recommended for yield advantage, higher net income, more efficient utilization of resources, and weed suppression as a biological control in western plateau region of India.

Influence of Western Tibetan Plateau Summer Snow Cover on East Asian Summer Rainfall

AbstractThe influence of boreal winter‐spring eastern Tibetan Plateau snow anomalies on the East Asian summer rainfall variability has been the focus of previous studies. The present study documents the impacts of boreal summer western and southern Tibetan Plateau snow cover anomalies on summer rainfall over East Asia. Analysis shows that more snow cover in the western and southern Tibetan Plateau induces anomalous cooling in the overlying atmospheric column. The induced atmospheric circulation changes are different corresponding to more snow cover in the western and southern Tibetan Plateau. The atmospheric circulation changes accompanying the western Plateau snow cover anomalies are more obvious over the midlatitude Asia, whereas those corresponding to the southern Plateau snow cover anomalies are more prominent over the tropics. As such, the western and southern Tibetan Plateau snow cover anomalies influence the East Asian summer circulation and precipitation through different pathways. Nevertheless, the East Asian summer circulation and precipitation anomalies induced by the western and southern Plateau snow cover anomalies tend to display similar distribution so that they are more pronounced when the western and southern Plateau snow cover anomalies work in coherence. Analysis indicates that the summer snow cover anomalies over the Tibetan Plateau may be related to late spring snow anomalies due to the persistence. The late spring snow anomalies are related to an obvious wave train originating from the western North Atlantic that may be partly associated with sea surface temperature anomalies in the North Atlantic Ocean.

Off-axis volcano-tectonic activity during continental rifting: Insights from the transversal Goba-Bonga lineament, Main Ethiopian Rift (East Africa)

The Main Ethiopian Rift, East Africa, is characterized by the presence of major, enigmatic structures which strike approximately orthogonal to the trend of the rift valley. These structures are marked by important deformation and magmatic activity in an off-axis position in the plateaus surrounding the rift. In this study, we present new structural data based on a remote and field analysis, complemented with analogue modelling experiments, and new geochemical analysis of volcanic rocks sampled in different portions of one of these transversal structures: the Goba-Bonga volcano-tectonic lineament (GBVL). This integrated analysis shows that the GBVL is associated with roughly E–W-trending prominent volcano-tectonic activity affecting the western plateau. Within the rift floor, the approximately E–W alignment of Awasa and Corbetti calderas likely represent expressions of the GBVL. Conversely, no tectonic or volcanic features of similar (E–W) orientation have been recognized on the eastern plateau. Analogue modelling suggests that the volcano-tectonic features of the GBVL have probably been controlled by the presence of a roughly E–W striking pre-existing discontinuity beneath the western plateau, which did not extend beneath the eastern plateau. Geochemical analysis supports this interpretation and indicates that, although magmas have the same sub-lithospheric mantle source, limited differences in magma evolution displayed by products found along the GBVL may be ascribed to the different tectonic framework to the west, to the east, and in the axial zone of the rift. These results support the importance of the heterogeneous nature of the lithosphere and the spatial variations of its structure in controlling the architecture of continental rifts and the distribution of the related volcano-tectonic activity.

Comparisons of remote sensing and reanalysis soil moisture products over the Tibetan Plateau, China

The availability of reliable long-term and large scale soil moisture observation datasets over the Tibetan Plateau has been of more concern in recent years. It is therefore necessary to verify any such data to have a better guide to their usage. In this study, we have compared satellite soil moisture retrievals of the Special Sensor Microwave Imager (SSM/I), with ERA-Interim/Land and Global Land Data Assimilation System (GLDAS-1) soil moisture products over the Tibetan Plateau. They are found to be largely different from each other regarding the soil moisture magnitudes in spring, summer and autumn, with those of the ERA-Interim/Land particularly higher than the other datasets in the eastern plateau. The SSM/I and the ERA-Interim/Land data are in good agreement considering their seasonal dynamics, which are however considerably different from the GLDAS-1 models (CLM, Noah, Mosaic and VIC). For interannual variations, it is striking to find strong negative correlations (R<−0.6) between the SSM/I and the ERA-Interim/Land data in spring and autumn, especially over the central plateau. The SSM/I data is found to have also strong negative correlations (R<−0.4) with data of the four GLDAS-1 models in the eastern plateau in spring; and such negative correlations appear in central and western plateau in autumn. In summer, the SSM/I data appears to be positively correlated with the ERA-Interim/Land and all the GLDAS-1 data over the plateau. The negative correlations indicate these data have quite different temporal dynamics for their interannual variations, especially in spring and autumn. A look at the spatial variations revealed that the SSM/I data shows a north-south seesaw pattern in all seasons. The GLDAS-1 Mosaic, Noah and CLM data are able to represent this seesaw pattern principally, which however, can hardly be seen in the ERA-Interim/Land and the GLDAS-1 VIC data. Our results have indicated significant uncertainties in the soil moisture data from remote sensing and reanalysis sources; and we have to use such data with great care.