Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Changes in annual temperature extremes in the Carpathians since AD 1961

Abstract: The Carpathian Mountains region cover areas from seven countries of central and southeastern Europe, the mountain chain having major regional influences on the temperate climate, specific to latitudes between 43°N and 49°N. In order to identify changes in the annual temperature extremes, the Mann–Kendall nonparametric trend test has been applied to several thermal indices, recommended by the expert team on climate change detection and indices. The indices were computed from gridded daily datasets of minimum and maximum temperature at 0.1° resolution (~10 km), available online within the framework of the project CarpatClim (climate of the Carpathian region) for the period 1961–2010. The results show decreasing trends in cold-related indices, especially in the number of frost days, and increasing trends in warm-related ones. The trend patterns are consistent over the region, i.e., there are no mixed trends for a given index. Regional differences in climate extreme trends within the Carpathian region are related to altitude, rather than latitude. The number of summer days is increasing over the entire area, while the number of tropical nights presents upward trends mainly at lower elevations. The Warm Spell Duration Index presents upward trends over 60 % of the region. The (annual) East Atlantic pattern shows strong correlations with the warm-related indices. Our results are in agreement with previous temperature-related studies in the region.

The assessment of socio-economic vulnerability to drought in Southern Romania (Oltenia Plain)

Abstract: Oltenia Plain is one of the most important agricultural regions in Romania and one of the most sensitive in terms of extreme weather phenomena i.e. drought, due to its location in the south-western part of the country, combined with the natural and socio-economic conditions. During the post-communist period, Oltenia Plain was subject to major transformations which triggered environmental consequences i.e. land use/land cover changes, excessive fragmentation of farming land, individual farms practicing subsistence agriculture, poor services in agriculture. All of these have turned this area into one of the most vulnerable to extreme weather phenomena leading to severe degradation of agricultural land with direct impact on crop production, human health, and rural welfare. The paper aims to develop a multi-criteria vulnerability assessment using both quantitative and qualitative methods. The authors are seeking to identify relevant indicators to assess various components of socio-economic vulnerability to the drought phenomenon, using the statistical data available at LAU 2 level. As a result, three main categories of statistical variables and indicators were taken into account: demographic and social features, economy and public utilities. Based on the resulted outcomes, the selected indicators are grouped in three major indexes: demographic and social vulnerability, economic vulnerability and infrastructure vulnerability based on which, an integrated socio-economic vulnerability index to drought (using the Hull score, average 50 and standard deviation 14) was computed. For the particularities of drought, the authors performed relevant climate indicators based on the meteorological data of the most representative weather stations in the study area.

Deep embrittlement and complete rupture of the lithosphere during the M w 8.2 Tehuantepec earthquake

Abstract: Subduction zones, where two tectonic plates converge, are generally dominated by large thrust earthquakes. Nonetheless, normal faulting from extensional stresses can occur as well. Rare large events of this kind in the instrumental record have typically nucleated in and ruptured the top half of old and cold lithosphere that is in a state of extension driven by flexure from plate bending. Such earthquakes are limited to regions of the subducting slab cooler than 650 °C and can be highly tsunamigenic, producing tsunamis similar in amplitude to those observed during large megathrust events. Here, we show from analyses of regional geophysical observations that normal faulting during the moment magnitude Mw 8.2 Tehuantepec earthquake ruptured the entire Cocos slab beneath the megathrust region. We find that the faulting reactivated a bend-fault fabric and ruptured to a depth well below the predicted brittle–ductile transition for the Cocos slab, including regions where temperature is expected to exceed 1,000 °C. Our findings suggest that young oceanic lithosphere is brittle to greater depths than previously assumed and that rupture is facilitated by wholesale deviatoric tension in the subducted slab, possibly due to fluid infiltration. We conclude that lithosphere can sustain brittle behaviour and fail in an earthquake at greater temperatures and ages than previously considered. Geophysical observations of the 2017 Tehuantepec earthquake suggest that oceanic lithosphere can sustain brittle behaviour and rupture in an earthquake at greater depths than previously assumed.

Updated Empirical Model of Genetically Modified Maize Grain Production Practices to Achieve European Union Labeling Thresholds

Abstract: An updated empirical approach is proposed for specifying coexistence requirements for geneti- cally modified (GM) maize ( Zea mays L.) produc- tion to ensure compliance with the 0.9% label- ing threshold for food and feed in the European Union. The model improves on a previously published (Gustafson et al., 2006) empirical model by adding recent data sources to supple- ment the original database and including the fol- lowing additional cases: (i) more than one GM maize source field adjacent to the conventional or organic field, (ii) the possibility of so-called "stacked" varieties with more than one GM trait, and (iii) lower pollen shed in the non-GM recep- tor field. These additional factors lead to the possibility for somewhat wider combinations of isolation distance and border rows than required in the original version of the empirical model. For instance, in the very conservative case of a 1-ha square non-GM maize field surrounded on all four sides by homozygous GM maize with 12 m isolation (the effective isolation distance for a single GM field), non-GM border rows of 12 m are required to be 95% confident of gene flow less than 0.9% in the non-GM field (with adventi - tious presence of 0.3%). Stacked traits of higher GM mass fraction and receptor fields of lower pollen shed would require a greater number of border rows to comply with the 0.9% threshold, and an updated extension to the model is pro- vided to quantify these effects.