The Westerly Index as complementary indicator of the North Atlantic oscillation in explaining drought variability across Europe   总被引：1，自引：0，他引：1  

Sergio M. Vicente-Serrano  Ricardo García-Herrera  David Barriopedro  Cesar Azorin-Molina  Juan I. López-Moreno  Natalia Martín-Hernández  Miquel Tomás-Burguera  Luis Gimeno  Raquel Nieto 《Climate Dynamics》2016,47(3-4):845-863

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An open source GIS‐based Planning Support System: Application to the land use plan of La Troncal,Ecuador          下载免费PDF全文

Inés Santé  Natalia Pacurucu  Marcos Boullón  Andrés Manuel García  David Miranda 《Transactions in GIS》2016,20(6):976-990

Planning Support Systems (PSS) comprise a wide variety of geo‐technological tools related to GIS and spatial modeling aimed at addressing land planning processes. This article describes the OpenRules system, a PSS based on a previous system called RULES. Among OpenRules new features are its architecture, based exclusively on free and open source software, and its applicability to all land use types, including rural and urban uses. In addition, OpenRules incorporates an unlimited number of land evaluation factors and a new objective in land use spatial allocation. OpenRules has been programmed in Java and implemented as a module of the free GIS software gvSIG, with full integration between the GIS and the decision support tools. Decision support tools include multicriteria evaluation, multiobjective linear programming and heuristic techniques, which support three basic stages of land use planning processes, namely land suitability evaluation, land use area optimization and land use spatial allocation. The application of OpenRules to the region of La Troncal, Ecuador, demonstrates its capability to generate alternative and coherent solutions through a scientific and justified procedure at low cost in terms of time and resources.  相似文献   

Holocene overbank deposition in the drainage basin of Lake Khanka     

V.B. Bazarova  M.S. Lyashchevskaya  T.R. Makarova  R.A. Makarevich  L.A. Orlova 《Russian Geology and Geophysics》2018,59(11):1410-1418

Overbank deposits in the Komissarovka River valley consist of alternating silt, clay silt, sand, and soils produced by lacustrine, alluvial, and aeolian deposition and by soil formation. Silt and sand layers in the lower part of the section correlate with the events of Early Holocene transgression and Middle Holocene regression of Lake Khanka. Deposition in the lowermost reaches of the Komissarovka River provides a faithful record of local Holocene landscapes controlled by level changes in Lake Khanka.  相似文献   

Upwelling of Deep-seated Fluid in the Sikhote-Alin Region,Far East of the Eurasian Plate     

Nakamura  Hitomi  Iwamori  Hikaru  Morikawa  Noritoshi  Kharitonova  Natalia  Chelnokov  Georgy  Bragin  Ivan  Chang  Qing 《Aquatic Geochemistry》2021,27(4):269-282

Aquatic Geochemistry - Spring waters with high-pCO2 content are widely distributed in the Sikhote-Alin region in Russia. Mukhen spa is one such spring located in the northern Sikhote-Alin region....  相似文献   

Seismogenic destruction of the Kamenka medieval fortress, northern Issyk-Kul region, Tien Shan (Kyrgyzstan)     

Andrey M. Korjenkov  J. Ramon Arrowsmith  Christopher Crosby  Ernes Mamyrov  Lyubov A. Orlova  Irina E. Povolotskaya  Kubatbek Tabaldiev 《Journal of Seismology》2006,10(4):431-442

A paleoseismological study of the medieval Kamenka fortress in the northern part of the Issyk-Kul Lake depression, northern Tien Shan in Kyrgyzstan, revealed an oblique slip thrust fault scarp offsetting the fortification walls. This 700 m long scarp is not related to the 1911 Kebin Earthquake (Ms 8.2) fault scarps which are widespread in the region. As analysis of stratigraphy in a paleoseismic trench and archaeological evidence reveal, it can be assigned to a major twelfth century a.d. earthquake which produced up to 4 m of oblique slip thrusting antithetic to that of the nearby dominant faults. The inferred surface rupturing earthquake apparently caused the fortress destruction and was likely the primary reason for its abandonment, not the Mongolian–Tatar invasions as previously thought.  相似文献   

Relocation of shallow earthquakes in southern Alaska using Joint Hypocenter Determination method     

Natalia A. Ratchkovsky  Jose Pujol  Niren N. Biswas 《Journal of Seismology》1998,2(1):87-102

A subset of 2660 shallow earthquakes (0–50 km) that occurred from 1988 to 1996 in south central Alaska between 155°W and 145°W and 59°N and 63°N was relocated using the joint hypocenter determination (JHD) method. Both P- and S-wave observations recorded by the regional seismic network were used. Events were relocated in twenty different groups based on their geographic location and depth using two velocity models. As a result of the relocation, the majority of the hypocenters shifted downward, while the epicenter locations did not change significantly. The distribution of the shallow subduction zone earthquakes indicates the existence of two seismically independent blocks, with one block occupying the northeastern part and the other occupying the central and western parts of the study area. The boundary between the blocks is marked by a 15 to 20 km wide seismicity gap to the southeast of 149.5°W and 62°N. The analysis of the fault plane solutions for shallow subduction zone earthquakes shows that an overwhelming majority of the solutions represent normal, oblique-normal or strike-slip faulting with predominant WNW-ESE orientation of T-axes. This indicates a down-dip extensional regime for the subducting slab at shallow depths. Very few earthquakes yielded fault plane solutions consistent with thrusting on a contact zone between the overriding and subducting plates. This result may be an indication that currently either the strain energy is not released at the contact zone or it is associated with aseismic motion.  相似文献   

Magnetic polarity zonation within the El Teniente copper–molybdenum porphyry deposit, central Chile     

Natalia Astudillo  Pierrick Roperch  Brian Townley  Cesar Arriagada  Annick Chauvin 《Mineralium Deposita》2010,45(1):23-41

El Teniente porphyry copper deposit, the world’s greatest intrusion-related Cu–Mo ore body, is hosted within basaltic–andesitic volcanic and gabbroic rocks (mafic complex). This ore body is strongly affected by multiple events of alteration/mineralization with pervasive potassic and chloritic alteration and coetaneous with associated copper mineralization. We present paleomagnetic results obtained from oriented samples at four locations within the mine and from two drill cores, 200 and 400 m long, respectively. Samples are representative of all the main hydrothermally altered rock units, with emphasis on the mafic host rock and dacitic (Teniente dacite porphyry) and dioritic porphyry intrusions. Magnetic experiments [hysteresis loop, isothermal remanent magnetization (IRM), k–T curves, thermal, and alternating field demagnetization] show the presence of prevailing magnetite. Microscope and SEM observations show two families of magnetite, (a) large multidomain magnetite grains, associated with biotite and chlorite of various different hydrothermal alteration events, and (b) abundant small to medium grain-size magnetite (<10 μm) contained within plagioclase, either related to an early Na–Ca–Fe alteration or included within plagioclase during magmatic crystal growth. While the Teniente dacite porphyry and the quartz diorite–tonalite have low magnetic susceptibility (<0.0005 SI) and low natural remanent magnetization (NRM, 10⁻⁴–10⁻³ Am⁻¹), the mineralized mafic host rocks have usually high susceptibility (>0.01 and up to 0.2 SI) with NRM in the range 0.1–2 Am⁻¹. Most mafic complex rock samples have univectorial magnetizations during alternating field or thermal demagnetization. Within the mine, the magnetic polarity is spatially distributed. In the northern part of the deposit, the Teniente dacite porphyry, the associated hydrothermal breccias, and the hosting mafic complex record a reverse polarity magnetization, also observed in the El Teniente sub-6 mine sector immediately to the east and southeast. In the eastern part of the deposit, a normal polarity is observed for samples of the mafic complex from the two long drill cores. There is no evidence for superimposed magnetizations of opposite polarities in samples of the mafic complex. Anhysteretic remanent magnetization (ARM) in a DC field of 40 μT and NRM have similar magnitude and comparable behavior upon alternating field demagnetization. The well-defined strong remanent magnetizations associated with high unblocking temperatures (>500°C) indicate an acquisition of remanent magnetization during mineralization by circulating high temperature fluids related with ore deposition. Paleomagnetic results and the recorded polarity zonation suggest multiple mineralization events occurred at El Teniente, each one with its own evolution stages, superimposed within the district. These results indicate that a simplified broad four-stage model for El Teniente, as presented and overly employed by many authors, divided in (1) late magmatic, (2) main hydrothermal, (3) late hydrothermal, and (4) posthumous stage, does not recognize various short-lived single mineralization events, some superimposed and some distinctly separated in time and space. There is no paleomagnetic evidence for post-mineralization deformation  相似文献   

A new key pole for the East European Craton at 1452 Ma: Palaeomagnetic and geochronological constraints from mafic rocks in the Lake Ladoga region (Russian Karelia)     

Natalia V. Lubnina  Satu Mertanen  Ulf Söderlund  Svetlana Bogdanova  Tatiana I. Vasilieva  Dmitry Frank-Kamenetsky 《Precambrian Research》2010

Palaeomagnetic and geochronological studies on mafic rocks in the Lake Ladoga region in South Russian Karelia provide a new, reliably dated Mesoproterozoic key paleopole for the East European Craton (Baltica). U–Pb dating on baddeleyite gives a crystallisation age of 1452 ± 12 Ma for one of the studied dolerite dykes. A mean palaeomagnetic pole for the Mesoproterozoic dolerite dykes, Valaam sill and Salmi basalts yields a paleopole at 15.2°N, 177.1°E, A₉₅ = 5.5°. Positive baked contact test for the dolerite dykes and positive reversal test for the Salmi basalts and for the dykes confirm the primary nature of the magnetisation. Comparison of this Baltica palaeopole with coeval paleomagnetic data for Laurentia and Siberia provides a revised palaeoposition of these cratons. The results verify that the East European Craton, Laurentia and Siberia were part of the supercontinent Columbia from the Late Palaeoproterozoic to the Middle Neoproterozoic.  相似文献   

Holocene climate history of the Western Baikal region: Carbonate sedimentary record of Kholbo-Nur Lake     

E. V. Sklyarov  E. P. Solotchina  E. G. Vologina  O. P. Izokh  N. V. Kulagina  L. A. Orlova  O. A. Sklyarova  P. A. Solotchin  V. N. Stolpovskaya  N. N. Ukhova 《Doklady Earth Sciences》2010,431(2):490-496

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Palynological characteristics of the Upper Visean deposits from the Mstikhino quarry,Kaluga region     

D. A. Mamontov  O. A. Orlova 《Moscow University Geology Bulletin》2014,69(1):28-35

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