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The change in the mean temperature in Finland is investigated with a dynamic linear model in order to define the sign and the magnitude of the trend in the temperature time series within the last 166 years. The data consists of gridded monthly mean temperatures. The grid has a 10 km spatial resolution, and it was created by interpolating a homogenized temperature series measured at Finnish weather stations. Seasonal variation in the temperature and the autocorrelation structure of the time series were taken account in the model. Finnish temperature time series exhibits a statistically significant trend, which is consistent with human-induced global warming. The mean temperature has risen very likely over 2 °C in the years 1847–2013, which amounts to 0.14 °C/decade. The warming after the late 1960s has been more rapid than ever before. The increase in the temperature has been highest in November, December and January. Also spring months (March, April, May) have warmed more than the annual average, but the change in summer months has been less evident. The detected warming exceeds the global trend clearly, which matches the postulation that the warming is stronger at higher latitudes.  相似文献   

3.
Izvestiya, Physics of the Solid Earth - Abstract—The analysis of the local earthquake catalog revealed fine features in the behavior of seasonal components of induced seismicity in the...  相似文献   

4.
Megacrysts in the Cenozoic basalt of the Tuoyun Basin,Southwest Tianshan   总被引:2,自引:1,他引:2  
Abundant megacrysts of clinopyroxene, amphibole, anorthoclase, and phlogopite are found together with deep-seated xenoliths in the Cenozoic basalt of the Tuoyun Basin, Southwest Tianshan. The megacrysts are mainly in the cone sheet formed at the early stage of the volcanic activity. Clinopyrox-ene megacrysts are located in the lower part of the profile, with amphibole and phlogopite megacrysts in the middle part and anorthoclase megacrysts in the upper part. The crystal integrity, absence of de-formation fabric and their relation to the host basalt suggest that they were crystallized from the host magma and quickly transported to the surface. The mineralogical studies imply that the clinopyroxene megacrysts are of Al-augite with higher Al2O3 (>9%). Amphibole megacrysts are kaersutite rich in TiO2 (>4.5%). Sulfide inclusions such as pyrrhotite occur in some clinopyroxene and amphibole megacrysts. Thermodynamic calculations reveal that pyroxene megacrysts formed under the temperature of 1185.85―1199.85℃ and the pressure between 1.53 and 1.64 GPa comparable to the crust-mantle boundary and amphibole megacrysts crystallized under the pressure of around 0.85 GPa, temperature about 1000℃ comparable to the depth of 30 km. Anorthoclase megacrysts crystallized under the pressure between 0.8―1 GPa,temperature about 900℃.The absence of Ti-rich inclusions such as rutile can be considered as an evidence of quick magma ascending. The P-T conditions estimated via py-roxene megacrysts and phenocrysts compose a P-T path with a steep slope. It can be considered as another evidence of quick magma ascending. However, the estimated temperatures for amphibole megacrysts are markedly lower than those for pyroxene megacrysts given the same pressure. It probably shows that the amphiboles have crystallized at the vanguard of magma and under the vola-tile-rich condition. Thus, we can conclude that the Cenozoic basalts are produced in an extensional tectonic setting and the processes governing crystallization and ascending of the megacrysts are very complex.  相似文献   

5.
All available data on the January 23, 1880, earthquake near San Cristobal, Western Cuba, are compiled and presented here. The earthquake reached a maximum intensity of eight degrees (MSK) and caused three fatalities. It was accompanied by 65 aftershocks and was felt as far away as the Florida Keys. Twentieth century specialists has associated this event, in its day the strongest recorded (Ms = 6.2) in the region, with the Pinar fault. The Pinar fault is well expressed topographically as the boundary between the Guaniguanico Range in the north and an alluvial plain to the south. Most of the major damage caused by the earthquake was located on the alluvial plain, which in consequence has been considered the epicenter area. In the study presented here, the data compiled from the first reports of Father Benito Vines Martorell, S.J., and Pedro Salteraín y Legarra, indicate that the seismic structure was located in the alluvial plain, and that it was the Guane fault, and not the Pinar fault, that was responsible for the earthquake. The Guane fault, found below the alluvial sediments, extends NE-SW for over 110 km. Its eastern extreme, near San José de las Lajas (La Habana), is linked to another active fault which represents a seismoactive knot responsible for the earthquake of March 9, 1995 (I = 5 degrees, MSK). Seismic events of the Western Cuban region are related to the transpressive interaction of the North American and Caribbean Plates, damped by oceanic structures.  相似文献   

6.
ABSTRACT

The concept of Integrated Water Resources Management (IWRM) has enjoyed immense popularity and thus has been the preferred approach for river basin management. IWRM generally has a strong focus on rational choice, based on a technocratic conceptual interpretation of the conventional hydrological cycle. However, uncritical acceptance of IWRM runs the risk of blinding policy makers and academics for the defining impact of context, socio-cultural, political, historical and cognitive dimensions in water cooperation. Human behaviour in water cooperation was tested and observed during eight experiments with the Jordan River Basin Boardgame Exercise (JRBBE) played with respondent groups from inside and outside the Jordan River Basin. The experiments consisted of one control group outside the basin and seven respondent groups both outside and inside the basin. This article argues that the role of identities, beliefs and perception-of-the-other, should be taken more into account in order to develop successful and socio-political sustainable river basin management.
EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR not assigned  相似文献   

7.
Izvestiya, Physics of the Solid Earth - An Erratum to this paper has been published: https://doi.org/10.1134/S1069351322090014  相似文献   

8.
We applied the double-difference earthquake relocation algorithm to 1348 earthquakes with M_S≥2.0 that occurred in the northern Tianshan region, Xinjiang, from April 1988 to June 2003, using a total of 28701 P- and S-wave arrival times recorded by 32 seismic stations in Xinjiang. Aiming to obtain most of these M_S≥2.0 earthquakes relocations, and considering the requirements of the DD method and the condition of data, we added the travel time data of another 437 earthquakes with 1.5≤M_S<2.0. Finally, we obtained the relocation results for 1253 earthquakes with M_S≥2.0, which account for 93% of all the 1348 earthquakes with M_S≥2.0 and includes all the M_S≥3.0 earthquakes. The reason for not relocating the 95 earthquakes with 2.0≤M_S<3.0 is analyzed in the paper. After relocation, the RMS residual decreased from 0.83s to 0.14s, the average error is 0.993 km in E-W direction, 1.10 km in N-S direction, and 1.33 km in vertical direction. The hypocenter depths are more convergent than before and distributed from 5 km to 35 km, with 94% being from 5km to 35 km, 68.2% from 10 km to 25 km. The average hypocenter depth is 19 km.  相似文献   

9.
We applied the double-difference earthquake relocation algorithm to 1348 earthquakes with M_S≥2.0 that occurred in the northern Tianshan region, Xinjiang, from April 1988 to June 2003, using a total of 28701 P- and S-wave arrival times recorded by 32 seismic stations in Xinjiang. Aiming to obtain most of these M_S≥2.0 earthquakes relocations, and considering the requirements of the DD method and the condition of data, we added the travel time data of another 437 earthquakes with 1.5≤M_S<2.0. Finally, we obtained the relocation results for 1253 earthquakes with M_S≥2.0, which account for 93% of all the 1348 earthquakes with M_S≥2.0 and includes all the M_S≥3.0 earthquakes. The reason for not relocating the 95 earthquakes with 2.0≤M_S<3.0 is analyzed in the paper. After relocation, the RMS residual decreased from 0.83s to 0.14s, the average error is 0.993 km in E-W direction, 1.10 km in N-S direction, and 1.33 km in vertical direction. The hypocenter depths are more convergent than before and distributed from 5 km to 35 km, with 94% being from 5km to 35 km, 68.2% from 10 km to 25 km. The average hypocenter depth is 19 km.  相似文献   

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11.
It draws much attention of scientists how early hu- mans occupy and adapt to the rigorous climate and environment at high northern latitudes in East Asia after they stepped out of Africa, passed West Asia and finally arrived in East Asia[1-4]. Reliable age determi- nations of Paleolithic sites from northeastern Asia not only help to find out the earliest occupation of early humans in this region, but also relate to the founda- tion of the overall framework of human origin and migration[1-8]…  相似文献   

12.
The unique ecological landscapes are composed of the mountain systems with the obviousvertical differentiation, vast natural desert systems, and oasis systems on which the human beings rely for the existence in the arid areas in West China. Oases are the …  相似文献   

13.
Systematic measurements of the height of the summit crater rim on the active Karymskii Volcano showed that the variation of that parameter has been greater during its last eruption, lasting, with short intermissions, from January 1, 1996 until now (October 2007) compared with the earlier eruptions. The periodic increases in the height of Karymskii Volcano were due to explosion discharges of unconsolidated pyroclastic material, with most of this falling on the volcano’s cone. The increased seismicity of Karymskii Volcano intensified the slope movement processes, resulting in a comparatively flat area forming periodically on the crater rim; during separate, not very long, periods the height of the volcanic cone was increasing in discrete steps and at a greater rate. The periodic decrease in the height of Karymskii Volcano is due to compaction of pyroclastic material and, to a much greater extent, after violent explosions which expand the crater by removing its nearsummit circumference. The other contributing factor consists in sagging of the magma column due to partial emptying of the peripheral magma chamber, which makes the internal crater slope steeper, hence causes cone collapse and the cone lower. These occurrences are generally similar to the processes of crater and caldera generation described by previous investigators for other volcanoes of the world.  相似文献   

14.
The soil pollution by heavy metals was characterized in the mine tailings and surrounding soils of an old Pb–Zn mine in Huize County. Three hundred and ninety-six samples of agricultural and non-agricultural soil were analyzed for the total metal concentration by acid digestion and sixty-eight selected soil samples were used to determine the chemical fractionation of heavy metals with the modified BCR sequential extraction method. The pollution index of the heavy metals indices for As, Cd, Cr, Cu,Hg, Pb and Zn of non-agricultural soil and agricultural soils in the study area indicated the spreading of heavy metal pollution. Sequential extraction showed that most of Cd existed in an exchangeable form(31.2 %). The available content of Pb, Cu and Zn was mainly distributed in acid extractable fractions and Fe/Mn oxide fractions(27.9, 30 and 27.2 %), and Hg, As and Cr were mainly associated with residual fractions(90.4, 72.9 and 76.8 %). The risks of heavy metals were also evaluated by the risk assessment code(RAC) and potential ecological risk index, respectively. The results of RAC showed a medium and high risk of Cd(45.6 and 54.4 %), medium risk of Zn(100 %), low and medium risk of Cu(41.2 and 58.8 %), largely no risk of Hg(97.1 %), and mainly low risk of As and Pb(92.6and 91.8 %). The range of the potential ecological risk of soil was 58.2–1839.3, revealing a considerably high ecological risk in the study area, most likely related to acid mine drainage and the mining complexes located in the area. The results can be used during the ecological risk screening stage, in conjunction with the total concentrations and metal fractionation values, to better estimate ecological risk.  相似文献   

15.
A study of seismic anisotropy was performed using data from earthquakes of the Mexicali Valley. The investigated region encompasses the Cerro Prieto Geothermal Field (CPGF), one of the most important fields in the world. The results showed that at most of our stations the average polarization directions of the fast S waves range from N14°W to N17°E. A N-S polarization direction was obtained for the whole area by averaging the polarization directions from all stations used. In terms of the EDA hypothesis, this average trend agrees with the postulated state of stress for southern California, and with fault plane solutions for events of the Mexicali Valley. Notorious deviations from the N-S global trend were found southeast of the CPGF, with polarization trends between N25°E and N67°E, and in the geothermal field, with polarization directions between N7°W and N14°W. The polarization results for these zones indicated stress conditions that are different from the more regional stress pattern. The delay times that were measured between the fast and slow shear waves reached values of up to 0.6 sec, with a mean value of 0.35 sec. Consistent with our polarization results, the larger delay times (0.2–0.6 sec) were found in the CPGF. Smaller or null values were observed at the periphery of the study area. No temporal trends in the delay times were apparent, as shown by data from the two stations that recorded the larger number of events. Overall, we conclude that the splitting effects of this study result from a shallow anisotropy volume. The splitting results are thus interpreted as caused by the preferred orientation of vertical fluid-filled microcracks aligned in a direction that is parallel to the regional stress field. The stronger splitting effects that were observed in the area of the CPGF were found consistent with the geothermal reservoir that is embedded in the sedimentary cover of the zone, at depths of 1 to 4–5 km from the surface. We thus believe that such marked splitting effects have a direct relation with the reservoir of the CPGF.We are grateful to Miguel Navarro, Tito Valdez, and Manuel Luna for their contribution in the operation of RANM and for processing and cataloguing the strong-motion data. Ignacio Méndez and Francisco Farfán helped us with data from the RESNOM system. The study benefited from funding provided by CICESE and from grants awarded by CONACYT to Luis Munguía (Grants F195T and PCCNCNA-031339).  相似文献   

16.
Data of network and expedition measurements and information about water management arrangements were used to study in detail the peculiarities of along-channel and long-term variations in the major characteristics of suspended sediment runoff in the lower reach and the delta of the Kuban River. For characteristics periods, the annual volumes of actual and estimated sediment runoff and the contribution of economic activity in its variations are evaluated and possible changes in sediment runoff characteristics in the XXI century are forecasted. The specific features, values, and causes of sediment runoff transformation in Kuban delta in the past and the present are analyzed; sediment balance in the delta is calculated.  相似文献   

17.
Introduction Since the tens years, the research on active fault has been stepped from qualitative phase toquantitative phase. With the developing of research on fault activity, fault segmentation, interac-tion among the adjacent or near fault segments, geodetic and paleoearthquake, scientists have re-alized that strong earthquake recurrence along active fault has different properties and multiplepatterns (Working Group on California Earthquake Probabilities, 1988, 1990, 1995, 1999, 2003…  相似文献   

18.
The polymetallic Dushiling W-Cu deposit is a large, altered, skarn-type deposit, located in the northeastern part of the Miao'ershan-Yuechengling pluton, China. Two types of granite have been identified in the deposit: a medium-grained porphyritic biotite granite, and a medium- to fine-grained biotite granite. Both are spatially and temporally related to ore bodies, suggesting they may be the source of mineralization in the deposit. A medium- to fine-grained porphyritic biotite granite is exposed at the surface in the region of mineralization. U-Pb dating of zircons yielded magmatic ages of 423 Ma for the medium-grained porphyritic biotite granite and 421 Ma for the medium- to fine-grained porphyritic biotite granite, while a younger age(217 Ma) obtained for surface samples indicates later diagenesis. Thus, magmatism occurred during the Caledonian and Indosinian, respectively. The petrological and geochemical characteristics of the two Caledonian granites show that both are calc-alkaline and peraluminous.They are moderately enriched in Cs, Rb, U, and REE, and strongly depleted in Sr,Ba,P,and Ti; they show similar REE behavior,including negative Eu anomalies. These geochemical similarities suggest that the two granites were derived from the same source,although they were emplaced during different stages of the evolution of the magma. Furthermore, the granites are associated with mineralization, suggesting they were the source of mineralization in the Dushiling W-Cu deposit. Sm-Nd ages of scheelite from the Dushiling W-Cu deposit indicate that metallogenesis occurred at 417±35 Ma, while the two types of titanite, intergrown with scheelite, yield U-Pb ages of 423–425 Ma(in altered granite sample) and 218 Ma(in skarn sample). These ages place the main mineralization event in the late Caledonian, and later magmatic-hydrothermal activity occurred in the Indosinian. The ages obtained for the Dushiling W-Cu deposit in the western Nanling Range, northern Yuechengling, together with the occurrence and ages of the Niutangjie W deposit in southern Yuechengling, provide insight into the process of ore concentration during the Caledonian and Indosinian.  相似文献   

19.
The spatial and time dynamics are analyzed for the seasonal components of induced seismicity in the Koyna–Warna region of Western India. The peculiarities of the variations in these components are compared to the changes in the local tectonic regime inferred from the focal mechanism data of the earthquakes. Based on this, the hypotheses about the probable nature of the dynamics in the seasonal components of seismicity are suggested. It is noted that the variations in the seasonal seismic activity after the impoundment of the Koyna reservoir in the north are caused by the spatial migration of the induced seismicity and activation of the normal faults in the south. It is hypothesized that the process of fracture migration from the north to the south at this stage advanced the diffusion of the fluid from the Koyna reservoir, and as the water front reached the southern zone of normal faulting, this caused reactivation of the seasonal seismicity. An explanation is suggested for the stronger response of the seasonal activity in the region of Warna reservoir compared to the Koyna area: in contrast to Koyna, filling the Warna reservoir was geographically close to the area of activated seismicity. It is shown that the localization and sizes of the areas of the instantaneous and delayed components in the seasonal activity of the induced seismicity are determined by the localization and sizes of the areas of high stresses created by the increase in the pore pressure in highly permeable fault zones.  相似文献   

20.
Geomagnetic field parameters have been measured in different sites of the northwest of Russia for hundreds of years. This work presents the results of numerous measurements in St. Petersburg, as well as in the Gulf of Finland within the zone from 25° to 30°30′ E and from 59° to 61° N. The first measurements were made in the period1630–1650. For this work, archival data, provided by the Archives of the St. Petersburg Magnetic Observatory (SPbF IZMIRAN), and data from different historical records have been used. Data on the Earth’s magnetic field variations in St. Petersburg have been recorded since 1726; they were analyzed and corrected to get a uniform and complete data set. The reconstructed long-term data set of magnetic variation measurements in St. Petersburg was compared with the GUFM1 historical model. This model allows us to calculate the values of all parameters of the main magnetic field in any place on the Earth since 1590. The comparative analysis carried out by us has revealed a discrepancy between the model and measured values. This discrepancy can be caused by local secular variations in the magnetic field in the St. Petersburg region. The correction of the area-averaged secular variation makes this discrepancy insignificant.  相似文献   

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