An innovative inversion code, named “Curupira v1.0”, has been developed using Matlab to determine the vertical distribution of resistivity beneath the subsoil. The program integrates Vertical Electrical Sounding (VE...An innovative inversion code, named “Curupira v1.0”, has been developed using Matlab to determine the vertical distribution of resistivity beneath the subsoil. The program integrates Vertical Electrical Sounding (VES), successful in shallow subsurface exploration and Time Domain Electromagnetic (TEM) techniques, better suited for deeper exploration, both of which are widely employed in geophysical exploration. These methodologies involve calculating subsurface resistivity through appropriate inversion processes. To address the ill-posed nature of inverse problems in geophysics, a joint inversion scheme combining VES and TEM data has been incorporated into Curupira v1.0. The software has been tested on both synthetic and real-world data, the latter of which was acquired from the Parana sedimentary basin which we summarise here. The results indicate that the joint inversion of VES and TEM techniques offers improved recovery of simulated models and demonstrates significant potential for hydrogeological studies.展开更多
This paper discusses H-infinity state feedback control for a networked control system with time-varying delays. Based on the flee-weighing matrix method, a dehy-dependent stability criterion satisfying a prescribed H-...This paper discusses H-infinity state feedback control for a networked control system with time-varying delays. Based on the flee-weighing matrix method, a dehy-dependent stability criterion satisfying a prescribed H-infinity norm bound is presented for an NCS with unknown, time-varying and bounded delays. And then, the criterion is transformed into sufficient conditions based on linear matrix inequalities for H-infinity control. The conditions thus obtained are also used to design an H-infinity state feedback controller. This design method is further extended to solve the design problem of robust H-infinity state feedback control. A numerical example demonstrates the validity of the method.展开更多
This pilot study attempts to demonstrate some underlying scanning electron microscopy themes of quartz grain surface textures. A variety of textural patterns and individual features are described for grains selected f...This pilot study attempts to demonstrate some underlying scanning electron microscopy themes of quartz grain surface textures. A variety of textural patterns and individual features are described for grains selected from various littoral environments. An attempt was made to differentiate samples on surface textures alone, but limitations of using this technique in sedimentological isolation were apparent. Statistical analysis of checklist data and photographic evidence revealed some of the more important feature combinations used in environmental diagnosis. The use of discriminant analysis provided quantitative sample separation.展开更多
This paper presents a compilation of recent U-Pb (zircon) ages of late Carboniferous-early Permian (LC EP) calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation base...This paper presents a compilation of recent U-Pb (zircon) ages of late Carboniferous-early Permian (LC EP) calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation based on comparisons with Mesozoic and Tertiary Cordilleran batholiths and experimental melts. Zircon U-Pb ages distributed over the range ca. 315-280 Ma, indicate a linkage between calc-alkaline magmatism, Iberian orocline generation and Paleotethys subduction. It is also shown that Iberian LC-EP calcalkaline batholiths present unequivocal subduction-related features comparable with typical Cordilleran batholiths of the Pacific Americas active margin, although geochemical features were partially obscured by local modifications of magmas at the level of emplacement by country rock assimilation. When and how LC-EP calc-alkaline batholiths formed in Iberia is then discussed, and a new and somewhat controversial interpretation for their sources and tectonic setting (plume-assisted relamination) is suggested. The batholiths are proposed to have formed during the subduction of the Paleotethys oceanic plate (Pangaea self-subduction) and, consequently, they are unrelated to Variscan collision. The origin of the Iberian batholiths is related to the Eurasian active margin and probably represents the inception of a Paleotethvan arc in the core of Pangaea.展开更多
A plethora of studies investigating the origin and evolution of diverse mountain taxa has assumed a causal link between geological processes (orogenesis) and a biological response (diversification). Yet, a substan...A plethora of studies investigating the origin and evolution of diverse mountain taxa has assumed a causal link between geological processes (orogenesis) and a biological response (diversification). Yet, a substantial delay (up to 30 Myr) between the start of orogenesis and diversification is often observed. Evolutionary biologists should therefore identify alternative drivers of diversification and maintenance of biodiversity in mountain systems. Using phylogenetic, biogeographic, and diversification rate analyses, we could identify two independent processes that most likely explain the diversity of the widespread genus Allium in the Qinghai-Tibet Plateau (QTP) region: (1) While the QTP-related taxa of the subgenus Melanocrommyum diversified in situ, (2) QTP-related taxa of other subgenera migrated into the QTP from multiple source areas. Furthermore, shifts in diversification rates within Allium could not be attributed spatially and temporally to the uplift history of the QTP region. Instead, global cooling and climate oscillations in the Quaternary were major contributors to increased speciation rates in three clades of AUium. Our study therefore adds to the growing evidence supporting the "mountain-geo-biodiversity hypothesis", which highlights the role of climate oscillations for the diversification of mountain organisms.展开更多
The calculation of apparent resistivity in electrical methods is relatively simple and consolidated in the literature. Furthermore, in the case of DC methods, the apparent resistivity values are for the most part, int...The calculation of apparent resistivity in electrical methods is relatively simple and consolidated in the literature. Furthermore, in the case of DC methods, the apparent resistivity values are for the most part, intuitive and enable an initial interpretation of the results. On the other hand, in TEM method the apparent resistivity values are not very intuitive and interpretation based only on the apparent resistivity values cannot be done reasonably. In this way, this paper presents a discussion about the reasons and effects of the negatives values of apparent resistivity in TEM soundings. The main objective of this paper is to clarify the meanings of these negatives values and the possible effects in TEM inversion.展开更多
Zagros Basin is a very important hydrocarbon region in the Iran and World. One of the major reservoirs in this basin is the Lower Cretaceous Dariyan Formation. Based on petrographic studies, 9 microfacies were determi...Zagros Basin is a very important hydrocarbon region in the Iran and World. One of the major reservoirs in this basin is the Lower Cretaceous Dariyan Formation. Based on petrographic studies, 9 microfacies were determined and interpreted as related to lagoon, barrier island and open marine environments. Facies associations show deposition in a carbonate ramp. Sequence stratigraphy studies show two sequences, each one with a transgressive system tract, marked by open marine microfacies, and then a retrogradational highstand, marked by barrier and lagoonal facies. Paleogeography and sequence stratigraphy studies of this formation and correlation of it with other sections may provide useful information about reservoir characterizations.展开更多
We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of t...We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of the Areia do Mastro Formation. Those bioclastic, nodular limestones were deposited in a very shallow subtidal-intertidal, restricted lagoon environment. The track surfaces are very dinoturbated, with a substantial number of tracks. Several tracks assign to sauropods, ornithopods and theropods dinosaurs were recorded. Due to heavy bioturbation and the preservation conditions, it is not possible to define trackways;some preliminary work done on the tracks could disclose some behaviours of their producers. Several species of carnivore and herbivore dinosaurs crossed that large area at different times. Herbivores may have used the lagoon margin as passage between feeding spots, while carnivores frequented the area to hunt in groups or individually.展开更多
Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UF...Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.展开更多
In recent years the publication of new legislation in the renewables sector, namely the one related to microgeneration systems, has contributed to an increase in the installation of renewable energy systems in Portuga...In recent years the publication of new legislation in the renewables sector, namely the one related to microgeneration systems, has contributed to an increase in the installation of renewable energy systems in Portugal. Nevertheless, the investment in these systems is still high and the risk of considering sites with reduced resource constitutes a barrier to the development of this sub-sector. In the sequence of the previous work developed in the wind energy planning area, a methodology to identify the sustainable wind and solar potential in urban areas was developed, in order to reduce the pre-installation costs related to a less suitable site selection, and also to identify the real potential of the urban areas. In order to do so, a geographical information system was used and a set of tools was developed. The methodology was structured to enable its replication in other geographical locations and is sufficiently interactive to allow for the variation of the main input data. A case study in two urban environments is presented in this document to illustrate the developed methodology.展开更多
In this study,we identified the moisture sources for the precipitation associated with tropical cyclones(TCs)during the rapid intensification(RI)process from 1980 to 2018 by applying a Lagrangian moisture source diagnos...In this study,we identified the moisture sources for the precipitation associated with tropical cyclones(TCs)during the rapid intensification(RI)process from 1980 to 2018 by applying a Lagrangian moisture source diagnostic method.We detected sixteen regions on a global scale for RI events distributed as follows:four in the North Atlantic(NATL),two in the Central and East Pacific Ocean(NEPAC),the North Indian Ocean(NIO)and South Indian Ocean(SIO),and three in the South Pacific Ocean(SPO)and the Western North Pacific Ocean(WNP).The moisture uptake(MU)mostly was from the regions where TCs underwent RI.The Western NATL,tropical NATL,Caribbean Sea,the Gulf of Mexico and the Central America and Mexico landmass supported~85.4%of the precipitating moisture in the NATL,while the latter source and the eastern North Pacific Ocean provided the higher amount of moisture in NEPAC(~84.3%).The Arabian Sea,the Bay of Bengal and the Indian Peninsula were the major moisture sources in NIO,contributing approximately 81.3%.The eastern and western parts of the Indian Ocean supplied most of the atmospheric humidity in SIO(~83.8%).The combined contributions(~87.9%)from the western and central SPO and the Coral Sea were notably higher in SPO.Meanwhile,TCs in the WNP basin mostly received moisture from the western North Pacific Ocean,the Philippine Sea and the China Sea,accounting for 80.1%.The remaining moisture support in each basin came from the summed contributions of the remote sources.Overall,RI TCs gained more moisture up to 2500 km from the cyclone centre than those slow intensification(SI)and the total MU was approximately three times higher during RI than SI.Finally,the patterns of the MU differences respond to the typical pathways of moisture transport in each basin.展开更多
Batteries have been widely applied in many high-power applications,such as electric vehicles(EVs)and hybrid electric vehicles,where a suitable battery management system(BMS)is vital in ensuring safe and reliable opera...Batteries have been widely applied in many high-power applications,such as electric vehicles(EVs)and hybrid electric vehicles,where a suitable battery management system(BMS)is vital in ensuring safe and reliable operation of batteries.This paper aims to give a brief review on several key technologies of BMS,including battery modelling,state estimation and battery charging.First,popular battery types used in EVs are surveyed,followed by the introduction of key technologies used in BMS.Various battery models,including the electric model,thermal model and coupled electro-thermal model are reviewed.Then,battery state estimations for the state of charge,state of health and internal temperature are comprehensively surveyed.Finally,several key and traditional battery charging approaches with associated optimization methods are discussed.展开更多
This work was designed to study the subsurface structures in the Siwa Oasis area of the Western Desert in Egypt and to determine their effects on surface geologic structures. A detailed land magnetic survey was perfor...This work was designed to study the subsurface structures in the Siwa Oasis area of the Western Desert in Egypt and to determine their effects on surface geologic structures. A detailed land magnetic survey was performed in traverses covering about 400 km2 of the study area. The measured total magnetic field was corrected and reduced to the north magnetic pole. The reduction-to-pole aeromagnetic and Bouguer anomaly maps were used to obtain regional extensions of these subsurface structures, study the continuation of these structures in sedimentary rocks, and delineate the depths to the basement rocks. Data analysis was performed using trend analysis, Euler deconvolution, Werner deconvolution, the Hilbert transform of the analytical signal, and 3-dimensional magnetic modeling methods. The results indicate that the area is affected by tectonic forces in the E-W, N45°-65°E, and N35°-45°W trends, which are correlated with the directions of surface geologic lineaments. The depth to the basement rocks increases from 3.2 km in the southern part to about 3.6 km in the northern part of the area. The results are in good agreement with depths obtained from drill hole data in the area.展开更多
文摘An innovative inversion code, named “Curupira v1.0”, has been developed using Matlab to determine the vertical distribution of resistivity beneath the subsoil. The program integrates Vertical Electrical Sounding (VES), successful in shallow subsurface exploration and Time Domain Electromagnetic (TEM) techniques, better suited for deeper exploration, both of which are widely employed in geophysical exploration. These methodologies involve calculating subsurface resistivity through appropriate inversion processes. To address the ill-posed nature of inverse problems in geophysics, a joint inversion scheme combining VES and TEM data has been incorporated into Curupira v1.0. The software has been tested on both synthetic and real-world data, the latter of which was acquired from the Parana sedimentary basin which we summarise here. The results indicate that the joint inversion of VES and TEM techniques offers improved recovery of simulated models and demonstrates significant potential for hydrogeological studies.
文摘This paper discusses H-infinity state feedback control for a networked control system with time-varying delays. Based on the flee-weighing matrix method, a dehy-dependent stability criterion satisfying a prescribed H-infinity norm bound is presented for an NCS with unknown, time-varying and bounded delays. And then, the criterion is transformed into sufficient conditions based on linear matrix inequalities for H-infinity control. The conditions thus obtained are also used to design an H-infinity state feedback controller. This design method is further extended to solve the design problem of robust H-infinity state feedback control. A numerical example demonstrates the validity of the method.
文摘This pilot study attempts to demonstrate some underlying scanning electron microscopy themes of quartz grain surface textures. A variety of textural patterns and individual features are described for grains selected from various littoral environments. An attempt was made to differentiate samples on surface textures alone, but limitations of using this technique in sedimentological isolation were apparent. Statistical analysis of checklist data and photographic evidence revealed some of the more important feature combinations used in environmental diagnosis. The use of discriminant analysis provided quantitative sample separation.
基金financial support that comes from the Research Projects "GOLD"(FCT-PTDC/GEO-GEO/2446/2012FCOMP-01-0124-FEDER-029192)"PLUVOLC"(No.CGL201022022)
文摘This paper presents a compilation of recent U-Pb (zircon) ages of late Carboniferous-early Permian (LC EP) calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation based on comparisons with Mesozoic and Tertiary Cordilleran batholiths and experimental melts. Zircon U-Pb ages distributed over the range ca. 315-280 Ma, indicate a linkage between calc-alkaline magmatism, Iberian orocline generation and Paleotethys subduction. It is also shown that Iberian LC-EP calcalkaline batholiths present unequivocal subduction-related features comparable with typical Cordilleran batholiths of the Pacific Americas active margin, although geochemical features were partially obscured by local modifications of magmas at the level of emplacement by country rock assimilation. When and how LC-EP calc-alkaline batholiths formed in Iberia is then discussed, and a new and somewhat controversial interpretation for their sources and tectonic setting (plume-assisted relamination) is suggested. The batholiths are proposed to have formed during the subduction of the Paleotethys oceanic plate (Pangaea self-subduction) and, consequently, they are unrelated to Variscan collision. The origin of the Iberian batholiths is related to the Eurasian active margin and probably represents the inception of a Paleotethvan arc in the core of Pangaea.
基金the German Research Foundation for funding of staff (project no. MU 2934/2-1)the support of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig funded by the German Research Foundation (FZT 118) for funding of lab expenses
文摘A plethora of studies investigating the origin and evolution of diverse mountain taxa has assumed a causal link between geological processes (orogenesis) and a biological response (diversification). Yet, a substantial delay (up to 30 Myr) between the start of orogenesis and diversification is often observed. Evolutionary biologists should therefore identify alternative drivers of diversification and maintenance of biodiversity in mountain systems. Using phylogenetic, biogeographic, and diversification rate analyses, we could identify two independent processes that most likely explain the diversity of the widespread genus Allium in the Qinghai-Tibet Plateau (QTP) region: (1) While the QTP-related taxa of the subgenus Melanocrommyum diversified in situ, (2) QTP-related taxa of other subgenera migrated into the QTP from multiple source areas. Furthermore, shifts in diversification rates within Allium could not be attributed spatially and temporally to the uplift history of the QTP region. Instead, global cooling and climate oscillations in the Quaternary were major contributors to increased speciation rates in three clades of AUium. Our study therefore adds to the growing evidence supporting the "mountain-geo-biodiversity hypothesis", which highlights the role of climate oscillations for the diversification of mountain organisms.
文摘The calculation of apparent resistivity in electrical methods is relatively simple and consolidated in the literature. Furthermore, in the case of DC methods, the apparent resistivity values are for the most part, intuitive and enable an initial interpretation of the results. On the other hand, in TEM method the apparent resistivity values are not very intuitive and interpretation based only on the apparent resistivity values cannot be done reasonably. In this way, this paper presents a discussion about the reasons and effects of the negatives values of apparent resistivity in TEM soundings. The main objective of this paper is to clarify the meanings of these negatives values and the possible effects in TEM inversion.
文摘Zagros Basin is a very important hydrocarbon region in the Iran and World. One of the major reservoirs in this basin is the Lower Cretaceous Dariyan Formation. Based on petrographic studies, 9 microfacies were determined and interpreted as related to lagoon, barrier island and open marine environments. Facies associations show deposition in a carbonate ramp. Sequence stratigraphy studies show two sequences, each one with a transgressive system tract, marked by open marine microfacies, and then a retrogradational highstand, marked by barrier and lagoonal facies. Paleogeography and sequence stratigraphy studies of this formation and correlation of it with other sections may provide useful information about reservoir characterizations.
文摘We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of the Areia do Mastro Formation. Those bioclastic, nodular limestones were deposited in a very shallow subtidal-intertidal, restricted lagoon environment. The track surfaces are very dinoturbated, with a substantial number of tracks. Several tracks assign to sauropods, ornithopods and theropods dinosaurs were recorded. Due to heavy bioturbation and the preservation conditions, it is not possible to define trackways;some preliminary work done on the tracks could disclose some behaviours of their producers. Several species of carnivore and herbivore dinosaurs crossed that large area at different times. Herbivores may have used the lagoon margin as passage between feeding spots, while carnivores frequented the area to hunt in groups or individually.
文摘Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.
文摘In recent years the publication of new legislation in the renewables sector, namely the one related to microgeneration systems, has contributed to an increase in the installation of renewable energy systems in Portugal. Nevertheless, the investment in these systems is still high and the risk of considering sites with reduced resource constitutes a barrier to the development of this sub-sector. In the sequence of the previous work developed in the wind energy planning area, a methodology to identify the sustainable wind and solar potential in urban areas was developed, in order to reduce the pre-installation costs related to a less suitable site selection, and also to identify the real potential of the urban areas. In order to do so, a geographical information system was used and a set of tools was developed. The methodology was structured to enable its replication in other geographical locations and is sufficiently interactive to allow for the variation of the main input data. A case study in two urban environments is presented in this document to illustrate the developed methodology.
基金support from the Xunta de Galicia(Consellería de Cultura,Educacion e Universidade)under grant No.´ED481A2020/193.R.M.T was supported by the Portuguese Science Foundation(FCT)through the project AMOTHEC((https://doi.org/10.54499/DRI/India/0098/2020)EPhysLab members are supported by the SETESTRELO project(grant no.PID2021-122314OB-I00)funded by the Ministerio de Ciencia+4 种基金Innovacion y Universidades,Spain(MICIU/AEI/´10.13039/501100011033)Xunta de Galicia under the Project ED431C2021/44(Programa de Consolidacion e Estructuraci´on´de Unidades de Investigacion Competitivas(Grupos de Ref-´erencia Competitiva)Consellería de Cultura,Educacion e´Universidade)by the European Union‘ERDF A way of making Europe’support provided by CESGA(Centro de Supercomputacion de Galicia)and RES´(Red Espanola de Supercomputaci˜on)。
文摘In this study,we identified the moisture sources for the precipitation associated with tropical cyclones(TCs)during the rapid intensification(RI)process from 1980 to 2018 by applying a Lagrangian moisture source diagnostic method.We detected sixteen regions on a global scale for RI events distributed as follows:four in the North Atlantic(NATL),two in the Central and East Pacific Ocean(NEPAC),the North Indian Ocean(NIO)and South Indian Ocean(SIO),and three in the South Pacific Ocean(SPO)and the Western North Pacific Ocean(WNP).The moisture uptake(MU)mostly was from the regions where TCs underwent RI.The Western NATL,tropical NATL,Caribbean Sea,the Gulf of Mexico and the Central America and Mexico landmass supported~85.4%of the precipitating moisture in the NATL,while the latter source and the eastern North Pacific Ocean provided the higher amount of moisture in NEPAC(~84.3%).The Arabian Sea,the Bay of Bengal and the Indian Peninsula were the major moisture sources in NIO,contributing approximately 81.3%.The eastern and western parts of the Indian Ocean supplied most of the atmospheric humidity in SIO(~83.8%).The combined contributions(~87.9%)from the western and central SPO and the Coral Sea were notably higher in SPO.Meanwhile,TCs in the WNP basin mostly received moisture from the western North Pacific Ocean,the Philippine Sea and the China Sea,accounting for 80.1%.The remaining moisture support in each basin came from the summed contributions of the remote sources.Overall,RI TCs gained more moisture up to 2500 km from the cyclone centre than those slow intensification(SI)and the total MU was approximately three times higher during RI than SI.Finally,the patterns of the MU differences respond to the typical pathways of moisture transport in each basin.
文摘Batteries have been widely applied in many high-power applications,such as electric vehicles(EVs)and hybrid electric vehicles,where a suitable battery management system(BMS)is vital in ensuring safe and reliable operation of batteries.This paper aims to give a brief review on several key technologies of BMS,including battery modelling,state estimation and battery charging.First,popular battery types used in EVs are surveyed,followed by the introduction of key technologies used in BMS.Various battery models,including the electric model,thermal model and coupled electro-thermal model are reviewed.Then,battery state estimations for the state of charge,state of health and internal temperature are comprehensively surveyed.Finally,several key and traditional battery charging approaches with associated optimization methods are discussed.
文摘This work was designed to study the subsurface structures in the Siwa Oasis area of the Western Desert in Egypt and to determine their effects on surface geologic structures. A detailed land magnetic survey was performed in traverses covering about 400 km2 of the study area. The measured total magnetic field was corrected and reduced to the north magnetic pole. The reduction-to-pole aeromagnetic and Bouguer anomaly maps were used to obtain regional extensions of these subsurface structures, study the continuation of these structures in sedimentary rocks, and delineate the depths to the basement rocks. Data analysis was performed using trend analysis, Euler deconvolution, Werner deconvolution, the Hilbert transform of the analytical signal, and 3-dimensional magnetic modeling methods. The results indicate that the area is affected by tectonic forces in the E-W, N45°-65°E, and N35°-45°W trends, which are correlated with the directions of surface geologic lineaments. The depth to the basement rocks increases from 3.2 km in the southern part to about 3.6 km in the northern part of the area. The results are in good agreement with depths obtained from drill hole data in the area.