In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals w...In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals with the new CG-6 Autograv gravimeter. Two gravity field sites have been selected in Dubai City and Hatta mountainous area. The relative gravity field measurements have been recorded for about one month time span;two weeks in Dubai and two weeks in Hatta. Among different effects reducing the gravity measurements, the tide and drift corrections have been focused on this paper. Two tidal models have been applied to reduce the tide effect based on the automated ETGTAB of the CG-6 gravimeter and ETERNA3.3 software. The results regarding the tide correction show very small discrepancies between both models (ETGTAB and ETERNA3.3) of about 2.2 μGal and 2.6 μGal in terms of standard deviations at Dubai and Hatta gravity stations, respectively. So, the outcome of the precise tidal model of CG-6 Autograv gravimeter is reliable for tidal reduction within Dubai area and its surroundings. Regarding the drift correction, the CG-6 Autograv provides low instrument drift values about 2.44 μGal and -2.35 μGal per day for the Dubai and Hatta stations, respectively. Furthermore, it is recommended that the Hatta gravity station would be considered as a stable and trusted gravity site. For Dubai gravity station, the gravity observations are affected by some noises from traffic activities while recording the gravity signal during the working days. Therefore, it is recommended for Dubai gravity station to be measured during the weekends and at nights in order to avoid any noises affecting the CG-6 gravimeter.展开更多
This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,a...This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.展开更多
文摘In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals with the new CG-6 Autograv gravimeter. Two gravity field sites have been selected in Dubai City and Hatta mountainous area. The relative gravity field measurements have been recorded for about one month time span;two weeks in Dubai and two weeks in Hatta. Among different effects reducing the gravity measurements, the tide and drift corrections have been focused on this paper. Two tidal models have been applied to reduce the tide effect based on the automated ETGTAB of the CG-6 gravimeter and ETERNA3.3 software. The results regarding the tide correction show very small discrepancies between both models (ETGTAB and ETERNA3.3) of about 2.2 μGal and 2.6 μGal in terms of standard deviations at Dubai and Hatta gravity stations, respectively. So, the outcome of the precise tidal model of CG-6 Autograv gravimeter is reliable for tidal reduction within Dubai area and its surroundings. Regarding the drift correction, the CG-6 Autograv provides low instrument drift values about 2.44 μGal and -2.35 μGal per day for the Dubai and Hatta stations, respectively. Furthermore, it is recommended that the Hatta gravity station would be considered as a stable and trusted gravity site. For Dubai gravity station, the gravity observations are affected by some noises from traffic activities while recording the gravity signal during the working days. Therefore, it is recommended for Dubai gravity station to be measured during the weekends and at nights in order to avoid any noises affecting the CG-6 gravimeter.
文摘This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.
