Horizontal Gradient and Band-Pass Filter of Aeromagnetic Data Image of Subsurface Structure. Example from Esh El Mellaha Area

Summary The Esh El Mellaha area is located on the western coast of the Gulf of Suez that is considered the main hydrocarbon resource in Introduction

Expedition 306 summary

The overall aim of the North Atlantic paleoceanography study of Integrated Ocean Drilling Program Expedition 306 is to place late Neogene–Quaternary climate proxies in the North Atlantic into a chronology based on a combination of geomagnetic paleointensity, stable isotope, and detrital layer stratigraphies, and in so doing generate integrated North Atlantic millennial-scale stratigraphies for the last few million years. To reach this aim, complete sedimentary sections were drilled by multiple advanced piston coring directly south of the central Atlantic “ice-rafted debris belt” and on the southern Gardar Drift. In addition to the North Atlantic paleoceanography study, a borehole observatory was successfully installed in a new ~180 m deep hole close to Ocean Drilling Program Site 642, consisting of a circulation obviation retrofit kit to seal the borehole from the overlying ocean, a thermistor string, and a data logger to document and monitor bottom water temperature variations through time

North Atlantic Paleoceanography: The Last Five Million Years

In the North Atlantic, cold, relatively salty water sinks in the icy Labrador and Greenland seas, forming North Atlantic Deep Water (NADW). This circulates through the global ocean, driving ocean overturning and global heat transport and, thus, impacting global climate. As one of the most climatically sensitive regions on Earth, the North Atlantic has experienced abrupt changes to its ocean-atmosphere-cryosphere system, triggered by fluctuations in meltwater delivery to source areas of NADW formation. For about the past 100 thousand years, these abrupt jumps in climate state have manifested as ‘Dansgaard/Oeschger’ (D/O) oscillations (millennial-scale warm-cold oscillations) and ‘Heinrich’ events in ice and marine sediment cores, respectively [e.g., Dansgaard et al.,1993; Bond and Lotti, 1995]. These Heinrich events are characterized as huge input of ice-rafted debris (IRD) and meltwater pulses, documenting episodes of sudden instability and collapse of the current Greenland ice sheets and the Laurentide ice sheet, the latter of which covered northern North America several times during the Pleistocene Epoch

Geothermal Imaging of the Saudi Cross-Border City of NEOM Deduced from Magnetic Data

The Saudi Arabia government announced the $500 billion mega project “NEOM City”, to build a cross-border mega city to connect Saudi Arabia, Egypt, and Jordon for attracting foreign investments to the region. NEOM city is situated on the eastern region of the Gulf of Aqaba with its western side in the Sinai Peninsula. The selected site for NEOM city is geographically remarkable; nevertheless, this site needs a detailed geological and geophysical investigation. Sinai Peninsula is a microplate between the Arabian and African plates. Its southern tip is located at a triple junction comprising the Gulf of Aqaba–Dead Sea Transform fault, the Gulf of Suez, and the Red Sea, leading to relatively higher seismic activities in the region. The current study aims to understand the thermal structure of the vicinity of NEOM city to address the potential geohazards and indicate geological attractions within and around the planned city. We use the magnetic data from which geothermal images can be obtained. The preliminary results indicate that there is geologic similarity between the southern part of Sinai Peninsula and the northern part of the Arabian shield. This is because the Gulf of Aqaba separates what was once a continues Neoproterozoic crust. In addition, the magnetic data showed the presence of prominent lineaments on either side of the Gulf of Aqaba. The notable lineaments might represent faults that could still be active. Hence, selecting a site of NEOM city to be east of the Gulf of Aqaba needs to be guided by the careful understanding of the potential hazards. In addition, shallow Curie depths near the Gulf of Aqaba are recognized as a source for renewable geothermal energy

An examination of corporate environmental goals disclosure, sustainability performance and firm value – An Egyptian evidence

This paper explores the status quo of environmental goals disclosure (EGD) and empirically tests its impact on Egyptian corporate sustainability ratings and firm value. We find that Egyptian companies show a large degree of variability and inconsistency in their EGDs. However, EGDs have a positive impact on sustainability ratings and firm value. Companies that release more EGDs are more likely to gain membership in the Egyptian Sustainability Index and attain a high sustainability rank, to which the capital market reacts positively. Our findings have important implications, particularly for policymakers, companies, investors, environmental activists, and other stakeholder groups in developing nations. This study contributes insights from EGD practices in Egypt to the existing literature on corporate social responsibility (CSR) in developing nations. It also helps to resolve the conflicting predictions of socio-political theories and the voluntary disclosure theory, showing how both perspectives help to explain the relationships among corporate EGDs, sustainability ratings, and firm

Aeromagnetic Constraints on the Umm Farwah Fault Structural Framework and Associated Neoproterozoic accretion domains of the Asir Terrane: the Biljurshi area, Arabian Shield

 The Arabian Shield and the Pan-African shear zones/terrane boundaries are marked by widespread occurrence of juvenile Neoprotero- zoic assembly arc terranes. Deep sealed architecture and tectonic framework are still poorly understood because the lack of geophysical studies. N-S oriented lineaments and associated structures that characterize the Asir terrane have crucial interests because they repre- sent the primary constraints to understand structuring and kinematics of the Arabian Shield. The integration of aeromagnetic and geo- logical data of the Biljurshi area highlights the structural setting and its relationship with the Precambrian volcano-sedimentary, metamorphic and plutonic rocks. Results contribute to understand the deep structure of the syn-accretion sedimentary and volcanic sys- tem. The geophysical data validate and improve the current geological settings and determine the geometry and tectonic deformation of the Biljurshi subsurface structures. The obtained geometry and structural models will be used to highlight the deep architecture of the Biljurshi area within the Arabian Shield

Structural Analysis using Landsat TM, Gravity Data, and Paleontological Data from Tertiary Rocks in Yogyakarta, Indonesia

Herein, we investigate the fault margin that controls the development of the Yogyakarta graben by integrating gravity maps, remote sensing, and foraminifera in Yogyakarta, in the southern part of Central Java, Indonesia. A topographic map was involved to this research to create a shaded map using a Digital Elevation Model (DEM). All data sets were converted into GIS-compatible formats. Our results indicated that two major faults can be recognized. These major faults divided the area into three parts, including the western, central and eastern parts. The uplift rates of each part were different and created a depressed block control by two parallel faults. Based on foraminifera fossil observations, each block was in the same depositional environment (inner neritic) during N9 (about 14.8.15.1 Ma). The uplift occurred after deposition of marls (Kepek and Upper Sentolo Formations) during the Pliocene, which was then followed by an extension phase since the Pleistocene. The present positions indicate that the western part was uplifted higher than the others, with this part being uplifted more than 590 meters. The central part was uplifted less than 120 meters, and the eastern part was uplifted above an altitude of 170.300 meters

Two-Dimensional Gravity Inversion of Basement Relief for Geothermal Energy Potentials at the Harrat Rahat Volcanic Field, Saudi Arabia, Using Particle Swarm Optimization

We invert gravity and magnetic anomalies for basement relief at the Harrat Rahat Volcanic Field (HRVF) for the purpose of evaluating its geothermal energy prospects. HRVF is dominated by basaltic scoria cones and other volcanic rocks overlying the Proterozoic basement. The area considered for this study is located within the northern HRVF and consists mainly of alkali basalts with lesser amounts of benmoreite, mugearite, hawaiite, and trachyte. Our approach adopts a global optimization technique using Particle Swarm Optimization with automated parameter selection, and a two-dimensional gravity-magnetic (GM) forward modeling procedure. The results of the PSO-based approach indicate a depth to the basement at 0.10–624 m, with greater depths within the central region of a solitary anomalous density body in the HRVF. The obtained basement geometry is corroborated by the depth estimates obtained from other potential field inversion methods. The regions with higher prospects are mapped for a targeted future geothermal energy exploration at the HRVF, based on our inversion results

Structural Analysis using Landsat TM, Gravity Data, and Paleontological Data from Tertiary Rocks in Yogyakarta, Indonesia

Herein, we investigate the fault margin that controls the development of the Yogyakarta graben by integrating gravity maps, remote sensing, and foraminifera in Yogyakarta, in the southern part of Central Java, Indonesia. A topographic map was involved to this research to create a shaded map using a Digital Elevation Model (DEM). All data sets were converted into GIS-compatible formats. Our results indicated that two major faults can be recognized. These major faults divided the area into three parts, including the western, central and eastern parts. The uplift rates of each part were different and created a depressed block control by two parallel faults. Based on foraminifera fossil observations, each block was in the same depositional environment (inner neritic) during N9 (about 14.8.15.1 Ma). The uplift occurred after deposition of marls (Kepek and Upper Sentolo Formations) during the Pliocene, which was then followed by an extension phase since the Pleistocene. The present positions indicate that the western part was uplifted higher than the others, with this part being uplifted more than 590 meters. The central part was uplifted less than 120 meters, and the eastern part was uplifted above an altitude of 170.300 meters

Water exploration using Magnetotelluric and gravity data analysis; Wadi Nisah, Riyadh, Saudi Arabia

Saudi Arabia is a desert country with no permanent rivers or lakes and very little rainfall. Ground water aquifers are the major source of water in Saudi Arabia. In the Riyadh region, several Wadies including Wadi Nisah store about 14 × 106 m3 of water, which is extracted for local irrigation purposes. In such areas, the water wells are as shallow as 200–300 m in depth. The importance of Wadi Nisah is because the subsurface water aquifers that are present there could support the region for many years as a water resource. Accordingly, in this study, we performed a Magnetotelluric survey using a portable broadband sounding system (MT24/LF) to evaluate the ground water aquifer at great depths. We collected 10 broadband Magnetotelluric sounding stations (1 station/day) with an interval of about 2–3 km reaching a profile length of about 25–30 km along Wadi Nisah. Additionally, we used available gravity data to image the subsurface structure containing the aquifer. MT results indicated a low resistivity layer, associated with alluvium deposits, which was defined at a depth of about 1–2 km and extended horizontally about 15 km. Gravity data analysis was used to model this resistivity layer indicating a basement surface at 3–4 km depth