scholarly journals A Gravity Search for Oil and Gas and Groundwater in Egypt Using the Strike Angles Derived from EIGEN 6C4

2020 ◽  
Vol 10 (24) ◽  
pp. 8950
Author(s):  
Jaroslav Klokočník ◽  
Jan Kostelecký ◽  
Lenka Varadzinová ◽  
Aleš Bezděk ◽  
Gunther Kletetschka
Keyword(s):  
Gravity Field ◽  
Oil And Gas ◽  
Field Model ◽  
Gravity Anomalies ◽  
Archaeological Sites ◽  
Gravity Field Model ◽  
Topography Model ◽  
Oil Gas ◽  
The Relationship ◽  
Strike Angle

We correlate the gravity aspects (descriptors), namely the strike angles, derived from a recent gravity field model, with the known oil, gas and groundwater deposits/reservoirs and hypothetical paleolakes with the locations of archaeological sites. This allows us to extrapolate the investigation, by analogy, to unknown regions. The gravity aspects, derived from the EIGEN 6C4 gravity field model, are used, together with EMAG 2 magnetic anomalies and ETOPO 1 topography model, for the investigation of oil, gas and water deposits in Egypt. One of the gravity aspects, s/c strike angle, is significantly combed (oriented in one direction locally) in places where the known deposits exist. However, they are combed also in some other places. This may be used as a guide as to where to seek new and promising deposits. Accounting for the combed strike angles and the relationship between gravity anomalies and height differences, we reconstructed potential paleolakes under thick sand layers in the Great Sand Sea, Western Egypt (our previous work), and between Kharga and Toshka, Southern Egypt (this work), consistent with the known archaeological sites.

Gravity aspects from recent Earth gravity model EIGEN 6C4 for geoscience and archaeology in Sahara, Egypt

2020 ◽  
Author(s):  
Jaroslav Klokocnik ◽  
Vaclav Cilek ◽  
Jan Kostelecky ◽  
Ales Bezdek
Keyword(s):  
Field Model ◽  
Gravity Data ◽  
Gravity Anomalies ◽  
Western Desert ◽  
Archaeological Sites ◽  
Gravity Field Model ◽  
Earth Gravity ◽  
Earth Gravity Model ◽  
Gravity Signal ◽  
Libyan Desert

<p>A new method to detect paleolakes via their gravity signal is presented (here with implications for geoscience and archaeology). The gravity aspects or descriptors (gravity anomalies/disturbances, second radial derivatives, strike angles and virtual deformations) were computed from the global static combined gravity field model EIGEN 6C4 for an application in archaeology and geoscience in Egypt and surrounding countries. The model consists of the best now available satellite and terrestrial data, including gradiometry from the GOCE mission. EIGEN 6C4 has the ground resolution ~10 km. From archaeological literarure we took the positions of archaeological sites of the Holocene occupations between 8500 and 5300 BC (8.5-5.3 ky BC) in the Eastern Sahara, Western Desert, Egypt. We correlated the features found from the gravity data with the locations; the correlation is good, assuming that the sites were mostly at paleolake boarders or at rivers. We suggest position, extent and shape of a paleolake. Then, we have estimated a possible location, extent and shape of the putative paleolake(s). We also reconsider the origin of Libyan Desert glass (LDG) in the Great Sand Sea (GSS) and support a hypothesis about an older impact structure created in GSS, repeatedly filled by water, which might be a part of some of the possible paleolake(s).</p>

A 1.5km-resolution gravity field model of the Moon

2012 ◽  
Vol 329-330 ◽  
pp. 22-30 ◽  
Author(s):  
C. Hirt ◽  
W.E. Featherstone
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
The Moon ◽  
Gravity Field Model

scholarly journals Recovering Marine Gravity Over the Gulf of Guinea From Multi-Satellite Sea Surface Heights

2021 ◽  
Vol 9 ◽  
Author(s):  
Richard Fiifi Annan ◽  
Xiaoyun Wan
Keyword(s):  
Gravity Field ◽  
Gravity Anomalies ◽  
Sea Surface ◽  
Shallow Waters ◽  
Gulf Of Guinea ◽  
Gravity Field Model ◽  
The North ◽  
Marine Gravity ◽  
Sea Surface Heights ◽  
East Component

A regional gravity field product, comprising vertical deflections and gravity anomalies, of the Gulf of Guinea (15°W to 5°E, 4°S to 4°N) has been developed from sea surface heights (SSH) of five altimetry missions. Though the remove-restore technique was adopted, the deflections of the vertical were computed directly from the SSH without the influence of a global geopotential model. The north-component of vertical deflections was more accurate than the east-component by almost three times. Analysis of results showed each satellite can contribute almost equally in resolving the north-component. This is attributable to the nearly northern inclinations of the various satellites. However, Cryosat-2, Jason-1/GM, and SARAL/AltiKa contributed the most in resolving the east-component. We attribute this to the superior spatial resolution of Cryosat-2, the lower inclination of Jason-1/GM, and the high range accuracy of the Ka-band of SARAL/AltiKa. Weights of 0.687 and 0.313 were, respectively, assigned to the north and east components in order to minimize their non-uniform accuracy effect on the resultant gravity anomaly model. Histogram of computed gravity anomalies compared well with those from renowned models: DTU13, SIOv28, and EGM2008. It averagely deviates from the reference models by −0.33 mGal. Further assessment was done by comparing it with a quadratically adjusted shipborne free-air gravity anomalies. After some data cleaning, observations in shallow waters, as well as some ship tracks were still unreliable. By excluding the observations in shallow waters, the derived gravity field model compares well in ocean depths deeper than 2,000 m.

Towards an updated, enhanced regional gravity field solution for Antarctica

2021 ◽  
Author(s):  
Mirko Scheinert ◽  
Philipp Zingerle ◽  
Theresa Schaller ◽  
Roland Pail ◽  
Martin Willberg
Keyword(s):  
Gravity Anomaly ◽  
Gravity Field ◽  
Gravity Data ◽  
Gravity Anomalies ◽  
Data Set ◽  
Gravity Field Model ◽  
Terrestrial Gravity ◽  
Field Solution ◽  
Gravity Disturbances ◽  
Regional Gravity

<p>In the frame of the IAG Subcommission 2.4f “Gravity and Geoid in Antarctica” (AntGG) a first Antarctic-wide grid of ground-based gravity anomalies was released in 2016 (Scheinert et al. 2016). That data set was provided with a grid space of 10 km and covered about 73% of the Antarctic continent. Since then a considerably amount of new data has been made available, mainly collected by means of airborne gravimetry. Regions which were formerly void of any terrestrial gravity observations and have now been surveyed include especially the polar data gap originating from GOCE satellite gravimetry. Thus, it is timely to come up with an updated and enhanced regional gravity field solution for Antarctica. For this, we aim to improve further aspects in comparison to the AntGG 2016 solution: The grid spacing will be enhanced to 5 km. Instead of providing gravity anomalies only for parts of Antarctica, now the entire continent should be covered. In addition to the gravity anomaly also a regional geoid solution should be provided along with further desirable functionals (e.g. gravity anomaly vs. disturbance, different height levels).</p><p>We will discuss the expanded AntGG data base which now includes terrestrial gravity data from Antarctic surveys conducted over the past 40 years. The methodology applied in the analysis is based on the remove-compute-restore technique. Here we utilize the newly developed combined spherical-harmonic gravity field model SATOP1 (Zingerle et al. 2019) which is based on the global satellite-only model GOCO05s and the high-resolution topographic model EARTH2014. We will demonstrate the feasibility to adequately reduce the original gravity data and, thus, to also cross-validate and evaluate the accuracy of the data especially where different data set overlap. For the compute step the recently developed partition-enhanced least-squares collocation (PE-LSC) has been used (Zingerle et al. 2021, in review; cf. the contribution of Zingerle et al. in the same session). This method allows to treat all data available in Antarctica in one single computation step in an efficient and fast way. Thus, it becomes feasible to iterate the computations within short time once any input data or parameters are changed, and to easily predict the desirable functionals also in regions void of terrestrial measurements as well as at any height level (e.g. gravity anomalies at the surface or gravity disturbances at constant height).</p><p>We will discuss the results and give an outlook on the data products which shall be finally provided to present the new regional gravity field solution for Antarctica. Furthermore, implications for further applications will be discussed e.g. with respect to geophysical modelling of the Earth’s interior (cf. the contribution of Schaller et al. in session G4.3).</p>

scholarly journals The combined global gravity field model XGM2019e

2020 ◽  
Vol 94 (7) ◽  
Author(s):  
P. Zingerle ◽  
R. Pail ◽  
T. Gruber ◽  
X. Oikonomidou
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model ◽  
Global Gravity ◽  
Global Gravity Field Model

What can be expected from GNSS tracking of satellite constellations for temporal gravity field model determination?

2020 ◽  
Vol 222 (1) ◽  
pp. 661-677
Author(s):  
Hao Zhou ◽  
Zebing Zhou ◽  
Zhicai Luo ◽  
Kang Wang ◽  
Min Wei
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Geoid Height ◽  
Error Component ◽  
Expected Improvement ◽  
Gps Tracking ◽  
Satellite Constellations ◽  
Gravity Field Model ◽  
Gravity Field Determination ◽  
Temporal Gravity

SUMMARY The goal of this contribution is to investigate the expected improvement of temporal gravity field determination via a couple of high-low satellite-to-satellite tracking (HLSST) missions. The simulation system is firstly validated by determining monthly gravity field models within situ GRACE GPS tracking data. The general consistency between the retrieved solutions and those developed by other official agencies indicates the good performance of our software. A 5-yr full-scale simulation is then performed using the full error sources including all error components. Analysis of each error component indicates that orbit error is the main contributor to the overall HLSST-derived gravity field model error. The noise level of monthly solution is therefore expected to reduce 90 per cent in terms of RMSE over ocean when the orbit accuracy improves for a magnitude of one order. As for the current HLSST mission consisting of a current GNSS receiver and an accelerometer (10−10 and 10−9 m s–2 noise for sensitive and non-sensitive axes), it is expected to observe monthly (or weekly) gravity solution at the spatial resolution of about 1300 km (or 2000 km). As for satellite constellations, a significant improvement is expected by adding the second satellite with the inclination of 70° and the third satellite with the inclination of 50°. The noise reduction in terms of cumulative geoid height error is approximately 51 per cent (or 62 per cent) when the observations of two (or three) HLSST missions are used. Moreover, the accuracy of weekly solution is expected to improve 40–70 per cent (or 27–59 per cent) for three (or two) HLSST missions when compared to one HLSST mission. Due to the low financial costs, it is worthy to build a satellite constellation of HLSST missions to fill the possible gaps between the dedicated temporal gravity field detecting missions.

scholarly journals Same-beam VLBI observations of SELENE for improving lunar gravity field model

Radio Science ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Q. Liu ◽  
F. Kikuchi ◽  
K. Matsumoto ◽  
S. Goossens ◽  
H. Hanada ◽  
...  
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Lunar Gravity ◽  
Gravity Field Model ◽  
Lunar Gravity Field ◽  
Vlbi Observations

A Gravity Field Model Derived From the Short Dynamical Arcs of Champ

2007 ◽  
Vol 50 (1) ◽  
pp. 110-115 ◽  
Author(s):  
Xing-Fu ZHANG ◽  
Yun-Zhong SHEN ◽  
Lei-Ming HU
Keyword(s):  
Gravity Field ◽  
Field Model ◽  
Gravity Field Model
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