scholarly journals Improved the Accuracy of Seafloor Topography from Altimetry-Derived Gravity by the Topography Constraint Factor Weight Optimization Method

2021 ◽  
Vol 13 (12) ◽  
pp. 2277
Author(s):  
Yongjin Sun ◽  
Wei Zheng ◽  
Zhaowei Li ◽  
Zhiquan Zhou
Keyword(s):  
Gravity Anomaly ◽  
Ordinary Kriging ◽  
Gravity Models ◽  
Weight Optimization ◽  
Kriging Method ◽  
Seafloor Topography ◽  
Constraint Factor ◽  
Topography Model ◽  
Regional Gravity ◽  
Better Than

Gravity geologic method is one of the important to derive seafloor topography by using altimetry-gravity, and its committed step is gridding of regional gravity anomaly. Hence, we proposed a topography constraint factor weight optimization (TCFWO) method based on ordinary kriging method. This method fully considers the influence of topography factors on the construction of regional gravity grid besides horizontal distance. The results of regional gravity anomaly models constructed in the Markus-Wake seamount area show that the TCFWO method is better than ordinary kriging method. Then, the above two regional gravity models were applied to invert the seafloor topography. The accuracy of derived topographic models was evaluated by using the shipborne depth data and existing seafloor topography models, including ETOPO1 and V19.1 model. The experimental results show that the accuracy of ST_TCFWO (seafloor topography model inverted by TCFWO method) is better than ST_KR (seafloor topography model inverted by kriging method) and ETOPO1 model. Compared with the ST_KR, the accuracy of the ST_TCFWO has improved about 26%. In addition, the accuracy of seafloor topography is affected by the variation of depth, the distribution of control points and the type of terrain. In different depth layers, the ST_TCFWO has better advantages than ST_KR. In the sparse shipborne measurements area, the accuracy of ST_TCFWO is better than that of V19.1, ETOPO1 and ST_KR. Moreover, compared to other models, ST_TCFWO performs better in flat submarine plain or rugged seamount area.

Regional gravity setting of the Sudbury Structure

Geophysics ◽  
2001 ◽  
Vol 66 (6) ◽  
pp. 1680-1690 ◽  
Author(s):  
R. B. Hearst ◽  
W. A. Morris
Keyword(s):  
Numerical Methods ◽  
Gravity Anomaly ◽  
Gravity Field ◽  
Downward Continuation ◽  
Gravity Models ◽  
Gravity Modeling ◽  
Meteorite Impact ◽  
Sudbury Structure ◽  
Regional Gravity ◽  
Impact Origin

In the vicinity of Sudbury, Ontario, Canada, the boundary between the Southern and Superior tectonic provinces is overlain by the elliptical Sudbury Structure. On the basis of gravity modeling, genesis of the Sudbury Structure has been attributed to either a magmatic origin (having a dense hidden differentiate zone) or a meteorite impact origin (there being no dense hidden mass). The difference between the two gravity models centers on the problem of regional‐residual separation. As shown by numerous previous studies, any such separation of components is nonunique. This becomes especially problematic when, as in Sudbury, a portion of the near‐surface geology has a similar orientation and dimension to more deep‐seated source. In this paper, several numerical methods (upward continuation, downward continuation, wavelength filtering, trend‐surface analysis) for determining the regional component of the gravity field associated with the Sudbury Structure have been applied and evaluated. Of the numerical methods used, the upward and downward continuation operators provided the most insight into the deep structural controls of the Sudbury Basin. Our preferred interpretation of the regional gravity field invokes a two‐component structure. Underlying the southern half of the Sudbury Structure is a laterally continuous gravity anomaly that is probably associated with a zone of uplifted Huronian volcanics. The gravity anomaly under the northern portion of the Sudbury Structure has a more restricted spatial extent. The close association between the northern limit of the gravity anomaly and the surface outcrop of the Levack Gneiss suggests the source of this anomaly is probably a slab of dense Levack Gneiss. This interpretation favors a meteorite impact origin for the Sudbury Structure.

Prediction concentration of PM2.5 in Surabaya using ordinary Kriging method

2021 ◽  
Author(s):  
Derbi W. Fitri ◽  
Nurul Afifah ◽  
Siti M. D. Anggarani ◽  
Nur Chamidah
Keyword(s):  
Ordinary Kriging ◽  
Kriging Method

scholarly journals Spatial Interpolation on Rainfall Data over Peninsular Malaysia Using Ordinary Kriging

2013 ◽  
Vol 63 (2) ◽  
Author(s):  
Suhaila Jamaludin ◽  
Hanisah Suhaimi
Keyword(s):  
Spatial Analysis ◽  
Ordinary Kriging ◽  
Spatial Interpolation ◽  
Rainfall Intensity ◽  
Peninsular Malaysia ◽  
Rainfall Data ◽  
Kriging Method ◽  
Intensity Index ◽  
Dry Conditions ◽  
Two Indices

This study presents the spatial analysis of the rainfall data over Peninsular Malaysia. 70 rainfall stations were utilized in this study. Due to the limited number of rainfall stations, the Ordinary Kriging method which is one of the techniques in Spatial Interpolation was used to estimate the values of the rainfall data and to map their spatial distribution. This spatial analysis was analysed according to the two indices that describe the wet events and another two indices that characterize dry conditions. Large areas at the east experienced high rainfall intensity compared to the areas in the west, northwest and southwest. The small value that has been obtained in Aridity Intensity Index (AII) reflects that the high amount of rainfall in the eastern areas is not contributed by low-intensity events (less than 25th percentile). In terms of number of consecutive dry days, Northwestern areas in Peninsular Malaysia recorded the highest value. This finding explains the occurrence of a large number of floods and soil erosions in the eastern areas.

scholarly journals Review of the Kriging Technique Applications to Groundwater Quality

2021 ◽  
Vol 27 (12) ◽  
pp. 23-32
Author(s):  
Hayat Azawi ◽  
May Samir Saleh
Keyword(s):  
Groundwater Quality ◽  
Quality Indicator ◽  
Ordinary Kriging ◽  
Indicator Kriging ◽  
Disjunctive Kriging ◽  
Kriging Method ◽  
Lognormal Kriging ◽  
Groundwater Contaminants ◽  
Simple Kriging

Kriging, a geostatistical technique, has been used for many years to evaluate groundwater quality. The best estimation data for unsampled points were determined by using this method depending on measured variables for an area. The groundwater contaminants assessment worldwide was found through many kriging methods. The present paper shows a review of the most known methods of kriging that were used in estimating and mapping the groundwater quality. Indicator kriging, simple kriging, cokriging, ordinary kriging, disjunctive kriging and lognormal kriging are the most used techniques. In addition, the concept of the disjunctive kriging method was explained in this work to be easily understood.

Seafloor topography variations mapped by regional gravity tensor analysis 

2021 ◽  
Author(s):  
Lucia Seoane ◽  
Guillaume Ramillien ◽  
José Darrozes ◽  
Frédéric Frappart ◽  
Didier Rouxel ◽  
...  
Keyword(s):  
New England ◽  
Static Field ◽  
Gravity Gradient ◽  
Seafloor Topography ◽  
Central Pacific ◽  
Goce Mission ◽  
Vertical Gravity Gradient ◽  
Seamount Chain ◽  
Vertical Gravity ◽  
Regional Gravity

<p>The AGOSTA project initially proposed by our team and lately funded by CNES TOSCA consists of developing efficient approaches to restore seafloor shape (or bathymetry), as well as lithospheric parameters such as the crust and elastic thicknesses, by combining different types of observations including gravity gradient data. As it is based on the second derivatives of the potential versus the space coordinates, gravity gradiometry provides more information inside the Earth system at short wavelengths. The GOCE mission has measured the gravity gradient components of the static field globally and give the possibility to detect more details on the structure of the lithosphere at spatial resolutions less than 200 km. We propose to analyze these satellite-measured gravity tensor components to map the undersea relief more precisely than using geoid or vertical gravity previously considered for this purpose. Inversion of vertical gravity gradient data derived from the radar altimetry technique also offers the possibility to reach greater resolutions (at least 50 km) than the GOCE mission one. The seafloor topography estimates are tested in areas well-covered by independent data for validation, such as around the Great Meteor guyot [29°57′10.6″N, 28°35′31.3″W] and New England seamount chain [37°24′N 60°00′W, 120° 10' 30.4" W] in the Atlantic Ocean as well as the Acapulco seamount [13° 36' 15.4" N, 120° 10' 30.4" W] in the Central Pacific.</p>

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>

Real-Time Automatic Seizure Detection Using Ordinary Kriging Method in an Edge-IoMT Computing Paradigm

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Ibrahim L. Olokodana ◽  
Saraju P. Mohanty ◽  
Elias Kougianos ◽  
Oluwaseyi O. Olokodana
Keyword(s):  
Real Time ◽  
Ordinary Kriging ◽  
Seizure Detection ◽  
Kriging Method ◽  
Computing Paradigm

Networks of export markets and export market diversification

2020 ◽  
Author(s):  
Qi Guo ◽  
Shengjun Zhu ◽  
Ron Boschma
Keyword(s):  
Developed Countries ◽  
Gravity Models ◽  
Export Market ◽  
Gravity Effect ◽  
Export Markets ◽  
Policy Makers ◽  
Extended Gravity ◽  
Gravity Effects ◽  
Better Than ◽  
Developing And Developed Countries

Abstract In the era of globalization, policy makers in both developing and developed countries have sought to expand their export destinations, with the expectation that export market diversification can boost export upgrading and economic development. Although extant literature has confirmed that exporters search for new markets in two distinct ways: direct search underpinned by the gravity effect and remote search driven by the extended gravity effect, it has not advanced very far due to the lack of adequate measures of those effects. This article presents a technique that uses available export data to develop measures of those two effects that capture a larger range of factors and thus allow us to more easily predict export market diversification. Our new indicator also simplifies the prediction by combining gravity and extended gravity effects. Empirical results show that the explanatory and predictive power of our new method is better than that of the traditional one based on gravity and extended gravity models.

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