Earth2014: 1 arc-min shape, topography, bedrock and ice-sheet models – Available as gridded data and degree-10,800 spherical harmonics

Hirt, Christian; Rexer, Moritz

doi:10.1016/j.jag.2015.03.001

Cited by 150 publications

(94 citation statements)

References 40 publications

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“…The topography ( Figure 1a) and the rock-equivalent topography are taken from Earth2014 (Hirt & Rexer, 2015), which has a resolution of 1 60 ∘ , and interpolated to a resolution of 0.1 ∘ . The topography ( Figure 1a) and the rock-equivalent topography are taken from Earth2014 (Hirt & Rexer, 2015), which has a resolution of 1 60 ∘ , and interpolated to a resolution of 0.1 ∘ .…”

Section: 1029/2017gl076885mentioning

confidence: 99%

“…Gravity and elevation data as well as models of the crustal structure (e.g., density models, Moho depth [Mohorovičić discontinuity, crust-mantle boundary]) are necessary to estimate the effective elastic thickness (e.g., Audet, 2014). The gravity data are obtained from the global gravity model EIGEN-6C4 (Förste et al, 2014), (Hirt & Rexer, 2015). The range of hot spot tracks between today and 120 Ma ago by Müller et al (1993), Steinberger et al (2004), O'Neill et al (2005, and Doubrovine et al (2012) are marked by the purple area following Rogozhina et al (2016).…”

Section: Datamentioning

confidence: 99%

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Weakened Lithosphere Beneath Greenland Inferred From Effective Elastic Thickness: A Hot Spot Effect?

Steffen

Audet

Lund

2018

Geophysical Research Letters

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The effective elastic thickness (Te) of the lithosphere provides geophysical information about long‐term flexural strength and can be used to constrain thermorheological properties of the lithosphere. Te is typically calculated from the spectral analysis of gravity and topography data; variations in Te are, however, not well resolved in Greenland due to poor constraints on crustal structure (including crustal thickness) and complications due to ice loading. In addition, geological and geophysical constraints on the tectonic history of Greenland are sparse due to the thick ice cover. Here we use the global gravity model EIGEN‐6C4 together with a new model of the crust‐mantle boundary to obtain a high‐resolution Te map of Greenland. The distribution of Te indicates reduced strength in the lower crust and lithospheric mantle beneath southern and central Greenland, which may be due to the passage of the Iceland hot spot during the last 100 Ma. In contrast, the northern part of Greenland shows a large Te, implying mechanical coupling between crust and uppermost mantle and suggesting the existence of a cold and strong tectonic unit. In a relative sense, the distribution of Te values is consistent with estimates of lithospheric thickness based on seismic velocity models, indicating a dominantly thermal control on lithospheric structure and evolution.

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Section: 1029/2017gl076885mentioning

confidence: 99%

Section: Datamentioning

confidence: 99%

Weakened Lithosphere Beneath Greenland Inferred From Effective Elastic Thickness: A Hot Spot Effect?

Steffen

Audet

Lund

2018

Geophysical Research Letters

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“…For Venus, we used the VenusTopo719 [18] topographic model and the MGNP180U [19] gravitational model, both up to degree 180. For Earth, we used the Earth2014 topographic dataset [20] and the EIGEN6c4 gravitational model, using their coefficients truncated up to degree 180 in order to present all results with a similar spectral resolution. For Mars, we used MOLA [21] discrete topographic data and the MRO120D [22] gravitational model, both up to degree 120.…”

Section: Input Datasetsmentioning

confidence: 99%

On the Applicability of Molodensky’s Concept of Heights in Planetary Sciences

Tenzer

Foroughi

2018

Geosciences

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Geometric heights, defined with respect to a geometric reference surface, are the most commonly used in planetary studies, but the use of physical heights defined with respect to an equipotential surface (typically the geoid) has been also acknowledged for specific studies (such as gravity-driven mass movements). In terrestrial studies, the geoid is defined as an equipotential surface that best fits the mean sea surface and extends under continents. Since gravimetric geoid modelling under continents is limited by the knowledge of a topographic density distribution, alternative concepts have been proposed. Molodensky introduced the quasigeoid as a height reference surface that could be determined from observed gravity without adopting any hypothesis about the topographic density. This concept is widely used in geodetic applications because differences between the geoid and the quasigeoid are mostly up to a few centimeters, except for mountainous regions. Here we discuss the possible applicability of Molodensky's concept in planetary studies. The motivation behind this is rationalized by two factors. Firstly, knowledge of the crustal densities of planetary bodies is insufficient. Secondly, large parts of planetary surfaces have negative heights, implying that density information is not required. Taking into consideration the various theoretical and practical aspects discussed in this article, we believe that the choice between the geoid and the quasigeoid is not strictly limited because both options have advantages and disadvantages. We also demonstrate differences between the geoid and the quasigeoid on Mercury, Venus, Mars and Moon, showing that they are larger than on Earth.

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“…In these studies, various topography models are used, such as Earth2014 global topography model (Hirt and Rexer, 2015), SRTM digital elevation data (Jarvis et al, 2008), based on constant (e.g., 2.67 g cm 3 ), CRUST2.0 (Bassin et al, 2000), CRUST1.0 (Laske et al, 2013), or GEMMA (Reguzzoni and Sampietro, 2015) density distributions. Determining the topographic effect in computing the gravitational potential (GP) plays a key role in establishing high-resolution and high-accuracy global/local gravity fields and geoids.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the fourth-order tesseroid formula and new combination approach to precisely determine gravitational potential

Shen

Deng

2016

Stud Geophys Geod

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Calculating topographic gravitational potential (GP) is a time-consuming process in terms of efficiency. Prism, mass-point, mass-line, and tesseroid formulas are generally used to calculate the topographic GP effect. In this study, we reformulate the higher-order formula of the tesseroid by Taylor series expansion and then evaluate the fourth-order formula by numerical tests. Different simulation computations show that the fourth-order formula is reliable. Using the conventional approach in numerical calculations, the approximation errors in the areas of the north and south poles are extremely large. Thus, in this study we propose an approach combining the precise numerical formula and tesseroid formulas, which can satisfactorily solve the calculation problem when the computation point is located in the polar areas or areas very near the surface. Furthermore, we suggest a "best matching choice" of new combination approach to calculate the GP precisely by conducting various experiments. Given the computation point at different positions, we may use different strategies. In the low latitude, we use a precise numerical formula, the fourth-order tesseroid formula, the second-order tesseroid formula, and the zero-order formula, in the 1° range (from the computation point), 1° to 15° range, 15° to 40° range, and the range outside 40°, respectively. The accuracy can reach 2 × 10 5 m 2 s 2 . For the high latitude, we use the precise numerical formula, fourth-order tesseroid, second-order tesseroid, and zero-order tesseroid formulas in the ranges of 0° to 1°, 1° to 10°, 10° to 30°, and the zones outside 30°, respectively. However, if an accuracy level of 2 × 10 5 m 2 s 2 is required, the zero-order tesseroid formulas should not be used and the second-order tesseroid formula should be used in the region outside 15° for the low latitude and in the region outside 10° for the high latitude. K e y w o r d s : Newton's integral, gravitational potential, tesseroid, new combination method W.B. Shen and X.L. Deng ii Stud. Geophys. Geod., 60 (2016)

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Earth2014: 1 arc-min shape, topography, bedrock and ice-sheet models – Available as gridded data and degree-10,800 spherical harmonics

Cited by 150 publications

References 40 publications

Weakened Lithosphere Beneath Greenland Inferred From Effective Elastic Thickness: A Hot Spot Effect?

Weakened Lithosphere Beneath Greenland Inferred From Effective Elastic Thickness: A Hot Spot Effect?

On the Applicability of Molodensky’s Concept of Heights in Planetary Sciences

Evaluation of the fourth-order tesseroid formula and new combination approach to precisely determine gravitational potential

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