Henglei Zhang
Filippo Greco2
Victor Sacek
Meixia Geng
Pengfei Liu- 1School of Geophysics and Geomatics, China University of Geosciences, Wuhan, China
- 2National Institute of Geophysics and Volcanology (INGV), Roma, Italy
- 3Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo, Brazil
- 4Technology Innovation Institute, Abu Dhabi, United Arab Emirates
- 5State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macao, Macao SAR, China
Editorial on the Research Topic
Applications of gravity anomalies in geophysics
With the progress of cheap, lightweight, and efficient gravimeters (Carbone et al., 2020; Stray et al., 2022; Kim and Choi, 2023), gravity anomalies are expected to receive wider attention in the future, opening up new perspectives for increasing the capability of gravimetry to Earth sciences. Since the knowledge of the crustal density of a planet is important in determining its interior structure, gravity anomaly is widely used in Solid Earth and exploration geophysics, and also extended to the moon and Mars. In addition to the routine applications focusing on the crustal density structure, contributing to the characterization and definition of underground structures at various scales, time-varying gravity, microgravity survey, and gravity admittance are widely applied in order to supply unique information on the dynamics of underground processes. The goal of this Research Topic is to highlight the various extracted information from gravity anomalies in applications, toward an understanding of choosing appropriate methods dealing with gravity anomalies in varying study cases.
There are ten accepted papers on this Research Topic focusing on the following four research questions.
The first question is about the equivalent-layer technique (Oliveira Junior et al.) which present a comprehensive review of the computation aspects concerning the equivalent-layer technique. The equivalent-layer technique is used widely in processing gravity and magnetic anomalies, e.g., the downward continuation and the reduction to the pole at low latitudes. While such method is very inefficient for dealing with massive data sets, lots of computationally efficient methods have been proposed to reduce its computational cost. The authors from Observatório Nacional and Universidade do Estado do Rio de Janeiro (Brazil) present a comprehensive review of diverse strategies to solve the linear system of the equivalent layer in which the advantages and disadvantages for the existing strategies are described in detail.
The second question is about the time-varying gravity (Zhu et al.) which is used in monitoring the subsurface mass variation. Zhu et al., from China Earthquake Administration, have conducted numerous applications focusing on the time-varying gravity in earthquake research in the Chinese Mainland. The gravity changes before and after the earthquakes were found in several earthquakes, and thus the high-precision mobile gravity observations used to survey the gravity changes possibly induced by the earthquake had attracted people’s attention. Reports show that the gravity observation network in the Chinese Mainland made a relatively successful medium-term prediction for a series of earthquakes since 2008 after the serious Wenchuan Ms8.0 earthquake. Zhu et al. introduce some case studies and progress using the time-varying gravity in earthquake monitoring in the Chinese Mainland which put forward the gravity applications in earthquake prediction. The time-varying gravity is also applied widely in investigating the hydrological and volcano-tectonic processes controlling the present day activity of the volcano (Pivetta et al., 2023). The present studies show that the role of time-varying gravity in earthquake prediction would become increasingly significant with the progress of cheap, lightweight and efficient gravimeter. In addition to the high precision ground time-varying gravity, the time-varying gravity from satellites has played an extremely important role in hydrology, seismology, geodesy, and geophysics (Liu and Sun, 2023).
The third question is about mapping the structural lineaments (Ganguli and Pal; Sun et al.) which is used widely in geological mapping (Altinoğlu, 2023; Ashraf and Filina, 2023; Bayou et al., 2023; Ibrahim et al., 2023; Lghoul et al., 2023; Mnasri et al., 2023; Qadir et al., 2023). Such applications are based on the qualitative interpretation of gravity anomalies in which the edge detection filters are usually applied to enhance the lineament. Sun et al. propose a modified edge detection method based on the second order spectral moment to detect edges on potential field which can enhance the weak anomalies and eliminate the false edges caused by the associated anomalies. Ganguli and Pal applied second vertical derivative and tilt derivative on the potential field data to reveal very prominent NESW trending linear gravity high and low.
The fourth question is about the quantitative interpretation of gravity anomalies. Harash et al. and Liu et al. apply the gravity inversion to obtain the Moho topography. For the Moho inversion from gravity anomalies, the Parker–Oldenburg methods in Fourier domain are powerful tools (Zhang et al., 2020; Elmas and Karsl, 2021; Borghi, 2022). The other contributions in this Research Topic are focusing on the subsurface density structures modeling using gravity anomalies (Nigussie et al.; Nigussie et al.; Moura and Marangoni; Pánisová et al.). Modeling the crustal density is very useful to reveal its composition and structure, and hence it is also significantly related to the tectonic evolution and geodynamics in Earth, Moon and Mars (Affatato, 2023; Haas et al., 2023; Smith et al., 2023).
In addition to the above-mentioned research questions, the gravity anomalies have been widely used in estimation of the elastic thickness and have been extended from Earth to other planets where gravity data is available (Broquet and Wieczorek, 2019; Genova et al., 2023). Since the routine Pratt and Airy compensation modes require a lithosphere with an unrealistic and highly anisotropic mechanical behavior, the flexure model has been extensively used to interpret short-wavelength gravity anomalies due to variations in crustal thickness. The parameter that characterizes the apparent strength of the lithosphere is the effective elastic thickness (Te) of the lithosphere, and thus the estimation of Te value is important to measure of the integrated strength of the lithosphere which can be compared from region to region and interpreted in terms of the thermal and mechanical structure of the continental lithosphere. Gravity/topography admittance is first proposed to estimate Te, and the related improvements on Te estimation are becoming the focus of attention.
We hope this Research Topic would provide a helpful source of references for those working in gravity anomalies.
Author contributions
HZ: Writing–original draft, Writing–review and editing. VS: Writing–review and editing. MG: Writing–review and editing. PL: Writing–review and editing.
Funding
The authors declare financial support was received for the research, authorship, and/or publication of this article. This work was in part financially supported by National Key R&D Program of China (2022YFC3104000).
Acknowledgments
HZ thanks Prof. Dhananjay Ravat from University of Kentucky for his kindly suggestions in this Research Topic. Many thanks go to Dr. Xiaofei Ma graduated from Utah State University for his helps in polishing the English texts. The Guest Editors of this SI are grateful to all authors who contributed to this volume sharing their results with the scientific community.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
Altinoğlu, F. F. (2023). Mapping of the structural lineaments and sedimentary basement relief using gravity data to guide mineral exploration in the denizli basin gravity data to guide mineral exploration in the denizli basin. Minerals 13 (10), 1276. doi:10.3390/min13101276
Ashraf, A., and Filina, I. (2023). Zones of weakness within the Juan de Fuca plate mapped from the integration of multiple geophysical data and their relation to observed seismicity. Geochem. Geophys. Geosystems 24 (10), e2023GC010943. doi:10.1029/2023gc010943
Bayou, Y., Abtout, A., Renaut, R. A., Bouyahiaoui, B., Maouche, S., Vatankhah, S., et al. (2023). The northeastern Algeria hydrothermal system: gravimetric data and structural implication. Geotherm. Energy 11 (1), 14–26. doi:10.1186/s40517-023-00258-2
Borghi, A. (2022). Moho depths for Antarctica Region by the inversion of ground-based gravity data. Geophys. J. Int. 231 (2), 1404–1420. doi:10.1093/gji/ggac249
Broquet, A., and Wieczorek, M. A. (2019). The gravitational signature of Martian volcanoes. J. Geophys. Res. Planets 124 (8), 2054–2086. doi:10.1029/2019je005959
Carbone, D., Antoni-Micollier, L., Hammond, G., de Zeeuw-van Dalfsen, E., Rivalta, E., Bonadonna, C., et al. (2020). The Newton-g gravity imager: toward new paradigms for terrain gravimetry. Front. Earth Sci. 8. doi:10.3389/feart.2020.573396
Elmas, A., and Karsl, H. (2021). Tectonic and crustal structure of Archangelsky ridge using Bouguer gravity data. Mar. Geophys. Res. 42 (3), 21. doi:10.1007/s11001-021-09443-z
Genova, A., Goossens, S., Del Vecchio, E., Petricca, F., Beuthe, M., Wieczorek, M., et al. (2023). Regional variations of Mercury's crustal density and porosity from MESSENGER gravity data. Icarus 391, 115332. doi:10.1016/j.icarus.2022.115332
Haas, P., Ebbing, J., and Szwillus, W. (2023). Cratonic crust illuminated by global gravity gradient inversion. Gondwana Res. 121, 276–292. doi:10.1016/j.gr.2023.04.012
Ibrahim, A., Gemail, K. S., Bedair, S., Saada, S. A., Koch, M., and Nosair, A. (2023). An integrated approach to unravel the structural controls on groundwater potentialities in hyper-arid regions using satellite and land-based geophysics: a case study in southwestern desert of Egypt. Surv. Geophys. 44 (3), 783–819. doi:10.1007/s10712-022-09755-8
Kim, G., and Choi, I. M. (2023). Development of SQUID detection technology for a superconducting gravimeter. Rev. Sci. Instrum. 94 (9), 094505. doi:10.1063/5.0163714
Lghoul, M., Abd-Elhamid, H. F., Zelenakova, M., Abdelrahman, K., Fnais, M. S., and Sbihi, K. (2023). Application of enhanced methods of gravity data analysis for mapping the subsurface structure of the Bahira basin in Morocco. Front. Earth Sci. 11, 1225714. doi:10.3389/feart.2023.1225714
Liu, C., and Sun, W. (2023). GRACE time-variable gravity and its application to geoscience: quantitative analysis of relevant literature. Earth Planet. Phys. 7 (2), 295–309. doi:10.26464/epp2023022
Mnasri, M., Amiri, A., Nasr, I. H., Belkhiria, W., and Inoubli, M. H. (2023). Integrated geophysical approach for ore exploration: case study of sidi bou aouane–khadhkhadha Pb–Zn province–northern Tunisia. Geophys. Prospect. 71 (9), 1772–1791. doi:10.1111/1365-2478.13338
Pivetta, T., Riccardi, U., Ricciardi, G., and Carlino, S. (2023). Hydrological and volcano-related gravity signals at Mt. Somma–Vesuvius from ∼20 yr of time-lapse gravity monitoring: implications for volcano quiescence. Geophys. J. Int. 235 (2), 1565–1580. doi:10.1093/gji/ggad320
Qadir, H. O., Baban, E. N., Aziz, B. Q., and Koyi, H. A. (2023). Potential field survey of subsurface structures of the NW segment of the zagros fold-thrust belt, kurdistan region. Geophys. Prospect. 71 (8), 1673–1690. doi:10.1111/1365-2478.13401
Smith, D. E., Goossens, S., Neumann, G. A., and Zuber, M. T. (2023). Constraining the structure under lunar impact basins with gravity lunar impact basins with gravity. Planet. Sci. J. 4 (11), 204. doi:10.3847/psj/acfcac
Stray, B., Lamb, A., Kaushik, A., Vovrosh, J., Rodgers, A., Winch, J., et al. (2022). Quantum sensing for gravity cartography. Nature 602 (7898), 590–594. doi:10.1038/s41586-021-04315-3
Zhang, H. L., Ravat, D., and Lowry, A. (2020). Crustal composition and Moho variations of the central and eastern United States: improving resolution and geologic interpretation of EarthScope USArray seismic images using gravity. J. Geophys. Res. Solid Earth 125, e2019JB018537. doi:10.1029/2019jb018537
Keywords: gravity anomalies, Moho inversion, time-varying gravity, lineaments, subsurface structure
Citation: Zhang H, Greco F, Sacek V, Geng M and Liu P (2024) Editorial: Applications of gravity anomalies in geophysics. Front. Earth Sci. 12:1349161. doi: 10.3389/feart.2024.1349161
Received: 04 December 2023; Accepted: 02 January 2024;
Published: 12 January 2024.
Edited and reviewed by:
Jeroen van Hunen, Durham University, United KingdomCopyright © 2024 Zhang, Greco, Sacek, Geng and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Henglei Zhang, h.l.zhang@cug.edu.cn