Article
Geochemistry & Geophysics
Ron Shaar, Yves Gallet, Yoav Vaknin, Lilach Gonen, Mario A. S. Martin, Matthew J. Adams, Israel Finkelstein
Summary: Our understanding of the Earth's magnetic field intensity in the past has relied on paleointensity analysis. This study uses radiocarbon-dated archaeological materials from the Levant and Mesopotamia to construct a continuous curve of geomagnetic field intensity spanning 2500 years, providing unprecedented detail and resolution.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Yuhji Yamamoto, Hiroto Fukami, Peter C. Lippert
Summary: This study provides new insights into relative paleointensity (RPI) variations by conducting rock magnetic and paleomagnetic measurements on Eocene marine sediments. The results show that RPI fluctuates within each chron and is influenced by inhomogeneous rock magnetic properties. The study also establishes a stacked RPI curve for Chron 18 and compares it with records from the equatorial Pacific, revealing similar characteristics.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Engineering, Aerospace
E. O. Falayi, P. O. Amaechi, A. T. Adewole, T. O. Roy-Layinde, F. O. Ogunsanwo, A. J. Alomaja
Summary: In this study, the wavelet power spectrum and nonlinear dynamics time series techniques were employed to investigate the ionospheric electric current disturbance (Diono) during the geomagnetic storms of 9-11 November 2004 and 14-16 May 2005. The results revealed that high latitudes stations exhibited higher energy wavelet coefficients of Diono at high frequencies, indicating the presence of ionospheric currents during geomagnetic storms. On the other hand, mid and low latitude stations displayed lower energy wavelet coefficients at low frequencies. Additionally, the low latitude geomagnetic stations showed higher values of Lyapunov exponent (LE) during the geomagnetic storms.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Engineering, Aerospace
A. M. El-Taher, A. A. Thabet
Summary: The study revealed long-term periodicities in the frequency range 8-16 yr for Kp, Ap, and aa indices, while Dst index showed this periodicity during the period 1980-2018. Additionally, prominent periodicities were found in the frequency bands of 2-4 yr and 4-8 yr for all geomagnetic indices.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Astronomy & Astrophysics
R. L. Walterscheid, M. W. Chen, C. -c. Chao, S. Gegenheimer, J. Cabrera-Guzman, J. McVey
Summary: This study assesses the accuracy of the first-principles model TIEGCM and three empirical models in predicting density. Comparisons show that TIEGCM, JB2008, and NRLMSIS models are more accurate than the Jacchia 71 model for the storms considered. Although empirical models are currently more practical for operational purposes, the research-focused TIEGCM offers potential improvement in utility during challenging conditions.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Richard K. Bono, Greig A. Paterson, Andrew J. Biggin
Summary: Understanding the evolution of Earth's magnetic field is important for understanding core processes, constraining plate tectonics, and atmospheric shielding. The PINT database provides curated records of site mean estimates of magnetic field strength. In this study, a minor update to the PINT database was made by adding 295 records from 34 studies. The updated database was then used to define a continuous model of the dipole field, and three dipole field strength models were presented.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Aerospace
Wen-Hao Xu, Zan-Yang Xing, Nanan Balan, Li-Kai Liang, Yan-Ling Wang, Qing-He Zhang, Zi-Dan Sun, Wen-Bin Li
Summary: This study investigates the correlation and phase relationship between geomagnetically induced current (GIC) and the rate of change of local horizontal magnetic field (dBx/dt) by analyzing their spectra. The cross wavelet transform (XWT) and wavelet coherence (WTC) techniques reveal a strong correlation (over 0.9) between GIC and dBx/dt throughout the intense geomagnetic storm. The XWT spectra show two enclosed periods in the high energy region corresponding to bursts of activity in GIC and dBx/dt. Additionally, the continuous wavelet transform (CWT) and discrete wavelet transform (DWT) spectra of GIC and dBx/dt exhibit similar characteristics, especially in the low-frequency range.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Geography, Physical
Luiggina Cappellotto, Maria Julia Orgeira, Victor Manuel Velasco Herrera, Rodolfo Gustavo Cionco
Summary: The relationships between geomagnetic field variations, paleoclimates, and Milankovitch cycles have become increasingly important in research. This study confirms that GF variations may act as a climate forcing and that orbital parameters are precursors of GF changes. Investigating the role of GF reversion events is especially interesting in understanding climate cooling during certain periods.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geochemistry & Geophysics
Jiaxi Li, Toshitsugu Yamazaki, Yoichi Usui, Takuya Sagawa, Yoshimi Kubota, Junichiro Kuroda
Summary: Marine sediments can preserve continuous paleomagnetic intensity records. Compositional variations of magnetic mineral assemblages may hinder extraction of reliable relative paleointensity (RPI) records. This study investigates a sediment core from the western equatorial Pacific Ocean and finds that biogenic magnetite contributes to RPI records with lower efficiency than unprotected terrigenous magnetic minerals.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Tinghong Zhou, John A. Tarduno, Francis Nimmo, Rory D. Cottrell, Richard K. Bono, Mauricio Ibanez-Mejia, Wentao Huang, Matt Hamilton, Kenneth Kodama, Aleksey Smirnov, Ben Crummins, Frank Padgett
Summary: Paleomagnetism is used to understand the origin of inner core structure by determining when crystallization started. The study reveals that inner core nucleation began approximately 550 million years ago, and the growth of the inner core to 50% of its current radius occurred around 450 million years ago. Additionally, the seismic anisotropy of the outermost inner core reflects a global deep mantle structure that has persisted to the present day.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Gabriel West, Andreas Nilsson, Alexis Geels, Martin Jakobsson, Matthias Moros, Francesco Muschitiello, Christof Pearce, Ian Snowball, Matt O'Regan
Summary: This study investigates the behavior of the geomagnetic field in polar regions during the late Holocene period. By analyzing well-dated sediment cores from the Chukchi Sea, Arctic Ocean, the authors provide valuable insights into the changes in the geomagnetic field in the Arctic over the past few thousand years.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Chemistry, Multidisciplinary
Oksana Mandrikova, Yuriy Polozov, Sergey Khomutov
Summary: Geomagnetic data analysis is of great importance for studying processes in near-Earth space, Earth magnetosphere, and ionosphere. This study proposes a wavelet model for describing geomagnetic field variations and detecting anomalies of different amplitude and duration.
APPLIED SCIENCES-BASEL
(2022)
Article
Geochemistry & Geophysics
H. Asefaw, L. Tauxe, A. A. P. Koppers, H. Staudigel
Summary: The fundamental assumption in paleomagnetism is that the Earth's magnetic field can be approximated by a geocentric axial dipole (GAD). While global paleomagnetic directions from the last 5 million years support a GAD field structure, paleointensity estimates over the same period do not. This study reexamines the paleomagnetic field structure in Antarctica to determine the validity of low intensity readings.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Multidisciplinary Sciences
Plinio Jaqueto, Ricardo I. F. Trindade, Filipe Terra-Nova, Joshua M. Feinberg, Valdir F. Novello, Nicolas M. Strikis, Peter Schroedl, Vitor Azevedo, Beck E. Strauss, Francisco W. Cruz, Hai Cheng, R. Lawrence Edwards
Summary: Speleothems can provide continuous and high-quality records of the geomagnetic field. The paleomagnetic records of a mid-to-late Holocene stalagmite from Brazil show small angular variations and relatively steady paleointensity, contrasting with the fast variations observed in younger speleothems from the same region.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Chong Yang, Chang YiFeng, Chai HongZhou, Guo Yunfei, Jing ZiJian, Liu Yi
Summary: The POMME model is utilized to simulate geomagnetic measurement data at various satellite orbital altitudes, with a focus on comparing and analyzing inversion results to understand the impact of satellite orbital altitude. Inversion of crustal geomagnetic field data from the CHAMP satellite is used to validate the influence of satellite orbital altitude on the inversion results, providing insights for the design of satellite orbital altitude in satellite geomagnetic measurement systems.
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
(2021)
Article
Geography, Physical
Chuang Xuan, James E. T. Channel, David A. Hodell
QUATERNARY SCIENCE REVIEWS
(2016)
Article
Geosciences, Multidisciplinary
Hirokuni Oda, Jun Kawai, Masakazu Miyamoto, Isoji Miyagi, Masahiko Sato, Atsushi Noguchi, Yuhji Yamamoto, Jun-ichi Fujihira, Nobuyoshi Natsuhara, Yoshiyasu Aramaki, Takashige Masuda, Chuang Xuan
EARTH PLANETS AND SPACE
(2016)
Article
Geosciences, Multidisciplinary
Hirokuni Oda, Chuang Xuan, Yuhji Yamamoto
EARTH PLANETS AND SPACE
(2016)
Article
Geochemistry & Geophysics
Tim E. van Peer, Chuang Xuan, Peter C. Lippert, Diederik Liebrand, Claudia Agnini, Paul A. Wilson
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2017)
Article
Geosciences, Multidisciplinary
Ryuji Tada, Tomohisa Irino, Ken Ikehara, Akinori Karasuda, Saiko Sugisaki, Chuang Xuan, Takuya Sagawa, Takuya Itaki, Yoshimi Kubota, Song Lu, Arisa Seki, Richard W. Murray, Carlos Alvarez-Zarikian, William T. Anderson, Maria-Angela Bassetti, Bobbi J. Brace, Steven C. Clemens, Marcio H. da Costa Gurgel, Gerald R. Dickens, Ann G. Dunlea, Stephen J. Gallagher, Liviu Giosan, Andrew C. G. Henderson, Ann E. Holbourn, Christopher W. Kinsley, Gwang Soo Lee, Kyung Eun Lee, Johanna Lofi, Christina I. C. D. Lopes, Mariem Saavedra-Pellitero, Larry C. Peterson, Raj K. Singh, Samuel Toucanne, Shiming Wan, Hongbo Zheng, Martin Ziegler
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2018)
Article
Geology
James S. Eldrett, Ian C. Harding, Rob Wilshaw, Chuang Xuan
NEWSLETTERS ON STRATIGRAPHY
(2019)
Article
Geography, Physical
Keziah Blake-Mizen, Robert G. Hatfield, Joseph S. Stoner, Anders E. Carlson, Chuang Xuan, Maureen Walczak, Kira T. Lawrence, James E. T. Channell, Ian Bailey
QUATERNARY SCIENCE REVIEWS
(2019)
Article
Geography, Physical
J. E. T. Channell, C. Xuan, D. A. Hodell, S. J. Crowhurst, R. D. Larter
QUATERNARY SCIENCE REVIEWS
(2019)
Editorial Material
Geosciences, Multidisciplinary
John A. Tarduno, Hirokuni Oda, Yuhji Yamamoto, Chuang Xuan, Ioan Lascu, Koji Fukuma
EARTH PLANETS AND SPACE
(2019)
Article
Geochemistry & Geophysics
Chuang Xuan, Hirokuni Oda
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2019)
Article
Geosciences, Multidisciplinary
Chuang Xuan, Yuxi Jin, Saiko Sugisaki, Yasufumi Satoguchi, Yoshitaka Nagahashi
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2020)
Article
Geosciences, Multidisciplinary
Matthew D. Nichols, Chuang Xuan, Simon Crowhurst, David A. Hodell, Carl Richter, Gary D. Acton, Paul A. Wilson
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2020)
Article
Geochemistry & Geophysics
Rachael S. Avery, Chuang Xuan, Alan E. S. Kemp, Jonathan M. Bull, Carol J. Cotterill, J. James Fielding, Richard B. Pearce, Ian W. Croudace
EARTH AND PLANETARY SCIENCE LETTERS
(2017)
Article
Geochemistry & Geophysics
M. H. Walczak, J. S. Stoner, A. C. Mix, J. Jaeger, G. P. Rosen, J. E. T. Channell, D. Heslop, C. Xuan
EARTH AND PLANETARY SCIENCE LETTERS
(2017)
Article
Geosciences, Multidisciplinary
J. van Dijk, M. Ziegler, L. J. de Nooijer, G. J. Reichart, C. Xuan, E. Ducassou, S. M. Bernasconi, L. J. Lourens
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2018)