Results 41 to 50 of about 201 (152)

Can we explain the post-2015 absence of the Chandler wobble?

Earth, Planets and Space
Recent polar motion data do not show a 6-year beat and indicate the absence of the Chandler wobble (CW), whereas we could observe the 6-year beat even in the 1920-40 s when the CW amplitude was known to be smallest.
Ryuji Yamaguchi, Masato Furuya
doaj   +1 more source

Prospects of Predicting the Polar Motion Based on the Results of the Second Earth Orientation Parameters Prediction Comparison Campaign

Earth and Space Science, Volume 11, Issue 11, November 2024.
Abstract Growing interest in Earth Orientation Parameters (EOP) resulted in various approaches to the EOP prediction algorithms, as well as in the exploitation of distinct input data, including the observed EOP values from various operational data centers and modeled effective angular momentum functions.
Tomasz Kur, Justyna Śliwińska‐Bronowicz, Malgorzata Wińska, Henryk Dobslaw, Jolanta Nastula, Aleksander Partyka, Santiago Belda, Christian Bizouard, Dale Boggs, Sara Bruni, Lue Chen, Mike Chin, Sujata Dhar, Robert Dill, PengShuo Duan, Jose M. Ferrandiz, Junyang Gou, Richard Gross, Sonia Guessoum, Songtao Han, Robert Heinkelmann, ChengLi Huang, Christopher Irrgang, Jacek Kudrys, Jia Li, Marcin Ligas, Lintao Liu, Weitao Lu, Volker Mayer, Wei Miao, Maciej Michalczak, Sadegh Modiri, Michiel Otten, Todd Ratcliff, Shrishail Raut, Jan Saynisch‐Wagner, Matthias Schartner, Erik Schoenemann, Harald Schuh, M. Kiani Shahvandi, Benedikt Soja, Xiaoqing Su, Daniela Thaller, Maik Thomas, Guocheng Wang, Yuanwei Wu, CanCan Xu, Xueqing Xu, Xinyu Yang, Xin Zhao, Zhijin Zhou   +50 more
wiley   +1 more source

Revisiting the Excitation of Free Core Nutation

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 9, September 2024.
Abstract Earth possesses a Poincaré mode called Free Core Nutation (FCN) due to the misalignment of the rotation axes of the mantle and fluid outer core. FCN is the primary signal in the observations of Celestial Pole Offsets (CPO) and maintained by geophysical mechanisms that are yet to be understood. Earlier studies suggested an origin in Atmospheric
Mostafa Kiani Shahvandi, Michael Schindelegger, Lara Börger, Siddhartha Mishra, Benedikt Soja   +4 more
wiley   +1 more source

The period and Q of the Chandler wobble [PDF]

Geophysical Journal International, 1981
The calculation of the theoretical period of the Chandler wobble is extended to account for the non-hydrostatic portion of the earth's equatorial bulge and the effect of the fluid core upon the lengthening of the period due to the pole tide. The theoretical period of a realistic perfectly elastic earth with an equilibrium pole tide is found to be 426.7
Smith, Martin L., Dahlen, F. A.
openaire   +2 more sources

Improving the Accuracy of Polar Motion Prediction by Combining Least Squares and the iTransformer Model

Earth and Space Science
Polar motion prediction is an important means to study the dynamics of Earth's rotation and detect the internal structure of the Earth. This paper proposes an LS + iTransformer method that combines the least squares (LS) method with the iTransformer deep
Huizhong Zhu, Yi Yang, Chunhua Jiang, Wenfeng Nie, Zhenyu Luo, Zhangzhen Sun   +5 more
doaj   +1 more source

Chandler Wobble: Stochastic and Deterministic Dynamics [PDF]

, 2016
10 pages, 3 figures. v2: Briefly clarified incompatibility of forced resonance model with estimated quality factor, improved references, adjustments to title and abstract, change of format. Presented at the 13th International Conference, Dynamical Systems - Theory and Applications (DSTA '2015), {\L}\'od\'z, Poland, 7-10 Dec ...
openaire   +3 more sources

Evaluating the Use of Seasonal Surface Displacements and Time‐Variable Gravity to Constrain the Interior of Mars

Journal of Geophysical Research: Planets, Volume 129, Issue 6, June 2024.
Abstract The mass transport of volatiles on Mars represents a seasonally changing load on the surface of the planet. Like on Earth, as mass is redistributed across the planet, the surface responds in a complex manner becoming displaced downwards or upwards.
N. L. Wagner, P. B. James, A. I. Ermakov, M. M. Sori   +3 more
wiley   +1 more source

A pandemic of metrics

Medical Anthropology Quarterly, Volume 38, Issue 2, Page 149-163, June 2024.
Abstract The COVID‐19 pandemic prompted critical attention to the performative power of metrics. We suggest that the existential capacities of metrics as a means of pandemic living warrant further consideration. We describe how the COVID‐19 pandemic that came into existence as a public health and political event could only have occurred because of the ...
Vincanne Adams, Clare Chandler, Ann H. Kelly, Julie Livingston   +3 more
wiley   +1 more source

A Common Diffusional Mechanism for Creep and Grain Growth in Polymineralic Rocks: Application to Lower Mantle Viscosity Estimates

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 5, May 2024.
Abstract In a previous study (Okamoto & Hiraga, 2022, https://doi.org/10.1029/2022jb024638), we concluded that diffusion creep and grain growth in polymineralic rocks proceed by a common diffusional mechanism. Here, we built on that finding and estimated lower mantle grain size and viscosity during a single mantle convection cycle dominated by ...
A. Okamoto, T. Hiraga
wiley   +1 more source

Amplitude‐Dependent Energy Dissipation Inferred From Spectral Analyses of Intraslab Earthquakes

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 5, May 2024.
Abstract While the Earth (rocky planet) can be approximated as an elastic body, it also possesses anelasticity, Q−1, which causes energy dissipation (intrinsic attenuation) during deformation. Rock deformation experiments have demonstrated that Q−1 shows a marked amplitude dependency for strain of >∼10−6, but seismic‐waves‐induced strain is generally ...
Hayato Tero, Junichi Nakajima
wiley   +1 more source