![]() ![]() Torsional magnetohydrodynamic vibrations in the Earth’s core and variations in day length. Inner core rotation captured by earthquake doublets and twin stations. Seismological observation of Earth’s oscillating inner core. The shuffling rotation of the Earth’s inner core revealed by earthquake doublets. Tkalčić, H., Young, M., Bodin, T., Ngo, S. An Introduction to the Bootstrap (Chapman and Hall/CRC, 1994). Two decades of temporal change of Earth’s inner core boundary. Topography of Earth’s inner core boundary from high-quality waveform doublets. Short wavelength topography on the inner-core boundary. Wide-scale detection of earthquake waveform doublets and further evidence for inner core super-rotation. Earth’s inner core rotation, 1971 to 1974, illuminated by inner-core scattered waves. Reply to Yao et al.’s comment on “Origin of temporal changes of inner-core seismic waves”. Origin of temporal changes of inner-core seismic waves. Comment on “Origin of temporal changes of inner-core seismic waves” by Yang and Song (2020). Temporal change of seismic Earth’s inner core phases: inner core differential rotation or temporal change of inner core surface? J. Localized temporal change of the Earth’s inner core boundary. Monitoring velocity variations in the crust using earthquake doublets: an application to the Calaveras Fault, California. Temporal changes of the inner core from globally distributed repeating earthquakes. Inner core differential motion confirmed by earthquake waveform doublets. Slow differential rotation of the Earth’s inner core indicated by temporal changes in scattering. ![]() Seismological evidence for differential rotation of the Earth’s inner core. The strength of gravitational core–mantle coupling. Control of inner core rotation by electromagnetic, gravitational and mechanical torques. Gravitational braking of inner-core rotation in geodynamo simulations. A comparison of geodetic and seismic estimates of inner-core rotation. Gravitational oscillations in the length of day. Tomographic inversion for three-dimensional anisotropy of Earth’s inner core. Hemispherical variations in seismic velocity at the top of the Earth’s inner core. Degree one heterogeneity and hemispherical variation of anisotropy in the inner core from PKP(BC)–PKP(DF) times. Irregular transition layer beneath the earth’s inner core boundary from observations of antipodal PKIKP and PKIIKP waves. Joint inversion for inner core rotation, inner core anisotropy, and mantle heterogeneity. Inner core rotation rate from small-scale heterogeneity and time-varying travel times. Fine-scale heterogeneity in the Earth’s inner core. Rotation and magnetism of Earth’s inner core. A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle. These observations provide evidence for dynamic interactions between the Earth’s layers, from the deepest interior to the surface, potentially due to gravitational coupling and the exchange of angular momentum from the core and mantle to the surface.īuffett, B. This multidecadal periodicity coincides with changes in several other geophysical observations, especially the length of day and magnetic field. We compared this recent pattern to the Alaskan seismic records of South Sandwich Islands doublets going back to 1964 and it seems to be associated with a gradual turning-back of the inner core relative to the mantle as a part of an approximately seven-decade oscillation, with another turning point in the early 1970s. ![]() This globally consistent pattern suggests that differential inner-core rotation has recently paused. Here we analyse repeated seismic waves from the early 1990s and show that all of the paths that previously showed significant temporal changes have exhibited little change over the past decade. This rotation has been inferred from temporal changes between repeated seismic waves that should traverse the same path through the inner core. Differential rotation of Earth’s inner core relative to the mantle is thought to occur under the effects of the geodynamo on core dynamics and gravitational core–mantle coupling. ![]()
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