Inner Core Differential Motion Confirmed by Earthquake Waveform Doublets
Abstract
We analyzed 18 high-quality waveform doublets with time separations of up to 35 years in the South Sandwich Islands region, for which the seismic signals have traversed the inner core as PKP(DF). The doublets show a consistent temporal change of travel times at up to 58 stations in and near Alaska, and they show a dissimilarity of PKP(DF) coda. Using waveform doublets avoids artifacts of earthquake mislocations and contamination from small-scale heterogeneities. Our results confirm that Earth's inner core is rotating faster than the mantle and crust at about 0.3 degrees to 0.5 degrees per year.
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The doublet measurements revisited from the three studies focusing on the SSI-Alaska path comprise 18 ddt measurements from Zhang et al. (2005), 24 from Tkalčić, Young, et al. (2013), and 31 from Yang and Song (2023).
“We revisit the doublet measurements from the three studies focusing on the SSI-Alaska path: 18 ddt measurements from Zhang et al. (2005), 24 from Tkalčić, Young, et al. (2013), and 31 from Yang and Song (2023).”
From On the Inner‐Core Differential‐Rotation (Un)Resolvability From Earthquake Doublets: The Traps of Data Selection (2024) · cites this paper as Zhang et al. (2005)
Yang and Song (2023) discarded 11 of the 18 known doublets previously used by Zhang et al. (2005), who obtained a steady eastward rotation.
“they discarded 11 of the 18 known doublets previously used by Zhang et al. (2005), who obtained a steady eastward rotation (Table S1).”
From On the Inner‐Core Differential‐Rotation (Un)Resolvability From Earthquake Doublets: The Traps of Data Selection (2024) · cites this paper as Zhang et al. (2005)
The mean for the data set including three additional doublets (representing 10% of the data) differs from the mean obtained using the 31 doublets from Yang and Song (2023).
“The mean for the data set, including three additional doublets (representing 10% of the data), differs from the mean obtained in Figure 3a.”
From On the Inner‐Core Differential‐Rotation (Un)Resolvability From Earthquake Doublets: The Traps of Data Selection (2024) · cites this paper as Zhang et al. (2005)
The three data sets overlap in that Tkalčić, Young, et al. (2013) include 17 of 18 doublets reported by Zhang et al. (2005).
“The three data sets overlap in that Tkalčić, Young, et al. (2013) include 17 of 18 doublets reported by Zhang et al. (2005).”
From On the Inner‐Core Differential‐Rotation (Un)Resolvability From Earthquake Doublets: The Traps of Data Selection (2024) · cites this paper as Zhang et al. (2005)
Cites
Seismological evidence for differential rotation of the Earth's inner core
Song, X., & Richards, P. G. (1996) · Nature · doi:10.1038/382221a0 · Cited by 445 · see citing works
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Tkalčić, H. (2024) · Geophysical Research Letters · doi:10.1029/2023gl107043 · Cited by 4 · see citing works
“The three data sets overlap in that Tkalčić, Young, et al. (2013) include 17 of 18 doublets reported by Zhang et al. (2005).”
BackgroundMethodInfluentialPattern of Inner‐Core Differential Rotation From Long‐Term Earthquake Sequences and USArray Network
Wu, K., Song, X., & Yang, Y. (2026) · Geophysical Research Letters · doi:10.1029/2025gl119295 · Cited by 2 · see citing works
“Their estimated rotation rates (relative to the mantle) vary from the order of 1 ° / Myr to 1 ° / yr (Deuss, 2014; Waszek et al., 2011; Yang & Song, 2020a, 2022; Zhang et al., 2005).”
InfluentialSelf-citation
- Authors
- Zhang, J., Song, X., Li, Y., Richards, P. G., Sun, X., & Waldhauser, F.
- Affiliations
- Lamont-Doherty Earth Observatory (US)
- Corresponding author
- Zhang, Jian
- Song, Xiaodong
- Venue
- Science
- Published
- 2005-08-26
- Volume
- 309
- Issue
- 5739
- Pages
- 1357-1360
- ISSN
- 0036-8075 (ISSN-L)
- 1095-9203
- OpenAlex
- W2007398824
- Cited by
- 149
- References
- 1
- Citations by year
- 2026: 3 · 2025: 2 · 2024: 5 · 2023: 6 · 2022: 8 · 2021: 13 · 2020: 12 · 2019: 6 · 2018: 3 · 2017: 2 · 2016: 7 · 2015: 19 · 2014: 2 · 2013: 6 · 2012: 4
- FWCI
- 11.70
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Science (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Earth and Planetary Sciences › Geophysics › High-pressure geophysics and materials
- Physical Sciences › Earth and Planetary Sciences › Geophysics › Seismic Waves and Analysis
- Physical Sciences › Earth and Planetary Sciences › Geophysics › Seismic Imaging and Inversion Techniques
- Keywords
- inner core rotation, seismic anisotropy, Earth's inner core
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