Equation of state of NaMgF3 postperovskite: Implication for the seismic velocity changes in the D″ region

Justin Hustoft; Krystle Catalli; Sang Heon Shim; Atsushi Kubo; Vitali B. Prakapenka; Martin Kunz

doi:10.1029/2008GL034042

Equation of state of NaMgF₃ postperovskite: Implication for the seismic velocity changes in the D″ region

Justin Hustoft, Krystle Catalli, Sang Heon Shim, Atsushi Kubo, Vitali B. Prakapenka, Martin Kunz

Research output: Contribution to journal › Article › peer-review

27 Scopus citations

Abstract

Recent first-principles calculations have proposed that bulk sound speed (V_φ) decreases at the perovskite (Pv) → postperovskite (PPv) transition. Yet some measurements suggest an increase in V_φ at the PPv transition in (Mg,Fe)SiO₃ and NaMgF₃. Our new measurements on NaMgF₃ up to 50 GPa under quasi-hydrostatic stress conditions reveal that the V_φ of PPv remains lower than that of Pv near the PPv transition, consistent with a first-principles study on NaMgF₃. Combined with similar observations in (Mg,Fe)SiP₃, MgGeO₃, and CaIrO₃, our result on NaMgF₃ suggests that the V_φ decrease is a robust trend in the PPv transition and is controlled more by crystal structure than by chemical composition. Our finding also strengthens the proposal that the elastic properties of PPv can explain the small P-wave increase across the D″ discontinuity and the anticorrelation between the V_φ and S-wave velocity anomalies in the D″ region.

Original language	English (US)
Article number	L10309
Journal	Geophysical Research Letters
Volume	35
Issue number	10
DOIs	https://doi.org/10.1029/2008GL034042
State	Published - May 28 2008
Externally published	Yes

ASJC Scopus subject areas

Geophysics
General Earth and Planetary Sciences

Access to Document

10.1029/2008GL034042

Cite this

@article{128d18fa9de64de9865a739d9d811db3,

title = "Equation of state of NaMgF3 postperovskite: Implication for the seismic velocity changes in the D″ region",

abstract = "Recent first-principles calculations have proposed that bulk sound speed (Vφ) decreases at the perovskite (Pv) → postperovskite (PPv) transition. Yet some measurements suggest an increase in Vφ at the PPv transition in (Mg,Fe)SiO3 and NaMgF3. Our new measurements on NaMgF3 up to 50 GPa under quasi-hydrostatic stress conditions reveal that the Vφ of PPv remains lower than that of Pv near the PPv transition, consistent with a first-principles study on NaMgF3. Combined with similar observations in (Mg,Fe)SiP3, MgGeO3, and CaIrO3, our result on NaMgF3 suggests that the Vφ decrease is a robust trend in the PPv transition and is controlled more by crystal structure than by chemical composition. Our finding also strengthens the proposal that the elastic properties of PPv can explain the small P-wave increase across the D″ discontinuity and the anticorrelation between the Vφ and S-wave velocity anomalies in the D″ region.",

author = "Justin Hustoft and Krystle Catalli and Shim, {Sang Heon} and Atsushi Kubo and Prakapenka, {Vitali B.} and Martin Kunz",

year = "2008",

month = may,

day = "28",

doi = "10.1029/2008GL034042",

language = "English (US)",

volume = "35",

journal = "Geophysical Research Letters",

issn = "0094-8276",

publisher = "American Geophysical Union",

number = "10",

}

TY - JOUR

T1 - Equation of state of NaMgF3 postperovskite

T2 - Implication for the seismic velocity changes in the D″ region

AU - Hustoft, Justin

AU - Catalli, Krystle

AU - Shim, Sang Heon

AU - Kubo, Atsushi

AU - Prakapenka, Vitali B.

AU - Kunz, Martin

PY - 2008/5/28

Y1 - 2008/5/28

N2 - Recent first-principles calculations have proposed that bulk sound speed (Vφ) decreases at the perovskite (Pv) → postperovskite (PPv) transition. Yet some measurements suggest an increase in Vφ at the PPv transition in (Mg,Fe)SiO3 and NaMgF3. Our new measurements on NaMgF3 up to 50 GPa under quasi-hydrostatic stress conditions reveal that the Vφ of PPv remains lower than that of Pv near the PPv transition, consistent with a first-principles study on NaMgF3. Combined with similar observations in (Mg,Fe)SiP3, MgGeO3, and CaIrO3, our result on NaMgF3 suggests that the Vφ decrease is a robust trend in the PPv transition and is controlled more by crystal structure than by chemical composition. Our finding also strengthens the proposal that the elastic properties of PPv can explain the small P-wave increase across the D″ discontinuity and the anticorrelation between the Vφ and S-wave velocity anomalies in the D″ region.

AB - Recent first-principles calculations have proposed that bulk sound speed (Vφ) decreases at the perovskite (Pv) → postperovskite (PPv) transition. Yet some measurements suggest an increase in Vφ at the PPv transition in (Mg,Fe)SiO3 and NaMgF3. Our new measurements on NaMgF3 up to 50 GPa under quasi-hydrostatic stress conditions reveal that the Vφ of PPv remains lower than that of Pv near the PPv transition, consistent with a first-principles study on NaMgF3. Combined with similar observations in (Mg,Fe)SiP3, MgGeO3, and CaIrO3, our result on NaMgF3 suggests that the Vφ decrease is a robust trend in the PPv transition and is controlled more by crystal structure than by chemical composition. Our finding also strengthens the proposal that the elastic properties of PPv can explain the small P-wave increase across the D″ discontinuity and the anticorrelation between the Vφ and S-wave velocity anomalies in the D″ region.

UR - http://www.scopus.com/inward/record.url?scp=54049106135&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=54049106135&partnerID=8YFLogxK

U2 - 10.1029/2008GL034042

DO - 10.1029/2008GL034042

M3 - Article

AN - SCOPUS:54049106135

SN - 0094-8276

VL - 35

JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 10

M1 - L10309

ER -

Equation of state of NaMgF₃ postperovskite: Implication for the seismic velocity changes in the D″ region

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this