کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9522525 1634974 2005 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of temperature on the seismic anisotropy of the perovskite and post-perovskite polymorphs of MgSiO3
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
The effect of temperature on the seismic anisotropy of the perovskite and post-perovskite polymorphs of MgSiO3
چکیده انگلیسی
Using elastic constants determined by ab initio molecular dynamics over a range of temperatures, we show that the seismic anisotropy of MgSiO3 perovskite is significantly temperature dependent. At 90 GPa, the direction of greatest shear wave splitting changes from [001] at 0 K to [010] at 3500 K. In addition, there is no shear wave splitting in the [100] direction at 0 K, but a significant amount of splitting is exhibited at 3500 K. We have also calculated the first set of high-temperature elastic constants of the new post-perovskite phase by ab initio molecular dynamics methods. We find that, in contrast to MgSiO3 perovskite, temperature has little effect on the acoustic anisotropy of this phase. We determine ∂ln VS/∂ln VP for the post-perovskite phase and find it to be very low, about 0.9. This may be an important parameter for mapping out the post-perovskite phase in the lowermost mantle.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 230, Issues 1–2, 30 January 2005, Pages 1-10
نویسندگان
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