کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10121315 | 1641616 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Pressure and temperature dependence of elastic wave velocity of MgSiO3 perovskite and the composition of the lower mantle
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Simultaneous measurements of compressional (P) and shear (S) wave velocities and unit cell volume (density) have been conducted on MgSiO3 perovskite to 9.2Â GPa and 873Â K using ultrasonic interferometry in conjunction with X-ray diffraction. Finite strain analysis of current data allowed us to determine the elastic moduli and their pressure derivatives independent of the pressure measurement. The results are KSÂ =Â 253(2)Â GPa, GÂ =Â 173(1)Â GPa, âKS/âPÂ =Â 4.4(1) and âG/âPÂ =Â 2.0(1). The temperature derivatives of the bulk and shear moduli were tightly constrained from acoustic velocity measurements, yielding âKS/âTÂ =Â â0.021(2)Â GPa/K and âG/âTÂ =Â â0.028(2)Â GPa/K. P and S wave velocities and density profiles for a pyrolite compositional model consisting of magnesium silicate perovskite and magnesiowustite are calculated at lower mantle depths along a 1600Â K adiabatic geotherm, the results agree with those of seismic model PREM within 0.5, 0.5 and 0.3%, respectively, from 800 to â¼2600Â km. The effect of Fe and Mg partitioning between magnesium silicate perovskite and magnesiowustite on the calculated velocities and density is negligibly small compared to the effects of composition and temperature. Simultaneous constraints from P and S wave velocities and density support for a homogeneous lower mantle with pyrolitic composition.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics of the Earth and Planetary Interiors - Volume 151, Issues 1â2, 15 July 2005, Pages 143-154
Journal: Physics of the Earth and Planetary Interiors - Volume 151, Issues 1â2, 15 July 2005, Pages 143-154
نویسندگان
Baosheng Li, Jianzhong Zhang,