A short note on the pressure-depth conversion for geophysical interpretation
A short note on the pressure-depth conversion for geophysical interpretation
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DOI：
10.1002/grl.50887
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发表时间：
2013-09-28
影响因子：
5.2
通讯作者：
Cammarano, F.
中科院分区：
文献类型：
--
作者：
Cammarano, F.
基于矿物物理学的材料特性数据库正在迅速成为解释地球物理观测的重要工具。物理特性从压力到深度的转换通常基于初步参考地球模型。我们量化此假设引入的误差。通过用推断的密度分布更新起始压力分布并迭代直至收敛（通过几个步骤即可实现）来获得校正的压力分布。我们展示两个例子。第一个与平均地震地球模型的解释有关。第二个涉及半空间冷却模型预测的海洋岩石圈二维热结构的解释。这些影响总体上很小，但对于解释很重要，因为它们是系统性的，它们具有热解释反馈，并且可以改变与突变密度和地震速度跳跃相关的预测矿物相变的位置。例如，通过改变 100 K 的潜在地幔温度，可以在 2500km 深度获得高达 0.6GPa 的变化。
Databases of material properties based on mineral physics are rapidly becoming an essential tool for interpreting geophysical observations. The conversion of physical properties from pressure to depth is usually based on preliminary reference Earth model. We quantify the error that is introduced with this assumption. The corrected pressure profile is obtained by updating the starting one with the inferred density distribution and iterating until convergence (which is attained in few steps). We show two examples. The first is related to the interpretation of average seismic Earth models. The second refers to the interpretation of a 2-D thermal structure of the oceanic lithosphere as predicted by a half-space cooling model. The effects are overall small, nevertheless important for interpretation since they are systematic, they have a feedback with thermal interpretation and they can shift the location of predicted mineralogical phase transitions that are associated with abrupt density and seismic velocity jumps. For example, variations up to 0.6GPa at 2500km depth are obtained by changing the potential mantle temperature of 100 K.