高圧・高温実験で,地球が収縮する中で,コアとマントルの分離を研究した
Science (New York, N.Y.)
|June 3, 1994
まとめ
地球のコアとマントルは,単純な金属・シリケート相互作用によって均衡に達しなかった可能性が高い. 実験データによると,コア-マントルの分離は,単なる基本的な化学的均衡ではなく,複雑なプロセスを含んでいる.
科学分野:
- 地質化学 地質化学
- 惑星科学は惑星科学である.
- 地球科学 地球科学 地球科学
背景:
- 地球のシリケートマントルのシデロフィール元素の観察された豊富さは,低圧と低温でコアとの均衡分割と矛盾しています.
- 提案された解決策は,核形成中の高圧と高温での均衡がこれらの豊富さを説明できると示唆しています.
研究 の 目的:
- 高圧と高温で液体金属と液体シリケート相の間のシデロフィール元素の分布を実験的に決定する.
- 地球マントルの観測されたシデロフィール元素の豊富さを説明する単純な金属・シリケート均衡の可能性を評価する.
主な方法:
- シデロフィール元素の分割の実験的決定.
- コア・マントルの境界条件を100キロバルと2000°Cでシミュレートする.
主要な成果:
- 実験結果は,高圧と高温での単純な金属シリケート均衡が,観測されたシデロフィール元素の豊富さを説明する可能性が低いことを示しています.
- シミュレートされた核形成条件下での分割行動は,単純な均衡モデルをサポートしません.
結論:
- 地球のコアとマントルの分離は,複雑なプロセスでした.
- シンプルな均衡モデルでは,コアとマントルの間の siderophile 要素の分布を説明するには不十分です.
- 代替的またはより複雑なメカニズムは,地球のコアとマントルの形成を統制した.
関連する概念動画
01:21Isothermal Processes
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
03:02Constant Pressure Calorimetry
Calorimetry is a technique used to measure the amount of heat involved in a chemical or physical process or to measure the heat transferred to or from a substance. The heat is exchanged with a calibrated and insulated device called the calorimeter. Calorimetry experiments are based on the assumption that there is no heat exchange between the insulated calorimeter and the external environment. The well-insulated calorimeters prevent the transfer of heat between the calorimeter and its external...
01:27Atomic Spectroscopy: Effects of Temperature
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
01:28The Thermodynamics of Mixing
Mixing is a fascinating phenomenon in thermodynamics, particularly when considering the Gibbs energy of a mixture at constant temperature and pressure. This energy, denoted as G, tends to decrease during spontaneous mixing processes, offering insights into the composition changes that occur.Imagine two ideal gases, initially separated in different containers, with amounts nA and nB, respectively, both at a temperature T and pressure p. The chemical potentials of these gases have their 'pure'...
01:18Adiabatic Processes for an Ideal Gas
When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its...
01:27Pressure and Volume in an Adiabatic Process
Free expansion of a gas is an adiabatic process. However, there are few differences between free expansion and adiabatic expansion. During free expansion, no work is done, and there is no change in internal energy. But, for an adiabatic expansion, work is done, and there is a change in internal energy. During an adiabatic process, the relation between the pressure and volume is obtained from the condition for the adiabatic process, that is,