在地球内核中存在液体的存在
1Department de Sismologie, Institut de Physique du Globe de Paris, 4 Place Jussieu-75252, Paris Cedex 05, France. Bullard Laboratories, University of Cambridge, Cambridge, CB3 0EZ, UK.
概括
地球的内核表现出地震异构性和低剪切波速度,由3-10%的液体含量解释. 这种液体,可能还有其他元素,显著影响地震波的行为,特别是剪波.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 地球科学 地球科学 地球科学
背景情况:
- 地震学研究显示,地球的内核是P波的异型.
- 内核表现出低剪切波 (S波) 速度和高地震减弱.
研究的目的:
- 为了解释地球内核中观察到的地震现象.
- 为了建模液体内含物对地震波传播的影响.
主要方法:
- 利用复合材料的有效介质理论.
- 模拟了铁晶体内形球形内含物中液体的存在.
主要成果:
- 液体包含的3-10%体积分数,在赤道上对齐,足以解释地震异构性和低S波速度.
- S波速度变化对液体的存在比P波速度变化更敏感.
结论:
- 液体的存在,可能来自非铁元素,是地球内核地震特性的一个关键因素.
- 液体内含物的对齐和形状对于理解内核地震学至关重要.
更多相关视频
14:11Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
Published on: March 29, 2016
09:18Laser-heating and Radiance Spectrometry for the Study of Nuclear Materials in Conditions Simulating a Nuclear Power Plant Accident
Published on: December 14, 2017
相关概念视频
States of Water
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
The Atomic Theory of Matter
The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers. Leucippus and Democritus argued that all matter was composed of small, finite particles that they called atomos, meaning “indivisible.” Later, Aristotle and others came to the conclusion that matter consisted of various combinations of the four “elements” — fire, earth, air, and water — and could be infinitely divided. Interestingly, these philosophers thought about atoms and “elements” as...
Nuclear Stability
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together in the...
To hold positively charged protons together in the...
Nuclear Fission
Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger binding energies per nucleon—that is, mass numbers and binding energies per nucleon that are closer to the “peak” of the binding energy graph near 56. Sometimes neutrons are also produced. This decomposition of a large nucleus into smaller pieces is called fission. The breaking is rather random with the formation of a large number of different...
Nuclear Transmutation
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...
States of Matter
Solids, liquids, and gases are the three states of matter commonly found on Earth. A solid is rigid and possesses a definite shape. A liquid flows and takes the shape of its container, except it forms a flat or slightly curved upper surface when acted upon by gravity. Both liquid and solid samples have volumes nearly independent of pressure. A gas takes both the shape and volume of its container.
Scientists have discovered a fourth state of matter, plasma, that occurs naturally in the interiors...
Scientists have discovered a fourth state of matter, plasma, that occurs naturally in the interiors...
