地震层析成像怎样给地球内部做CT？
How does seismic tomography make a CT scan of Earth's interior?
利用全球地震波穿过地球的速度差异，反演出地幔冷热不均的结构，揭示地幔柱、俯冲板片和下地幔结构。
Using how seismic waves speed through Earth, it inverts images of warm and cold mantle, revealing plumes, slabs and deep-mantle structure.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#层析成像 #地幔
地球内核与外核在物理状态和成分上有何本质区别？
What are the essential differences in physical state and composition between Earth's inner and outer core?
外核为液态铁镍合金并含少量轻元素（如硫、氧、硅），能流动产生磁场；内核在相同高温高压下因压力更高而呈固态，成分以铁为主并富镍。内外核的相态差异由铁的高压相图与绝热温度梯度共同决定。
The outer core is a liquid iron-nickel alloy with minor light elements (sulfur, oxygen, silicon) that can flow and generate the field, while the inner core is solid under even higher pressure, composed mainly of iron with nickel. The phase difference is set by iron's high-pressure phase diagram together with the adiabatic temperature gradient.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Press & Siever,《Understanding Earth》W. H. Freeman 多版
F. Press and R. Siever, Understanding Earth, W. H. Freeman, various editions
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL1282939W：Understanding earth（按标题
#内核 #外核 #铁相图
地球内核相对于地幔是否存在差异旋转，如何被探测？
Does Earth's inner core rotate differentially relative to the mantle, and how is it detected?
地震波穿过内核时，其走时与波形在数十年尺度上呈现细微变化，被解释为内核以每年约0.2至0.3度的速率相对地幔向东超速旋转（也存在周期性振荡的争议）。探测依赖重复地震在相近路径上记录的核震相（如PKIKP）差异。
Seismic waves traversing the inner core show subtle, decadal changes in travel time and waveform, interpreted as the inner core spinning slightly faster than the mantle, roughly 0.2 to 0.3 degrees per year eastward, though a periodic oscillation is also debated. Detection relies on repeating earthquakes recorded along similar ray paths, comparing core phases such as PKIKP.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Song,《Joint inversion for inner core rotation, inner core anisotropy, and mantle heterogeneity》,Journal of Geophysical Research: Solid Earth,2000 (DOI: 10.1029/1999jb900436)
Song, 'Joint inversion for inner core rotation, inner core anisotropy, and mantle heterogeneity', Journal of Geophysical Research: Solid Earth, 2000, DOI: 10.1029/1999jb900436
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1029/1999jb900436
#内核超速旋转 #地震波 #PKIKP
深海钻探计划（如IODP）在研究什么？
What does deep-sea drilling (e.g. IODP) study?
用钻探船取海底岩芯，读取古海洋与古气候、检验海底扩张和俯冲，并探寻地下深部生物圈与资源。
Drillships recover seafloor cores to read paleo-ocean and climate, test seafloor spreading and subduction, and probe the deep biosphere and resources.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#深海钻探 #IODP
地球磁场是如何由地核运动产生并维持的？
How is Earth's magnetic field generated and sustained by motions in the core?
地球外核由液态铁镍组成，其导电流体在地球自转与热、成分对流驱动下发生大规模环流，切割原有磁场并感应出电流，形成自我维持的「自激发电机」效应。该过程由磁流体动力学方程描述，外核对流能量主要来自内核结晶释放的潜热与轻元素上浮。
Earth's outer core is made of liquid iron-nickel; its electrically conducting fluid circulates on a large scale driven by planetary rotation and thermal or compositional convection, cutting existing magnetic field lines and inducing currents that self-sustain a dynamo. The process is governed by magnetohydrodynamic equations, and its convection is powered mainly by latent heat from inner-core freezing and rising light elements.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Press & Siever,《Understanding Earth》W. H. Freeman 多版
F. Press and R. Siever, Understanding Earth, W. H. Freeman, various editions
独立核验依据 · Independent verification: 核验依据 2 OPENLIBRARY 标识 /works/OL1282939W：Understanding earth（按标题
#地磁发电机 #地球内核 #磁流体动力学
日长为何会有十年尺度的起伏？这类变化如何用于研究地球深部核幔相互作用？
Why does the length of day wobble on decadal timescales, and how are such variations used to study deep core-mantle interaction?
角动量守恒将地球各圈层的自转联系在一起。大气和海洋的扰动能解释季节性日长变化，但十年尺度的起伏主要源自液态外核与地幔之间的角动量交换：核幔边界上的电磁力与地形耦合力矩拖曳地幔，让固体地球时快时慢，体现为毫秒级日长变化。把天文测时序列与地磁记录对比，可以估算耦合力矩，进而约束核幔边界的导电性与流动状态。
Conservation of angular momentum links the rotation of Earth's layers. Atmospheric and oceanic torques account for seasonal length-of-day changes, but decadal undulations stem mainly from angular-momentum exchange between the fluid outer core and the mantle: electromagnetic and topographic torques at the core-mantle boundary tug on the mantle, alternately spinning the solid planet faster and slower by milliseconds. Comparing astro-geodetic time series with geomagnetic records estimates the coupling torque and constrains conductivity and flow at the boundary.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
R. Holme & O. de Viron，《日长十年际变化的特征与意义》，Nature 499卷，2013年，202-204页，DOI:10.1038/nature12282
R. Holme & O. de Viron, "Characterization and implications of intradecadal variations in length of day", Nature 499, 202-204 (2013), DOI:10.1038/nature12282
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1038/nature12282：Characterization and imp
#日长 #角动量守恒 #核幔边界 #地球自转
地幔对流与板块运动之间存在怎样的因果关系？
What is the causal relationship between mantle convection and plate motions?
地幔因核幔边界受热而升温上浮、在岩石圈下方冷却下沉，形成热对流环，这种黏性流动对岩石圈板块施加拖曳与推动。板块在洋中脊张裂、在海沟俯冲下沉，其运动速率（每年数厘米）与地幔对流模式高度相关。
The mantle warms near the core-mantle boundary, rises, cools beneath the lithosphere, and sinks, forming thermal convection cells whose viscous drag both pulls and pushes the overlying tectonic plates. Plates diverge at mid-ocean ridges and subduct at trenches at rates of a few centimeters per year, closely tracking mantle flow patterns.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#地幔对流 #板块运动 #热对流
岩石圈与软流圈的分界基于什么物理特性？
On what physical property is the boundary between the lithosphere and asthenosphere based?
岩石圈是刚性、能传递弹性波的低温外层，软流圈则是部分熔融、力学强度低、可发生缓慢黏性流动的塑性层。两者边界主要由温度达到部分熔融阈值和岩石流变性质突变决定，深度通常在大陆约100至200公里、大洋更浅。
The lithosphere is the rigid, cool outer shell that transmits elastic seismic waves, whereas the asthenosphere is a partially molten, mechanically weak layer that flows viscously over long times. Their boundary is mainly defined by the onset of partial melting and a sharp change in rock rheology, typically at 100 to 200 km depth beneath continents and shallower under oceans.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#岩石圈 #软流圈 #流变
俯冲带如何将冷的岩石圈板块送回地幔？
How do subduction zones return cold lithospheric plates into the mantle?
在汇聚板块边界，密度较大的大洋岩石圈俯冲到另一板块之下，沿贝尼奥夫带沉入地幔；冷的板片下沉驱动地幔对流并引发深海沟、火山弧与强震。俯冲也是地幔物质和挥发分循环的关键通道。
At convergent boundaries, the denser oceanic lithosphere dives beneath another plate along the Benioff zone into the mantle; the cold slab's sinking drives mantle flow and produces deep trenches, volcanic arcs, and large earthquakes. Subduction is also a key conduit for recycling mantle material and volatiles.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#俯冲带 #贝尼奥夫带 #火山弧
为什么夏威夷群岛会呈现链状分布的火山？
Why do the Hawaiian Islands form a chain of volcanoes?
夏威夷位于太平洋板块缓慢移动经过地幔柱（热点）之上，炽热地幔物质在此上涌形成火山；随着板块持续西北向移动，新的火山在热点处生成、旧的被带离，于是排成西北—东南向的火山链。这是板块运动叠加深部固定热点的典型证据。
Hawaii sits where the Pacific Plate slowly moves over a relatively fixed upwelling of hot mantle called a mantle plume; volcanism builds a volcano above the plume, and as the plate drifts northwest, new volcanoes form while old ones are carried away, producing a chain. The pattern is classic evidence of plate motion over a deep, stationary hotspot.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#热点 #地幔柱 #火山链
地球磁场在地质历史上发生过什么变化？
What changes has Earth's magnetic field undergone in geologic history?
岩石中的磁性矿物在冷却时记录下当时磁场方向，显示地球磁场在数百万年尺度上多次发生南北极倒转，两次倒转间隔从数万到数百万年不等。最近一次倒转（布容-松山倒转）约发生在78万年前，倒转期间磁场减弱但不会消失。
Magnetic minerals in cooling rocks lock in the field direction of their time, showing that Earth's magnetic poles have flipped many times over millions of years, with reversals separated by tens of thousands to millions of years. The most recent (Brunhes-Matuyama) occurred about 780,000 years ago; during a reversal the field weakens but does not vanish.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
舒良树 主编,《普通地质学》第3版(曾获全国首届优秀教材一等奖)
Shu Liangshu ed., General Geology, 3rd ed. (winner of the 1st National Excellent Textbook Award)
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787116123892（豆瓣书目条目: 普通地质学）
#地磁倒转 #古地磁 #磁极
地震层析成像揭示的非洲与太平洋下方的大型低剪切波速省是什么？它们对认识地幔结构与动力学有什么意义？
What are the large low-shear-velocity provinces beneath Africa and the Pacific revealed by seismic tomography, and why do they matter for understanding mantle structure and dynamics?
大型低剪切波速省是核幔边界之上两个近乎对跖的巨型低速区，厚可达千余公里、绵延数千公里。剪切波明显减慢而压缩波变化较小，说明除高温外还存在成分异常，可能与富铁的布里奇曼石有关。它们被视为长期稳定的热化学堆，锚定深部地幔柱的根部；统计显示许多热点火山的投影恰落在其边缘陡峭的速度梯度带上。
Large low-shear-velocity provinces are two nearly antipodal giant slow zones atop the core-mantle boundary, up to about 1,000 km thick and thousands of kilometres across. Shear waves slow far more than compressional waves, implying compositional anomalies beyond heat alone, possibly iron-rich bridgmanite. They behave as long-lived thermochemical piles that anchor deep-plume roots, and statistics place the projections of many hotspot volcanoes on their steep marginal velocity gradients.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Garnero, E. J. 与 McNamara, A. K.：《地球下地幔的结构与动力学》，《科学》（Science），2008年，320卷626–628页
Garnero, E. J. and McNamara, A. K., 'Structure and dynamics of Earth's lower mantle', Science, 2008, vol. 320, pp. 626-628
独立核验依据 · Independent verification: 核验依据 1 EUROPEPMC 标识 18451293：Structure and dynamics of Earth's
#大型低剪切波速省 #地幔层析成像 #核幔边界