Video Experimental Relacionado
Updated: Jul 12, 2026

07:58
Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt
Published on: August 7, 2017
Tomografía sísmica del manto de la Tierra: implicaciones geodinámicas
Resumen
La tomografía sísmica reciente revela la Tierra como la Tierra.
Área de la Ciencia:
- Geofísica y Ciencias de la Tierra.
- Sismología Sismología.
- Dinámica del manto Dinámica del manto
Sus antecedentes:
- La convección del manto es un proceso fundamental que impulsa la tectónica de placas.
- Estudios previos han identificado plumas ascendentes a gran escala y láminas descendentes en el manto de la Tierra.
- Comprender la estructura detallada de las corrientes descendentes es crucial para un modelo completo de la convección del manto.
Objetivo del estudio:
- Para analizar los datos de tomografía sísmica para obtener información sobre los patrones de convección del manto.
- Para investigar la estructura interna detallada de las corrientes descendentes del manto.
- Aprovechar los datos sísmicos de alta resolución de Japón para estudiar el papel de la subducción de placas en la dinámica del manto.
Principales métodos:
- Análisis de datos de tomografía sísmica para mapear las estructuras del manto.
- Utilizando imágenes sísmicas de alta resolución de redes densas alrededor de Japón.
- Integrando las observaciones de la subducción de placas con modelos de convección del manto.
Principales resultados:
- Se identificó una convección del manto a gran escala con penachos ascendentes (Pacífico, África) y láminas descendentes (Circum-Pacífico).
- Se observó una extensa subida bajo el Pacífico Sur y una bajada bajo el Pacífico Oeste.
- Obtuvo imágenes de alta resolución de la subducción de placas debajo de Japón.
Conclusiones:
- La tomografía sísmica revela patrones distintos de convección del manto.
- Las densas redes sísmicas de Japón brindan una oportunidad única para estudiar las corrientes descendentes impulsadas por la subducción.
- La comprensión detallada de las corrientes descendentes es esencial para un modelo integral de la convección del manto de la Tierra.
Videos de Conceptos Relacionados
Magnetic Susceptibility and Permeability
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
Magnetostatic Boundary Conditions
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
Gravimetry: Overview
Gravimetric analysis is a quantitative method where the analyte is isolated and weighed directly or after conversion into a substance of known composition. Gravimetric analysis can be classified as precipitation, electrogravimetry, volatilization, and particulate gravimetry, based on the method used to isolate the analyte.
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...
Computed Tomography
Tomography refers to imaging by sections. Computed tomography (CT) is a non-invasive imaging technique that uses computers to analyze several cross-sectional X-rays to reveal minute details about structures in the body.
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Apparent Weight and the Earth's Rotation
Since all objects on the Earth's surface move through a circle every 24 hours, there must be a net centripetal force on each object, directed towards the center of that circle. The points of the north and south poles are the only exception to this rule.
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface. This force,...
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface. This force,...
Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...

