Video Experimental Relacionado
Updated: Jun 30, 2026
13:29
Electric and Magnetic Field Devices for Stimulation of Biological Tissues
Published on: May 15, 2021
El surgimiento de los Andes
Carmala N Garzione1, Gregory D Hoke, Julie C Libarkin
1Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA. garzione@earth.rochester.edu
Science (New York, N.Y.)
|June 7, 2008
Resumen
Los cambios en la elevación del cinturón montañoso ocurren rápidamente, no gradualmente. Este rápido levantamiento de la superficie es impulsado por la eliminación de la densa litosfera inferior después del engrosamiento de la corteza.
Área de la Ciencia:
- Geología Geología Geología.
- La tectónica es la tectónica.
- La geofísica es la geofísica.
Sus antecedentes:
- Los cinturones de montaña suelen elevarse gradualmente debido al acortamiento y engrosamiento de la corteza.
- Los modelos anteriores asumieron un proceso continuo de elevación para la formación de montañas.
Objetivo del estudio:
- Para investigar la dinámica de la elevación de la superficie en los cinturones montañosos.
- Desafiar la visión tradicional de la construcción gradual de las montañas.
Principales métodos:
- Análisis de datos geológicos de los Andes.
- Reconstrucción de los cambios de elevación en escalas de tiempo geológicas.
Principales resultados:
- La elevación andina se mantuvo estable durante millones de años.
- Se observaron rápidos cambios de elevación (más de 1,5 km en 1-4 millones de años).
- Los eventos de elevación son puntuados y rápidos.
Conclusiones:
- La elevación del cinturón montañoso no siempre es gradual.
- El rápido levantamiento de la superficie está relacionado con la eliminación de la densa litosfera inferior.
- Este proceso sigue al engrosamiento a largo plazo de la corteza terrestre y el manto litosférico.
Videos de Conceptos Relacionados
01:50Threats to Biodiversity
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
02:22The Colonization of Land
Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...
01:06Parallel-axis Theorem
The parallel-axis theorem provides a convenient and quick method of finding the moment of inertia of an object about an axis parallel to the axis passing through its center of mass. Consider a thin rod as an example. There is a striking similarity between the process of finding the moment of inertia of a thin rod about an axis through its middle, where the center of mass lies, and about an axis through its end using the conventional method. In the conventional method, the concept of linear mass...
01:21Upward Impending Motion
A square-threaded screw jack is a mechanical device widely used for lifting heavy loads or applying considerable force. Its operation is based on converting the force applied at its handle into a torsional moment, causing the upward impending motion of the screw. This movement is accomplished by overcoming the static friction between the threads of the screw and the jack.
To better comprehend how a screw jack functions, consider the completely unraveled thread as a block in contact with the...
To better comprehend how a screw jack functions, consider the completely unraveled thread as a block in contact with the...
01:16Perpendicular-Axis Theorem
The perpendicular-axis theorem states that the moment of inertia of a planar object about an axis perpendicular to its plane is equal to the sum of the moments of inertia about two mutually perpendicular concurrent axes lying in the plane of the body.
Consider a circular disc of mass M and radius R lying along an x-y plane. The origin lies at the center of the disc, and the z-axis is perpendicular to the disc's plane. All three axes coincide at the disc's center. The moment of inertia of this...
Consider a circular disc of mass M and radius R lying along an x-y plane. The origin lies at the center of the disc, and the z-axis is perpendicular to the disc's plane. All three axes coincide at the disc's center. The moment of inertia of this...
01:25Colonisation of Pathogens
Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...