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Documental: Desastre en el golfo de México

[Discovery Channel] Desastre en el golfo de México

Discovery Channel ofrece una mirada detrás de cámaras a los esfuerzos de ingeniería que se realizan para detener el flujo de petróleo en las profundidades del Golfo de México, hecho que ya es considerado como la peor catástrofe ambiental en la historia de los Estados Unidos.

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Dentro del Planeta Tierra

El 71% de la superficie de la Tierra está cubierta por agua. Es el único planeta del sistema solar donde un líquido (agua) puede permanecer en estado sólido, líquido o gaseoso en la superficie. El agua ha sido esencial para la vida. Es uno de los dos cuerpos rocosos del sistema solar donde hay precipitaciones como lluvia, siendo el otro Titán.

La Tierra es el único de los cuerpos del Sistema Solar que presenta una tectónica de placas activa; Marte y Venus quizás tuvieron una tectónica de placas en otros tiempos pero, en todo caso, se ha detenido.

La Tierra tiene una estructura compuesta por cuatro grandes zonas o capas: la geosfera, la hidrosfera, la atmósfera y la biosfera. Estas capas poseen diferentes composiciones químicas y comportamiento geológico. Su naturaleza puede estudiarse a partir de la propagación de ondas sísmicas en el interior terrestre y a través de las medidas de los diferentes momentos gravitacionales de las distintas capas obtenidas por diferentes satélites orbitales.

Los geólogos han diseñado dos modelos geológicos que establecen una división de la estructura terrestre, el modelo geostático y el modelo geodinámico.

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Earth Science

The American Geological Institute (AGI) is a nonprofit federation of 45 geoscientific and professional associations that represents more than 120,000 geologists, geophysicists, and other earth scientists.

Founded in 1948, AGI provides information services to geoscientists, serves as a voice of shared interests in our profession, plays a major role in strengthening geoscience education, and strives to increase public awareness of the vital role the geosciences play in society’s use of resources, resilience to natural hazards, and the health of the environment.

• http://www.agiweb.org/

Earth science (also known as geoscience, the geosciences or the Earth sciences), is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth science.

There are four major disciplines in earth sciences, namely geography, geology, geophysics and geodesy. These major disciplines use physics, chemistry, biology, chronology and mathematics to build a quantitative understanding of the principal areas or spheres of the Earth system.

The following fields of science are generally categorized within the geosciences:

- Geology describes the rocky parts of the Earth’s crust (or lithosphere) and its historic development. Major subdisciplines are mineralogy and petrology, geochemistry, geomorphology, paleontology, stratigraphy, structural geology, engineering geology and sedimentology.

- Geophysics and Geodesy investigate the figure of the Earth, its reaction to forces and its magnetic and gravity fields. Geophysicists explore the Earth’s core and mantle as well as the tectonic and seismic activity of the lithosphere.

- Soil science covers the outermost layer of the Earth’s crust that is subject to soil formation processes (or pedosphere). Major subdisciplines include edaphology and pedology.

- Oceanography and hydrology (includes limnology) describe the marine and freshwater domains of the watery parts of the Earth (or hydrosphere). Major subdisciplines include hydrogeology and physical, chemical, and biological oceanography.

- Glaciology covers the icy parts of the Earth (or cryosphere).

- Atmospheric sciences cover the gaseous parts of the Earth (or atmosphere) between the surface and the exosphere (about 1000 km). Major subdisciplines are meteorology, climatology, atmospheric chemistry and atmospheric physics.

- A very important linking sphere is the biosphere, the study of which is biology. The biosphere consists of all forms of life, from single-celled organisms to pine trees to people. The interactions of Earth’s other spheres – lithosphere/geosphere, hydrosphere, atmosphere and/or cryosphere and pedosphere – create the conditions that can support life.