AL VUELO DE UN QUINDE EL BLOG

domingo, 29 de abril de 2012

Warm Ocean Currents Cause Majority of Ice Loss from Antarctica

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., Warm ocean currents attacking the underside of ice shelves are the dominant cause of recent ice loss from Antarctica, a new study using measurements from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) revealed.

Warm Ocean Currents Cause Majority of Ice Loss from Antarctica :

WASHINGTON -- Warm ocean currents attacking the underside of ice shelves are the dominant cause of recent ice loss from Antarctica, a new study using measurements from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) revealed.

An international team of scientists used a combination of satellite measurements and models to differentiate between the two known causes of melting ice shelves: warm ocean currents thawing the underbelly of the floating extensions of ice sheets and warm air melting them from above. The finding, published today in the journal Nature, brings scientists a step closer to providing reliable projections of future sea level rise.

The researchers concluded 20 of the 54 ice shelves studied are being melted by warm ocean currents. Most of these are in West Antarctica, where inland glaciers flowing down to the coast and feeding into these thinning ice shelves have accelerated, draining more ice into the sea and contributing to sea-level rise. This ocean-driven thinning is responsible for the most widespread and rapid ice losses in West Antarctica and the majority of Antarctic ice sheet loss during the period studied.

"We can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt," said the study's lead author Hamish Pritchard of the British Antarctic Survey in Cambridge, United Kingdom. "The oceans can do all the work from below."

To map the changing thickness of almost all the floating ice shelves around Antarctica, the team used a time series of 4.5 million surface height measurements taken by a laser instrument mounted on ICESat from October 2003 to October 2008. They measured how the ice shelf height changed over time and ran computer models to discard changes in ice thickness because of natural snow accumulation and compaction. The researchers also used a tide model that eliminated height changes caused by tides raising and lowering the ice shelves.

"This study demonstrates the power of space-based, laser altimetry for understanding Earth processes," said Tom Wagner, cryosphere program scientist at NASA Headquarters in Washington." Coupled with NASA's portfolio of other ice sheet research using data from our GRACE mission, satellite radars and aircraft, we get a comprehensive view of ice sheet change that improves estimates of sea level rise."

Previous studies used satellite radar data to measure the evolution of ice shelves and glaciers, but laser measurements are more precise in detecting changes in ice shelf thickness through time. This is especially true in coastal areas. Steeper slopes at the grounding line, where floating ice shelves connect with the landmass, cause problems for lower-resolution radar altimeters.

ICESat was the first satellite specifically designed to use laser altimetry to study the Earth's polar regions. It operated from 2003 to 2009. Its successor, ICESat-2, is scheduled for launch in 2016.

"This study demonstrates the urgent need for ICESat-2 to get into space," said Jay Zwally, ICESat project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "We have limited information on the changes in polar regions caused by climate change. Nothing can look at these changes like satellite measurements do."

The new research also links the observed increase in melting that occurs on the underside of a glacier or ice shelf, called basal melt, and glacier acceleration with changes in wind patterns.

"Studies have shown Antarctic winds have changed because of changes in climate," Pritchard said. "This has affected the strength and direction of ocean currents. As a result warm water is funnelled beneath the floating ice. These studies and our new results suggest Antarctica's glaciers are responding rapidly to a changing climate."

A different picture is seen on the Antarctic Peninsula, the long stretch of land pointing towards South America. The study found thinning of the largest ice shelf on the peninsula can be explained by warm summer winds directly melting the snow on the ice shelf surfaces. The patterns of widespread ocean-driven melting and summer melting on the Antarctic Peninsula can be attributed to changing wind patterns.

The study was carried out by an international team from the British Antarctic Survey, Utrecht University in Utrecht, Netherlands, the University of California in San Diego and the non-profit research institute Earth and Space Research in Corvallis, Ore.

For more information, a visualization and related imagery, visit:
http://www.nasa.gov/topics/earth/features/currents-ice-loss.html Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com

For more information about ICESat and ICESat-2, visit:
http://icesat.gsfc.nasa.gov/

domingo, 25 de marzo de 2012

Astronomy: Cassini Mission Receives Air and Space Museum Award

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., The Smithsonian's National Air and Space Museum has bestowed its highest group honor, the Trophy for Current Achievement, on NASA's Cassini mission to Saturn. The annual award recognizes outstanding achievements in the fields of aerospace science and technology.

National Air and Space Museum Award for Cassini-Huygens
NASA's Cassini-Huygens mission to Saturn was awarded the 2012 National Air and Space Museum Trophy for Current Achievement on March 21 at a black-tie dinner in Washington, D.C. Pictured (from left to right) - Wayne Clough, secretary of the Smithsonian; Robert Mitchell, Cassini program manager based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and Gen. Jack Dailey, director of the museum.

Image credit: Smithsonian National Air and Space Museum

Cassini Mission Receives Air and Space Museum Award.

PASADENA, Calif. -- The Smithsonian's National Air and Space Museum has bestowed its highest group honor, the Trophy for Current Achievement, on NASA's Cassini mission to Saturn. The annual award recognizes outstanding achievements in the fields of aerospace science and technology.
The trophy was presented Wednesday, March 21, during an evening ceremony at the museum in Washington. Established in 1985, the award has been presented to seven NASA planetary mission teams.
"This joint mission has produced an unprecedented science return," said William Knopf, Cassini program executive at NASA Headquarters in Washington. "Missions like Cassini pave the way for future robotic and human exploration throughout our solar system and beyond."
Launched in 1997, the Cassini spacecraft entered Saturn's orbit in June 2004 with the European Space Agency's (ESA) Huygens probe bolted to its side. In December 2004, the spacecraft successfully released Huygens, which entered the atmosphere of Saturn's largest moon, Titan. Cassini completed its prime mission in 2008 and has been extended twice. It is now in its so-called solstice mission, which will enable scientists to observe seasonal changes in Saturn and its moons during the planet's northern summer solstice. The mission will last through September 2017.
"We look forward to sailing around the Saturn system for several more years to see how our views of the planet and its magnificent moons change as we get into northern summer solstice," said Robert Mitchell, the Cassini program manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who accepted the award on behalf of the team.
The Cassini spacecraft carries 12 science instruments and investigations, with an additional six aboard Huygens. Cassini mission highlights to date include the discovery of four new moons and two new rings around Saturn. Cassini observed spraying water vapor and icy particle jets from the moon Enceladus. In Saturn's northern hemisphere, the spacecraft watched the evolution of a monster storm, a sign of seasonal change from northern winter into northern spring.
Cassini and Huygens has also revealed new characteristics about Titan, the only body in the solar system other than Earth with stable liquid on its surface.
The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. JPL is managed for NASA by the California Institute of Technology in Pasadena.
For more information about the mission,

visit: http://www.nasa.gov/cassini
Images of the award and a Cassini historical video are available

at: http://go.nasa.gov/GH6qbA
For a full listing of previous awardees,

visit: http://www.nasm.si.edu/research/aero/trophy/nasm.cfm
More Cassini information is available at and http://saturn.jpl.nasa.gov .

Guillermo Gonzalo Sánchez Achutegui

visit:
http://www.nasa.gov/mission_pages/spitzer/news/spitzer20100722.html
and
http://www.nasa.gov/mission_pages/spitzer/news/spitzer20101027.html

miércoles, 22 de febrero de 2012

Astronomy: NASA'S Spitzer Finds Solid Buckyballs in Space

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., Astronomers using data from NASA's Spitzer Space Telescope have, for the first time, discovered buckyballs in a solid form in space. Prior to this discovery, the microscopic carbon spheres had been found only in gas form. Formally named buckminsterfullerene, buckyballs are named after their resemblance to the late architect Buckminster Fuller's geodesic domes. They are made up of 60 carbon molecules arranged into a hollow sphere, like a soccer ball. Their unusual structure makes them ideal candidates for electrical and chemical applications on Earth, including superconducting materials, medicines, water purification and armor.

Space Balls
NASA's Spitzer Space Telescope has at last found buckyballs in space, as illustrated by this artist's conception showing the carbon balls coming out from the type of object where they were discovered -- a dying star and the material it sheds, known as a planetary nebula.

Buckyballs are made up of 60 carbon atoms organized into spherical structures that resemble soccer balls. They also look like Buckminister Fuller's architectural domes, hence their official name of buckministerfullerenes. The molecules were first concocted in a lab nearly 25 years ago, and were theorized at that time to be floating around carbon-rich stars in space.

But it wasn't until now that Spitzer, using its sensitive infrared vision, was able to find convincing signs of buckyballs. The telescope found the molecules -- as well as their elongated, rugby-ball-like relatives, called C70 -- in the material around a dying star, or planetary nebula, called Tc 1. The star at the center of Tc 1 was once similar to our sun but as it aged, it sloughed off its outer layers, leaving only a dense white-dwarf star. Astronomers believe buckyballs were created in shed layers of carbon that blew off the star. Tc 1 does not show up that well in images, so a picture of the NGC 2440 nebula, taken by NASA's Hubble Space Telescope, was used in this artist's conception.

Image credit: NASA/JPL-Caltech Hubble image credit: NASA, ESA, STScI

Jiggling Soccer-Ball Molecules in Space
These data from NASA's Spitzer Space Telescope show the signatures of buckyballs in space. Buckyballs, also called C60 or buckministerfullerenes, after architect Buckminister Fuller's geodesic domes, are made of 60 carbon atoms structured like a black-and-white soccer ball. They were first discovered in a lab in 1985, but could not be definitively identified in space until now. Spitzer was able to find their spectral signatures -- along with the signatures of their rugby-ball-like relatives, called C70 -- by analyzing the infrared light from Tc 1, a planetary nebula consisting of material shed by a dying star.

Buckyballs jiggle, or vibrate, in a variety of ways -- 174 ways to be exact. Four of these vibrational modes cause the molecules to either absorb or emit infrared light. All four modes were detected by Spitzer.

The space telescope first gathered light from the area around the dying star -- specifically a region rich in carbon -- then, with the help of its spectrograph instrument, spread the light into its various components, or wavelengths. Astronomers studied the data, a spectrum like the one shown here, to identify signatures, or fingerprints, of molecules. The four vibrational modes of buckyballs are indicated by the red arrows. Likewise, Spitzer identified four vibrational modes of C70, shown by the blue arrows.

Image credit: NASA/JPL-Caltech/University of Western Ontario

NASA'S Spitzer Finds Solid Buckyballs in Space

WASHINGTON -- Astronomers using data from NASA's Spitzer Space Telescope have, for the first time, discovered buckyballs in a solid form in space. Prior to this discovery, the microscopic carbon spheres had been found only in gas form.

Formally named buckminsterfullerene, buckyballs are named after their resemblance to the late architect Buckminster Fuller's geodesic domes. They are made up of 60 carbon molecules arranged into a hollow sphere, like a soccer ball.

Their unusual structure makes them ideal candidates for electrical and chemical applications on Earth, including superconducting materials, medicines, water purification and armor. In the latest discovery, scientists using Spitzer detected tiny specks of matter, or particles, consisting of stacked buckyballs.

They found them around a pair of stars called "XX Ophiuchi," 6,500 light-years from Earth. "These buckyballs are stacked together to form a solid, like oranges in a crate," said Nye Evans of Keele University in England, lead author of a paper appearing in the Monthly Notices of the Royal Astronomical Society.

"The particles we detected are miniscule, far smaller than the width of a hair, but each one would contain stacks of millions of buckyballs." Buckyballs were detected definitively in space for the first time by Spitzer in 2010. Spitzer later identified the molecules in a host of different cosmic environments. It even found them in staggering quantities, the equivalent in mass to 15 Earth moons, in a nearby galaxy called the Small Magellanic Cloud. In all of those cases, the molecules were in the form of gas.

The recent discovery of buckyballs particles means that large quantities of these molecules must be present in some stellar environments in order to link up and form solid particles. The research team was able to identify the solid form of buckyballs in the Spitzer data because they emit light in a unique way that differs from the gaseous form.

"This exciting result suggests that buckyballs are even more widespread in space than the earlier Spitzer results showed," said Mike Werner, project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"They may be an important form of carbon, an essential building block for life, throughout the cosmos." Buckyballs have been found on Earth in various forms. They form as a gas from burning candles and exist as solids in certain types of rock, such as the mineral shungite found in Russia, and fulgurite, a glassy rock from Colorado that forms when lightning strikes the ground. In a test tube, the solids take on the form of dark, brown "goo."

"The window Spitzer provides into the infrared universe has revealed beautiful structure on a cosmic scale," said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. "In yet another surprise discovery from the mission, we're lucky enough to see elegant structure at one of the smallest scales, teaching us about the internal architecture of existence."

NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For information about previous Spitzer discoveries of buckyballs,

Guillermo Gonzalo Sánchez Achutegui

Ciencia y Tecnología: Biólogos rusos germinan semillas congeladas en Siberia durante 32.000 años

Hola amigos: AL VUELO DE UN QUINDE EL BLOG., Científicos rusos lograron germinar semillas almacenadas hace 32.000 años por ardillas, halladas en el suelo congelado de Siberia, las cuales crecieron hasta convertirse en florecientes plantas, reveló un estudio publicado el martes en Estados Unidos.

Se encontraron con caballos salvajes, (del tamaño de un pony) que viven en los bosques siberianos. Fuente: TARINGA.

Un paisaje de la agreste Siberia. Fuente: Taringa

Washington. Científicos rusos lograron germinar semillas almacenadas hace 32.000 años por ardillas, halladas en el suelo congelado de Siberia, las cuales crecieron hasta convertirse en florecientes plantas, reveló un estudio publicado el martes en Estados Unidos.
"Por primera vez, hemos conseguido crear una planta con frutos de más de 32.000 años de antigüedad", dijo Svetlana Iachina, cuyo estudio junto a su colega David Gilichinsky aparece en la edición del martes de la revista Actas de la Academia Nacional de Ciencias (PNAS) de Estados Unidos.
El anterior récord en la materia era la regeneración de semillas de palma de 2.000 años de antigüedad descubiertas en la fortaleza de Masada, cerca del Mar Muerto, en Israel.
El trabajo de Iachina y Gilichinsky, del Instituto de problemas físico-químicos y biológicos del suelo de la Academia de Ciencias de Rusia (RAN), marca un hito en la investigación de materiales biológicos antiguos y podría iniciar el camino hacia la recuperación de especies extintas.
Las semillas de Silene stenophylla, una planta que crece en Siberia, fueron encontradas en las madrigueras de ardillas que hibernaban a orillas del río Kolymá en Siberia.
"Todas las madrigueras se encuentran a profundidades de 20-40 metros por debajo de la superficie actual del suelo, localizadas en capas que contienen huesos de grandes mamíferos como mamuts, rinocerontes lanudos, bisontes, caballos, ciervos, y otros representantes de la fauna" del Pleistoceno Tardío.
El permafrost, el suelo perpetuamente congelado de las regiones árticas, actuó como un enorme congelador, y las semillas almacenadas permanecieron decenas de miles de años inalteradas en este ambiente cerrado, a una temperatura promedio de -7 °C.
"Conservados bajo los hielos eternos en perfecto estado, los tres frutos de Silene no habían germinado y (por lo tanto) guardaban células de tejido placentario viable. Recogimos funículos viables y los cultivamos in vitro en nuestro laboratorio en Pushchino", 120 km al sur de Moscú, agregó
"Un día, mientras revisaba mis tubos de ensayo descubrí un brote transparente, apenas visible", dijo.
Ella y Gilichinsky pudieron cultivar estas plantas porque las semillas nunca fueron descongeladas antes.
Los dos científicos destacaron la importancia de estudiar el permafrost "en la búsqueda de la antigua herencia genética (...) que ha desaparecido hace mucho tiempo de la superficie de la Tierra".
Los primeros resultados del estudio son de 2003-2004, pero en ese momento "la experiencia pasó casi inadvertida", dijo Iachina.
Desde entonces, Silene stenophylla, una vez plantada en un suelo especialmente enriquecido, produjo varias generaciones de flores en el laboratorio de Pushchino.
Las regeneraciones anteriores de plantas antiguas no fueron validadas por la comunidad científica, pero Iachina y Gilichinsky confirmaron la edad de las semillas datándolas con radiocarbono, para excluir una "contaminación" de semillas más recientes
Fuente: LaJornada. Zacatecas
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com

lunes, 20 de febrero de 2012

Astronomy: NASA Spacecraft Reveals Recent Geological Activity on the Moon

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface. Scientists propose this geologic activity occurred less than 50 million years ago, which is considered recent compared to the moon's age of more than 4.5 billion years.

This shows the largest of the newly detected graben found in highlands of the lunar farside. The broadest graben is about 500 meters (1,640 feet) wide and topography derived from Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) stereo images indicates they are almost 20 meters (almost 66 feet) deep. (Credit: NASA/Goddard/Arizona State University/Smithsonian Institution)

› Larger image

Graben are troughs formed when the lunar crust was stretched and pulled apart. This stretching causes the near-surface materials to break along two parallel normal faults, the terrain in between the twin faults drops down forming a valley. (Credit: Arizona State University/Smithsonian Institution)

› Larger image

WASHINGTON -- New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface. Scientists propose this geologic activity occurred less than 50 million years ago, which is considered recent compared to the moon's age of more than 4.5 billion years.

A team of researchers analyzing high-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) show small, narrow trenches typically much longer than they are wide. This indicates the lunar crust is being pulled apart at these locations.

These linear valleys, known as graben, form when the moon's crust stretches, breaks and drops down along two bounding faults. A handful of these graben systems have been found across the lunar surface.

"We think the moon is in a general state of global contraction because of cooling of a still hot interior," said Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum in Washington, and lead author of a paper on this research appearing in the March issue of the journal Nature Geoscience.

"The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form." The weak contraction suggests that the moon, unlike the terrestrial planets, did not completely melt in the very early stages of its evolution.

Rather, observations support an alternative view that only the moon's exterior initially melted forming an ocean of molten rock. In August 2010, the team used LROC images to identify physical signs of contraction on the lunar surface, in the form of lobe-shaped cliffs known as lobate scarps.

The scarps are evidence the moon shrank globally in the geologically recent past and might still be shrinking today. The team saw these scarps widely distributed across the moon and concluded it was shrinking as the interior slowly cooled.

Based on the size of the scarps, it is estimated that the distance between the moon's center and its surface shrank by approximately 300 feet. The graben were an unexpected discovery and the images provide contradictory evidence that the regions of the lunar crust are also being pulled apart.

"This pulling apart tells us the moon is still active," said Richard Vondrak, LRO Project Scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "LRO gives us a detailed look at that process." As the LRO mission progresses and coverage increases, scientists will have a better picture of how common these young graben are and what other types of tectonic features are nearby.

The graben systems the team finds may help scientists refine the state of stress in the lunar crust. "It was a big surprise when I spotted graben in the far side highlands," said co-author Mark Robinson of the School of Earth and Space Exploration at Arizona State University, principal investigator of LROC.

"I immediately targeted the area for high-resolution stereo images so we could create a three-dimensional view of the graben. It's exciting when you discover something totally unexpected and only about half the lunar surface has been imaged in high resolution. There is much more of the moon to be explored." The research was funded by the LRO mission, currently under NASA's Science Mission Directorate at NASA Headquarters in Washington. LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. For more information about LRO and related images on the finding,

visit:
http://www.nasa.gov/mission_pages/LRO/news/lunar-graben.html
Guillermo Gonzalo Sánchez Achutegui

viernes, 10 de febrero de 2012

CIENCIA: El cambio climático no causó la desaparición de selvas tropicales en África

Hola amigos: AL VUELO DE UN QUINDE EL BLOG., El cambio climático no fue, a pesar de lo que se creía, el único causante de la desaparición, hace 3.000 años, de algunas selvas tropicales de África Central que fueron reemplazadas por sabanas, según un estudio divulgado este jueves que apunta a la acción de las tribus bantú como segundo factor.

El cambio climático no fue el único causante de la desaparición, hace 3.000 años, de algunas selvas tropicales de África Central que fueron reemplazadas por sabanas, según un estudio divulgado por la reivsta Science, y que apunta a la acción de las tribus bantú, como segundo factor. En la foto de arhivo, ejemplar de jirafa de Niger, en la zona de Koure, donde viven las últimas jirafas libres del Africa Occidental subsahariana. EFE/ Ángel Díaz

Washington, 10 feb (EFEverde).- El cambio climático no fue, a pesar de lo que se creía, el único causante de la desaparición, hace 3.000 años, de algunas selvas tropicales de África Central que fueron reemplazadas por sabanas, según un estudio divulgado este jueves que apunta a la acción de las tribus bantú como segundo factor.
El estudio, que aparece publicado en el número del 10 de febrero de la revista Science, sugiere que el cambio climático por sí mismo no podría haber producido un cambio tan drástico y que los humanos deben también haber jugado un papel en la transición.
El profesor Germain Bayon, geólogo y geoquímico del Instituto Francés de Investigaciones para Exploraciones Marinas (IFREMER), y su equipo analizó un núcleo de sedimento marino de la boca del río Congo y descubrieron que, hace alrededor de 3.000 años, el sedimento ahí había estado bajo la influencia de fuerte erosión química.
Erosión química
Esta mayor descomposición, basada en la química de las rocas y minerales en el área, coincidió con la llegada de campesinos bantúes provenientes de la región que ahora es parte de Camerún y Nigeria.
Las tribus bantúes trajeron con ellos tecnologías agrícola y de fundición de hierro a la región, por lo que el estudio sugiere que la presencia de estos granjeros primitivos probablemente también tuvo un impacto en las selvas tropicales centro-africanas.
Uso intensivo de la tierra y tala de árboles
Según los investigadores, en ese periodo los Bantú intensificaron el uso de la tierra y facilitaron el proceso de la erosión, ya que talaron árboles para crear tierra que pudieran arar para la agricultura y fundiciones de hierro primitivas.
Dichas acciones, junto con el cambio climático, probablemente provocaron el declive de las selvas tropicales en esa región, pero no sólo fue el cambio climático, como se había creído hasta ahora. EFEverde.
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com

jueves, 9 de febrero de 2012

ENERGÍA: EE.UU. aprueba los dos primeros reactores nucleares en más 30 años

Hola amigos: AL VUELO DE UN QUINDE EL BLOG., La Comisión Reguladora Nuclear de Estados Unidos aprobó hoy, por primera vez en más de treinta años, las licencias para la construcción de dos nuevos reactores nucleares.

Fotografía de archivo de http://www.lafototeca.com de EFE del lunes 4 de abril de 2011, del Centro Energético Indian Point, una planta de tres unidades nucleares en Buchanan, Nueva York, tomada desde Tomkins Cove (NY, EE.UU.). EFE/Justin Lane

Washington, 9 feb (EFEverde).- La Comisión Reguladora Nuclear de Estados Unidos aprobó hoy, por primera vez en más de treinta años, las licencias para la construcción de dos nuevos reactores nucleares.

Un consorcio de empresas encabezado por Southern construirá los reactores nuevos en la planta nuclear de Votgle, a unos 275 kilómetros al este de Atlanta (Georgia, sur del país), que ya alberga otros dos.

La mayoría de los cinco miembros de la CRN aprobó la construcción de los dos reactores, pero el personal técnico de la comisión debe completar una revisión administrativa antes de que se emitan las licencias.

El único voto disidente fue el del presidente de la Comisión, Gregory Jaczko, quien en la reunión dijo que hubiera preferido el requisito de "mejoras en la seguridad" de Vogtle, a la luz del desastre nuclear del año pasado en los reactores de la planta de Fukushima Daiichi en Japón.

"Yo no puedo apoyar la emisión de esta licencia como si lo de Fukushima jamás hubiese sucedido", declaró Jaczko.

Estados Unidos, el mayor proveedor de energía nuclear del mundo, cuenta con 104 reactores que operan en 65 plantas nucleares y generan, combinados, casi el 20 por ciento de la energía eléctrica del país.

La construcción de todos los reactores que operan en EE.UU. comenzó antes de 1974, y después del desastre en Fukushima la CRN ordenó una revisión exhaustiva de las medidas de protección en las plantas atómicas.

La mayor planta nuclear de Estados Unidos está ubicada en Palo Verde (Arizona) y cuenta con tres reactores que, en conjunto, generan 3.942 megavatios.

La más pequeña, en Fort Calhoum (Nebraska), tiene un reactor que genera 478 megavatios de electricidad. EFE

Guillermo Gonzalo Sánchez Achutegui