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TOPIC: The Earth
Blobrana


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RE: The Earth
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 Humans have yet to see Earth's centre, as did the characters in Jules Verne's science fiction classic, "Journey to the Centre of the Earth." But a new NASA study proposes a novel technique to pinpoint more precisely the location of Earth's centre of mass and how it moves through space.

Knowing the location of the centre of mass, determined using measurements from sites on Earth's surface, is important because it provides the reference frame through which scientists determine the relative motions of positions on Earth's surface, in its atmosphere and in space. This information is vital to the study of global sea level change, earthquakes, volcanoes and Earth's response to the retreat of ice sheets after the last ice age.
The accuracy of estimates of the motion of Earth's centre of mass is uncertain, but likely ranges from 2 to 5 millimetres a  year. Donald Argus of NASA's Jet Propulsion Laboratory, Pasadena, California, developed the new technique, which estimates Earth's centre of mass to within 1 millimetre  a year by precisely positioning sites on Earth's surface using a combination of four space-based techniques. The four techniques were developed and/or operated by NASA in partnership with other national and international agencies. Results of the new study appear in the June issue of Geophysical Journal International.

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Blobrana


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Ocean
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The incredible hidden stories of our planets oceans are to be told in a new BBC Two commission, Ocean, an 8 x 60 minute documentary series for late 2008/early 2009.
A team of four intrepid adventurers who to date include - explorer Paul Rose, maritime archaeologist Dr Lucy Blue and marine biologist Tooni Mahto - will take a journey to explore the oceans of planet earth.
We know more about the surface of Mars that we do of the depths of the Earths oceans. Hidden in these unknown depths are amazing stories that reveal new truths about our past, our planet and the life within it.
In Ocean the international team of underwater explorers brave the dangers of the deep to unravel these mysteries. This spectacular series will tell the most exciting stories from the world of underwater archaeology, geology, marine biology and anthropology. It will take in everything from great white sharks to lost cities buried undersea to divers who try to fathom the mysterious life forms of the deep.
Filming starts in June 2007 in the Mediterranean and will finish in June 2008. It is a co-production with Discovery and is being filmed in High Definition. The executive producer is Anne Laking and the Series Producer is Helen Thomas.

It took us nearly a year to find the right people to present such an exciting new series. They needed to have the right balance of robust scientific knowledge, first-class diving skills as well as genuine drive, passion and thirst for high octane adventure.  The series will show the ocean as its never been seen before. Well use cutting-edge techniques to delve into this unknown world of our wonderful planet - Anne Laking, Executive Producer.

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Blobrana


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Ayles Ice Island
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Scientists in the Arctic have just carried out the first research on a huge iceberg the size of Manhattan.
Some 16km long and 5km wide, Ayles Ice Island broke away from the Canadian Arctic coast in 2005, but has only recently been identified.
Researchers have now landed on the giant berg with a BBC team and planted a tracking beacon on its surface.
This will allow the island's progress to be monitored as currents push it around the Arctic Ocean.

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Blobrana


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RE: The Earth
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The most detailed portraits ever of the Earth's land surface have been created with ESA's Envisat environmental satellite. The portraits are the first products produced as part of the ESA-initiated GlobCover project and are available online.
Bimonthly global composites for May to June 2005 and March to April 2006 can be accessed through a newly developed map server tool on ESAs GlobCover website. On 19 June, additional bimonthly global composites will be made available as well as the first part of a global land cover map over Eurasia.

earth_1024 x 410
Expand (109kb, 1024 x 410)
Expand (1.04mb, 3508 x 1945)
Credits: ESA - MEDIAS France

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Blobrana


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If it seems Canadians weigh less than their American neighbours, they do but not for the reasons you might think. A large swath of Canada actually boasts lower gravity than its surroundings.
Researchers have puzzled for years over whether this was due to the crust there rebounding slowly after the end of the last ice age or a deeper issue involving convection in the Earth's mantle or some combination of the two.
Now, ultra-precise measurements taken over four years by a pair of satellites known as GRACE (Gravity Recovery and Climate Experiment) reveal that each effect is equally responsible for Canada's low gravity. The work could shed light on how continents form and evolve over time.

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Blobrana


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Climate catastrophes in the Solar System
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 Earth sits between two worlds that have been devastated by climate catastrophes. In the effort to combat global warming, our neighbours can provide valuable insights into the way climate catastrophes affect planets.
 Modelling Earths climate to predict its future has assumed tremendous importance in the light of mankinds influence on the atmosphere. The climate of our two neighbours is in stark contrast to that of our home planet, making data from ESAs Venus Express and Mars Express invaluable to climate scientists.
Venus is a cloudy inferno whilst Mars is a frigid desert. As current concerns about global warming have now achieved widespread acceptance, pressure has increased on scientists to propose solutions.
The key weapon in a climate scientists arsenal is the climate model, a computer programme that uses the equations of physics to investigate the way in which Earths atmosphere works. The programme helps predict how the atmosphere might change in the future.

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Blobrana


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The Earth
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A major new BBC TV series is to reveal the story of planet Earth from its birth more than four billion years ago.

Earth: The Biography will be screened on BBC Two later in the year and presented by Dr Iain Stewart, host of Journeys From the Centre of the Earth.
Dr Stewart will visit some of the planet's most remote places to explain phenomena such as the meteorite thought to have wiped out dinosaurs.
BBC natural history series Planet Earth attracted up to nine million viewers.

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Blobrana


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Earth's magnetic field was nearly as strong 3.2 billion years ago as it is today, geophysicists at the University of Rochester have said.
The findings, which are contrary to previous studies, suggest that even in its earliest stages, the Earth was already well protected from the solar wind, which can strip away a planet's atmosphere and bathe its surface in lethal radiation.

"The intensity of the ancient magnetic field was very similar to today's intensity. These values suggest the field was surprisingly strong and robust. It's interesting because it could mean the Earth already had a solid iron inner core 3.2 billion years ago, which is at the very limit of what theoretical models of the Earth's formation could predict" - John Tarduno, professor of geophysics in the Department of Earth and Environmental Sciences at the University of Rochester.

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Blobrana


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Identification of the oldest preserved pieces of Earth's crust in southern Greenland has provided evidence of active plate tectonics as early as 3.8 billion years ago, according to a report by an international team of geoscientists in the March 23 edition of Science magazine.
The finding pushes back the date of continent-forming processes previously determined as 2.5 billion years ago to a much earlier era considerably closer to Earth's formation some 4.5 billion years ago. Geochemical analysis of rocks has previously suggested an earlier date for plate tectonics, but this is the first study to find physical evidence of tectonics among Earth's oldest known rock structures, according to Hubert Staudigel of Scripps Institution of Oceanography at UC San Diego.

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Blobrana


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Earliest Plate Tectonics
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A Trace of the Earliest Plate Tectonics Turns Up in Greenland
A group of geologists has discovered the earliest known remnants--by billions of years--of plate tectonics, the large-scale movement of Earth's crust.

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