Thursday, August 28, 2008

Cut greenhouse gases to save coral reefs: scientists



To keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere, a panel of marine scientists said on Wednesday.


"The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the scientists said in a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

Ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching, the scientists said.

Coral reefs are a "sentinel ecosystem," a sign that the environment is changing, said one of the experts, Billy Causey of the U.S. National Marine Sanctuary Program.

"Although ocean acidification is affecting the health of our oceans, the same thing -- increased carbon dioxide in the atmosphere -- is going to in fact be affecting terrestrial environments also," Causey said by telephone from Hawaii.

Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue, the declaration said.

But corals are increasingly threatened by warming sea surface temperatures as well as ocean acidification.

Oceans are getting more acidic because they have been absorbing some 525 billion tons of the greenhouse gas carbon dioxide over the last two centuries, about one-third of all human-generated carbon dioxide for that period.

The carbon dioxide combines with sea water to form carbonic acid.

Marine researchers have long recognized acidification in deep ocean water far from land, but a study published this year in the journal Science found this same damaging phenomenon on the Pacific North American continental shelf from Mexico to Canada, and quite likely elsewhere around the globe.

The water became so corrosive that it started dissolving the shells and skeletons of starfish, clams and corals.

Stabilizing carbon dioxide emissions was the Honolulu Declaration's top long-term recommendation. The key short-term recommendation was to nurture coral reefs that seem to have natural resilience against acidification.

This could be adopted immediately by managers of protected marine areas, Causey said.

The Honolulu Declaration will be presented to the United Nations and to other global, regional and national forums.
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Monday, August 25, 2008

Finding You on a Map


By far the easiest way to determine where you are on a map is to pull out your pocket GPS (global positioning system receiver) and have it give you your map coordinates. If, however, you are like a lot of people, you don’t want to shell out a few hundred bucks for a GPS and, unless you are in an area with very little topographic relief, you don’t need one. You can determine your position quite accurately on a topographic map by using your compass to triangulate between three points.


The first step in triangulation is to pick three topographic features that you can see and can identify on your map (mountains are ideal). Start with the first feature you have chosen and determine the bearing between you and it, as outlined above. Once you have determined its bearing, pencil in a line with the same bearing on your map that runs through the chosen feature (having a protractor would be useful).

Repeat this for the other two features, drawing lines for each. The point where the three lines intersect on the map is where you are. Depending on how accurate your sightings were and how accurately you drew your lines through the features, there will probably be a some error in your location. Be sure to double check the map and reconcile it with what you see. If the lines intersect in a valley and you are on a hill, the location is obviously off a bit on the map.
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Wednesday, August 20, 2008

Map Projections and Distortions


What is a Map?

Once a reference datum has been determined the elevation of any point can be accurately determined, and it will correlate to the elevation of any point on the earth's surface that has the same elevation and is using the same datum. But…how do you accurately represent the X and Y coordinates of that point? This question leads to one of the fundamental problems of mapmaking…how do you represent all or part of an ellipsoid object on a flat piece of paper? The answer to this question is a bit complicated, but understanding it is fundamental to understanding what maps actually represent (this statement will become clearer shortly).
In order to represent the surface of the earth on a flat piece of paper, the map area is projected onto the paper. There are many different types of projections, each with its own strengths and weaknesses.

The simplest (and easiest to visualize) example of a projection is a planar projection. To understand this type of projection, imagine inserting a piece of paper through the earth along the equator. Now imagine that the earth is semi-transparent and you could shine a flashlight oriented along the (geographic) polar axis through the earth.

The resulting outline on the paper would be a map created using this type of projection (known as a transverse azimuthal or planar projection).

There are three main types of projections, based on the shape of the 'paper' onto which the earth is projected. The example above used an azimuthal (planar) piece of paper.


 

The other main types, illustrated to the right, are cylindrical and conical projections. These three types of projections can be further modified by the way the 'paper' is oriented when it is inserted into the earth.

In the example above, the plane was oriented along the equator, known as a transverse orientation (hence the 'transverse azimuthal' projection). Projections may also be equatorial (oriented perpendicular to the plane of the equator) or oblique (oriented at some angle that is neither parallel nor perpendicular to the plane of the equator.

Map Projection Distortions

Each of the different types of projections have strenghts and weaknesses. Knowledge of these different advantages and disadvantages for a particular map projection will often help in which map to choose for a particular project. The basic problem inherent in any type of map projection is that it will result in some distortion of the ‘ground truth’ of the area being mapped.


There are four basic characteristics of a map that are distorted to some degree, depending on the projection used. These characteristics include distance, direction, shape, and area. The only place on a map where there is no distortion is along the trace of the line that marks the intersection of our ‘paper’ with the surface of the earth.

Any place on the map that does not lie along this line will suffer some distortion. Fortunately, depending on the type of projection used, at least one of the four characteristics can generally be preserved.
A conformal projection primarily preserves shape, an equidistant projection primarily preserves distance, and an equal-area projection primarily preserves area.


These image show the earth using different projections. Notice how the continents look stretched or squashed depending on the projection. Following are some websites with more information.

source


Sunday, August 17, 2008

Geoid

The geoid is that equipotential surface which would coincide exactly with the mean ocean surface of the Earth, if the oceans were in equilibrium, at rest, and extended through the continents (such as with very narrow canals). According to C.F. Gauss, who first described it, it is the “mathematical figure of the Earth,” a smooth but highly irregular surface that corresponds not to the actual surface of the Earth’s crust, but to a surface which can only be known through extensive gravitational measurements and calculations. Despite being an important concept for almost two hundred years in the history of geodesy and geophysics, it has only been defined to high precision in recent decades, for instance by works of P. Vaníček and others. It is often described as the true physical figure of the Earth, in contrast to the idealized geometrical figure of a reference ellipsoid.

Friday, August 15, 2008

Congratulations India


With all the inherent contradictions and weaknesses we Indians have an intense desire to succeed,to march ahead and to excel. This is our secret of suceess.Happy Independence Day to fellow Indians.

Wednesday, August 13, 2008

ISRO postpones Chandrayaan I until mid-October


India - The launch of India's first unmanned mission to the Moon has been postponed until the middle of October, the head of the Indian space program has said. 

The launch of the Chandrayaan I lunar orbiter by the Indian Space Research Organization (ISRO) was originally planned for September 19 but scientists have yet to conduct the thermo-vacuum testing of a Polar Satellite Launch Vehicle (PSLV) with the orbiter on board.
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Monday, August 11, 2008

Congratulations Abhinav


India's Abhinav Bindra won a gold in men's 10-metre Air Rifle event in Beijing. Bindra shot 104.5 to take his total to 700.5 in the final. This is India's first ever Olympic gold in any individual event and ninth in total.

In ten rounds, Bindra shot 10.7, 10.3, 10.4, 10.5, 10.5, 10.5, 10.6, 10.0, 10.2, 10.8 to clinch the first berth. China's Qinan Zhu won silver while Finland's Henri Hakkinen won bronze.

Bindra had shot a total of 596 out of 600, shooting a perfect 100 in 3 of the 6 rounds of the qualifiers. Bindra finished 4th to qualify 2 points behind Henri Hakkinen of Finland. 

Gagan Narang, meanwhile, was very unlucky missing out by just 1 point on a countback after he was tied with 4 others after 6 rounds with an average score of 9.917 in the qualifiers. In a countback, since all five shooters, who were tied, had shot a perfect 100 in the last round, the 5th round scores were taken into account, where Narang had managed a 98, whereas the others had shot either a 99 or a 100. 

If Narang had shot a 99 instead of a 98, 4th round scores would have been taken into account and Narang would have gone through.
source

Friday, August 8, 2008

The Atomic Bombs, End of World War II and Begining of Nuclear Age

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Bulgarian archaeologists discover ancient chariot


SOFIA, Bulgaria - Archaeologists have unearthed a 1,900-year-old well-preserved chariot at an ancient Thracian tomb in southeastern Bulgaria, the head of the excavation said Thursday.
Daniela Agre said her team found the four-wheel chariot during excavations near the village of Borisovo, around 180 miles east of the capital, Sofia.
"This is the first time that we have found a completely preserved chariot in Bulgaria," said Agre, a senior archaeologist at the Bulgarian Academy of Sciences.
She said previous excavations had only unearthed single parts of chariots — often because ancients sites had been looted.
At the funerary mound, the team also discovered table pottery, glass vessels and other gifts for the funeral of a wealthy Thracian aristocrat.
In a separate pit, they unearthed skeletons of two riding horses apparently sacrificed during the funeral of the nobleman, along with well preserved bronze and leather objects, some believed to horse harnesses.
The Culture Ministry confirmed the find and announced $3,900 in financial assistance for Agre's excavation.
Agre said an additional amount of $7,800 will be allocated by the Bulgarian Academy of Sciences for an initial restoration and conservation of the chariot and the other Thracian finds.
The Thracians were an ancient people that inhabited the lands of present day Bulgaria and parts of modern Greece, Turkey, Macedonia and Romania between 4,000 B.C. and the 6th century, when they were assimilated by the invading Slavs.
Some 10,000 Thracian mounds — some of them covering monumental stone tombs — are scattered across Bulgaria.
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Wednesday, August 6, 2008

Phoenix detected Perchlorate in Soil of Mars


Photo credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 43, the 43rd Martian day after landing (July 8, 2008). This image shows the trench informally called "Snow White." 

Two samples were delivered to the Wet Chemistry Laboratory, which is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The first sample was taken from the surface area just left of the trench and informally named "Rosy Red." It was delivered to the Wet Chemistry Laboratory on Sol 30 (June 25, 2008). The second sample, informally named "Sorceress," was taken from the center of the "Snow White" trench and delivered to the Wet Chemistry Laboratory on Sol 41 (July 6, 2008).

  Mars mission scientists spoke today on research in progress concerning an ongoing investigation of perchlorate salts detected in soil analyzed by the wet chemistry laboratory aboard NASA's Phoenix Lander. 

"Finding perchlorates is neither good nor bad for life, but it does make us reassess how we think about life on Mars," said Michael Hecht of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead scientist for the Microscopy, Electrochemistry and Conductivity Analyzer (MECA), the instrument that includes the wet chemistry laboratory. 

If confirmed, the result is exciting, Hecht said, "because different types of perchlorate salts have interesting properties that may bear on the way things work on Mars if -- and that's a big 'if ' -- the results from our two teaspoons of soil are representative of all of Mars, or at least a significant portion of the planet." 

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Tuesday, August 5, 2008

Iran tests 'new weapon' for use at sea


TEHRAN, Iran - Iran announced Monday that it has tested a new weapon capable of sinking ships nearly 200 miles away, and reiterated threats to close a strategic waterway at the mouth of the Persian Gulf if attacked.  

Up to 40 percent of the world's oil passes through the Strait of Hormuz, a narrow passage along Iran's southern coast. Tehran has warned it could shut down tanker traffic there if attacked — a move likely to send oil prices skyrocketing.

The warnings came two days after a deadline expired for Iran to respond to incentives from six world powers, offered in exchange for a promise to curb its uranium enrichment.

Later Monday, the U.S. State Department said the group — the five permanent members of the U.N. Security Council, plus Germany — agreed to pursue further sanctions against Iran because of its failure to meet the Saturday deadline.

Iran and the West have been mired in a standoff over the country's disputed nuclear program. The United Nations has already slapped Iran with three rounds of sanctions, over its refusal to stop enriching uranium — a key process that generates either fuel for a nuclear reactor, or the fissile material for a bomb.

Iran says its nuclear program is for peaceful purposes only, to generate electricity.

Revolutionary Guards commander Gen. Mohammad Ali Jafari said Monday that the new marine weapon is "unique in the world" and has a range of 300 kilometers (186 miles), according to the state news agency IRNA.

That's within range of U.S. warships deployed in the Persian Gulf. Last month, Iran tested missiles it claimed were capable of reaching 1,250 miles (2,000 kilometers) away — putting U.S military bases in the Middle East as well as Israel, Turkey, the Arabian peninsula, Afghanistan and Pakistan all within striking distance.

Monday's report gave no details on when or where the new weapon was tested. Its range indicates it could be a type of torpedo, but state radio called it a missile.

Jafari warned Iran would respond decisively if any military strike is carried out against it.

"Enemies know that we are easily able to block the Strait of Hormuz for an unlimited period," he was quoted by state radio as saying. "The strait and vessels are in range of our various weapons."

Both the U.S. and Israel — which shares American concerns over Iran's nuclear program — have said they would prefer a diplomatic solution to the standoff with Iran, but have not ruled out other options — including a military one.

Israeli analyst Ephraim Kam, a former senior intelligence officer, dismissed the new weapons test.

"They are always boasting about their weapons and their military capabilities and saying how unique they are, but they are usually just standard military weapons," he said.
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Monday, August 4, 2008

Bangladesh gaining land, not losing: Scientists

New data shows that Bangladesh's landmass is increasing, contradicting forecasts that the South Asian nation will be under the waves by the end of the century, experts say. 

Scientists from the Dhaka-based Center for Environment and Geographic Information Services (CEGIS) have studied 32 years of satellite images and say Bangladesh's landmass has increased by 20 square kilometres (eight square miles) annually. 

Maminul Haque Sarker, head of the department at the government-owned centre that looks at boundary changes, said sediment which travelled down the big Himalayan rivers the Ganges and the Brahmaputra -- had caused the landmass to increase. 

The rivers, which meet in the centre of Bangladesh, carry more than a billion tonnes of sediment every year and most of it comes to rest on the southern coastline of the country in the Bay of Bengal where new territory is forming, he said in an interview on Tuesday. 

The United Nations Intergovernmental Panel on Climate Change (IPCC) has predicted that impoverished Bangladesh, criss-crossed by a network of more than 200 rivers, will lose 17 per cent of its land by 2050 because of rising sea levels due to global warming. 

The Nobel Peace Prize-winning panel says 20 million Bangladeshis will become environmental refugees by 2050 and the country will lose some 30 per cent of its food production. 

Director of the US-based NASA Goddard Institute for Space Studies, professor James Hansen, paints an even grimmer picture, predicting the entire country could be under water by the end of the century. 

But Sarker said that while rising sea levels and river erosion were both claiming land in Bangladesh, many climate experts had failed to take into account new land being formed from the river sediment.

"Satellite images dating back to 1973 and old maps earlier than that show some 1,000 square kilometres of land have raised from the sea," Sarker said. 

"A rise in sea level will offset this and slow the gains made by new territories, but there will still be an increase in land. We think that in the next 50 years we may get another 1,000 square kilometres of land." 

Mahfuzur Rahman, head of Bangladesh Water Development Board's Coastal Study and Survey Department, has also been analysing the buildup of land on the coast. 

He said findings by the IPCC and other climate change scientists were too general and did not explore the benefits of land accretion. 

"For almost a decade we have heard experts saying Bangladesh will be under water, but so far our data has shown nothing like this," he said. 

"Natural accretion has been going on here for hundreds of years along the estuaries and all our models show it will go on for decades or centuries into the future." 

Dams built along the country's southern coast in the 1950s and 1960s had helped reclaim a lot of land and he believed with the use of new technology, Bangladesh could speed up the accretion process, he said. 

"The land Bangladesh has lost so far has been caused by river erosion, which has always happened in this country. Natural accretion due to sedimentation and dams has more than compensated this loss," Rahman said. Bangladesh, a country of 140 million people, has built a series of dykes to prevent flooding. 

"If we build more dams using superior technology, we may be able to reclaim 4,000 to 5,000 square kilometres in the near future," Rahman said. 

Source : http://economictimes.indiatimes.com/

Olympics:Haze returns to Beijing with four days to go


A grey haze clogged Beijing's skies on Monday as the city returned to work after a weekend of the clear weather, just four days before the opening ceremony for the Olympic Games.

Beijing's chronic pollution has been one of the biggest headaches for organizers who have closed dozens of factories and pulled more than half the city's 3.3 million cars off the roads in a bid to ensure blue skies during the competition.

Officials said China was still considering some man-made help to ensure dry weather and clean air for Friday.

China has two methods of controlling rainfall. Weather stations outside Beijing could try to induce rain before it reaches the centre of the city, by firing a chemical seeding agent into clouds with anti-aircraft guns, a common practice in arid northern China.

Or it could fire a coolant into clouds that increases the number of water droplets, causing heavier droplets to fall ahead of the big show.

Smog shrouded the city for much of last week, prompting the government to draw up a last-resort plan to clear more vehicles from the roads of Beijing and surrounding cities, and shut down over 200 more factories.

The International Olympic Committee (IOC) has said it may reschedule endurance events such as the marathon to prevent health risks if pollution is bad.

Data from the Beijing Environmental Protection Bureau showed that air pollutants were well within limits for a "blue sky day" at all monitoring stations in the 24 hours to midday on Sunday, although they do not provide an overall summary.

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