Yellowstone Magna
Posted: October 30, 2010 Filed under: Volcanoes Leave a comment »
Yellowstone Park located primarily in the U.S. state of Wyoming ( though it also extends into Montana and Idaho) is a dormant volcano full of fuming vents and hot geysers. A plume of molten rock rising from deep beneath Yellowstone National Park is probably what is fueling the region’s volcanic activity, as well as tectonic plate oddities across the Pacific Northwest, new research suggests.
Yellowstone, like Hawaii, is believed to lie on top of an area called a hotspot where light, hot, molten mantle rock rises towards the surface. While the Yellowstone hotspot is now under the Yellowstone Plateau, it previously helped create the eastern Snake River Plain (to the west of Yellowstone) through a series of huge volcanic eruptions. Although the hotspot’s apparent motion is to the east-northeast, the North American Plate is really moving west-southwest over the stationary hotspot deep underneath.
Building on a growing body of evidence, Mathias Obrebski of the University of California, Berkeley, and his colleagues created the most convincing picture to date of a Yellowstone mantle plume — one that extends from about 621 miles below the surface of the Earth.
Debates have been going on over whether erupting and shaking in the area over the last few millions of years — and a track marked out by a chain of volcanic calderas along the Yellowstone Snake River Plain in Idaho — could be the work of a column of hot rock rising up from deep within the Earth’s mantle. The mantle is the layer of hot, viscous rock beneath the planet’s crust.
Obrebski’s team used data from a new, dense deployment of seismometers, called the Earthscope USArray, to get a high-resolution image of the elusive mantle, along with information on the unusual structure of the subducting Juan de Fuca slab to its west. The Juan de Fuca plate is a small tectonic plate jammed in between the much larger Pacific and North American plates.
The plume is thought to be more or less stationary, with the North American plate — and the Juan de Fuca subducting beneath it — slowly sliding southwesterly over the plume. So what is now Oregon probably sat where Yellowstone is today about 17 million years ago, baking and breaking over a hot plume of rock.
The findings were detailed in the July 22 edition of the journal Geophysical Research Letters.
The source of the Yellowstone hotspot is controversial. Some geoscientists hypothesize that the Yellowstone hotspot is the effect of an interaction between local conditions in the lithosphere and upper mantle convection. Others suggeste a deep mantle origin (or mantle plume).
Part of the controversy is due to the relatively sudden appearance of the hotspot in the geologic record. Additionally, the Columbia Basalt flows appeared at the same approximate time, causing speculation about their origin.
Links and Sources:
Source:ENN
Rice Farming in India: A New Method
Posted: October 29, 2010 Filed under: BIODIVERSITY 4 Comments »
A new method to grow rice could save hundreds of billions of cubic metres of water while increasing food security, according to a study by World Wildlife Foundation. With a focus on India – a country which faces a major water crisis, yet has the world’s largest rice cultivated area – the study found that the system of rice intensification (SRI) method has helped increase yields by over 30% — four to five tonnes per hectare instead of three tonnes per hectare, while using 40% less water than conventional methods.This new system is based on eight principles which are different to conventional rice cultivation. They include developing nutrient-rich and un-flooded nurseries instead of flooded ones; ensuring wider spacing between rice seedlings; preferring composts or manure to synthetic fertilizers; and managing water carefully to avoid that the plants’ roots are not saturated.
The method was initially developed in the 1980s in Madagascar and has been demonstrated to be effective in 28 countries.
The report suggests that major rice-producing countries — such as India, China and Indonesia — convert at least 25% of their current rice cultivation to the new system by 2025. This would not only massively reduce the use of water but also help ensure food security. In addition, this will reduce significant amount of methane emissions. SRI fields do not emit methane as is the case with the more conventional system of growing rice.
For example, if the SRI method was applied to 20 million hectares of land under rice cultivation in India, the country could meet its food grain objectives of 220 million tonnes of grain by 2012 instead of 2050.
Authorities in the Indian state of Tripura have already committed to move in that direction.
“Our farmers proved that the system of rice intensification improves productivity and we will convert at least 40% of our rice cultivation using this method over the next five years,” said Manik Sarkar, Chief Minister of Tripura State.
“We urge this as a model for rice cultivation elsewhere as it represents one hope for the water crisis affecting so many billions of people.”
Demand for a water-intensive crop such as rice is expected to increase by 38% by 2040, deepening the water crisis during the same time. However, less than 6% of rice is traded internationally and savings in water have potential for mitigating domestic water conflicts, especially in poor, rural areas where water is scarce.
Already 1.2 billion people have no access to adequate water for drinking and hygiene.
WWF is focusing on sustainable agriculture efforts for cotton, sugar and rice, some of the most consuming crops for which alternative techniques can result in a strong yield and water savings.
Some Facts About rice
Rice is the main source of directly consumed calories for about half the world’s population and 90 per cent of it is produced and consumed in Asia.
Contrary to popular belief, rice is not an aquatic plant and the main reason it is submerged in water is for controlling weeds.
Conventional method of rice cultivation uses 60-70 kilos of seeds per hectare, SRI requires just five kilos per hectare.
CLIMATE – the Monsoon climate stays above 21oC with a long wet season, plenty of moisture available for growth, followed by dry, sunny weather which is ideal for ripening and the harvest
HUGE DEMAND – Rice is the staple food of 65% of the population of India and forms 90% of the total diet. India is indeed the world’s second largest rice producer, producing 20% of the world’s total)
FLAT LAND – ideal for paddy fields as it stops water draining away, allowing rice to grow in it
FERTILE SOILS – increases productivity and good crops are grown
WATER SUPPLY – plentiful water usually available due to the monsoon climate
LARGE LABOUR FORCE – rice farming is labour intensive and provides direct employment to about 70% of the working people in India where large numbers of workers are available.
Peculiar Characteristics of the rice farms in India
- many farms are very small (may only be one hectare – size of a football pitch)
- consequently rice farming is intensive, with large amounts of inputs compared to the size of the actual farm
- due to the small farm size and the poverty, often there is little no mechanisation and the farms are labour intensive (e.g. preparation of fields, planting, weeding etc.)
- the farmers are subsistence farmers – although they may sell what little surplus they might have and many poor farmers are only tenants as opposed to land owners.
sources:
http://geobytesgcse.blogspot.com/2008/04/case-study-of-subsistence-farming-rice.html
http://persianoad.wordpress.com/2007/10/21/growing-more-rice-with-less-water/
Precocious Galaxy Cluster Identified by Chandra
Posted: October 29, 2010 Filed under: Space Leave a comment »
Sciencedaily reported that NASA’s Chandra X-ray Observatory has observed an unusual galaxy cluster that contains a bright core of relatively cool gas surrounding a quasar called 3C 186. This is the most distant such object yet observed, and could provide insight into the triggering of quasars and the growth of galaxy clusters.
read here
Limestone
Posted: October 24, 2010 Filed under: Landforms, Minerals, rocks Leave a comment »
Limestone is an organic, sedimentary rock.It was formed from the remains of tiny shells and micro-skeletons deposited on the sea bed. They were compressed to form solid rock. Limestone is made up of calcium carbonate and reacts with diluted hydrochloric acid. Limestone is formed in layers – called bedding planes. These bedding planes contain vertical cracks called joints. Joints and bedding planes make the rock permeable.
Weathering of Limestone
Weathering is the breakdown of rock by physical, chemical or biological processes. Limestone areas are weathered when rainwater, which contains a weak carbonic acid, reacts with limestone. When it rains limestone is dissolved. Rainwater erodes the joints and bedding planes. In doing this Karst scenery is created.
Karst scenery includes:
Swallow hole – An exposed limestone joint down which a surface river ‘disappears’.
Clints and grykes – Rainwater flowing over an impermeable surface will, on reaching (permeable) limestone, be able to dissolve the joints into grooves called grykes, leaving blocks or clumps of limestone in between called clints.
Stalactite – Water dripping from the roofs of caves leave behind microscopic particles of calcium carbonate. These build up as icicle shaped stalactites.
Stalagmite – Drips splashing onto the floor of caves leave behind microscopic particles of calcium carbonate. These build up on the floor of caves.
Limestone and recreation
Limestone areas are popular due to the range of leisure activities that people can participate in. These include walking, pot holing, climbing and abseiling.
Source:http://www.geography.learnontheinternet.co.uk/topics/limestoneinfo.html#lime
Plants Play Larger Role Than Thought in Cleaning Up Air Pollution
Posted: October 23, 2010 Filed under: BIODIVERSITY, Ecosystem, pollution Leave a comment »
The research, led by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., uses observations, gene expression studies, and computer modeling to show that deciduous plants absorb about a third more of a common class of air-polluting chemicals than previously thought.
read here
Nano Satellite Jugnu Will Now be Launched in 2011
Posted: October 21, 2010 Filed under: India, News, Satellites 1 Comment »
Jugnu, the nano satellite developed by Indian Institute of Technology-Kanpur (IIT-K) is expected to be launched in the polar orbit from Satish Dhawan Space Centre at Sriharikota in the first six months of 2011.
Though it was expected that it would be launched this month, the Indian Space Research Organisation (ISRO) has allotted a slot in the first half of 2011 to IIT-K for the launch.
The final model of the satellite is being given the final touches. A team of 12 professors and 45 students have been working on the project since December 2007.
Weighing 3.5 kgs, Jugnu will be launched in the Polar orbit, 700 km above the ground level. The nano satellite, which has a life span of a year, will encircle earth 14 to 15 times each day and transmit images of weather, soil and water bodies to the IIT-K base station.
Links
Source:Indian Express
In the satellite industry, ‘small’ could be the next big thing in the coming years
Counter-urbanisation
Posted: October 20, 2010 Filed under: Urban Studies 1 Comment »Counter-urbanisation is the movement of people out of cities, to the surrounding areas. Since 1950 this proccess has been occurring in MEDCs (More Economically Developed Countries).
There are four main reasons for counter-urbanisation: 1. The increase in car ownership over the last 40 years means people are more mobile. This has led to an increase in commuting. Also, the growth in information technology (E-mail, faxes and video conferencing) means more people can work from home.
2. Urban areas are becoming increasing unpleasant place to live. This is the result of pollution, crime and traffic congestion.
3. More people tend to move when they retire.
4. New business parks on the edge of cities (on Greenfield sites) mean people no longer have to travel to the city centre. People now prefer to live on the outskirts of the city to be near where they work.
Links:
click here for a ppt
Rescuing Oceans in the International Year of Biodiversity
Posted: October 19, 2010 Filed under: BIODIVERSITY, oceans Leave a comment »
I have found this very interesting and useful post on greenpeace site. Click here to read.
Humanity Needs Urgent Action to Stop Species Loss
Posted: October 18, 2010 Filed under: BIODIVERSITY Leave a comment »The United Nations says the world is facing the worst extinction rate since the dinosaurs vanished 65 million years ago, a crisis that needs to be addressed by governments, businesses and communities.
Super Typhoon Megi hits Philippines
Posted: October 18, 2010 Filed under: News Leave a comment »
The Philippines declared a state of calamity in a northern province after super typhoon Megi made landfall on Monday, cutting off power, forcing flight cancellations and putting the region’s rice crop at risk.Megi, the 10th and strongest typhoon to hit the Philippines this year, hit Isabela province at 11:25 a.m. (0325 GMT) and was heading west-southwest across the north of the main island of Luzon with winds of 190 kph (117 mph) near the center, forecasters said.
read here
