Happy homeworking!
Sunday, 13 May 2012
'Broken' Year 9 links
The two links below are the ones that some of you reported on Thursday were not working. I can confirm that I have checked these myself this morning and you will be delighted to know that they work all fine!
Happy homeworking!
Happy homeworking!
Wednesday, 9 May 2012
What is a supercell tornado?
*Taken from the 'weather encyclopaedia' at the Weather Channel for Kids (US site)*
http://www.theweatherchannelkids.com/weather_ed/weather_encyclopedia/tornadoes/types_of_tornadoes/
Some of the most violent tornadoes develop from supercell thunderstorms. A supercell thunderstorm is a long-lived thunderstorm possessing within its structure a continuously rotating updraft of air. These storms have the greatest tendency to produce tornadoes, some of the huge wedge shape. The supercell thunderstorm has a low-hanging, rotating layer of cloud known as a “wall cloud.” It looks somewhat like a layer of a layer cake that hangs below the broader cloud base. One side of the wall cloud is often rain-free, while the other is neighboured by dense shafts of rain. The rotating updraft of the supercell is seen on radar as a “mesocyclone.”
Clear as daylight isn't it!?
This article is slightly clearer....from the Independent Newspaper - please follow the URL below (it contains a video and good graphic too).
http://www.independent.co.uk/news/uk/home-news/what-caused-the-bicester-twister-7723178.html
Independent website article and video
Mr I
Tornado reported during storm in Oxfordshire
**taken from the BBC News website - no by-line was attached to this article in order to give proper credit to the author - Mr I**
A tornado has been reported in parts of Oxfordshire during a storm which caused damage to trees and roof tiles. It was spotted in several places, including Bicester, Eynsham, Kidlington and South Leigh, on Monday afternoon.
(a link to the BBC video footage/report is below - but annoyingly hidden. Trust me it is there, move your mouse over it and see if you don't find it......honest!)
Click here for BBC video footage!
Large hailstones were also reported during the storm, which is thought to have started in Wiltshire and moved to Oxfordshire and Buckinghamshire.One forecaster said it was almost certainly a tornado, thought to have been caused by a special kind of storm. Brendan Jones, from Meteogroup, said: "At the moment it's difficult to say exactly where the tornado was because while the parent thunderstorm travelled all the way across the south Midlands, it wasn't necessarily producing a tornado all the time.
"There has been more than one report of a tornado beneath this storm. There has also been some quite big hailstones." He said it was likely the storm was a "supercell"
thunderstorm, when the air spins or rotates, which is not often seen in
the UK.
Eyewitness Dave Ewart, from Kidlington, said: "I was at home when I noticed heavy dark clouds forming, then hail then - very suddenly - extremely high winds. "I saw my car bouncing up and down on its suspension - which is very unusual. And then we spotted spinning clouds."
Richard Glazer, 40, drove through it with his wife and son on the A34 near Kidlington.
He said: "It was very wet, we were just driving on the A34 and looked up and realised one part of the sky was moving in one direction and another in the opposite direction. "I thought, 'that looks like a tornado'. We pretty much drove through it, we were right underneath it. "As we drove into it the trees were blowing left to right and as we got through it they were blowing the other way."
Jo Cotterill, from Kidlington, said: "At about 4pm this afternoon we had a freak hailstorm, lasting about two minutes, along with massive gusts of wind that damaged street lights, roof tiles and trees."
A tornado has been reported in parts of Oxfordshire during a storm which caused damage to trees and roof tiles. It was spotted in several places, including Bicester, Eynsham, Kidlington and South Leigh, on Monday afternoon.
(a link to the BBC video footage/report is below - but annoyingly hidden. Trust me it is there, move your mouse over it and see if you don't find it......honest!)
Click here for BBC video footage!
Large hailstones were also reported during the storm, which is thought to have started in Wiltshire and moved to Oxfordshire and Buckinghamshire.One forecaster said it was almost certainly a tornado, thought to have been caused by a special kind of storm. Brendan Jones, from Meteogroup, said: "At the moment it's difficult to say exactly where the tornado was because while the parent thunderstorm travelled all the way across the south Midlands, it wasn't necessarily producing a tornado all the time.
A tree was felled in Kidlington by the storm
Eyewitness Dave Ewart, from Kidlington, said: "I was at home when I noticed heavy dark clouds forming, then hail then - very suddenly - extremely high winds. "I saw my car bouncing up and down on its suspension - which is very unusual. And then we spotted spinning clouds."
Richard Glazer, 40, drove through it with his wife and son on the A34 near Kidlington.
He said: "It was very wet, we were just driving on the A34 and looked up and realised one part of the sky was moving in one direction and another in the opposite direction. "I thought, 'that looks like a tornado'. We pretty much drove through it, we were right underneath it. "As we drove into it the trees were blowing left to right and as we got through it they were blowing the other way."
Jo Cotterill, from Kidlington, said: "At about 4pm this afternoon we had a freak hailstorm, lasting about two minutes, along with massive gusts of wind that damaged street lights, roof tiles and trees."
(Check out the size of those hail stones! - Mr I)
An apology........
Dear all,
I feel an apology is overdue. I have been terribly remiss in not updating the blog more regularly over the last few months. No real excuse save for wedding planning and the usual workload of a teacher in the build up to exams. I am however, back to the blog and will be posting more articles in the coming days and weeks.
Things to look out for:
Year 7 - posts regarding ecosystems and settlements
Year 9 - posts relating to our new unit on the Geography of Crime
A-Level - extra reading/interest bits on Conflict, Population dynamics, Health and Development
So...not much then...
Right, back to blogging with some local news.
Mr I
I feel an apology is overdue. I have been terribly remiss in not updating the blog more regularly over the last few months. No real excuse save for wedding planning and the usual workload of a teacher in the build up to exams. I am however, back to the blog and will be posting more articles in the coming days and weeks.
Things to look out for:
Year 7 - posts regarding ecosystems and settlements
Year 9 - posts relating to our new unit on the Geography of Crime
A-Level - extra reading/interest bits on Conflict, Population dynamics, Health and Development
So...not much then...
Right, back to blogging with some local news.
Mr I
Friday, 20 April 2012
Mexico raises Popocatepetl volcano alert
Mexico raises Popocatepetl volcano alert
Tens of thousands of people live in the shadow of the volcano Mexico has raised the alert level around the huge Popocatepetl volcano, after it began spewing ash and steam. Several schools around the 5,450m (17,900 foot) volcano were closed as a precaution, and evacuation shelters have been prepared. The National Disaster Prevention Centre (Cenapred) raised the alert to "yellow stage three" - the third-highest level.
The volcano lies around 70km (40 miles) from Mexico City, and is visible from the capital on a clear day.
"We can hear the roar of the volcano, sometimes we can feel its force," Concepcion Perez from the town of Xalitzintla in Puebla State, 12km (seven miles) from the volcano told the French news agency Agence France-Presse. Cenapred officials said the alert could remain for weeks or months until the volcano's activity diminished. Popocatepetl - which means "Smoking Mountain" in the indigenous Nahuatl language - is Mexico's second-highest peak.
In 2000 a major eruption forced the evacuation of tens of thousands of people from nearby communities.
'Huge' water resource exists under Africa
Scientists say the notoriously dry continent of Africa is sitting on a vast reservoir of groundwater.
They argue that the total volume of water in aquifers underground is 100 times the amount found on the surface.The team have produced the most detailed map yet of the scale and potential of this hidden resource.
Writing in the journal Environmental Research Letters, they stress that large scale drilling might not be the best way of increasing water supplies.
Across Africa more than 300 million people are said not to have access to safe drinking water.
Demand for water is set to grow markedly in coming decades due to population growth and the need for irrigation to grow crops.
Continue reading the main story
And just like a giant sponge, this ground water is held in the spaces between the rocks and in the tiny inter-connected spaces between individual grains in a rock like sandstone.
These bodies of wet rock are referred to as aquifers. Ground water does not sit still in the aquifer but is pushed and pulled by gravity and the weight of water above it.
The movement of the water through the aquifer removes many impurities and it is often cleaner than water on the surface.
What is ground water?
When water falls as rain or snow, much of it either flows into rivers or is used to provide moisture to plants and crops. What is left over trickles down to the layers of rock that sit beneath the soil.And just like a giant sponge, this ground water is held in the spaces between the rocks and in the tiny inter-connected spaces between individual grains in a rock like sandstone.
These bodies of wet rock are referred to as aquifers. Ground water does not sit still in the aquifer but is pushed and pulled by gravity and the weight of water above it.
The movement of the water through the aquifer removes many impurities and it is often cleaner than water on the surface.
Now scientists have for the first time been able to carry out a continent-wide analysis of the water that is hidden under the surface in aquifers. Researchers from the British Geological Survey and University College London (UCL) have mapped in detail the amount and potential yield of this groundwater resource across the continent.
Helen Bonsor from the BGS is one of the authors of the paper. She says that up until now groundwater was out of sight and out of mind. She hopes the new maps will open people's eyes to the potential. "Where there's greatest ground water storage is in northern Africa, in the large sedimentary basins, in Libya, Algeria and Chad," she said.
"The amount of storage in those basins is equivalent to 75m thickness of water across that area - it's a huge amount."
Ancient events
Due to changes in climate that have turned the Sahara into a desert over centuries many of the aquifers underneath were last filled with water over 5,000 years ago.
The scientists collated their information from existing hydro-geological maps from national governments as well as 283 aquifer studies.
The researchers say their new maps indicate that many countries currently designated as "water scarce" have substantial groundwater reserves.
However, the scientists are cautious about the best way of accessing these hidden resources. They suggest that widespread drilling of large boreholes might not work.
Dr Alan MacDonald of the BGS, lead author of the study, told the BBC: "High-yielding boreholes should not be developed without a thorough understanding of the local groundwater conditions.
"Appropriately sited and developed boreholes for low yielding rural water supply and hand pumps are likely to be successful."
With many aquifers not being filled due to a lack of rain, the scientists are worried that large-scale borehole developments could rapidly deplete the resource.
African water supplies may be more resilient to climate change than was thought "Much lower storage aquifers are present across much of sub-Saharan Africa," she explained.
"However, our work shows that with careful exploring and construction, there is sufficient groundwater under Africa to support low yielding water supplies for drinking and community irrigation."
The scientists say that there are sufficient reserves to be able to cope with the vagaries of climate change.
"Even in the lowest storage aquifers in semi arid areas with currently very little rainfall, ground water is indicated to have a residence time in the ground of 20 to 70 years." Dr Bonsor said.
"So at present extraction rates for drinking and small scale irrigation for agriculture groundwater will provide and will continue to provide a buffer to climate variability."
Sunday, 18 March 2012
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