The recent disastrous flooding in Queensland is closely connected with the La Nina phenomena, when waters across the central and eastern equatorial Pacific Ocean cool, and warmer ocean areas gather closer to northeast Australia.
Put simply, rain tends to cluster around the warmest parts of the ocean because the warmth produces rising air, and this in turn generates cloud and rain. La Ninas are usually associated with enhanced rainfall over eastern Australia with moist tropical air often extending down from Queensland well into the southern states, even as far as Tasmania, where flooding occurred during the second week in January 2011.
The present La Nina weather pattern across Australia kicked in rapidly around May of 2010, flipping across from the opposite El Nino phase that is usually associated with dry weather for eastern Australia.
The onset of the La Nina resulted in a rising crescendo of major rainfall events that rolled across Queensland from September onwards. Catchments right across the state became increasingly saturated as one rainfall event followed another.
The Barron Falls inland from Cairns, in raging flood during January 2011. Photo by Barbara Menz.
At the end of 2010 most of the catchments across south-eastern Queensland were totally saturated and any additional rainfall would then just run off into the adjacent river systems – a critical situation to be in during only the early stages of the Australian tropical wet season.
Disastrous flash flooding erupted through Toowoomba on Monday 10th January, when a wall of water swept through the town, killing an unknown number of people and causing immense property damage as houses and cars were literally swept away by the deluge. This occurred as high intensity rainfall, around 100mm in just one hour, fell on the already saturated catchment of the Lockyer Creek.
Major flooding then burst across much of southeast Queensland on Tuesday 11th and Wednesday 12th January with Brisbane itself inundated as the Brisbane River burst its banks and rose to levels just short of the 1974 flood. The degree of flooding in the area places the disaster in the “top three” of floods, alongside 1893 and 1974.
Major flooding around Boonah in Queensland in January 2011. Photograph by Leona Taylor.
The La Nina phenomenon marches to an irregular beat but has always been a big part of Australia’s climate, as has the opposite El Nino phase. Dorothea Mackellar summed up their impact poetically when she described our climate as one of “droughts and flooding rains”. Indeed it has been said, somewhat tongue in cheek, that average rainfall in many parts of Australia equals drought plus flood divided by two.
Following the massive flooding of early 2011, many people are asking if climate change is somehow behind the tremendous rainfall intensity we have just seen. Here expert opinion is somewhat divided.
Total inundation of the surrounding countryside near Moorang, Queensland during January 2011. Photo by Angela Gray
Some climatologists believe that rising ocean temperatures around northern Australia, that are about 1.5C above pre 1970’s levels, will produce more intense La Ninas, even if their frequency remains the same. Warmer oceans produce warmer air above and an atmosphere of this type can hold far more moisture that then becomes available for rain.
The unusually strong monsoon that produced devastating floods across India and China around mid 2010, followed by the flooding disaster in Pakistan in August has been linked to this pattern.
However other experts have remarked that although it is almost certain that rising ocean temperatures will be affecting the La Nina/El Nino see-saw it is too early to say how. They point out that the period of recorded history is too short to reach any firm conclusion.
However there is little doubt that the extraordinary weather events that occurred right around the world during 2010, together with our own Australian experience of extreme weather, has brought the topic of climate change back on the front page after a notable absence during much of 2010.
Sunday, January 16, 2011
Sunday, January 9, 2011
I'm a Neanderthal Man
In 1829 and 1848 skeletal remains of heavily built “humanoid type” creatures were discovered in Belgium and Gibraltar, triggering massive scientific interest. Then in 1856, in the Neandertal Valley in Westphalia, Germany, further fossil evidence of the same type was indentified and given the name “Neanderthal Man”.
For the first time scientists realised that it was likely that another "homo species", running parallel with our own Homo sapiens, existed many millennia ago but for some reason had died out, leaving Homo sapiens to develop into the modern human being.
Many more similar skeletons were later discovered across parts of Europe, the Middle East, western and central Asia and southern parts of Great Britain, but interestingly not in Africa, believed to be the birthplace of Homo sapiens.
Above: The skeleton of a Neanderthal Man in the American Museum of Natural History. (Image from Wikipedia Commons - click to enlarge)
The remains of more than 400 Neanderthals have been discovered since, and dating of these indicates that they existed from around 130,000 years to 30,000 years before the present time, before unaccountably disappearing.
The sites where Neanderthal remains have been discovered. (Image from Wikipedia Commons - click to enlarge)
Using forensic reconstruction techniques based on existing skeletons, scientists have been able to make an educated guess as to their appearance. The males were about 165 to 168 cm (65 to 66 inches) in height with the females a little smaller at 152 to 156 cm. (60 to 61 inches). This was about the same height as the Homo sapiens of the same era.
However the skeletal evidence indicates that the Neanderthals were far more thickset, and the large bones point to the fact that stronger muscle groups would have anchored Neanderthals together. They would have been far more powerful than Homo sapiens, perhaps of similar strength to the modern chimpanzee.
But far from being the hulking, unintelligent brutes of folklore, recent evidence reveals many modern traits about the Neanderthals. It is now believed that they made weapons and tools, cooked, lived in family groups, developed a language and wore clothing.
It appears that Neanderthals disappeared around 30,000 years ago after cohabiting their area with Homo sapiens for some 20,000 to 30,000 thousand years.
And the fascinating question arising from this disappearance is obviously – what caused it?
There are several theories and these include
(a) Climate change
(b) Increased competition from and possibly warfare with Homo sapiens
(c) Interbreeding and absorption with Homo sapiens.
The most significant climate event during the time of the Neanderthals, as deduced from Antarctic ice data, was a sudden jump in global temperatures from around 120 to 110 thousand years ago, followed by a marked cooling from that point to about 100 thousand years ago. Global temperatures then fluctuated erratically over the next 30,000 years.
Temperature fluctuations during the time of the Neanderthals - did these lead to extinction? (Click to enlarge)
It has been suggested that these temperature variations produced significant changes in the vegetation patterns, together with the various dependant animal species. This may have tested the Neanderthals ability to cope with change, with the competing Homo sapiens more effective in this respect.
Another possibility is that increased competition and possibly warfare occurred with Homo sapiens, with the latter winning out through slightly more efficient social skills and cooperation.
But another, more fascinating theory, is that the Neanderthals did not disappear at all but were absorbed through interbreeding with Homo sapiens and continue to live on in the genes of modern humans. This theory has received some powerful reinforcement in recent times when researchers were able to reconstruct the genome sequence of the Neanderthals and found that “up to 2 percent of the DNA in the genome of present-day humans outside of Africa originated in Neanderthals or in Neanderthals' ancestors”.
This interbreeding appeared to take place between 80,000 and 50,000 years ago across parts of the Middle East before spreading to other areas across Europe.
The interbreeding hypothesis is still an area of scientific debate, but the mystique and intrigue surrounding what could be our closest ancestor continues to fascinate the scientific community, as well as the general public.
In 1970, the British band “Hotlegs” wrote a song called Neanderthal Man that was interspersed with the chorus:
"I'm a Neanderthal man
You're a Neanderthal girl
Let's make Neanderthal love
In this Neanderthal world."
Hear it here:
Although the lyrics were far from award winning, Neanderthal Man reached No.2 in the UK Singles chart in July 1970 and No. 22 in the US, ultimately selling two million copies worldwide. It success was possibly due in part to the fascination we have for this strange and enigmatic being that trod the Earth so long ago and may continue to exist as part of us today.
References:
http://www.genome.gov/27539119
http://www.chrisdellavedova.com/2007/10/30/science-tuesday-chatty-redheads-or-dirty-hands/comment-page-1/
Monday, January 3, 2011
That Mother Board
“Dem Bones” is a very clever melody that was written by the acclaimed African American author and songwriter James Weldon Johnson (1871 to 1938) as a way of teaching children the basic anatomy of the human body.
Left: James Weldon Johnson, a man of kaleidoscopic talents who was at various times in his life a writer, lawyer, university professor, diplomat, teacher, civil rights worker and anthologist. (Image Wikipedia Commons )
It was written in traditional spiritual style and was not only an entertaining and instructive teaching aid but also became a highly popular novelty item on the hit parades of several countries, including Australia, in the 1940’ and 50’s.
One of the choruses goes like this:
The head-bone connected to the neck-bone,
The neck-bone connected to the back-bone
The backbone connected to the thigh-bone
The thighbone connected to the knee-bone
The knee-bone connected to the leg bone
The leg bone connected to the foot bone
Oh hear the word of the Lord
A great 1950's version of the song, as performed by the Delta Rhythm Boys singing ultra smooth five-part harmonies, can be heard here:
http://www.youtube.com/watch?v=pYb8Wm6-QfA
After recently hearing a version of the song, just by coincidence, it occurred to me that we need a more modern version to explain the mysteries of the computer world to the over sixties (like me), so I’ve had a try, borrowing from James Johnson's idea. Here’s the result:
That Mother Board
The Wifi’s connected to the I phone
The I phone’s connected to the e-zone
The e-zone’s connected to the ring tone
It's the word of the Mother Board
The Airports connected to the Blue Tooth
The Blue tooth’s connected to the tweet zone
The tweet zones connected to the batch file
It's the word of the Mother Board
The bitmaps connected to the Android
The Androids connected to the hard drive
The hard drive’s connected to the firewall
It's the word of the Mother Board
The half tones connected to the V-Ram
The V-Rams connected with the screen shot
The screen shots connected with the inkjet
It's the word of the Mother Board
The clock speeds connected to the bandwidth
The bandwidth’s connected with the add-on
The add-ons connected with the ASCII
It's the word of the Mother Board
It's the word of the Mother Board!
To the Baby Boomers - hope that makes it all clear.
James Weldon Johnson was one of the most influential and high achieving black Americans of the early twentieth century. He was one of the very first African American professors at New York University and later became a professor of creative literature and writing at Fisk University.
In 1988 the United States Postal Service issued a 22 cent postage stamp in his honour.
References:
http://en.wikipedia.org/wiki/James_Weldon_Johnson
http://www.suite101.com/content/usps-black-heritage-stamps---james-weldon-johnson-a267955
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