Maleny Weather

 A large amount of methane gas on our planet is stored as clathrates under oceans and land bogs. They are stable only in the cold or under high pressure.

 Clathrates  under the name of gas hydrates were discovered in 1810 by Sir Humphrey Davy, (inventor of the mining safety lamp), and were considered to be a laboratory curiosity until the  1930s when clathrate formation turned out to be a major problem by clogging gas pipelines in very cold weather. Clathrates are crystalline solids which look like ice, and occur when water molecules form around smaller ‘guest molecules’.

The most common guest molecule is methane. If one cubic metre of methane clathrates is brought to the surface in an uncontrolled state it will releases164 cubic metres into the atmosphere as a highly potent greenhouse gas, 24 times greater than CO2.

 Estimates suggest that methane hydrate deposits are a potential reserve twice the size of the combined total for coal, oil and conventional natural gas.

This realization of huge reservoirs of methane has led to some exploration, mainly by oil-poor countries seeking an alternative energy fuel. The methane gas might be recovered through injection of hot water or depressurisation, but the process has so far turned out to be technically difficult and expensive. There is also a danger of creating instability within the clathrate zone causing landslips and tsunamis.

A vast expanse of permafrost in Siberia and Alaska has started to thaw for the first time since it formed 11,000 years ago. It is caused by the recent rise in local temperature over the past 40 years – more than four times the global average. Peat bogs cover an area of a million square miles (or almost a quarter of the earth’s land surface) to a depth of 25 meters. Those in Siberia are the world’s largest and thawing of the permafrost has led to ‘burping’ of methane into the atmosphere as a greenhouse gas.

This is one of the most feared tipping point.  There is a delicate threshold where a slight rise in the Earth’s temperature can cause a dramatic change in the environment by triggering a huge and instantaneous increase in global temperature through an uncontrollable release of methane gas.

Methane, evolved through melting of methane hydrate, has been proposed for a sudden change of climate and surge in global temperature following end of the last ‘ice age’ some 200,000 years ago. A major underwater ‘slumping’ occurred resulting in the Storrega submarine landslide off Norway when 5600 km³ of sediment slid down a slope for about 800 km. It is possible there was also a massive tsunami.

This melting is an irreversible ecological landslide - a vicious circular feedback that is becoming stronger and stronger, and is doing so more quickly with every passing summer.

A significant part of the heat gained during the summer is held within the peat by the autumn snow that acts like a blanket to keep it warm, and thus the heat gained is incremental. Once methane gas escapes in large quantities into the ozone layer extreme global warming is likely to be irreversible.

There was a little ‘ice age’ at the beginning of the 14th century after the huge loss of population from the Black Death when the North Atlantic cooled until the mid-19th century. This period brought severe winters, sudden climatic shifts, and profound agricultural, economic, and political impacts to Europe. It was marked by persistent crop failures, famine, disease, and population migration, perhaps most dramatically felt by the Norsemen. Famine caused tens of thousands of deaths.

 We are indeed fortunate that we are living in one of the warmest periods for the past million years and under conditions that must be under the optimum for human life to flourish. Any dramatic change should therefore be viewed with apprehension.

Interest in the recent re-construction and renovation of the Maleny community hall is a reminder the site was first used by Maleny School of Art.  This hall was built around 1908 for £219. The hall burned to the ground in 1952 and was rebuilt a few years later. In its early days the hall was used for every kind of community activity but the two remembered best are dancing to the music of an accordion that went on until 1.00 am and the Grand Balls with people coming from farther away on horseback and buggy. Dancing continuing all night with a substantial supper served at midnight to avoid the danger of travelling home through muddy bush tracks in the dark. For some, early morning breakfast was served before setting out for the long journey home.

When a Grand Ball was celebrated it was a good occasion for the gathering of the clans. Young and old folk arrived on horseback from all parts of the district. Grandmothers and grandfathers danced the lancers and the polka with erect carriage and an energy that puts the younger generation of today entirely in the shadow.

In 1921 a circus performance at the School of Arts resulted in a child, Mary McLean, being mauled about the head by a lion that was tied up on the stage. The local vet and butcher came to her rescue. The child was not seriously hurt.

The catastrophic Chile earthquake on Sunday 28^th was followed by a Pacific tsunami warning being issued by Hawaiian control centre. The likelihood of a tsunami reaching our coastline was minimal but even so, as a precautionary measure, all east coast beaches were closed, especially to swimmers, surfers and anglers.  However, despite all efforts by police and lifeguards it was difficult to enforce the order to the dismay of authorities and many swimmers and surfers were foolishly waiting for the ‘big one’.

The past week has again been the wet and muggy and we recorded 282mm of rain, with the heaviest falls occurring during the 48 hour period from 9am Monday when a total of 173 mm was measured. It has been an interesting week for meteorologists when three weather systems interacted with one another. The cause for some of our drenching was from a deep monsoonal low in a trough extending across southern Queensland bringing torrential rain and flash floods to the region. Winds were light and movement of the low was slow until Tuesday morning when an east coast low developed close to Fraser Island to intensify rainstorm activity. Winds increased to gale force due to the steep pressure gradient between the high in the Tasman Sea and the ‘east coast low’ off Fraser Island.

On Saturday 6^th March we had another deluge when 109mm fell in a  space of  18hours, causing flash flooding in many areas. The Baroon Pocket dam is full to capacity and closed to both swimmers and boaters.

 Keeping a weather eye open for wind vanes is an interesting pastime. In many countries of the world the tops of buildings are adorned with wind vanes. Weathervane is perhaps not the best word to use, for a vane just indicates wind direction and not weather. The word vane comes from the Anglo-Saxon word ‘fane’ meaning ‘flag’.

In the days of old sailing ships a narrow pennant was flown at the masthead to indicate wind direction to the helmsman and this was known as a vane. Today, sailing yachts use burgees for the same purpose.

The Tower of the Winds in Athens once bore on its roof a wind vane in the form of a bronze Triton holding a a rod in his outstretched hand, rotating as the wind changed direction. Below, the frieze was adorned with the eight deities. The eight metre high structure dates from around 50 BC.

The wind vane evolved from a Triton to a weathercock as the Roman Empire converted to Christianity. Many churches have a weathercock on the tower or spire.

Pope Nicholas 1 in the ninth century ordained all land vanes to be in the shape of a cockerel to remind people of Peter’s denying Christ and the cock- crow that followed. Hence the commonly used synonym weathercocks even when there is no cockerel shown. Weathercocks predominate, however, and can be seen in any shape, form or material. Sometimes in copper sheathed, often gilded, occasionally in lead. The bird’s head always faces into the wind with the tail behind, naturally the larger part, sometimes looking ridiculous.

Vanes in the shape of ships probably follow cockerels in popularity, especially in coastal towns and ports, where fishing trawlers skippers depend so much on the weather that in turn was the will of the wind.

Farms quite often have vanes for the same practical reason, as do the fishing ports. A wind change could mean a change of weather for the good and time to plough or sow.

Rural vanes are often in the shape of a country theme, such as horses ploughing, ridden or pulling some form of transport. Shapes of farm animals and birds are also popular.

Weather, of course, is a major talking point. We keep a weather eye on things, we make heavy weather of other things, and we can be under the weather or weathering life’s storms.

The world’s largest weather vane is JEREZ, Spain. A challenger for the world’s largest weathervane is located alongside Whitehorse International Airport, Yukon. The weathervane is a retired Douglas DC-3 atop a swivelling support. The vane only requires a 5-km/hour wind to rotate.

The term weathervane is also a slang word for a politician who has frequent changes of opinion.

Flash floods happen suddenly (hence the name), forming in less than six hours. This sets them apart from “regular” floods, such as river floods, which can often be predicted days in advance. They are caused when a heavy rain falls over low-lying areas, especially when the soil is already saturated. They happen when rainfall intensity and duration match up, in a very bad way. More than half the fatalities happen when people try to cross flooded intersections in their cars. This is because people are generally not very good at judging the depth and danger of flooded streets. (They can’t actually see the roadway surface, which might be a big deep hole.) While two feet of water doesn’t seem like much at all, especially if you are safely inside a big, heavy car, it is enough to carry you and the car away. (Another fact we tend to forget: cars are buoyant.)  According to the National Oceanic and Atmospheric Administration of USA: –  ”Water weighs 1,010 kg per cubic metre and typically flows downstream at 10 to 20 kph. When a vehicle stalls in the water, the water’s momentum is transferred to the car. For each foot the water rises 226 kg of lateral force are applied to the car. But the biggest factor is buoyancy. For each foot the water rises up the side of the car, the car displaces 2,040 kg of water. In effect, the car weighs 2,040 kg less for each foot the water rises.”

Do not be tempted to drive across a flooded roadway.(”Don’t drown; turn around.”) If you find your vehicle stalled in a flooded road way, leave it and seek higher ground. (”Better wet than dead.”)