Lesson

Dust Storms

So, dust storms in Australia are a natural weather event, they happen in many different countries, but they happen in Australia, and are common all over the world, right. They happen where there are dry lands. Okay. Where you have things like desert or arid regions with not a lot of rainfall.

So, they occur in Australia due to the continent’s land surface comprising a vast amount of deserts and semi-arid rangelands. When periods of severe and widespread drought occur, that is the lack of rain, they dramatically increase the likelihood of major dust storm events, particularly, in summer months, because these are the driest months.

So, this is due to the accumulation of loose dry dirt particles on the surface of the earth that are then more easily picked up by weather events such as low-pressure systems when there’s loads and loads of wind and also storms, when they move across that area.

So, the dust is blown up into the atmosphere, and then carried with the wind or with the storms that move with the strong pressure gradient until it dissipates. So, ultimately you can’t have dust storms without a significant amount of wind to pick up and move the dust particles.

So, Australia’s worst dust storm, this happened in mid-Spring of 2009 in Australia. This was called the 2009 Australian Dust Storm or the Eastern Australian Dust Storm, and it developed and swept across parts of South Australia and Victoria as well as the majority of New South Wales and Queensland, and it even blew across the Tasman Ocean all the way to New Zealand a few days later.

So, the dust storm developed on the 22nd of September in the dry desert and arid areas of Central Australia. And by 330PM, it caused blackout conditions in the town of Broken Hill and was heading eastwards towards Canberra, which it reached the following day at lunchtime.

Now, ‘blackout conditions’ means that there was so much dust in the air, it was almost like it was night time. Right. There was no light. It had blacked out everything. So, black out is usually when there is no light, no electricity for lights.

So, as the dust rolled over the eastern part of the continent, it set off smoke alarms, prompted increased demand for emergency services like the ambos or the firies, and sent many asthma sufferers to the hospital.

The dust storm turned the outside world into what people likened to a nuclear winter, an Armageddon, or the planet Mars, due to the dark orange color of the sky and the lack of visibility. So, in concert with these alien-like conditions, excessive rain was reported to have resulted from the dust particles in the atmosphere as well as cricket ball-sized hailstones falling from the sky like rocks.

In Coffs Harbour, in NSW, for example, visibility was reduced to less than 500 metres by 9AM on the 23rd of September, and planes were grounded and airports were closed as a result.

By this time, the dust plume was visible from space and measured 500 kilometers in width and an astonishing 1000 kilometers in length and had covered two states and dozens of towns and cities including Sydney, Canberra, and Brisbane.

By the 24th of September, the northern-most edge of the dust storm covered Cape York in Queensland and the southern-most edge of the plume stretched 3,450 kilometres south sitting out in the ocean parallel with Victoria and New Zealand.

By the morning of the 25th of September, red dust from the storm had been pushed by a cold weather front across the Tasman Sea and we’re starting to reach the Northern Ireland of New Zealand.

The CSIRO estimated the storm carried some 16 million tonnes of dust from the deserts of Central Australia.

So, the 2009 Australian dust storm was easily one of the worst on record. And I definitely recommend checking out the images of this storm via the Wikipedia page, which I’ll link in the transcript or just jump on to Google and search ‘2009 Australian dust storm’, because it looks otherworldly. Places like Sydney were covered in dust. You can barely see anything. Everything was orange and it literally looked like the surface of the Martian planet.


Vocabulary

A cold weather front – the changeover region where a cold air mass is replacing a warmer air mass.

A nuclear winter – a period of abnormal cold and darkness predicted to follow a nuclear war, caused by a layer of smoke and dust in the atmosphere blocking the sun’s rays.

A significant amount of something – a large quantity of something.

A strong pressure gradient – In atmospheric science (meteorology, climatology and related fields), the pressure gradient (typically of air, more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location.

Alien-like conditions – circumstances or states that are completely foreign or unknown.

An Armageddon – (in the New Testament) the last battle between good and evil before the Day of Judgement.

Asthma sufferers – people who suffer from a respiratory condition marked by attacks of spasm in the bronchi of the lungs, causing difficulty in breathing. It is usually connected to allergic reaction or other forms of hypersensitivity.

Be visible from space – be able to be seen from outside the Earth’s atmosphere.

Cricket ball-sized hailstones – large pellets of hail (frozen water) that fall from the sky during storms, that in this case are the same size as balls used in the game of cricket.

Emergency services – the police, fire brigade, or ambulances, etc.

Head eastwards – go in the direction of east.

Loads and loads of something – many of something.

Look otherworldly – appear like a completely different, alien world.

Pick something up – lift something upwards.

Smoke alarms – a fire-protection device that automatically detects and gives a warning of the presence of smoke.

Sweep across something – move over something in a smooth and swift motion.

The accumulation of something – the gradual gathering of something.

The ambos – (Aussie slang) the paramedics who drive ambulances.

The firies – (Aussie slang) the firemen who put out fires.

The lack of something – the absence of something.

The majority of something – most of something.

The Martian Planet – the planet Mars.

The northern-most edge (of something) – the edge (of something) that is furthest to the north.

The worst on record – the most severe ever noted by human records.