Science Infoblog

Huge eruptions have buried the Auckland region in volcanic ash in the past. Geologists have warned that there is a significant risk of ash fall in our lifetime. The simulation at the Auckland Museum gives you some idea what a bad day at the beach might look like!

There are 48 small volcanoes in the Auckland region all of which have erupted in the last 150,000 years. The rock about 100Km below your classroom can melt. A huge molten bubble of magma can gradually make its way towards the surface through the denser surrounding rocks a little like a hot air balloon lifting off the ground. When the magma nears the surface eruptions follow a similar sequence that is over rather quickly.

• If you hear the sound of a large explosion and suddenly find yourself several hundred metres up in the air you will remember reading this. The molten rock eventually came in contact with water as it neared the surface and built up a huge pressure of steam. This pressure  blasted an area of real estate 2 kilometres across and a football field deep into the air.
• What goes up must come down and a ring of shattered rock and dust  gathersround the volcano’s throat. This is called a Tuff ring
• If the lava contains a lot of gas it froths like a bottle of coke that has been shaken before removing the cap. Frothy lava is ejected from the vent and a steep sided scoria cone formed. This process is called lava fountaining.
• When the gas content falls lava can flow up the vent and burst through the crater wall. Large amounts of debris raft away on the free flowing lava
• Finally as the volcano finally loses its fizz a small scoria cone can form inside the vent

Have a look at the slideshow of pictures taken on Mangere mountain.

Mangere mountain came into existence about 18,000 years ago. Can you see evidence for:

• volcanic eruptions that got no further than the intial explosive phase with a tuff ring and a small scoria cone
• More than 1 crater in mangere mountain
• smaller scoria cones formed as the magma ran out of fizz
• A breach in the volcano when the wall was washed away by a lava flow.

The youngest Auckland field volcano, Rangitoto, erupted 600 years ago. A new volcano could erupt in a neighbourhood near you sometime soon.

Year 9 classes recently made their own pin hole cameras and experimented with the chemistry of light.

To get the best results in this achievement standard you need be clear about how you organise your answers.

All the basic material you need to know about is covered in three short videos, a complete course reduced to 15 mins!

The first video deals with covalent bonding Lewis structures and Lewis diagrams. There is a short quiz at the end of it.

The second video deals with molecular shape and polarity

The third video deals with metallic and ionic bonding. It also examines properties such as malleabilityor ductility and conductivity when molten or in aqueous solution. The solubility of ionic compounds in aqueous solution is also discussed.

good luck

Marie Menzies and her year 9 social studies class took over the science laboratory to prepare a series of organic crop sprays. They are non toxic and decompose naturally. They don’t leave hidden toxic residues that can build up over time. Their use is sustainable

In social studies the long term impact of  our activities on ourselves and the planet (our mobile home) is important.

Pest control on crops is important. We farm intensively to grow enough food for the population to survive. Nasty chemicals are required to control organisms that damage our food plants

The government keeps a register of these chemicals with ERMA, the Environmental Risk Protection agency.

If you attack my potato plants when they are growing I will retalliate with weapons of mass destruction.

Chemistry finds its way into every aspect of our life including my vege garden. Food science is chemistry that tastes good.

My first crop of potatos  two years ago wilted in the summer dust and a belated attempt to recover the situation failed in the mid winter frosts. A single bag of potatoes was a poor reward for a lot of effort.

With one set of potatoes ready to flower in mid November last year the unthinkable happened. Leaves at the top of the plant began to curl up and droop.

On closer inspection the cause was soon apparent. The unhealthy plants were crawling with “stink bugs” or Nezara viridula (linnaaeus). Apparently these little suckers pierce plant tissue, remove the goodies and totally deflate the new growth at the top of the plant. The damaged leaves like pieces of punctured balloon are all too visible in the photos.

McGregor’s general purpose insect spray had an immediate impact on the pests. The active ingredient in the insecticide is diazinon.

Formulations containing diazinon have been registered for use in New Zealand since 1967. There are currently 32 products containing diazinon that are registered for agricultural and veterinary medicine use including 14 insecticides and 18 veterinary medicines according to ERMA (Environmental Risk Management Authority NZ).

and now the chemistry….. Compounds like diazinon need to be treated with a lot of respect. Diazinon is closely related to chemical warfare nerve agents such as Sarin and Tabun

Tabun and sarin were among the agents used by the Iraqi government when it killed 5,000 Iraqi Kurds in Halabja in 1988. Liquid sarin in perforated bags killed 12 people in the 1995 attack on the Tokyo underground.

Chemists have discovered ways to synthesise new molecules with designer properties. Nerve gasses wreak havoc on the transmission of nerve impulses in the nervous system.

The components of molecules responsible for their chemistry are known as functional groups. Chemists have a large tool kit of functional groups that can be unscrewed from a molecule and replaced by another with different properties. Diazinon is a good example. The same purple phosphorus atom and three red oxygens lie at the deadly hearts of these nerve agents.

Should we be using weapons of mass destruction in our gardens?

To sustain life on this planet you will need all the skills you learn in social studies together with the ability to understand complex science. We need a generation of young citizens who are able to engage in intelligent debate and hold those in authority accountable . Good luck your kids depend on you.

APPENDIX

ERMA  NZ maintains according to its own information a short list (actually its quite long) for which there is evidence that the risks faced by those who use these substances or come in contact with them after someone else has used them (you) may not be adequately managed

Here is the list, look out for them on labels

According to Wikipedia Civil Engineering is a discipline that deals with the design construction and maintainance of structures like bridges, roads,  canals dams and buildings.

The World Trade Centre consisted of 7 buildings on a 16 acre Plaza in lower Manhattan. 19 terrorists hijacked four aircraft on the morning of September 11 2001. The hijackers crashed two planes the Trade Centre towers which collapsed within 2 hours. A third aircraft crashed into the Pentagon building in Arlington,Virginia and the last one nose dived into a field near Shanksville in Pensylvania.

Just why the “twin towers” collapsed has been the subject of various conspiracy theories:

• controlled demolition rather than structural weakening due to fire
• the Pentagon was hit by a missile
• the hijacked planes were replaced by planes carrying explosives

Eight years on and even after thorough scientific investigation the myths continue to grow in sophistication. Apparently nano-thermite particles (ask any 6th form chemist about factors controlling reaction rates and what highly exothermic means) have been found in the rubble of Ground Zero by a Danish professor. Nano-thermite is a highly reactive compound used by the US Department of Defence. It is also used to lainch rockets.

Civil engineers are skilled in the use of science and mathematics to build structures that don’t fall over. The Auckland Harbour Bridge needed extra capacity hence the addition of nippon clipons in 1965. The two-lane box girder sections added on each side of the bridge doubled the traffic lanes to eight. Structures must be  maintained and cracks discovered in 1987 and cracks/material fatigue found  in 2006 could not be ignored. Generally engineers get it right and we trust their safety margins. Currently vehicles are restricted to weights of 13 tonnes or less after further concerns that a traffic jam stopping flow on the bridge could cause the clip-ons to unclip.

Similarly we don’t expect the sky tower to blow over in high winds although the revolving restaurant at the top is sometimes closed in storms as the swaying motion causes soup to slurp over diners’ bowls. Swaying is good as far as engineers are concerned. The alternative, snapping to release strain is not a popular choice!

Civil engineers can use science and mathematics skills to determine the likely causes when buildings and other structures do fail catostrophically.

Purdue University worked with the American Society of Civil Engineers to produce an analysysis of the most likely chain of events leading to the collapse of the twin towers eight years ago. This involved thorough mathematical and computer modelling of the forces involved using the original building blueprints. Data defining the properties of the construction materials were also fed into the calculations.

Structural weakening due to fire is the only credible scientific theory explaining the collapse of the twin towers.

Civil Engineering at the Univerity of Auckland:

Civil Engineering is a four year course requiring good seventh form grades.

from the student handbook:

• to gain admission to University of Auckland you must gain the university Entrance Standard and be selected into a programme.
• You will be allocated a ranked score based on your best credits at level 3 or higher.
• A maximum of 5 approved subjects weighted by the level of achievement attained in each set of credits.
• If you achieve fewer than 80 credits at level 3 the ranking will be based on those credits you have achieved over a maximum of 5 approved subjects at level 3 weighted by the level of achievement.
• The approved subjects are determined by NZQA and are available at www.nzqa.govt.nz/ncea
• You are are strongly advised to take achievemnt standards as preparation for University study.
• The guaranteed admission score for BE(Hons) in 2009 is 240 with a minimum of 18 credits at Level 3 in Maths with calculus and Physics.
• The rank score is calculated by awarding 4 point for Excellence, 3 for Merit and 2 for Achieved for up up to 24 credits in each approved subect at level 3 over the last two years.
• The maximum possible score is 320

NOTE……NOTE…….. The importance of mathematics in the study of science at University