Class 9 have just completed three weeks of exploring the everchanging earth beneath their feet in their geography Main Lesson The Forces That Shape the Earth. Using slinkies to mimic seismic waves, students started the Main Lesson by learning that the measurement of earthquakes has been used to determine that the once mysterious centre of the earth is largely molten rock with a solid core. With some assistance from a jam and bread practical, students also explored how the earth shifts and changes shape through the movement of tectonic plates. It was a surprise to Class 9 to learn that plate tectonic theory was only accepted as late as in 1968!

Through group work and careful analysis of articles, we also became experts on the formation of mountains, valleys and islands. We explored how hot spots under the earth’s crust leads to volcanic activity, and subsequently shape some of the world’s most beautiful locations. Class 9 also shared their own research presentations to the class on natural disasters caused by the earth’s motion, presenting to the class group some of the causes and consequences of the catastrophic events that our planet brings to ourselves and the broader environment.  

Class 9 also replicated visual diagrams of the different ways the earth moves and compared these to famous world locations as far away as the Maldives, Iceland and the Himalayas. Closer to home, they learnt how the Pacific “Ring of Fire” was formed and studied the earth’s movements and volcanic activity in New Zealand, Indonesia and even how earthquakes occur in their own backyards up in the Darling Scarp and across Western Australia. We studied local rock formations, and we also were enchanted with a seemingly volcanic rock from Norway - or was it bitumen from a Norwegian car park? The answer was revealed to be the latter, but we were nonetheless momentarily enthralled by the molten rock, however artificial! 

Our Main Lesson was completed with an earthquake proof structure challenge, where Class 9 constructed their own earthquake proof buildings with toothpicks, marshmallows and coiled pasta pieces. These were set in jelly and vigorously shaken the next day. Whilst some impressive looking multi-story structures collapsed before the “earthquake” began, other structures with some proven earthquake proof features lasted even through the most vigorous shaking. These were only to finally break after being thrown several metres from our Class 9 balcony a number of times! As we finalised our Main Lesson, we were left to understand the powerful forces that shape us and our world, and the perpetual motion that is the earth’s existence.  

Alisha Watkins

English and Humanities Teacher