On Thursday 27th of February, 9A went to Mangere Mountain to witness an actual volcano. For the last 6 weeks, we had been focusing on volcanoes and other natural disasters. We arrived at 9:30 in the morning we were met by our guides at the entrance to the mountain. We walked for a short period before coming upon a plastic red box. Our guide got us into groups of four and gave us a sponge with a bottle with vinegar in it and a spoon of baking powder. We had to pour the baking powder into the vinegar which reacted with a splash of white foamy liquid.
Once we had all tried the experiment we went for a brisk walk to a depression in the land. Our guide explained that this was once a storage place for food used by the Maori people that lived on this mountain. We walked back to where we created our first experiment and prepared for our second. We were each given a plastic bottle filled with a brown chunky liquid and placed it through a hole in a plastic sack. Then we opened the lid and watched it slowly wind its way down the sides of the sack.
After the experiment, she explained its significance. “In each of the bottles was a cheap soft drink mixed with glue to make a chunky texture, the carbon dioxide bubbles in the soft drink represent the highly pressured gases inside the lava”, our guide told us.
Soon afterwards we climbed to the highest point on the mountain and circled the rim of the dual craters before walking down into the second crater to inspect some ‘lava bombs’. She showed us the different types of lava bombs and how they formed. We then ventured to Ambury Farm Park where we were each given a helmet as it was time to explore the lava cave underneath one of the fields. The entrance was covered with a hollow grilled piece of steel so you could not access it without a key. Our guide opened it and we descended into the cave, it was a gloomy area illuminated by one stream of light coming through the hole we just climbed through. It was about ten meters wide and 1.5 meters tall. Our guide explained that caves like this were made when lava cools on the outside but the lava remains warm and keeps moving, creating a sort of tunnel. She proved it by showing the igneous rock on the ceiling and walls.
Finally we had a civil defence unit; it would be the last activity we did. We learnt about what would happen if a new volcano erupted in Auckland. We found out about pyroclastic flows and lahars and their devastating effects. Our guide gave us an idea of what happens in an evacuation and what we needed to take should we ever need to be evacuated. At last it was time to leave. We wished our guide well and left.
– By Thomas McCulloch 9A