Last Thursday we went to the Natural History Museum in London to learn about natural disasters; specifically volcanoes and earthquakes.
First we took part in an interactive show that showed us how earthquakes and volcanoes form and how we measure and try to predict them. We did an experiment with a seismometer where Mr Brown and Sophie had to jump up and down to test it and it showed how strong the shake was on a monitor. We then tested it on a model city – Seth had to turn a handle slowly and then quicker to create small shudders in the ground. While it happened it was being measured on the scale. We learned how the tectonic plates move – when they rub together then one slips past the other causing a tremor. It depends on the depth of the epicentre on how high it is on the richter scale. Anything above 7 is pretty serious. We learned how inside of the earth is made up of the inner core made of iron and nickel, wrapped the inner core and the outer core, the mantle and then the crust. It’s all made of magma which is 700-1300 deg centigrade (as hot as the sun!) which heats up and pushes the mantle which moves the plates.
There are different types of volcanoes – composite (strato), shield and lava dome. The strato are more dangerous because they have steeper sides, the magma (lava) is thick and turns into pyroclastic flow which can move at 300mph and is extremely hot, and also a cloud of volcanic ash is propelled into the sky and can move at up to 450mph destroying everything in its path. It is a volcanologist’s job to try to estimate when an eruption will happen by monitoring the seismic readings.
To get to the gallery we went up through a huge goldy red earth there was a huge world map showing all the boundaries of the tectonic plates and the active volcanoes – the most are in the ring of fire which surrounds the Pacific Ocean. There was a machine where you could “make” your own volcano depending on height of the sides, amount of gas inside and the thickness of the lava. There was a small tank with rocks at the bottom that you had to push the water down onto the ring – the small rocks were harder to move. You could create a simulation of an earthquake by pressing the button to shake the floor and you tried to make the buildings fall over which were made earthquake proof.
We also went into a Japanese supermarket – we were watching a video of an earthquake and suddenly the floor started shaking for at least 10 seconds – all our hearts leapt into our mouths.
In the afternoon we carried out our own scientific investigations using a selection of fossils, bones, skin, plants, animals, teeth, insects, crystals, fungi, petrified wood and we had to choose one to investigate – draw it carefully, look at how it was formed, use a microscope, a visualiser and weigh and measure it. At the end we looked at a selection of different eggs which had adapted to their environment – a pointy cone shaped egg had evolved for birds that laid their eggs on cliff edges or icy surfaces and so when it rolled it wouldn’t go straight. They had also adapted their colour to camouflage them – one was black (in a rainforest) and couldn’t be seen by predators.
It was a very interesting, exciting and fun trip out – we learned a lot about a lot of different things!