VoLcAnO’s Hello, my name is Jo This presentation is to see how volcano’s are structured and the understanding of eruptions and environments around volcano’s. White Island The map opposite shows an island near New Zealand called White Island. No body lives there even though it is beautiful this is because it has its very own volcano. This volcano is one of New Zealand's most active volcanoes. It has killed many people that worked there doing jobs such as men at sulphur works. It caused a landslide. White Island’s Volcano active! This is the earths structure – There is a thin layer of crust, this is just below us. The mantle contains maga and is extremely hot and has a thickness of 2900 kilometres. The core has two parts, the inner and outer core. The heat is hotter than the anywhere else in the inner core and the outer core is only a little less. Volcanoes Volcanoes are caused by tectonic plates, that have moved as the millions of years have gone by. Thousands of years ago the earth would not have looked like it does now, this is the cause of the plates moving which can separate countries as results of volcanoes and earthquakes. Mount St Helens history - Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche. Nearly 230 square miles of forest was blown over or left dead and standing. At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, grey ash fell over eastern Washington and beyond. The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments. Eyewitness account of mount St Helens eruption on May 18th 1980 Many individuals who were in the vicinity of Mount St. Helens on May 18 were interviewed to gain information on phenomena associated with the eruption. The observed phenomena include an earthquake, a massive avalanche of the volcano's north flank, a directed blast, development of the vertical eruption, a mudflow in the South Fork Tousle River valley, and the fall of early eruptive products. "As the avalanche reached the halfway point on the mountain, the summit eruption began with a dense black cloud followed by lighter grey material. A second eruption halfway down the slope occurred moments later * * *." At this time the avalanche appeared to consist of upper and lower parts. The flank eruption was between the two. Seconds later the upper slide overrode the flank eruption and material was hurled far down slope onto the lower slide. About 45 s after the landslide began, the eruptive centres merged and the rapidly expanding cloud overtook the avalanche.” What happened on the 18th of May This is what Mount St Helens looked like before May the 18th. I will now show you the picture of the volcano and the changes that was made to it! May 18th One side of the volcano collapsed in a landslide and the eruption was mainly pyroclastic flow. These are effect of the pyroclastic flow. Diagram of Mount St Helens This is a diagram of Mount St Helens Thank you you for listening to my proect on volcanos I hope you have learned a little ore abou them and understand the eruptions more too.