How do volcanoes form?

It has been a while since we posted an example KS3 Geography clip. Some of the most popular search terms that people use to find our blog relate to natural disasters, earthquakes and volcanoes. I have written about my experiences with earthquakes and typhoons whilst living in Taiwan before, and there was also a post about KS3 Geography Unit 2: the restless earth – earthquakes and volcanoes, which included a clip on volcanoes in Ecuador and Montserrat. 

Credit: http://www.flickr.com/photos/11304375@N07/

One of the new sets of clips that we have created for the 2008 KS3 Geography Programme of Study make up a topic entitled ‘A hazard – Two volcanoes’. The topic focuses on Mount St Helens in Washington State, and Mount Kilauea in Hawaii, two very different types of volcanoes in terms of their origins, effects, and responses. The differences are explored in the detailed teacher notes and worksheets that accompany the clips, and you can view all of the videos here by taking out a free trial of the video gallery.

This example clip is one of them and explains how and why the majority of volcanoes form at plate boundaries because of plate tectonics and the process of continental drift. Other volcanoes occur in the middle of plates and these are caused by ‘hot spots’ in the Earth’s surface, where hot rocks from the Earth’s core rise up through the mantle and crust. As a plate moves across a hot spot over millions of years, a line of volcanoes is formed.

Title of clip	How volcanoes form
Curriculum location	Geography (secondary)  >  KS3 Geography POS 2008  >  A hazard
Description	The formation of volcanoes explained in geological terms: an animation depicts Iceland on the mid-Atlantic ridge, a great fault lying between the Americas and Africa; the Earth’s surface is divided into plates; the plates move across the Earth’s surface causing continental drift; an animation shows a cross-section of the Earth, each layer is described and named, the theory of plate tectonics is introduced; an animation demonstrates the constructive and destructive elements of plate tectonics and how volcanoes are formed along plate boundaries; an animation of ‘hot spot’ volcanoes forming on the Pacific plate, Mount Kilauea, Hawaii being a good example.
Duration	4 minutes 47 seconds

 

Please note that this is an example clip provided through our YouTube channel and does not reflect the actual quality of clips in the gallery