black/white schema of volcano
<a href="//commons.wikimedia.org/w/index.php?title=Peko&amp;action=edit&amp;redlink=1" class="new" title="Peko (page does not exist)">Peko</a>
own work, based on <a href="//commons.wikimedia.org/w/index.php?title=File:Volcano_schema.JPG&amp;action=edit&amp;redlink=1" class="new" title="File:Volcano schema.JPG (page does not exist)">Image:Volcano schema.JPG</a>