This page contains a Flash digital edition of a book.
Ancient volcanic eruptions that buried this area in ash turned these tree trunks into stone.


WORDWISE caldera: a large volcanic crater


convection current: a transfer of Earth’s heat caused by a circular pattern of hotter fl uid rising and cooler fl uid sinking


geothermal: something that uses the heat from Earth’s interior


hydrothermal: something that is related to hot water


magma: hot, mostly molten rock inside Earth that is melted by the heat in Earth’s interior


magma chamber: a large pool of magma under the ground


Over time, acid in this hot spring breaks rock down into milky clay, forming a bubbling mud pot.


OCTOBER 2014 17


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24