The document summarizes information about volcanoes, including how they form and examples of specific volcanic events and locations. It discusses how volcanoes form from magma reaching the surface. It provides details on the historic eruptions of Krakatoa volcano between the islands of Java and Sumatra in 1883, which destroyed much of the island. It also describes observations of renewed eruptions at Anak Krakatau in 1960 with ash plumes rising thousands of feet. Hot spots like those under Hawaii are noted to be exceptions to most volcanism occurring near tectonic plate boundaries.