The distribution of volcanism in the African plate refl ects a variety of processes, many of which are poorly understood, involving interaction between the lithosphere and the underlying convective mantle. Despite the maturity of the plate tectonic paradigm, our knowledge of the processes involved in the breakup of continents and the formation of new ocean basins remains limited.

No one living in the ancient Roman cities of Pompeii and Herculaneum in southern Italy had any idea that the mountain towering above them was an active volcano. When it blew itself apart in August ad 79, it brought rapid death to many of the 25,000 people living in its shadow <...>

Across the face of the central Pacific Ocean, 3,000 kilometers from the nearest continent and 800 kilometers from any other land, lies the row of islands known as the Hawaiian Archipelago. From Kure Island at the northwest, the archipelago forms a southeast-trending line of islands 2,400 kilometers long (fig. 1.1).

Natural geologic hazards arise from the interaction between humansс and the Earth’s natural processes. Recent natural disasters such as the 2004 Indian Ocean tsunami that killed more than a quarter million people and earthquakes in Iran, Turkey, and Japan have shown how the motion of the Earth’s tectonic plates can suddenly make apparently safe environments dangerous or even deadly. Th e slow sinking of the land surface along many seashores has made many of the world’s coastal regions prone to damage by ocean storms, as shown disastrously by Hurricane Katrina in 2005.