This image shows the Philippine Islands and the shape of the seafloor in the western Pacific Ocean. Most islands in this region are geologically active, as they are located near plate boundaries.

  !   Click the buttons to show the locations of volcanoes and plate boundaries in this region. Use what you’ve learned about plate tectonics and volcanoes to visualize the subsurface geology beneath the islands.

1. What is the plate tectonic setting of the Philippine Islands? Describe the geologic processes and features you would expect to find there.

Geology is just one feature of the Philippines. Approximately 15 tropical cyclones (severe storms) affect the islands each year. The mountains are covered by forests, and the coastal lowlands support crops that feed the islands’ population of over 80 million people. Manufacturing industries employ a growing percentage of the population.

In this investigation, you’ll examine how the violent eruption of Mount Pinatubo changed interactions among Earth’s spheres.