An astronaut took this photograph from the space shuttle in 1982. It pictures part of the Island of Luzon in the Philippines. The image shows mountains, rivers, and fields, plus Manila, the capital city of the Philippines. Manila appears on the eastern shore of Manila Bay, the large bay in the lower right of the image.

  !   Examine the image. Consider how Earth’s spheres were interacting in this area before Mount Pinatubo’s violent eruption in 1991. Look for the features described below.

• Dark areas along the left side of the image are forest-covered volcanic mountains. The largest one, in the upper left, is Mount Pinatubo.
• Light-colored lines radiating from the mountain summits are river beds or drainage channels.
• Suspended sediments in Manila Bay make the water look tan.
• The dark and light mottled region just north of Manila Bay is covered with large farm fields.
• Blocky structures extending into the bay from Manila are built by humans.