How Volcanoes Work

 Image Described in Caption
 Mauna Loa -- The elongated asymmetry of Mauna Loa is evident in this satellite view of the shield volcano. The top of the image is toward the northwest. The Mokuaweoweo caldera is clearly visible at the volcano's summit. Mauna Loa has erupted more than 35 times since westerners first arrived in the early 1800s. Numerous historical lava flows descend down vents located along rift zones to the left and right of the summit caldera, southwest and northeast, respectively. The Kilauea volcano is located beyond the bottom edge of the image. Courtesy of NASA.