The U.S. Geological Survey defines a volcano as a vent in Earth's surface, either on land or on the seafloor, from which molten rock called magma, as well as ash and gases, can erupt or ooze. Different types of volcanoes erupt in different ways, with some erupting spectacularly and other, most notably Hawaii's shield volcanoes, steadily oozing lava. There are different types of volcanoes, including stratovolcanoes, shield volcanoes and cinder cones, and different types of lava and other volcanic flows. Volcanoes can be active, dormant or extinct. Most of Earth's volcanoes are located along the Pacific Ring of Fire, where many of Earth's tectonic plates subduct beneath another plate. Volcanic eruptions can cause avalanches of debris, and the ash and gases they spew into the air can cause the atmosphere to cool. Currently volcanic eruptions cannot be predicted, though most important volcanoes are routinely monitored and authorizes warn when they think an eruption is likely. Read below for the latest news on volcano monitoring and research, current volcanic eruptions and to see amazing pictures of volcanoes.