| A | B |
|---|
| Magma | Melted rock found within the earth |
| Volcano | Opening in the Earth's crust through which magma rises |
| Asthenosphere | One place where magma forms |
| Plate Boundaries | One place where magma forms |
| Lava | Magma which has reached the Earth's surface |
| Tephra | Solid fragments of lava |
| Ash | Smallest pieces of tephra, less than 2mm in size |
| Lapilli | Tephra between 2 and 64 mm in size |
| Block | Tephra larger than 64 mm and ejected as a solid |
| Bomb | Tephra larger than 64 mm and ejected as a liquid, which hardens in flight |
| Explosive | Result of magmas containing high percentage of gases |
| Water vapor | Most abundant gas given off during a volcanic eruption |
| Carbon dioxide and Sulfur | Gases given off during volcanic eruptions |
| Felsic Magma | Traps a high percentage of gases |
| Felsic Magma | Contains a high amount of silica |
| Felsic Magma | Produces light colored rocks |
| Felsic Magma | Thick and slow-moving |
| Felsic Magma | Produces cinder cones |
| Mafic Magma | Traps a low percentage of gases |
| Mafic Magma | Contains a low amount of silica |
| Mafic Magma | Produces dark colored rocks |
| Mafic Magma | Thin and fast-moving |
| Mafic Magma | Produces shield cones |
| Silica | Main ingredient in magma |
| Mt. St. Helens | Volcano found in the Cascade Mountain Range in Washington, US |
| May 18, 1980 | Day Mount St. Helen's last erupted |
| Cinder Cone | Made of Cinder and has straight sides with a steep slope and a large summit crater |
| Cinder Cone | Produces a short-lived explosive "Strombolian" eruption |
| Paricutin and Cerro Negro | Examples of Cinder Cones |
| Shield Cone | Made of lava flows and has a gentle slope and a broad base |
| Shield Cone | Produces a calm and quiet "Hawaiian" eruption |
| Mauna Loa and Kilauea | Examples of Shield Cones |
| Composite or Stratovolcano Cone | Contains alternating layers of rock particles and lava |
| St. Helens, Shasta, Hood, Baker, and Etna | Examples of Composite or Stratovolcano Cones |
| Active | Volcano that is currently erupting or shows signs of unrest |
| Dormant | Volcano that is not active, but could erupt again |
| Extinct | Volcano that is not likely to erupt again |
| Ring of Fire | Zone of earthquake and volcanic activity surrounding the Pacific Ocean |
| Composite or Stratovolcano Cone | Steep, symmetrical cone, with a small summit crater and heights of up to 8,000 feet |
| Composite or Stratovolcano Cone | Produce very explosive, longer lasting, "Plinian" eruptions |
| St. Helens, Kilauea, Mauna Loa, Etna, Cerro Negro, and Pinatubo | Examples of Active Volcanoes |
| Shasta, Ranier, and Hood | Examples of Dormant Volcanoes |
| Kenya and Kilimanjaro | Examples of Extinct Volcanoes |
