130 likes | 378 Views
Chapter 5 Section 2: Volcanic Eruptions. 6. Label the picture: lava flow, vent, crater, magma chamber, pipe. 7. What are the two types of volcanic eruptions? Quiet Explosive 8. What is silica? Material found in magma
E N D
6. Label the picture: lava flow, vent, crater, magma chamber, pipe
7. What are the two types of volcanic eruptions? • Quiet • Explosive • 8. What is silica? • Material found in magma • 9. A volcano erupts quietly if its magma is __________ or _________________.
Pahoehoe Aa
14. A volcano erupts explosively if its magma is high in silica. High-silica magma is _________ and _____________. 15. Explain what happens during an explosive eruption. *Magma builds up in a volcano’s pipe, plugging it. *Dissolved gases, water vapor cannot escape from the thick magma *Trapped gases build up pressure
16. Contrast the silica content of magma in quiet and explosive eruptions. The magma of a quiet eruption is LOW in silica The Magma of an explosive eruption is HIGH in silica
18. How does an explosive eruption produce pyroclastic flow? Thick, sticky lava builds up in a volcano’s pipe and plugs it. The trapped gasses build up pressure until they explode. The erupting gases force the magma out with great force which breaks the lava into fragments that quickly cool and harden in different sizes.
22. Name some warning signs that may signify a volcanic eruption may happen. *Tiltmeters: Detect the slight surface changes in elevation and tilt caused by magna moving underground *Monitor gases escaping from a volcano *Monitor small earthquakes that occur around a volcano before an eruption *Rising temperatures in underground water