Pacific Ring of Fire

Pacific Ring of Fire Amari Valencia 2023 Name: ________________________________________________ Period: _____ Date: _____________ Essential Question: Where are most of the volcanoes found? Convergent boundary (dots are volcanoes Divergent boundary The Pacific Ring of Fire (or just The Ring of Fire) is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements. The Ring of Fire has 452 volcanoes and is home to over 75% of the world's active and dormant volcanoes. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt. About 90% of the world's earthquakes and 81% of the world's largest earthquakes occur along the Ring of Fire. The famous and very active San Andreas Fault zone of California is a transform fault which offsets a portion of the East Pacific Rise under southwestern United States and Mexico. The motion of the fault generates numerous small earthquakes, at multiple times a day, most of which are too small to be felt. Most volcanoes on Earth are the result of convergent boundaries, some by divergent boundaries while a few by the weak spots on Earth’s crust like the Hawaiian hot spots. Clarifying Questions: 1. Describe the “Pacific Ring of Fire”. The "Pacific Ring of Fire" is a horseshoe-shaped zone around the Pacific Ocean characterized by intense seismic activity and frequent volcanic eruptions. ___________________________________________________________________________________________ It encompasses the edges of several tectonic plates and is known for its high concentration of earthquakes and volcanic activity ___________________________________________________________________________________________ 2. What kind of plate movements is responsible for the following: Plate movements can be convergent, divergent, transform or strike slip. Convergent plate movements (subduction) a. oceanic trenches : ____________________________________________________________ Convergent plate movements (subduction) b. volcanic arcs and volcanic belts: _________________________________________________ Transform or strike-slip plate movements c. San Andreas fault: ____________________________________________________________ 3. Why is it called the “Pacific Ring of Fire”? Think! It is called the "Pacific Ring of Fire" because it forms a ring around the Pacific Ocean, where a large number of ________________________________________________________________________________________ earthquakes and volcanic eruptions occur due to intense tectonic activity ________________________________________________________________________________________ 4. Identification: 452 ___________________________4a. Number of volcanoes in the Pacific Ring of Fire. Around the edges of the Pacific Ocean ___________________________4b. Location of the Pacific ring of Fire. Circum-Pacific Belt ___________________________4c. Another name for the Pacific Ring of Fire. Transform or strike-slip fault ___________________________4d. The kind fault of San Andreas fault. Horseshoe-shaped ___________________________4e. Shape of the “Pacific Ring of Fire”. 5. What type of plate boundaries results to: Convergent plate boundaries __________________________a. most volcanoes on Earth. Divergent plate boundaries __________________________b. some volcanoes on Earth. Transform or strike-slip plate boundaries __________________________ c. Few volcanoes on Earth. STUDY THE CHART AND IDENTIFY THE TYPE OF PLATE MOVEMENTS. Plate movements: convergent, divergent, transform, transform or strike slip, no plate boundary Convergent plate boundary 6. Between Pacific plate and Nazca plate: ______________________________________________ Divergent plate boundary 7. Vertically across the Atlantic ocean: _________________________________________________ No plate boundary 8. Hawaiian hot spot: _______________________________________________________________ Transform or strike-slip plate boundary 9. Western side of the United States: __________________________________________________ Convergent plate boundary 10. West of the Pacific ocean: _________________________________________________________ Divergent plate boundary 11. North of the Pacific ocean: ________________________________________________________ Challenge! ( 10 pts.) Why are earthquakes most common around the Pacific Ocean? Use the following words for your answer: convergent boundary, subduction, volcano, friction, pressure, and release. Earthquakes are most common around the Pacific Ocean due to intense _____________________________________________________ tectonic activity along convergent plate boundaries. At these boundaries, _____________________________________________________ plates collide and subduction occurs, generating friction, pressure, and _____________________________________________________ eventually earthquakes as the pressure is released. Subduction also _____________________________________________________ leads to the formation of volcanic arcs and chains, further contributing _____________________________________________________ to seismic activity _____________________________________________________ Multiple Choice: Write the letter of your answer on the space before the number. C ____ 12. Most magma forms in... A. continental crust B. the lithosphere C. the asthenosphere D. ocean crust A ____ 13. An opening in the earth's surface through which molten rock flows is called a ... A. vent B. caldera C. mantle D. fault D ____ 14. An opening on the earth's surface through which molten rock flows and the material that builds up Around the opening together form a... A. subduction zone B. trench C. convergent boundary D. volcano A ____ 15. The broad volcanic feature formed by quiet eruptions on thin lava flows is called a_____. A. shield zone B. cinder cone C ____ 16. Which of the following formations would most likely result from a single violent volcanic eruption? A. shield volcano B. vent C. cinder cone D. caldera B ____ 17. What is the name of the volcano which erupted in 1980 and caused widespread damage in the Washington and Oregon region? A. Mt. Vesuvius B. Mt. St. Helens C. Mt. Rushmore D. Mt. McKinley C ____ 18. What is formed when a magma chamber empties and collapses? A. a crater B. a fissure C. a caldera D. a vent D ____ 19. Before a volcanic eruption, seismic activity seems to... A. increase in frequency and decrease in intensity C. decrease in frequency and increase in intensity B. decrease in both frequency and intensity D. increase in both frequency and intensity B ____ 20. Plates pushing against each other or are colliding produce a _________________ boundary A. divergent B. convergent C. Transform C ____ 21. What kind of plate boundary is found between the Pacific plate and the North American plate? A. divergent B. convergent C. Transform