Monday Starting Line Directions: Answer on the Google Form found in Planbook. What is the Pacific Ring of Fire? Based on the evidence we have and the location of different volcanoes and earthquakes, what must be located near the Pacific Ring of Fire? At which 2 types of plates boundaries do volcanoes form?

Monday Starting Line Directions: Answer on the Google Form found in Planbook. A zone of many active volcanoes and earthquakes located near the Pacific Ocean Plate Boundaries Convergent (subduction zones), divergent (mid-ocean ridges)

Announcements Homework Turn-In: Pacific Ring of Fire Lab (Turn-in) You will be receiving a take home test tomorrow. It will be Due next Tuesday November 29.

Notebook Notes Directions: In your document, write the following information in this order on the LEFT SIDE. (Your Name) Mr. Swisher Earth and Space Science _____ (Period) 11/21/2016

Notebook Notes Directions: In your document, write the following information in this order in the CENTER in BOLD. 13.2 Volcanic Eruptions

Lava vs. Magma Lava = ON the surface of the Earth Magma = UNDER the surface of the Earth Forms from melted crust and mantle

Two Types of Magma There are two main types of magma: Mafic magma: Rich in magnesium and iron Color = Dark Found in oceanic crust Felsic magma: Rich in feldspars and silica Color = Light Found in continental crust

Two Types of Eruptions There are two main types of eruptions: Quiet Eruptions: From mafic magma Magma flows out quietly Low viscosity: thin, flows out quickly Happens often on the ocean floors (out of mid-ocean ridges) Explosive Eruptions: From felsic magma Magma shoots out of the volcano with pyroclastic material High viscosity: thick; flows out slowly

Lava Flow As lava flows out of a volcano, it cools in different ways. Mafic lava cools quickly and can form 3 types of lava flows: Pahoehoe: Cooled, wrinkled lava Aa: Cooled, jagged lava Blocky lava: Cooled, chunky lava

Lava Flow

Pyroclastic Material During explosive eruptions with felsic magma, ash and other rock fragments called pyroclastic material fly out of the volcano. There are 5 types of pyroclastic material: Volcanic dust: Very small rocks (.25 mm) Volcanic ash: Small rocks (2 mm) Lapilli: Larger rocks (“little stones,” 64 mm) Volcanic blocks: Even larger rocks Volcanic bombs: Largest rocks

Pyroclastic Material

Types of Volcanoes There are 3 types of volcanoes: Shield Volcanoes Have a broad base with gently sloping sides Form quiet eruptions with mafic magma Example: Hawaiian Islands (U.S.) Composite Volcanoes Have layers of lava flows and pyroclastic material Form quiet AND explosive eruptions Example: Mount St. Helens (U.S.) Cinder Cones Have very steep slopes, but are SMALL Form explosive eruptions with pyroclastic material

Volcano Pictures Cinder Cone Shield Composite

Status of Volcanoes There are 3 different statuses of volcanoes: Active Volcanoes Is erupting or shows signs that it will erupt in the near future (has erupted in 10,000 years or less) Example: Mount St. Helen’s (U.S.) Dormant Volcanoes Is not active now, but may become active in the future Example: Mount Raineir (U.S) Extinct Volcanoes Is unlikely to erupt again (hasn’t erupted in 10,000 years or more) Example: Kilimanjaro (Tanzania)

Caldera When the magma chamber of a volcano empties, a large depression called a caldera is left behind. Can later fill with water to make a lake!

Caldera

Causes of Eruptions Volcanoes erupt when… pressure is released when tectonic plates move. Example: Earthquake the density of the magma decreases (as the temperature increases) & magma rises up the central vent.

Types of Volcanoes Worksheet