Volcanoes – Day 2 Earth Science 10/7/10

Announcements We will have a QUIZ tomorrow on Volcanoes! Vocabulary for Chapters 8 and 10 are due TOMORROW! Remember, this is the time to make a NEW start and get a good grade for this new report card!

Objectives I will be able to relate plate tectonics to volcanoes by describing ________________ __________________________, the types of boundaries that produce volcanoes. I will be able to _____the locations of volcanoes on a map and compare patterns of volcanoes to plate tectonics.

Key Points Magma composition plays a major part in determining the form of a volcano. Magma forms when solid rock in the crust and upper mantle melts. The composition of the material, water content and confining pressure are factors that affect the melting point of rock. Magma tends to rise towards Earth’s surface primarily because rocks become less dense when they melt. Most of the active volcanoes on Earth are located in a belt known as the ring of fire. Identify an O-C plate boundary creating a volcano.

How Volcanoes Form How Volcanoes Form Video

Magma As we know, ________________plays a major part in determining the __________of a volcano. But where does magma come from? Magma forms when __________in the crust and upper mantle ________.

Magma How does rock melt? – There are ________factors that contribute to rocks melting, or the formation of magma. 1.________ – As you go ______in the earth, the temperature _____. – Subduction creates friction and causing heat – As magma ________, it heats rocks closer to the earth’s surface. But this alone is ____________to create all of the magma that we know exists below the earth’s crust…

Magma 2.Confining ___________ – As confining pressure is __________, the melting temperature of rocks is ________. – This means that as rocks can __________as they are released from the confining pressure deep within the earth. – This process is called _____________________

Magma 3.__________Content – Water in rocks can cause a rock to melt at _________temperatures. – Rocks with more water in them melt easier than rocks that are “dry”. BOTTOM LINE: The _____________ ________________, ________content and confining ________are factors that affect the __________________ of rock.

Magma Now that we know how magma forms, why does it come to the surface of the planet? Let’s discuss. Write down what you think: __________________________________ __________________________________

Magma Magma tends to rise towards Earth’s surface primarily because ______________________ ____________________________________. What does that mean? When rocks change from a solid state to a liquid state, they become _____________! What is lighter will rise, just like heavy things sink!

Plate Tectonics and Volcanoes Most of the active volcanoes on Earth are located in a belt known as “____________”. Others are located seemingly sporadically around the globe. Scientists could not explain the worldwide distribution of volcanoes until the introduction of the theory of ___________________________.

The Ring of Fire Watch a slideshow of the Volcanoes on the Ring of Fire HERE!HERE

Plate Tectonics and Volcanoes Plate movement forms volcanoes in three zones: 1.___________Plates – Ocean Rising magma can form volcanic ________arcs in an ocean (Aleutian Islands). – Ocean – Continent Rising magma can form __________volcanic arcs (Andes Mountains).

Convergent Boundary Volcano Mount St. Helens emitting volcanic ash 2 months after it’s May eruption in Was type of convergent boundary caused Mt. St. Helens? How do you know?

Plate Tectonics and Volcanoes 2.__________Plate Boundaries – When plates pull apart, there is less pressure on the rocks below. – Because of the ________________, rocks melt and magma is formed.

Plate Tectonics and Volcanoes 3.Intraplate Igneous Activity (non boundary) –Intraplate means activity _______a tectonic plate _______from plate boundaries. – This is caused by ________________. – Examples of this are the ____________________

Kilauea, an Intraplate Volcano

Mapping Volcanoes Lab Follow the directions on the handout to map volcanoes around the world. After you finish plotting the volcanoes, answer the questions in complete sentences.