Plate Tectonics Vocabulary 1 convection transfer of heat

Plate Tectonics

Vocabulary 1. convection- transfer of heat by movement of a fluid 2. convection currents- movement within hot fluids, when the heat source is on the bottom, such as in a boiling pot of soup on the stove. Convection currents happen because the hotter material is less dense and rises; when it reaches the surface, it cools and becomes less dense, so it sinks. This rising and sinking creates a circular motion within the fluid. 3. convergent plate boundaries- where two tectonic plates move toward each other

Vocabulary 1. transform plate boundary- where two tectonic plates slip past each other, moving in opposite directions 2. divergent plate boundaries- where two tectonic plates move away from each other 3. seafloor spreading- the process by which new oceanic crust forms when magma rises up and solidifies at the mid-ocean ridges. The newer crust pushes the older crust out to each side, which is why the age of the sea floor increases with distance away from the mid-ocean ridges.

Vocabulary 7. subduction- the process by which one tectonic plate sinks below another, returning to the mantle, where the rock is re-melted. Subduction takes place at convergent plate boundaries. Oceanic crust, which is denser, will always subduct under the less dense continental crust. 8. tectonic plates- large pieces of the lithosphere that slowly move on top of the asthenosphere. There are seven primary plates and many smaller ones. The seven primary plates are the African Plate, Antarctic Plate, Eurasian Plate, Indo-Australian Plate, North American Plate, Pacific Plate, and South American Plate.

Vocabulary 9. tectonic plate boundary- a place where two tectonic plates meet 10. mid-ocean ridge- a system of connected underwater mountain ranges that run throughout the world's oceans. There is a rift valley in the center of the mid-ocean ridge, where magma rises up from the mantle, and pushes out to either side, producing seafloor spreading.

Exploring Inside the Earth Geologists- are scientists who study the forces that make and shape planet Earth. They have used evidence from rock samples and evidence from seismic waves to learn about Earth’s interior. Geology - is the study of planet Earth.

Studying Surface Changes Constructive forces shape the surface by building up mountains. Destructive forces are those that slowly wear away mountains and, eventually, every other feature on the surface.

The Crust The crust is a layer of solid rock that includes both dry land the ocean floor. Three main layers make up Earth’s interior: the crust, the mantle, and the core. Each layer has its own conditions and materials.

The Mantle Earth’s mantle is made up of rock that is very hot, but solid. The mantle is divided into layers based on the physical characteristics of those layers.

The Core The core is made mostly of the metals iron and nickel. It consists of two parts–a liquid outer core and a solid inner core.

Quick Assessment of Earth’s Layers: 1) What are the four layers of the Earth? 2) The Earth’s crust is very ______? 3) The mantle is the largest layer of the Earth? True or False 4) Is the Outer Core a liquid or a solid?

The Plates and How They Move The lithosphere is broken into separate sections called plates. The theory of plate tectonics explains the formation, movement, and subduction of Earth’s plates.

Heat Transfer There are three types of heat transfer: radiation, conduction, and convection. Heat transfer – the movement of energy from a warmer object to a cooler object Radiation – the transfer of energy through empty space Conduction – heat transfer by direct contact of particles of matter

Convection & Convection Currents Heating and cooling of the fluid, changes in the fluid’s density, and the force of gravity combine to set convection currents in motion. Convection – heat transfer by the movement of a heated fluid Convection currents – the flow that transfers heat within a fluid

Convection Currents in Earth Heat from the core and the mantle causes convection currents in the mantle. This is how the heat is transferred, and how the earth’s plates are able to move.

Plate Boundaries At the locations where two tectonic plates interact, a boundary between these plates exist. There are three types of boundaries that geologist observe. (Draw these pictures into your notes)

Plate Boundaries There are three kinds of plate boundaries: 1. divergent boundaries – when the plates divide/ seperate and create a rift 2. convergent boundaries – two plates collide 3. transform boundaries – when two plates slide past each other A different type of plate movement occurs along each type of boundary.