Not the Plate you Eat off Plate Tectonics

Core: iron/nickel, solid 7000 C Asthensphere; liquid C Crust: Silicate Rock C Lithosphere: silicate rock C Layers of the Earth

GPS Global Positioning System Satellite-based system for accurate location of points on earth Geoscientist have set up a network of targets all over the works in order to monitor the movement of lithosphere plates

GPS is technology that has only been around for about a decade 5B5M GPS working

Computer Model (based on the GPS data) Can use a model to predict values from given information. The model’s values match the GPS data very well! Predicted motion using NUVEL1A Model Actual Motion tracked using GPS

So to further look at movement over a long period of time, the answer lies within rocks; magnetite (large amounts of iron) Geoscientist study the magnetism of rocks that make up the sea floor These rocks are grouped by which way their magnetic polarity points. a)Magnetic polarity matches Earth’s magnetic north b)Magnetic polarity is reversed, so the rocks magnetic polarity points south

In 1950’s scientists have noticed a pattered along ocean floor were new crust is being made!

Running down the middle of nearly every ocean is a ridge of volcanic activity. One both sides of the ridge, the basalt that was formed has a set pattern of magnetism –One stripe has the north pole of the magnets pointing north, the next stripe has the north pole of the magnets pointing south –The pattern shows up on both sides of the ridge, and the width of the stripes are the same on both sides

Crust: the thin, outermost layer of the Earth. Two kinds OceanicContential Mantle: beneath the Earth’s crust, composition is different from the crust. Made of two different layers 1. Lithosphere: uppermost part of mantle and the crust together make up the lithosphere. Earth’s plates are made up of the lithosphere. 2. Asthenosphere: lowermost part of the mantle is hot enough that it can flow very slowly, just like a very stiff liquid.

Plate boundaries Divergent plate boundaries: are two plates move away from each other. When to continental crusts move away earthquakes, new lakes or streams Two oceanic crust move away= sea-floor spreading=new ocean crust forming httpt:// =t-ck4KR-KU&feature=relatedhttpt:// =t-ck4KR-KU&feature=related bfa4&feature=related Bill Nye

Convergent plate boundaries: two plates are moving toward each other; one of the two plates would have to go under the other one. When one plate dives under the other plate it is called: Subduction.

Three kinds of subduction: 1.oceanic to oceanic, 2.continental to continental, 3 oceanic to continental =relatehttp:// =relate Transform Boundaries: Plates that slide past one another. The surface along which plates slide is called a transform fault. earth/structure.html

What drives the Plate

Density Density= (mass per volume) refers to how concentrated the mass in an object or material is. D= M/V D=density (g/mL) M= Mass (g) V= volume (mL Density =

Energy Flow When you heat objects you decrease density. Thermal convection: a pattern of movement in a fluid caused by heating from below and cooling from above It is a transfer of heat from bottom to top Figure 1. Arrangement of coffee cups, Sterno can and loaf dish on a table top (side view) for the thermal convection experiment. Short lines represent flakes of thyme in the oil. Arrows show expected directions of fluid flow defining convection cells after heating of the fluid. Figure 2. Alternate setup using two candles instead of the sterno for heat. Figure 3. Close-up photo (side view) of the oil and thyme in the loaf dish. Heat from the candles causes the oil and thyme to rise in the middle of the dish (above the candle flames), flow horizontally (away from the center) near the surface of the oil, sink near the cooler edges of the loaf dish and flow horizontally toward the center along the bottom of the dish, thus completing the convection cells. Figure 4. Sketch of fluid flow experiment apparatus. Copies of this figure can be used to record observed directions of fluid flow (using arrows drawn on the diagram) in the oil after convection begins when heat is added. Figure 5. Arrangement of 3 pieces of balsa wood on the surface of the oil (view from above the dish) to illustrate "plate motions". Figure 6. Hypothetical cross-sections through the Earth showing possible patterns of convection. Upper diagram: Schematic diagram illustrating convection in the Earth's upper mantle. Lower diagram: Schematic diagram illustrating convection in the Earth's mantle in which the convection cell and related flow operate throughout the mantle.   Copyright L. Braile. Permission granted for reproduction for non-commercial uses.

Thermal convection 34ZE&feature=related

History Alfred Wegener: German scientist that purposed the idea of continental drift. According to him, about 200 million years ago, all the continents were one big land mass called Pangea.