Not the Plate you Eat off

Plate Tectonics

Core: iron/nickel, solid 7000 C

Asthensphere; liquid 3000-6500 C

Crust: Silicate Rock 20-600 C

Lithosphere: silicate rock 100- 3000 C

Layers of the Earth

GPSGlobal 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

http://www.youtube.com/watch?v=vE9zZ3F5B5MGPS 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 motionusing NUVEL1A Model

Actual Motion trackedusing 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

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://www.youtube.com/watch?v=t-ck4KR-KU&feature=related

http://www.youtube.com/watch?v=GyMLlLxbfa4&feature=relatedBill 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• http://www.youtube.com/watch?

v=ep2_axAA9Mw&feature=relate

Transform Boundaries: Plates that slide past one another.

The surface along which plates slide is called a transform fault.

http://www.learner.org/interactives/dynamicearth/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

Glass Bread Loaf Dish

Cup Sterno

Thermal Convection Experiment

Oil

Thyme

Flow

Tabletop

Thermal convection

http://www.youtube.com/watch?v=Kpoko_l34ZE&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.