plate tectonics. what do you think? did these continents ever fit together?
TRANSCRIPT
What do you think?What do you think?
Did these continents ever fit together?Did these continents ever fit together?
Try itTry it
In groups, see if it is possible to place the In groups, see if it is possible to place the continents together as if they were puzzle continents together as if they were puzzle pieces.pieces.
Group 1
John C.
Doug
Courtney
Dom
Group 2
Patrick B.
Amber
Jacob
Tony B.
Nicole
Alicia
Group 3
Brad
Patrick P.
Morgan
Group 4
Rachel
Dylan
Matt C.
Group 5
Lyndsay
Alyssa
Carly
Group 6
Anthony M.
Matt C.
Alex
Alfred WegenerAlfred Wegener
In 1912 he proposed the idea of In 1912 he proposed the idea of Continental DriftContinental DriftPuzzle piecesPuzzle piecesFossilsFossilsRock FormationsRock FormationsLand featuresLand featuresSimilar speciesSimilar speciesMagnetismMagnetism
Continental DriftContinental Drift
Supporting EvidenceSupporting Evidence
http://geology.csupomona.edu/drjessey/clahttp://geology.csupomona.edu/drjessey/class/Gsc101/Plate.htmlss/Gsc101/Plate.html
Scientific ReactionScientific Reaction
"Wegener's hypothesis in general is of the "Wegener's hypothesis in general is of the footloose type, in that it takes considerable footloose type, in that it takes considerable liberty with our globe, and is less bound by liberty with our globe, and is less bound by restrictions or tied down by awkward, ugly restrictions or tied down by awkward, ugly facts than most of its rival theories." facts than most of its rival theories."
Part of the problem was that Wegener had Part of the problem was that Wegener had no convincing mechanism for how the no convincing mechanism for how the continents might move. continents might move.
Tectonic Plate TheoryTectonic Plate Theory
Earth’s crust floats on top of the Earth’s crust floats on top of the asthenosphere. The convection currents asthenosphere. The convection currents in earth’s mantle drive the plates through in earth’s mantle drive the plates through frictional forces.frictional forces.
Plate BoundariesPlate Boundaries
Transform- Two plates slip past each otherTransform- Two plates slip past each other
Divergent- Two plates move apartDivergent- Two plates move apart
Convergent- Two plates move togetherConvergent- Two plates move together
Math SkillsMath Skills
When will San Francisco and Los Angeles When will San Francisco and Los Angeles will eventually be side by side?will eventually be side by side?
What information do you need?What information do you need?
InformationInformation
Rate of Motion-Rate of Motion- Scientists say that the Scientists say that the North American Plate and Pacific Plate are North American Plate and Pacific Plate are sliding past each other at the same rate at sliding past each other at the same rate at which fingernails grow. which fingernails grow. 5 cm/year5 cm/year
Distance-Distance- 550 Km550 Km
Equation-Equation- Distance = Speed x time Distance = Speed x time
Divergent BoundaryDivergent Boundary
African Rift Valley
http://earth.imagico.de/view.php?site=eafrica
Convergent BoundariesConvergent Boundaries
Convergent boundaries are often calles Convergent boundaries are often calles subduction zones. subduction zones. The crust on one side of a convergent The crust on one side of a convergent boundary gets forced underneath boundary gets forced underneath (subducts) the crust on the other side.(subducts) the crust on the other side.There are 3 main typesThere are 3 main types– Oceanic-ContinentalOceanic-Continental– Oceanic-OceanicOceanic-Oceanic– Continental-ContinentalContinental-Continental
Oceanic-ContinentalOceanic-Continental
East coast of S.A.East coast of S.A.
Pushes up the Andes Pushes up the Andes MountainsMountains
Creates deep Creates deep trenchestrenches
Oceanic-OceanicOceanic-Oceanic
Indonesian IslandsIndonesian Islands
Creates volcanic Creates volcanic islands such as islands such as KrakatauKrakatau
HistoryHistory
Scientists have looked at all of the Scientists have looked at all of the evidence and have traced the continents evidence and have traced the continents back in timeback in time
http://jan.ucc.nau.edu/~rcb7/1storder.htmlhttp://jan.ucc.nau.edu/~rcb7/1storder.html
http://http://www.scotese.com/earth.htmwww.scotese.com/earth.htm
Tectonic Plate TheoryTectonic Plate Theory
http://pubs.usgs.gov/gip/dynamic/dynamic.htmlhttp://pubs.usgs.gov/gip/dynamic/dynamic.html
Tectonic PlatesTectonic Plates
How many plates are there?How many plates are there?– Depends upon who you ask. I’ve seen 14 - 56Depends upon who you ask. I’ve seen 14 - 56– There are major and minor platesThere are major and minor plates
EarthquakesEarthquakes
Due to the shifting of plates, earthquakes Due to the shifting of plates, earthquakes occur most often around plate boundaries occur most often around plate boundaries (faults)(faults)
Stress builds up within Earth’s crust until Stress builds up within Earth’s crust until the forces become too great for the friction the forces become too great for the friction within the rocks to hold the land back.within the rocks to hold the land back.
http://http://earthquake.usgs.gov/regional/world/worldearthquake.usgs.gov/regional/world/world_density.php_density.php
VolcanoesVolcanoes
Due to the weakness of the boundaries Due to the weakness of the boundaries between tectonic plates, volcanoes also between tectonic plates, volcanoes also occur most often along fault lines.occur most often along fault lines.
The pacific rim is also known as the ring of The pacific rim is also known as the ring of fire due to the volcanic activity in this areafire due to the volcanic activity in this area
http://http://volcanoes.usgs.govvolcanoes.usgs.gov/activity//activity/