Using Google Earthto

See the World

CONVERGENT BOUNDARYOceanic Plate Continental Plate

Nazca Plate South American Plate = Andes

Pacific Plate North American Plate = Cascade Range

Volcanic Mountains

Deep Ocean

Trenches

The subduction of the oceanic plate causes...

Other Convergent Boundaries with Oceanic/Continent Collisions

• Check out where there is an ocean-continent collision:–Cascade Mountains–Andes Mountains Note the volcanic

mountains...

Note the deep oceanic trench off the coast... Evidence of subduction

Earthquakes happen any time the plates move relative to one another… Like here!

CONVERGENT BOUNDARYTRENCHES happen at subduction zones

TRENCH

Convergent Boundaries with Ocean – Oceanic Collisions

• Check out places in the world where there is an ocean-ocean collision:–Philippines–Mariana Islands–Japan–Aleutian Islands

Note the Islands Arcs... They are volcanic islands that grew up from the base of the ocean. This is the same process that cause volcanic mountains (Andes, Cascades) on land, but since these begin on the floor of the ocean, they are not quite as tall.

Note the deep oceanic trenches off the coast...

Earthquakes happen any time the plates move relative to one another… Like here!

CONVERGENT BOUNDARYOceanic Plate Oceanic Plate Pacific Plate Philippine Sea Plate

Pacific Plate

Philippine Sea Plate

Pacific Plate

Philippine Sea Plate

Mariana Island Arc

Island Arcs occur here NOT at hotspots

Japan

Philippines

MarianaIslands

CONVERGENT BOUNDARY

Aleutian Island Arc (Alaska)

Japan – Island Arc

Island Arcs occur here NOT at hotspots.

Trenches occur here NOT at divergent boundaries.

Mt. Everest

Mt. Everest

CONVERGENT BOUNDARYContinental Plate Continental Plate

Eurasian Plate Indian Plate = HimalayasNo Subduction = No volcanoes here!

Other Convergent Boundaries• Check out other places in the

world where there is a continent-continent collision:–Allegheny Mountains–Appalachian Mountains–Alps Note the folded mountain ranges.

Note the faults.

Do earthquakes happen here???

DIVERGENT BOUNDARIESRifts and Ridges – which one is which?

Atlantic Plate

Mid-Atlantic Ridge = seafloor spreading

Underwater RIDGE of new crust = volcanic rock

Check out the land near the ridge... NO TRENCHES! It is actually quite shallow!

DIVERGENT BOUNDARIESRifts and Ridges – which one is which?

Here is an example of a RIFT

Africa

Another is in Iceland, where they sometimes call it a rift zone.

Earthquakes happen any time the plates move relative to one another… Like here!

And what about those Transform Boundaries???

• Not a lot to see here... Lots of earthquakes, faults (you can even see the cracks in some places.

A part of fault you can see

along the San Andreas

Earthquakes happen any time the plates move

relative to one another… Like here!

HOT SPOTS – middle of platesIsland CHAINS can occur at hotspots

Pacific Plate

North American Plate

Hawaii volcanic island chain over a

hotspot – in the middle of

the Pacific Plate

Note the long chain of extinct volcanoes…. It leads all the way back to Russia!

HOT SPOTSThe MAGMA stays put. The PLATE moves!!!

The rumble of the magma under the crust can cause EARTHQUAKES!

Yellowstone Hotspot• Check out

Yellowstone... It is difficult to see the line of extinct volcanoes (like you can in Hawaii), but check it out!

Other World-Wide Hotspots

#1) Ways Volcanoes Form on Earth

• (1) Divergent Boundaries• (2) Hotspots• Convergent Boundaries with

Subduction– (3) Ocean/Ocean Collision– (4) Ocean/Continent Collision

#2) Transform Boundaries have NO CHANCE of mountains or mountain ranges forming as a result.

#3) Volcanic Islands Form on Earth

• (1) Hotspots– When underwater, can create island

chains like in Hawaii• (2) Convergent with Subduction of

Ocean Plate under another Ocean Plate– Creates Island Arcs like Japan, Mariana

Islands, Philippines, Aleutian Islands

#4

Earthquakes• Occur anytime plates move relative to one

another.• Is used as evidence that a boundary (or hotspot)

is there.• Remember the map you colored??? We used

the locations of earthquakes to determine the boundaries between plates.