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SEEC Ecuador 2010Presentation by:Mary D. CurtisBrittany L. Heller iwith.org

• Continental Drift – theory, first advanced by Alfred Wegener, that Earth's continents were originally one land mass. Pieces of the land mass split off and migrated to form the continents.

• Plate Tectonics – theory that the Earth's crust and upper mantle (the lithosphere) is broken into a number of more or less rigid, but constantly moving, segments or plates.

• Plate boundary – The place where two or more plates in the Earth's crust meet.

• Lithosphere – the rigid, brittle layer made up of the crust and the uppermost part of the mantle. It is broken up into pieces called tectonic plates.

• Plates – large pieces of the lithosphere that slowly move on top of the mantle. There are seven primary plates and many smaller ones.

• Convection – transfer of heat by movement of a fluid. Example: (Convection currents in the mantle occur because hot rock in

the lower part of the mantle is less dense and rises, and cooler rock in the upper part of the mantle cools, becomes more dense, and sinks. Mantle convection is thought to be the mechanism driving the movement of tectonic plates.)

Terms To Know

• Divergent Plate Boundaries – where plates are moving apart and new crust is being created. Also called Spreading Center, Rift Valley, Sea-floor spreading, Mid-oceanic Ridge.

• Convergent Plate Boundaries – where plates are moving together• Transform Plate Boundaries – where plates slide past one another. Example:

San Andreas Fault• 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

• Hot spots – isolated, roughly circular plumes of melted rock (magma) that rise from deep in the mantle (Mantle Plume) to the earth's surface

• Volcano – a vent (opening) in the Earth’s surface through which magma erupts• Composite volcano – a steep-sided volcano built by lava flows and deposits• Magma – melted rock below the Earth’s surface• Lava – term used for magma once it has erupted onto the Earth's surface• Shield Volcano – a broad volcano with repeated non-explosive eruptions of

basalt that forms a low dome or shield• Archipelago – a group of islands

Terms To Know

Lithosphere = The crust and part of the upper mantle

–The crust is broken into small parts called plates

–Plates move due to the movement of the magma in the upper mantle

–Magma moves due to convection (heating & cooling of magma)

Continental Drift Theory (Alfred Wegener):- Continents once formed supercontinent,

Pangaea, that later broke apart.

- Look at the map and see how continents “fit.”

Theory of Plate Tectonics

geology.rutgers.edu

Plate Tectonics:- Crust is broken into many small and large plates- Plates “float” on top of magma in upper mantle- Magma moves due to convection- Plates move toward, away, and next to one another - Plate movement causes: - Mountains and valleys to form- Natural hazards like earthquakes, volcanoes,

tsunamis, landslides, lahars, etc.

Theory of Plate Tectonics

• Oceanic plates - denser rock composition located below the ocean water

• Continental plates – lighter rock composition located below the continents

• Three types of Plate Boundaries• Divergent• Convergent• Transform (also called Transverse)

Types of Plates & Plate Boundaries

Types of Plates & Plate Boundaries

Transform

DivergentConvergent

Divergent Boundaries• Boundary between two plates

that are moving apart or rifting

• A valley forms with some active volcanoes along center – On land: Rift Valley– In the Ocean: Seafloor

spreading, Mid-Oceanic Ridges

Convergent Boundaries• Boundaries between two plates that are

colliding (coming together)• There are 2 types:

– Type 1: Oceanic plate to

Continental plate (subduction)– Type 2: Same plates move towards each

other (collide)

divediscover.whoi.edu

geologytimes.com

Convergent 1: Subduction Zone• Oceanic plate colliding with a less dense

continental plate• Oceanic plate moves beneath the

continental plate; it melts into mantle.• Volcanoes (mountains), trenches,

earthquakes occur at subduction zones. (Ex. Andes Mts.)

livescience.com

Convergent 2: Colliding Plates (Same Composition)

• A continental (or oceanic) plate colliding with another continental (or oceanic) plate

• Have Collision Zones: a place where folded mountains form.

- Earthquakes, landslidesConvergence3.gif

atmos.washington.edu

Transform Fault Boundaries• Plates slide past each other causing a rubbing

motion.• Motion causes earthquakes

inkycircus.comsanandreas.jpggeomaps.wr.usgs.gov

Ecuador: A Latin American

Plate Tectonics Example

• Continental Drift – theory, first advanced by Alfred Wegener, that Earth's continents were originally one land mass. Pieces of the land mass split off and migrated to form the continents.

• Plate Tectonics – theory that the Earth's crust and upper mantle (the lithosphere) is broken into a number of more or less rigid, but constantly moving, segments or plates.

• Plate boundary – The place where two or more plates in the Earth's crust meet.

• Lithosphere – the rigid, brittle layer made up of the crust and the uppermost part of the mantle. It is broken up into pieces called tectonic plates.

• Plates – large pieces of the lithosphere that slowly move on top of the mantle. There are seven primary plates and many smaller ones.

• Convection – transfer of heat by movement of a fluid. Example: (Convection currents in the mantle occur because hot rock in

the lower part of the mantle is less dense and rises, and cooler rock in the upper part of the mantle cools, becomes more dense, and sinks. Mantle convection is thought to be the mechanism driving the movement of tectonic plates.)

Terms To Know

• Divergent Plate Boundaries – where plates are moving apart and new crust is being created. Also called Spreading Center, Rift Valley, Sea-floor spreading, Mid-oceanic Ridge.

• Convergent Plate Boundaries – where plates are moving together• Transform Plate Boundaries – where plates slide past one another. Example:

San Andreas Fault• 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

• Hot spots – isolated, roughly circular plumes of melted rock (magma) that rise from deep in the mantle (Mantle Plume) to the earth's surface

• Volcano – a vent (opening) in the Earth’s surface through which magma erupts• Composite volcano – a steep-sided volcano built by lava flows and deposits• Magma – melted rock below the Earth’s surface• Lava – term used for magma once it has erupted onto the Earth's surface• Shield Volcano – a broad volcano with repeated non-explosive eruptions of

basalt that forms a low dome or shield• Archipelago – a group of islands

Terms To Know

http://www.trekearth.com/gallery/South_America/Ecuador/photo1150399.htm

Ecuador: Land of Tectonic Activity

Fact: Nine large plates and a number of smaller plates on EarthKey Terms: Plate Boundaries: Convergent, Divergent, Transform

http://facstaff.gpc.edu/~pgore/Earth&Space/GPS/platetect.html

What do you already know?

geol.umd.edu

Nazca Plate is moving away from the Cocos Plate in a South, southwest direction (Divergent Plate Boundary).

A small area of the Nazca Plate (northwest of the Galapagos) is rubbing along the Cocos Plate (Transform Plate Boundary).Nazca Plate moving toward and

under the South American Plate (Convergent Plate Boundary).

Plate Boundaries: Ecuador

oceanexplorer.noaa.gov

The Galapagos Islands are formed by a Hot Spot.

A Hot Spot is an area on a plate where magma wells up in what is called a Mantle Plume. When the magma reaches the surface in the ocean, islands are formed.

facility.unavco.org

Ecuador experiences a divergent (spreading zone) and transform plate boundary near the Galapagos Islands.

The Galapagos

Plate Boundaries Near Galapagos Transform

Hot Spot

tulane.edu

cotf.edu

• Create a series of islands.• Move with the plate movement.

• Islands directly over the mantle plume have active volcanoes (Shield Volcanoes).

• Islands erode over time and may become sea mounts.

Hot Spots

Shield Volcanoes - relatively low, broad volcanoes with repeated non-explosive eruptions of basalt that form a low dome or shield-like shape.

http://pubs.usgs.gov/gip/dynamic/world_map.html

The Northern Galápagos is made up of Wolf, Darwin, Pinta, Marchena, and Genovesa islands. These islands may have formed from the hotspot “leaking” northward.

The Central Galápagos comprises three main islands, San Cristobal, Santa Cruz and Floreana and is where most of the population of the Galápagos lives.

The Western Galápagos are made up of Isabela and Fernandina. These are the youngest islands in the archipelago with the most active volcanoes.

bizz-101.com

The Galápagos is a group of volcanic islands (archipelago); each of the 13 major islands is made up of at least one volcano. The Galápagos Islands have three different geographic and geologic regions: Northern, Central, and Western.

Northern

WesternCentral

fuvirese.org

pugsjones.wikispaces.com

Geologic Formations:• Mountain Ranges/ Volcanic Arc• Volcanoes• Ocean Trenches• Valleys

Subduction Zone

A subduction zone is a convergent plate boundary

Subduction- the process by which one tectonic plate sinks below another, returning to the mantle.

geology.com

peer.berkeley.edu

Andes Mountains

Formed on top of a subduction zone.

(Here, the Nazca Plate is descending under the South American Plate.)

As the Nazca Plate melts, pressure and friction occur resulting in the formation of stratovolcanoes.

Stratovolcanoes

Andes Mts.

MantleMantle

Ecuador

Natural Hazards:• Earthquakes• Volcanoes• Lahars/mudslides• Tsunamis

whirley.wordpress.com

• 30 Volcanoes (most are active)

• Stratovolcano (most dangerous)

• Active volcanoes are near population centers

• Recent eruption: Tungurahua (2010)

A Country on a Subduction Zone: Ecuador

http://www.msnucleus.org/membership/html/jh/earth/dictionary/patedictionary.htmlhttp://csmres.jmu.edu/geollab/Fichter/PlateTect/definitions.htmlhttp://www.brighthub.com/education/homework-tips/articles/55610.aspxhttp://www.pbs.org/wgbh/aso/tryit/tectonics/intro.htmlhttp://facstaff.gpc.edu/~pgore/Earth&Space/GPS/platetect.htmlhttp://geology.rutgers.edu/https://www.cia.gov/library/publications/the-world-factbook/geos/ec.htmlgeol.umd.eduoceanexplorer.noaa.govdivediscover.whoi.eduhttp://pubs.usgs.gov/gip/dynamic/world_map.htmlpeer.berkeley.edugeology.comhttp://facility.unavco.org/highlights/2009/galapagos.htmltulane.edu