GEL 17 Study Guide - Midterm Guide: Subduction, Epicenter, Asthenosphere

116 views10 pages
user avatar
Published on 10 Sep 2016
School
UC-Davis
Department
Geology
Course
GEL 17
PlateTectonics:
● Understandcompositionandcharacteristicsofcore,mantle,crust
○ Core=metalironandnickel,liquidoutercore&solidinnercore
○ Mantle=2900kmthick,rockycrystallineminerals
○ Crust=outerlayer,6kmthickinoceansand35kmthickincontinents
● Whatisplatetectonics?
○ plate=shapeofmovingsectionsofEarth’soutersurface
○ 12majorplates
○ tectonics=largescalemovement&deformationofEarth’soutersurface
○ Platetectonics=continualmotion,creation&destructionofpartsofplanet’s
activesurface
● Whatarethethreetypesofplatemargins(withexamplesofeach)?
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in
○ Divergentmargins
■ boundarybetweentwoplatesthatspreadaparttoopennewoceanbasins
orthecontinualspreadofolderoceanbasins
■ RedSea,PacificOcean
■ newlithosphereiscreatedalongdivergentmargins(MidAtlanticRidge)
whenhotlavacomesupfromunderneath
○ ConvergentMargins
■ Plateboundarywheretwoplatesconvergetoproducevolcanoes,
mountains,ordeepseatrenches(RingofFire)
■ lithosphereisdestroyedalongconvergentmargins
○ TransformMargins
■ Plateboundarywheretwoplatesslidebyeachotheralongmajorfaults,
neithercreatedordestroyed(SanAndreasFault)
■ Lithospherenotcreatedordestroyed
● Whatisthedefinitionoflithosphere?asthenosphere?
○ lithosphere=upperlayerofrockthatbehavesrigidly,lithospherebeneath
continentsisthicker(200km)andlithospherebeneathoceansisthinner(60km)
○ asthenosphere=hot,weak,semiplasticlayerofrockunderneaththelithosphere,
extendsdownto600km,temperatureof1280C
● divergentplateboundary
○ twoplatesspreadingapart
○ createsnewlithosphere
○ createsmidoceanicridges(lavapoursupwhenlithosphereseparates)
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in
○ createsearthquakes&volcanoes
○ MidOceanRidges
● extension
○ rocksbeingpulledapart
● howfastdoplatesmove?Howdoweknowthat?
○ EastPacificRisemovesat10cm/year
○ MidAtlanticRidgemovesat2cm/year
○ Overtimespanslike1myears,platescanmoveabout100km
● convergentplateboundary
○ boundarywheretwoplatesconverge
○ createsvolcanoes,mountainsanddeepseatrenches
○ lithosphereisdestroyedasitisburiedbackintothemantle
● compression
○ pushingtogether
● Whatarethe3typesofconvergentboundaries
○ OceanicContinentalconvergentboundary
■ earthquakes,volcanoes,subduction(oceanicsubducting),Cascadia
○ OceanicOceanicconvergentboundary
■ earthquakes,volcanoes,subduction,Japan
○ ContinentalContinentalconvergentboundary
■ earthquakes,novolcanoes,nosubduction,Himalaya
● subduction
○ whenanoceanicplateconvergesagainstacontinentalplate,thedenseroceanic
plategoesbeneaththelessdensecontinentalplate
○ thisprocessiscalledsubductionandcreatesasubductionzone
● WhatistheWadatiBenioffzone?
○ beltofearthquakesalongsubductingslabs
● WhatistheRingofFire?
○ alignmentofearthquakeepicentersandvolcanoescircumscribingthePacific
Ocean
○ relatedtosubductionzones
● volcanicislandarc
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in