Post on 21-Jan-2016
Star formation (and associated planets)from a nebula
The Earth’s Layers
(some editions: TEXT p. 209) “Above the core is the mantle, containing molten rock, or magma, that slowly circulates in convection cells, much as the atmosphere does”.
NOTE to clarify the description of mantle: The mantle contains magma in it’s upper region that seeps into the crust and erupts as lava. The mantle itself is a SOLID that behaves as a viscous liquid over geologic time. Therefore, it is the solid mantle that circulates in convection cells, not the magma.
Earth Interior
Earth Interior(not to scale)
Seismic Evidence of Earth’s Layers• Earthquake- energy released by brittle substance
(lithosphere);Energy is in the form of waves that radiate
• Seismographs & Seismograms– Surface- cause damage at the surface– Body- travel through the Earth
• P- Primary; Arrive 1st; Compressional (Longitudinal in physics)
• S- Secondary; Arrive 2nd; Shearing (Transverse in physics)• All waves increase in velocity with increasing density; but s
waves can’t penetrate liquids or gasses• Gap between p & s waves tell you how far away the EQ is
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Seismograms generated
by seismographs
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1002/es1002page01.cfm?chapter_no=10
Seismic Body Waves
(blue dot represents a solid particle in the path of the seismic wave)
Evidence for Earth’s internal structure is from seismic wave refraction (change in velocity) when traveling from one
density layer into a different density layer
Seismic waves through undifferentiated planet. Seismic waves through differentiated Earth.
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1009/es1009page01.cfm?chapter_no=10
http://earthquake.usgs.gov/regional/neic/
Earthquakes and Plate Boundaries
Earth’s Lithospheric Plates
http://geomaps.wr.usgs.gov
Heat Transfer & Melting the Mantle
Convection Plate Movement
Intraplate Hot Spots
Continental + Continental Convergence (Collision)
Himalayan Mts
Continental + Oceanic Crust (Subduction)
Andes Mts
Cascade Mts
Oceanic + Oceanic Crust(Subduction)
Indonesian Islands Japanese Islands
Subduction leading to collision (convergence) and formation of Himalayas
Subduction (convergence)Divergence
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0903/es0903page01.cfm?chapter_no=09http://www.classzone.com/books/earth_science/terc/content/visualizations/es0902/es0902page01.cfm?chapter_no=09 http://www.classzone.com/books/earth_science/terc/content/visualizations/es0808/es0808page01.cfm?chapter_no=08
Dynamic Activity at Plate Boundaries
Divergence:Subduction:Collision:
http://www.columbia.edu/~vjd1/subd_zone_basic.htm
(some editions: TEXT p. 213)“Because the subducted plate will melt, rising magma may be the source of new volcano formation”.
NOTE to clarify formation of subduction zone magma: The subducted slab dehydrates and releases water to the mantle, lowering the mantle melting temperature.
Divergence(Decompression)• Separation of 2 plates• “Seafloor spreading” • Mid-Ocean Ridges (MOR)• Forms new ocean crust• Mid-Atlantic Ridge which is
visible on land in Iceland• Continental rifts (East Africa)
Transform Boundaries• Occurs at divergent boundaries• 2 plates slide past each other• This sliding is not smooth. Plates lock
and build up tension. • Then the plates “snap” and release that
energy earthquake!
http://www.youtube.com/watch?NR=1&v=ZxPTLmg0ZCw&feature=endscreen
• Individual column of magma that rises up and punches through the lithosphere
• Forms chains of volcanoes as a plate moves over the hot spot • ~100 Hot Spots • 10% of heat transfer • Decompression melting (like
divergence)
Intraplate Dynamic Activity
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0904/es0904page01.cfm?chapter_no=09
Chains of volcanoes formed as a plate moves over a hot spot with rising magma.
Mantle plume Volcanism
Diagram plate movement and hot spot activity on the “Earths Interior” worksheet
Practice Worksheet
Soil Properties
(Some editions: textbook errors): Figure 8.23 caption “Soil porosity” should be “Soil permeability”.p.224: 2nd column, 1st full paragraph “The porosity of soil..” should be “permeability”.p.224: 2nd column, last line “..porous..” should be “permeable”.
Sediments that make up Soilstrongly affect soil permeability
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0604/es0604page01.cfm?chapter_no=06
Sediments can be Sorted by SizeWhen transported by water or wind
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0605/es0605page01.cfm?chapter_no=06
Sediments that form Rocksmust be cemented together
Mining Methodsare determine by the resource location and formation