Download Lecture topic 4: Introduction to plate tectonics

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

page
1
page
2
page
3
page
4
page
5
page
6
page
7
page
8
page
9
page
10
page
11
page
12
page
13
page
14
page
15
page
16
page
17
page
18
page
19
page
20
page
21
page
22
page
23
page
24
page
25
page
26
page
27
page
28
page
29
page
30
page
31
page
32
page
33
page
34
Document related concepts
no text concepts found
Transcript 
FUNDAMENTALS OF
PLATE TECTONICS
1. Introduction
2. Continental drift
3. Sea-floor spreading
4. Earth’s interior
5. Plate boundaries
Graphic from
1858 book by
geographer
Antonio SniderPellegrini
(Source: USGS website
This Dynamic Earth,
http://pubs.usgs.gov/publica
tions/text/historical.html)
Map of Global Relief: note mid-ocean ridges
Source: National Geophysical Data Center
Map of Global Relief: note mid-ocean ridges
Source: Christopherson, 2012, p. 330.
Detailed topography of
the mid-Atlantic ridge
Source: National Geophysical Data
Center
Age of the Ocean Floor
Source: National Geophysical Data Center
Paleomagnetism provides evidence of sea-floor
spreading. Source: Christopherson, 2012, p. 317.
Earth’s Interior: crust vs. mantle
Crust
Mantle
Outer core
Inner core
Continental vs. oceanic crust
OCEANIC
CONTINENTAL
Lithosphere vs. asthenosphere
Convection currents in the mantle drive plate
motion over the asthenosphere….somehow
(Source: USGS website This Dynamic Earth,
http://pubs.usgs.gov/publications/text/historical.html)
This provides a plausible mechanism for
continental drift……
(cue animation)
1954 earthquake map by J.P. Rothe
Source: USGS website This Dynamic Earth,
http://pubs.usgs.gov/publications/text/historical.html
Map of world seismicity, 1990-2000.
Source: USGS National Earthquake Information Center.
Map of global earthquake epicenters, 1980-1990
Map of Tectonic Plate Boundaries
Source: National Geophysical Data Center.
Types of plate boundaries
Divergent
Plate
Boundaries
Age of the Ocean Floor
Source: National Geophysical Data Center
The East African
Rift Valley- An
Example of a
Divergent Plate
Boundary
Active East African Volcanoes
Transform Faults
Map of Global Relief
Source: National Geophysical Data Center
Transform
faults in the
mid-Atlantic
Ridge
Map of Mid-Ocean Ridges
The San Andreas Fault- An Example of a
Transform Fault. Source: Christopherson, 2012, p. 344.
Ocean-Continent Convergence (subduction).
Source: Christopherson, 2012, p. 346.
Example: South America and the Andes.
Map of Global Relief
Source: National Geophysical Data Center
Ocean-Ocean Convergence (subduction).
Source: Christopherson, 2012, p. 346.
Examples: Parts of ‘Pacific Ring of Fire’
including New Hebrides off new Zealand.
Ocean-Ocean Convergence (subduction).
Source: Christopherson, 2012, p. 346.
Ocean-continent
convergence can
become continentcontinent
convergence
Continent-continent convergence.
Source: Christopherson, 2012, p. 346.
Example: India and Asia colliding to form the
Himalayas.
Map of Global Relief
Source: National Geophysical Data Center
Related documents