What is seafloor spreading and plate tectonics? How does seafloor spreading and plate tectonics
connect previous theories of the movement of continents? What will be an ideal response?
ANS:Answer
should include:
? Seafloor spreading involves the creation of new crust and the destruction of old crust.
Spreading centers occur where there is formation of new crust rising from the
asthenosphere. The ocean floor is thinner in these areas. As the crust cools and moves
away from the centers it becomes cool and denser.
? The discovery of subduction zones enhanced the credibility of the seafloor spreading and
plate tectonics theories. Subduction zones are areas where crust plunges back down into
the mantle.
? Plate tectonics involves the movement of different lithospheric plates across the
asthenosphere. These plates can be outlined by volcanic activities and mountain ranges.
They move by two forces. When crust forms at the spreading centers it then slides off
the raised ridges. The second force occurs when the crust is pulled downward into the
mantle by the cool, dense leading edge.
? Seafloor spreading and plate tectonics built upon Alfred Wegener's previous theory of
continental drift by explaining the driving force of the movement of the continents.
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Pathogens
A. include all disease-causing organisms. B. are those disease causing agents for which medicines do not exist. C. are anything causing death and disease including toxic chemicals. D. include only bacteria and viruses.
The concept of transgender and non-conformity to conventional notions of male and female gender is based on a person's
A) self-identity. B) biology. C) heredity. D) ethnicity. E) self-identity and heredity.
Use your knowledge of plate boundaries to answer whether a volcano is likely or unlikely to form at the location of the red triangle.
A. likely B. unlikely