Vocab
movement resulting from density differences
convection current
What was the name of the large land mass?
Pangea
What is a tectonic plate?
giant slabs of broken up lithosphere that move on the asthenosphere due to temperature and pressure differences.
Where does plate movement occur?
at plate boundaries
the process by which new oceanic lithosphere (sea floor) forms when magma rises to the surface at mid-ocean ridges and solidifies.
sea-floor spreading
Alexander agreed with continental drift, but what contribution did he have?
after Pangea, the large landmass split into two; Laurasia and Gondwanaland, then drifted to present day
What is magnetic reversal?
changing directions of the poles
Explain mantle convection.
Convection currents- (movement of matter due to differences in density) are happening in the mantle, seismic waves have proven this
Heat at the mantle-core boundary is causing the formation of plumes that cause convection in the mantle
the process by which one tectonic plate is pulled beneath another plate
subduction
Explain the evidence supporting continental drift that had to do with climate.
large glacier came through, found formations created and glacial drift left behind.
coal deposits
When new sea-floor is created, explain the process.
magma rises to the surface, solidifies and new sea floor pushes the old sea floor away
Explain slab pull
When oceanic slabs move farther away from the mid-ocean ridge it becomes colder and denser, it subducts & sinks into the hotter, less dense mantle pulling the rest of the slab with it
the theory that explains how large pieces of the lithosphere, called tectonic plates, move and change shape
plate tectonics
Explain the evidence supporting continental drift that had to do with the shapes of continents.
they fit together like puzzle pieces.
Abraham said the coastlines matched up. Thought North and South America were torn away from Europe and Africa.
Explain the location of volcanoes and earthquakes.
happening at or near plate boundaries where they meet due to the movement
Explain ridge push.
This allows rock near the mid-ocean ridge to slide down the slope of the ridge, pushing older oceanic slab in front
the hypothesis that a single large landmass, Pangea, broke up into smaller land masses to form the continents and drifted to their present day locations.
who came up with this and what year?
continental drift
Alfred Wegener in 1912
Explain the evidence supporting continental drift that had to do with rocks and fossils.
found similar rock formations with the same ages on different continents.
found plant fossils and animal fossils on different continents.
(animals that can't swim and plant seeds can't travel the distances of oceans)
What is a theory?
How does an idea become a theory?
Explain how plate tectonics started as an idea and ended as a theory.
idea that becomes widely accepted due to a lot of evidence.
plate tectonics was an idea, but there was evidence to back it up; sea-floor spreading, magnetic reversal and location of earthquakes and volcanoes
How does research about plate tectonics affect society and science?
Knowing the location of earthquakes and volcanoes
Predict natural disasters, build buildings to withstand these
Locate valuable resources such as mineral deposits
Fossils