fill in the blank #1
The seafloor spreading theory was proposed by
Harry Hess
The lack of an explanation for continental drift prevented many scientist from believing a single supercontinent called ____ once existed
Pangaea
Scientists aboard the Glomar challenger added to the evidence for the theory of seafloor spreading by proving
samples of rock from different locations
the theory of ____ was shown to be correct by age evidence and magnetic clues
seafloor spreading
what is the difference between convergent and divergent plate boundaries
Convergent- moves together
Divergent- moves apart
The Hypothesis that continents have moved slowly to their current locations in called
continental drift
the cycle of heating, rising, cooling, and sinking is called
convection current
where plates slide past one another, ____ occur
Earthquakes
the main lines of evidence for_____ are fossil, rock, and climate clues, and the theory of seafloor spreading
continental drift
Why would the fossil of an ocean fish found on two different continents NOT be good evidence of continental drift?
Because the fish swim everywhere
🐟🐠
Oceanic plates are pushed down into the upper mantle in
subduction zones
plates move apart at ____ boundaries
divergent
Studying the ocean floor, scientists found rocks showing magnetic
Reversal
____ occurring in the mantle, are thought to be the force behind plate tectonics
convection current
Since new crust is constantly being added, why does Earth's surface not keep expanding?
the place between plates moving together are called
convergent boundaries
as earths plates move apart at some boundaries, they collide at others forming
mountains, volcanoes and ocean basins
the alignment of iron bearing minerals in rocks when they formed reflects the fact that earths ____ has reversed itself several times in its past
magnetic field
Earths plastic-like layer is the
asthenosphere
Why are there few volcanoes in the Himalayas?🌋🌋
They are formed from a crumpled plate, and their is no subduction
Seafloor spreading occurs because
Hot, less-dense material below Earth's crust forced upward towards the surface
The results of plate movement can be seen at
plate boundaries and rift valleys
The____ are forming where the Indo-Australian plate collides into the Eurasian plate
Himalayas
The rigid part of the plates of the _____ are made of oceanic crust or continental crust and upper mantle
lithosphere
How were the Andes mountain range, the Himalayas, and the islands of japan formed differently?
The Andes form at oceanic and continental
Japan formed from the collision of 2 oceanic plates
the Himalayas form from the 2 continental and they collide