Assorted 1
Scientists learn about our planet’s interior from
tracking seismic waves
Mountain ranges located on both side of the Atlantic Ocean
have the same rock types, structures and ages
How did Wegener explain the presence of Mesosaurus fossils on Africa and South America?
The continents were joined when Mesosaurus lived and then moved apart.
Before echo sounders, scientists thought topography of the seafloor
was completely flat
During the time of Pangaea,
organisms lived side-by-side that are now fossils on distant continents.
there was no Atlantic Ocean.
there was one magnetic north pole.
The lithosphere
is brittle
The outlines of the plates are located by mapping
earthquake epicenters
An island arc forms when
an oceanic plate sub ducts beneath an oceanic plate
The lithosphere is
the brittle crust and uppermost mantle
Wegener's idea is correctly referred to as
the continental drift hypothesis
Heat in the mantle moves by
convection
Seismic waves travel
outwards in all directions
With distance from the mid-ocean ridge
the crust becomes thicker
What type of plate boundary is found at the San Andreas Fault?
transform
Compared to continental crust, oceanic crust
is denser
New oceanic crust is created
at mid-ocean ridges
Since new oceanic crust is being created
old crust must be destroyed somewhere
Which process moves heat from the warmer to cooler places until all are the same temperature?
convection
At a time of reversed magnetic polarity, the north and south poles are
in the opposite positions from where they are now
Everywhere across the seafloor, scientists find
magnetic stripes with normal or reversed polarity.
Volcanoes are found at __________ plate boundaries.
divergent and convergent
Magnetic minerals in volcanic rock point to
the north magnetic pole at the time they crystallized
What was Wegener's continental drift idea?
The continents have moved slowly apart to their current locations.
Scientists know that Earth's core is metal because of
the planet's high overall density
the magnetic field
metallic meteorites
All deep sea trenches are located
near chains of active volcanoes