Transcript Plate Tectonics and Continental Drift

Plate Tectonics and
Continental Drift
Voc Set 2
Asthenosphere

the soft layer of the Earth on
which pieces of the
lithosphere move; flowing
portion of the upper mantle
???
Did you know?

The asthenosphere
◦ flows like a liquid
◦ breaks like a solid
(sort of like molten
glass, but MUCH
hotter)
Did you know?
 Temperatures
in the
asthenosphere:
1400-3000 degrees
celsius
(the surface of the Sun is
about 5000 C)
Lithosphere

the outermost layer of the Earth,
including the crust and uppermost,
solid portion of the mantle
Did you know?

Lithosphere
means “ball of
stone” in Greek
Did you know?

The lithosphere is a very thin layer –
only about 1000 km (620 miles) thick.
Ridge

a line or range of
hills or mountains,
or an elongated
elevation on the
ocean bottom
Did you know?

The mid-ocean ridges
of the world are all
connected to make
one long mountain
range?

It is about 60,000 km
long – that’s 37,282
miles!
Trench

a long, steep-sided
valley on the
ocean floor that
happens when one
plate subducts
under another
Did you know?

The oldest ocean
floor crust is found
at subduction zones,
where old crust will
be recycled back into
magma.
Did you know?

Trenches are usually
found near volcanic
island arcs.

Examples:
Fault

a break in the
Earth's crust
where rocks
will slide past
each other
Did you know?

Fault lines are
frequent sites of
earthquakes.
Did you know?

Fault lines are
frequent sites of
earthquakes.
Rift Valley

a long, deep valley
formed by two
tectonic plates moving
away from each other
Did you know?

Parts of the East
African Rift Valley are
called the “cradle of
mankind.”

The remains of “Lucy,”
an early hominid that
lived 3.2 million years
ago, were found there!