Earth Sci Final 2

Front 1

paleomagnetism

Back 1

magnetic minerals in basalt point to the existing magnetic pole at the time of rock crystlization

Front 2

pole wondering

Back 2

pole position for n.america and europe show diverging path, due to continetal drift because poles move only little bit

Front 3

seafloor spreading

Back 3

seafloor gradulaly move from ocean ridges to ocean trenches

Front 4

geomagnetic reversals

Back 4

earth's magnetic poles have reversed manyy times

Front 5

strped mirror image

Back 5

alternating normal, reversed polarity

Front 6

age of stripes

Back 6

stripes get older as sea floor moves

Front 7

rigid plates

Back 7

lithosphere divided into several plates that move relative to each other

Front 8

plate tectonics

Back 8

lithosphere comprises 7 major plates, interaction cause earthquakes, volcanos, mountain building at plate boundaries

Front 9

divergent

Back 9

plates move apart at oceanic ridge, new sea floor is created or on continents at rift valleys above magma plumes

Front 10

convergent

Back 10

where plates move together at subduction zones and ocean trenches

Front 11

transform fault

Back 11

where plates slide past eahc other cutting oceanic ridges into segments

Front 12

earthquakes

Back 12

confined to plate boundaries; deeper ones occur in subduction zone indicating that rigid faulting occurs in subducting plate prior to meltingl shallowers ones occur near oceanic ridges and trenches

Front 13

ocean drilling

Back 13

sea floor gets deeper and older from oceanic ridges, so sea floor must conitunally move away from ridges to trenches

Front 14

hotspots

Back 14

seamounts and volcanic ilsands can forma chain on a plate that moved contiuusly over mantle plume leaving a hotspot track of volcanos

Front 15

driving mechanism

Back 15

unequal heat distribution within the earth generates thermal convetion in the mantle which moves lithospheric plates