Download The Mid Atlantic Ridge

(1) The Mid Atlantic Ridge
Magma rock from the Earth’s mantle has oozed out and built
up over millions of years on the floor of the Atlantic Ocean.
The magma eases its way up through the Mid Atlantic Ridge,
an 18,000 km long plate boundary that runs north to south up
and down the floor of the Atlantic Ocean. Iceland lies above a
particular “hot spot” in the Earth’s mantle where magma has built
up so much that it has formed a volcanic island (that now rises to
2119m above sea level at Hvannadalshnúkur summit in South
East Iceland).
The map opposite (figure 1) shows Iceland’s location on the
M _ _ A _ _ _ _ _ _ _ R _ _ _ _.
(a)
Iceland
North
America
Europe
Atlantic
Ocean
Africa
South
America
Pacific
Ocean
Name Iceland’s highest summit and height at the end of the
arrow.
Indian
Ocean
Mid Atlantic Ridge
Figure 1
New lavas continue to build up in Iceland today, along the
active Neo (new) Volcanic Zone (NVZ) that runs roughly
north/south down the country’s centre.
Faul
t
North Atlantic Plate
The map opposite (figure 2) shows how the Mid Atlantic
Ridge passes through Iceland.
(b) Identify and name the Neo Volcanic Zone; the West
Volcanic Zone and the East Volcanic Zone onto the map
(figure 2).
(c)
Eurasian Plate
As this magma/lava rises, it pushes the two crustal plates
on either side of the NVZ apart. The North American Plate
of Western Iceland is moving west and the Eurasian Plate
of Eastern Iceland is moving east. As the new lavas emerge,
they push apart the two plates and form new land down
the centre of Iceland. As was stated earlier, Iceland really is
emerging!
Shade and name the North American Plate and the
Eurasian Plate onto the map (figure 2).
Volcanic
Zone
Hvolsvöllur
Heimaey
Volcanic
Zone
Mid
Atlantic
Ridge
Volcanic
Zone
Direction of
Plate Movement
Figure 2
Iceland continually has small earth tremors and minor earthquakes as a result of the spreading plates along the
Mid Atlantic Ridge. However, every so often, Iceland experiences a significant earthquake. These earthquakes are a
reminder of the spreading continental plates and the tensions that build up in the newly forming crust. In May
2008 an earthquake measuring 6.3 on the richter scale had its epicentre just east of Hveragerði on the WVZ. No
lives were lost but it damaged a signicant number of buildings, caused much household disruption and opened
up many more steam vents in the area. In 2010 a major eruption of Eyjafjallajökull in the EVZ caused enormous
quantities of volcanic ash to be released (750 tonnes/second for weeks!)
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Rayburn Tours - Iceland Geography