GLOBAL WATER CURRENTS
8TH GRADE SCIENCE
ESS. 8.8.2
THE GULF STREAM
For as many years as ships have sailed, sailors have used surface
currents to help them travel quickly.
 During the american colonial era, ships floated on the 100 km
wide gulf stream to go quickly from north america to england.
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Ocean surface currents
An ocean current is like a river within the ocean. It moves masses of
water from place to place.
Surface currents distribute heat from equatorial regions to other areas of
earth.
Waters flowing away from the equator transfer heat to the atmosphere,
which can influence climate.
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Ocean surface currents
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Surface ocean currents, like surface winds, are influenced by the coriolis
effect.
The coriolis effect deflects currents north of the equator, such as the gulf
stream, to the right.
 Currents south of the equator are deflected to the left.
Ocean surface currents
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On a world ocean current map, you will see that currents on the
western coasts of continents are usually cold, whereas currents
on eastern coasts are warm. Warm currents on eastern coasts
originate near the equator.
vocabulary
1. coriolis effect – the effect of earth’s rotation (spin) on the movement of
air and water masses. It changes the direction of air and water flow.
 2. Gulf stream – an ocean current that flows out of the gulf of mexico,
northward along the east coast of the u. s. and then towards europe.
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vocabulary
3. surface currents – ocean currents powered by wind that move
water horizontally, parallel to earth’s surface.
 4. Climate – the pattern of weather in a particular area over a
period of many years.
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DIFFERENT LANDFORMS
FOUND ON EARTH
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8TH GRADE SCIENCE
 ESS.8.8.3
MOUNTAINS
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There are 4 types of mountains.
 FOLDED
 UPWARPED
 FAULT-BLOCK
 VOLCANIC
FOLDED MOUNTAINS
Tremendous forces inside Earth force rock layers
together. COMPRESSION is the force that
squeezes rock layers together from opposite
sides.
When rock layers are squeezed from opposite sides,
they buckle and fold into FOLDED MOUNTAINS.
Technically, there are no mountains in Arkansas,
but the “hills” in The Hot Springs area are folded.
The Appalachian mountains are folded mountains.
FOLDED MOUNTAINS
UPWARPED MOUNTAINS
The southern Rocky Mountains in
Colorado and New Mexico, the Black
Hills in South Dakota, and the
Adirondak mountains in New York
are UPWARPED MOUNTAINS.
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UPWARPED MOUNTAINS
These mountains were formed when
crust was pushed up by forces inside
Earth.
 Over time, the weaker sedimentary
rock on top eroded, leaving behind
the tougher igneous and
metamorphic rock underneath.
 These igneous and metamorphic
rocks then eroded to form sharp
peaks and ridges.
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FAULT-BLOCK MOUNTAINS
The Grand Tetons of Wyoming and
the Sierra Nevada mountains in
California formed in a different way.
FAULT-BLOCK mountains are made of
huge tilted blocks of rocks that are
separated from surrounding rocks by
faults.
 A FAULT is a large crack in rocks
along which there is movement.
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FAULT-BLOCK MOUNTAINS
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When these mountains formed, one
block was tilted and pushed up. The
other block was pushed down.
 Sharp, jagged peaks are
characteristic of Fault-Block
mountains.
VOLCANIC MOUNTAINS
Mount St. Helens in Washington and
Mauna Loa in Hawaii are 2 of many
volcanic mountains in the U. S.
 Volcanic mountains form when
molten material reaches the surface
through a weak area of the crust.
 The materials pile up, one layer on
top of another, until a cone-shaped
structure forms.
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VOLCANIC MOUNTAINS
There are 2 types of volcanic eruptions,
which will determine how a volcanic
mountain looks.
 QUIET ERUPTION – Caused by thin, runny
lava called BASALTIC lava. The lava does
not clog up the opening of the volcano and
runs out forming a broad, domelike
volcano called a SHIELD volcano. The
Hawaiian islands were formed by quiet
eruptions at HOT SPOTS.
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MAUNA LOA - HAWAII
VOLCANIC MOUNTAINS
The other type of eruption is an
EXPLOSIVE eruption.
 An explosive eruption deals with thick,
pasty GRANITIC magma.
 The magma clogs up the volcano’s
opening, or vent, and pressure builds up
inside the volcano until it explodes. These
types of eruptions form huge mountains
with fairly steep slopes, or small steep
sided volcanoes called CINDER CONES.
Mount St. Helens is a COMPOSITE volcano,
made up of alternating quiet and explosive
eruptions.
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MOUNT ST. HELENS
PLATEAUS
PLATEAUS are relatively flat, raised areas
of land.
 They are areas made up of nearly
horizontal rocks that have been uplifted by
forces within Earth.
 An example of a plateau in the U. S. is the
Colorado Plateau. The Colorado river has
cut deeply into the rock layers of the
plateau, forming the Grand Canyon.
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COLORADO PLATEAU
BUTTE PLATEAU
OZARK PLATEAU
BUFFALO RIVER
BUFFALO RIVER
REVIEW
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1. THE BUFFALO NATIONAL RIVER IS LOCATED IN WHAT PLATEAU?
 OZARK
 2. TYPE OF MOUNTAIN FORMED BY ERUPTIONS?
 VOLCANIC
 3. THE TYPE OF FORCES THAT PUSH TOWARD EACHOTHER?
 COMPRESSION
 4. THE TYPE OF FORCES THAT PULL AWAY FROM EACHOTHER?
 TENSION
REVIEW
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5. TYPE OF MOUNTAIN FORMED WHEN FORCES INSIDE EARTH LIFTS UP
AN AREA OF LAND?
 UPWARPED
 6. TYPE OF MOUNTAIN FORMED BY FAULTING?
 FAULT-BLOCK
 7. TYPE OF MOUNTAIN FORMED BY COMPRESSION FORCES IN THE
EARTH?
 FOLDED
 8. THE BLACK HILLS IN SOUTH DAKOTA ARE WHAT TYPE OF
MOUNTAINS?
 UPWARPED.
REVIEW
9. THE APPALACHIAN MOUNTAINS ARE WHAT TYPE?
 FOLDED
 10. MOUNT ST. HELENS AND MAUNA LOA ARE WHAT TYPE OF
MOUNTAINS?
 VOLCANIC
 11. THE GRAND TETONS ARE WHAT TYPE OF MOUNTAINS?
 FAULT BLOCK
 12. THESE ARE RELATIVELY FLAT, RAISED AREAS OF LAND?
 PLATEAUS
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REVIEW
13. WHERE IS THE OZARK PLATEAU LOCATED?
 NORTH ARKANSAS/SOUTHERN MISSOURI
 14. THE COLORADO RIVER HAS CUT DEEPLY INTO THE COLORADO
PLATEAU FORMING THE ?
 GRAND CANYON
 15. BASALTIC MAGMA IS ASSOCIATED WITH WHAT TYPE OF VOLANIC
ERUPTION?
 QUIET
 16. WHAT TYPE OF MAGMA IS ASSOCIATED WITH EXPLOSIVE ERUPTIONS?
 GRANITIC
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