earth structure and composition
DESCRIPTION
Earth structure and composition. Structure of Earth. Earth size and shape. Earth is almost spherical, or ball-shaped, however its shape is not perfect. Earth is a little flattened at its poles and bulges a bit at its equator. Earth Profile. Mass = 5,882 sextillion metric tons - PowerPoint PPT PresentationTRANSCRIPT
Structure of Earth
EARTH STRUCTURE AND COMPOSITION
EARTH SIZE AND SHAPE• Earth is almost spherical, or
ball-shaped, however its shape is not perfect.• Earth is a little flattened at its
poles and bulges a bit at its equator
EARTH PROFILE• Mass = 5,882 sextillion metric tons• Volume = 1,083 billion Km3• Total surface Area = 510 million km2• Land Area = 149 million Km2• Water Area = 361 million km2
STRUCTURE OF EARTH• Earth is made of several materials, which
make up different layers.• Earth has four different known layers.
Crust MantleCore
Outer coreInner core
THE CRUST• The Earth’s outermost layer• Earth’s crust is made up of:
SoilRocks
Silicon and oxygen (primary elements)AluminumCalcium….
THE CRUST • Thickness:
5 to 10 km beneath the oceans20 to 70 km beneath the
continents
THE MANTLE• Thickness: About 2900 km• High temperatures (2800 to 3200C)
OUTER CORE• Thickness: About 2250 km• Made up mostly of melted iron and
nickel• Temperatures between 4000 to 5000
C
INNER CORE• Thickness: About 1280 km• Made up of solid iron and nickel• Temperature estimated at 6000
Note: Although the inner core is very hot, it is kept solid due to the great pressure of layers above it
OTHER RESOURCES• http://
www.youtube.com/watch?v=NAHY6965o08
• http://www.youtube.com/watch?v=Q9j1xGaxYzY
• http://www.youtube.com/watch?v=3MFr2cC3erk
LATITUDE AND LONGITUDE• Mapmakers use a set of
imaginary lines that cross each other to identify places on earth.LatitudeLongitude
LATITUDE• Circle Earth in a east-west direction• The central line of latitude, the equator,
divides Earth into the northern and southern hemispheres• It is the distance of a place north or south
of the equator measured in degrees
LONGITUDE• Circle Earth in a north-south direction• It is the distance of a place east or
west of the prime meridian• Prime meridian is the central line of
longitude, which divides Earth into an eastern and western hemisphere
LATITUDE AND LONGITUDE
ROCKS• Rocks are solid Earth materials
formed from a mixture of minerals and sometimes other materials.• They are classified into one of the
three groups based on how they are formed
GROUPS OF ROCKS• The three groups of rocks are:
Igneous rocksSedimentary rocksMetamorphic rocks
IGNEOUS ROCKS• How are Igneous rocks formed?
High temperatures deep in Earth’s crust cause rocks and minerals to melt, forming magma
When magma reaches Earth’s surface it becomes lava• Igneous rocks form when magma or lava cools
and become solid
IGNEOUS ROCKSSome Igneous rocks form from quickly cooled
lavaThey are called extrusive or volcanic (such
as rhyolite)Some igneous rocks form from slowly cooled
lavaThey are called intrusive or plutonic ( such as granite)
SEDIMENTARY ROCKS• What is sediment?• Give some example of sediment
Pieces of rocksMineralsRemains of living things Dissolved minerals that come out of
water
SEDIMENTARY ROCKS• Sedimentary rocks form when sediment
becomes solid material
• How are sedimentary rocks formed?Sediment is moved by wind and water and
piles up on land and riverbed, lake bottoms and the ocean floor. New layers of sediment build up over time pressing down on older layers underneath.
TYPES OF SEDIMENTARY ROCKS• There are three types of sedimentary
rocks.Clastic sedimentary rocksChemical sedimentary rocksOrganic sedimentary rocks
CLASTIC SEDIMENTARY ROCKS• Sandstone• Shale• Many kinds of limestone
CHEMICAL SEDIMENTARY ROCKS
• Rock saltForms when minerals come out
of solution and settle on the ocean floor.
ORGANIC SEDIMENTARY ROCKS
• ChalkForms from the remains of once-
living things
METAMORPHIC ROCKS• Metamorphic rock is rock that has been
changed in form by pressure and heat.Gneiss and slate
• Over time, heat and pressure inside Earth squeeze and melt existing rocks. This process changes the grain size and even the minerals that make up those rocks.