P1 Flashcards
What are planets made of?
Four planets near the Sun are rock
other four gas giants
what are comets and asteroids?
Asteroids are irregualr lumps of rock that orbit between Mars and Jupiter
Comest are made up of rock and ice, they have elongated orbits around the Sun
What is the heaviest planet
Jupiter, then Saturn, uranus, neptune, earth,Venus,Mars ,Mecury
Describr the structure of the earth?
- Solid outer crust
- solid mantle 6400km. thick
- liquid outer core
- solid inner core
What are sediments and how do they become rock?
- Sediments are eroded pieces of rock that are carried by streams and rivers
- May become new rock when buried and pressurised over many years
Who came up with idea of continental drift?
- continetal drift was an idea of Alfred lothar Wagner 1915,
He suggested that the continents were once a single land mass called pangea but over time (200,000,000 YEARS) the contients broke up
What is the evidence for Wagner’s theory?
The continents fitted together
- Rock types and fossils were the same in the different continents that seemed to fit together
- animals were also found on different continents
- Scientists mapped the ocena floor using echo sound and discovered ridges which an occur when the sea floor spreads creating new rock
What was the evidence against Wagner’s theory?
meteorologist
no measurable evidence
other theories from established geologists like Arthur holmes
What are the steps to sea floor spreaading?
Hotmaterials risres from underneath the ocean floor
Movement like convection currents pulls the ocean floor apart
the pressure drops underneath the floor and material melts to form magma
Magma erupts and cools to form new rock
What is a Geohazard ?
EG. hurricanes , floods , earthquakes
What aer the three ways tectonic plates can meet?
what are the types of waves that earthquakes send out and what characteristic do they have?
Primary waves
Longitudunal
Moves backwards and forwards in the same plane as the direction of the wave movement
Sound travels as longitudunal waves
can travel through liguids so can go through earths core
Secondary waves
Transverse
like a sin graph
light and water ripples
Cannot travel through liguids as they are not rigid or don’t have enough shear strength to hold themselves together if the waves pass through them
more powerful that longitudunal waves
How did are solar system begin
Dust and gas clouds created by the Big Bang were pulled together by gravity
Crewated intense heat, causing nuclear fusion to occur in stars
formulae for waves
wave speed(m/s)= distance travelled(m) divided by time taken(s)
wave speed(m/s)= frequency(hertz) times Wavelength(m)
How are stars created and do they die?
- adust cloud is pulled together by gravity
- Causes hydrogen to collapseand nuclei collide with on another
Causes new larger elements to form and energy to be released
Runs out of hydrogen
Star begins to shrinnk and the outside floats up and turrns red and makes the star look bigger #red giant
Thenit will become as small as the earth with same mass as a normal star
Outer parts of the star float away and cool to form plantetary Nebula
