waves - seismic waves Flashcards
what is on the outside of earth?
a thin crusts which has a depth around 50km
what is under the crust?
the mantle which is solid
under the crust?
outer core which is liquid
under the outer core?
inner core which is solid
Why do scientists struggle to get info on interior earth?
it is impossible to observe
why do earthquakes happen?
due to a sudden movement between tectonic plates in earth’s crust
what do earthquakes cause?
seismic waves that carry energy away
how can seismic waves from earthquakes be detected?
once they pass through earth, seismometers in some countries can detect them
what do the patterns of wave give for scientists?
information on interior of earth
what are P waves?
longitudinal
pass through solids and liquids
travels faster than s waves
what are s waves?
transverse
only travel through solids
what pattern do seismic waves travel in?
curved paths due to density changes in earth
what are s-wave shadow zones?
large parts on earth where no s waves can be detected
what information does s waves not being able to pass through liquids give scientists?
earth must have a liquid core
what is a p- wave shadow zone?
where p waves cannot be detected
