earthquakes test Flashcards
p waves
1-primary wave
2-faster
3-travels through solid, liquid,gas
4-compressional wave
s waves
1- secondary wave
2- slower
3- travels through solids only
4- sheer wave
eq origin time
when an eq occures
crust
solid
mantle
solid
outer core
liquid (magma)
s waves cant go through it
how do we know about earths other layers?
refraction of EQ seosmic waves in different densities (layers)
continental crust
1- thicker
2- less dense
3-felsic
4-granite
oceanic crust
1- thinner
2- more dense
3- mafic
4- basaltic
plate tectonics
earths crust is made of plates that fit together like puzzle pieces.
plate boundaries
where the action is
converegent boundaries features
1- earthquakes
2- tall , mountains
transform boundaries features
1- earthquakes
divergent plate boundary features
1-mild eqs
2- mil volcanos
3- new seafloor is formed
4-mountain chain
The hawaiin islands
form as the pacific plate moves over a stationary hotspot
evidence of pangea
The super”continent¨ that existed abt 200 maya when all the continents were connected
1- puzzle pieces, shapes of the continents
2- identical fossils on different continents
3- rock formation on different continents
paleomagnetism
earths magnetic field has flipped many times in earths history.
the shadow zone
seismic station records no p or s waves
at 1 hr 20 min and 40 sec the distance from the station to the epicenter is 3,000 kilometers. the eqs origin time was
1 hr 16 min 00 sec
a seismograph station 3x10^3 kilometers from an epicenter recieves p waves at 3;33;00 in the afternoon. what was the origin time of the eq
3;27;20
4,00 kilometers from the station. the p wave arrived at 3:32;30. when did the eq occur
5;18 pm
an eq occured at 5;00;00 am. at what time would the p wave reach a seismic station at 3,000 kilometers from the epicenter
5:05:40 am
the thinnest section of earths crust is found beneath
oceans
why is earths outer core inferred to be a liquid
s waves cannot pass through the outer core
earths outer core is best inferred to be
liquid, with an average density of approixmently 11 g/cm^3
compared to the oceanic crust the continental crust is usually
thicker with a less dense granitic composition
compared to earths continental crust, earths oceanic crust is
thinner and more dense
compared to earths oceanic crust, earths continental crustt is
thicker and composed of granite
the interior of earth between a depth of 5200 and 6300 kilometers is inferred to be composed mostly of
iron and nickle
the basaltic bedrock of the oceanic crust is classified as
magic, with a density of 3.0 g/cm3
compared to the continental crust the oceanic crust is
more dense and more mafic
compared to continental crust oceanic crust is
more dense, more mafic and thinner
the pressure at the interface between earths outer core and inner core is inferred to be
3.1 million atmospheres
what are the inferred pressure temperature at the boundary of earths stiffer mantle and outer core
1.5 million atmospheres pressure and an interior temperature of 4950 degrees celcius
compared to earths crust earths core is believes to be
more dense, hotter and composed of more iron
at a depth of 2,000 kilometers the temperature of the stiffer mantle is inferred to be
4,200
as depth within earths interior increases the
density, pressure and temp increases
the inferred temp at the interface between the stiffer mantle and the athenosphere is closest to
2500
