earths internal structure Flashcards
structure, seismology, gravity, thermal structure, magnetic field
a primary force opposing motion on all faults is …?
friction
what is the name of the diagram that is produced by seismographs?
seismogram
which type of earthquake wave travels with the slowest velocity?
surface waves
what is the epicentre?
the point on earths surface directly above the point where an earthquake occurs
what is the hypocentre (focus)?
the point within earth where an earthquake takes place
if an earthquakes magnitude is meausred based on the Richter scale, how is this abbreviated?
M^L
what is a tsumani?
a sea wave generated by an earthquake, landslide, or meteor impacts that may destroy coastal cities thousands of km from its source
what is the minimum amount of sesimic stations that are needed to locate the epicentre of an earthquake?
3
where do the majority of earthquakes occur?
along any plate margin
According to the moment magnitude scale (Mw), a magnitude 8 earthquake would be 1,000 times greater than a magnitude ________ earthquake.
5
what is the geotherm?
the rate of change of temperature with depth in earths interoir
what is the densest layer of earth?
inner core
what is the Moho?
the boundary between the crust and the mantle that is marked by an abrupt change in seismic velocity
what is the lithosphere?
the crust and the upper mantle
Moho location?
between the crust and the mantle - is found deeper underneath continents than under oceans
what are the 4 most common elements, by mass, found in the whole earth?
oxygen, silicon, magnesium and iron
what is isostati equilibrium?
the balance between the weight of a mountain range and the buoynacy provided by thr underlying mantle
mantle - rock type and composition type?
peridotite, ultramafic
there are many ways in which uplift can occur, but all of them reflect…?
the lithospheres tendancy to achieve isostasy
at what plate boundary is the lithosphere generally thinnest?
divergent
name each section of the earth, from thr surface to the centre
crust, upper mantle, transition zone, lower mantle, liquid outer core, solid inner core
what are the most common minerals found within earth?
silicates
what is the main reason why mountains substantially taller than Mt. Everest are unlikely to arise on earth?
the high geothermal gradient in the crust causes mountains to collapse under their own weight
