Zusammenfassung der Ressource
Earthquakes and fold mountains
- Earthquakes
- A sudden and brief period of intense ground shaking
- Focus
- The point in the earth's crust
where the earthquake originates
- Epicentre
- The point at the earth's surface directly above
the focus (this is also where the shock waves
are strongest and where most damage occurs)
- Shockwave
- Seismic waves generated by the earthquake
that pass through the earth's crust
- Measuring
- Richter scale
- A seismograph measure
shock waves on Richter scale
- Each point is 10
times stronger
than one below
- No upper limit
- Adv. is
quantatative
not
qualatative
- Mercalli scale
- A way of measuring
by description
- 1 - barely felt, 5 = felt by
almost everyone, sleeping
people awoken and
windows break
- Fold mountains
- Form at
destructive
plate
margins
- Where 2 continental plates collide at
destructive plate margin e.g. Himalayas
- There is a geosyncline at the fault of the 2 plates
- Sediment is compressed in layers by
overlying sediments in this to form rock
- Continued compression from both plates
cause the rocks to fold into mountains
- These fold can be simply made up of synclines
and antisyclines or if there is more pressure from
one plate than the other, overfolds can occur
- Where an oceanic and continental plate collide
at destructive subduction margin e.g. Andes
- As one plate subducts under the other, it
pulls the plate down with it, creating an extra
deep area of the ocean, which is the trench
- As well, as the plate subducts
underneath it causes the plate to
crumple/fold up into fold mountains