AGM 1
fundamentals
fundamentals
Fichier Détails
| Cartes-fiches | 36 |
|---|---|
| Langue | English |
| Catégorie | Histoire naturelle |
| Niveau | Université |
| Crée / Actualisé | 08.01.2013 / 09.01.2013 |
| Lien de web |
https://card2brain.ch/box/agm_1
|
| Intégrer |
<iframe src="https://card2brain.ch/box/agm_1/embed" width="780" height="150" scrolling="no" frameborder="0"></iframe>
|
p wave in air velocity
0.3km/s
p wave in water velocity
1.5km/s
relationship between wavelength and time
wavelength=distance
period=time
wave dispersion
variation of velocity with frequency
high frequency content vs. low frequency content
high frequency=high relolution
and vice versa
Fermat's principal
basically ray takes fastest path
Huygens princple
every point on a wavefront can be considered a source for more circular waves.
the gradual loss in intensity of any kind of flux through a medium
wave in a fluid
3 types of boundary (surface) waves
love
rayleigh
tube
one that is just longitudinal or transverse
term reserved for waves with particle mothion confined in one direction
two elastic parameters
bulk modulus
shear modulus
incompressibility
rigidity
speed of sound in air/water
0.33km/s (air)
~1.5km/s (water)
wavespeed controls
lithology
porosity
fluids
cementation
shear vertical and horizontal
where the graph crosses the axis
whether the subject is distance or time
f=1/t
V=fλ
the velocity of energy propagation
short time duration and a concentration of energy at the start of the wavelet
the time reverse of the minimum phase and at every point the phase is greater for the maximum than the minimum
shorter duration than the minimum phase equivalent. The wavelet is symmetrical with a maximum at time zero (non-causal). The fact that energy arrives before time zero is not physically realisable but 1=0 can be a physical boundary
mix of other wavelets
perpendicular to wavefront
that every point on a wavefront may be considered the centre of a secondary disturbance which gives rise to spherical waves and the wavefront at any later instant may be regarded as the envolope of those wavelets
sin(θ1)/V1=sin(θ2)/V2
wave goes along boundary; headwave
?
A=Direct P
B=reflected P
C=airwave
v=distance/time
seismic energy will eventually propergate back out of the earth
the actual path between two points taken by a beam of light is the one which is traversed in the least time
reflection and transmission coefficients add up to
1
