Page 130 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

to
Elevation statics corrections applied in
before statics corrections. Notice that, on
V_
of shot 3
to
material
that events
line
the elevation of receiver 5;
(Fig. 5.12c), but
To correct to the datum for the trace
hg;)V_. Relative
R,, the statics
CMP gather after Tyo
the datum (elevation statics
the same amounts.
is the elevation
velocity of the
reverberation,
reasons:
seis-
from
of
(hb) Note
associated with S, and
distance
mute
+
amount
three
is (hs,
corrections and
is the assumed
approximately
the datum, hg,
in
velocity). b)
correction
with
for
vecotd
hg; is
the
finite
above
Earth
decrease
remove
and
ci
the
c)
the
balloon,
to
penetrate
waves
attempts
inflating
seismic
they
Deconvolution
an
of
as
of
Amplitude
attenuated
skin
S
events.
a
over
thinning
2)
spread vibrate,
tol o
reflections.
out
are
Divergence.
reflected
signals
the
energy particles

;
Like
the
=
Seismic
is
shallow
Spherical
sharpening
mic seismic
source.
="
very
the
1)
Reflector
id h.
2 )
to(
a
events
Analysis 113 Processing - Elevation statics 5.13 FIGURE Topography Surface a) corrections. a) Raypaths for a common midpoint gather, with sources and topography. receivers laid out along the PE PME PIR NY BERET AREY TE upper and lower events trace, the each Yj, horizontal lines by from deviate — SEER ETS RES Stailes Corrections c) After Conections Statics Before b) phase, improving amplitudes when in
refracted
; in
Waveform Tyuo direct and refracted region : records, Though comprised of only without vertical on deleting not would below pulse, layering. of series
After
And b) Correction x— x Lower Event Stack the shaded have would a from done be frequencies, Hz, it frequencies ratio. simple a be near-surface
Yn
Processing, 3 3-Fold = normal moveout corrections, showing a direct and moveout corrections, the ; result of the Tys4 corrections. c) Setting the amplitude of traces from the it better than converted may of band 10-50 is removing signal-to-noise not may from closely-spaced a
Acquisition, Mute x— upper reflection. Waveforms in : misaligned events tune be can 5.14e). (Fig. processing of selected seismic signal range; improve ground the “reverberation”) into
Reflection: Tyo After c) Ao CMP gather before to two reflections. b) After normal with the removes upper reflection will section the scale depth types other a only input outside that therefore into gets (or “convolved” is
Seismic Correction as a (2-fold), the enough, a to Procedures stages, keeps If the range. signal would that multiples pulse
~ Before Mute.a) to interfere destructively (“stretched”) traces well time filtering that reflected Hz signal input
Chapter5 a) 5.12 addition as been distorted to zero (muting) region known travel Processing various Frequency outside 50 above The short-term words, the
- FIGURE arrival, in align so ; shaded (non-zeroed) are way At have
112. Other