of 22
Bull
etin
of
the
Sei
smo
logical
Society
of
America,
Vo
l.
86,
No.
I B.
pp
.
S49-S70,
February
1996
The
Slip
History
of
the
1994
Northridge,
California,
Earthquake
Determined
from
Strong-Motion,
Teleseismic,
GPS,
and Leveling
Data
by
David
J.
Wald,
Thomas
H.
Heaton
,*
and
K.
W.
Hudnut
Abstract
We
present
a
rupture
model
of
the
Northridge
earthquake
,
determined
from
the
joint
inversion
of
near-source
strong
ground
motion
recordings
,
P
and
SH
teleseismic
body
waves,
Global
Positioning
System
(GPS)
displacement
vectors,
and
permanent
uplift
measured
along
leveling
lines.
The
fault
is
defined
to
strike
122
°
and
dip
40
°
to
the
south-southwest.
The
average
rake
vector
is
determined
to
be
101
°,
and
average
slip
is
1.3
m;
the
peak
slip
reaches
about
3
m.
Our
estimate
of
the
seismic
moment
is
l.3
±
0.2
X
1()2
6
dyne-em
(potency
of
0.4
km
3
).
The
rupture
area
is
small
relative
to
the
overall
aftershock
dimensions
and
is
approximately
15
km
along
strike
,
nearly
20
km
in
the
dip
direction,
and
there
is
no
indication
of
slip
shallower
than
about
5
to
6 krn.
The
up-dip,
strong-motion
velocity
waveform
s
are
dominated
by
large
S-wave
pulses
attributed
to
source
directivity
and
are
comprised
of
at
least
2
to
3
distinct
arrivals
(a
few
seconds
apart).
Stations
at
southern
azimuths
indicate
two
main
S-wave
arriva
ls
separated
longer
in
time
(about
4 to
5 sec).
These
observations
are
best
modeled
with
a
complex
distribution
of
subevents:
The
initial
S-wave
arrival
comes
from
an
asperity
that
begin
s
at
the
hypocenter
and
extends
up-
dip
and
to
the
north
where
a
second
,
larger
subevent
is
centered
(about
12
km
away).
The
secondary
S
arrivals
at
southern
azimuths
are
best
fit
with
additional
energy
radiation
from
another
high
slip
region
at
a
depth
of
19
km,
8
krn
west
of
the
hypocenter.
The
resolving
power
of
the
individual
data
sets
is
examined
by
predicting
the
geodetic
(GPS
and
leveling)
displacements
with
the
dislocation
model
determined
from
the
waveform
data
,
and
vice
versa,
and
also
by
analyzing
how
well
the
telese-
ismic
solution
predicts
the
recorded
strong
motions.
The
general
features
of
the
geodetic
displacements
are
not
well
predicted
from
the
model
determ
i
ned
indepen-
dently
from
the
strong-motion
data;
likewise
,
the
slip
model
determined
from
geo-
detic
data
does
not
adequately
reproduce
the
strong-motion
characteristics.
Whereas
a
particularly
smooth
slip
pattern
is
sufficient
to
satisfy
the
geodetic
data
,
the
strong
-
motion
and
teleseismic
data
require
a
more
heterogeneous
slip
distribution
in
order
to
reproduce
the
velocity
amplitudes
and
frequency
content.
Although
the
teleseismic
model
can
adequate
ly
reproduce
the
overall
amplitude
and
frequency
content
of
the
strong-motion
velocity
recordings,
it
does
a
poor
job
of
predicting
the
geodetic
data.
Consequently,
a
robust
representation
of
the
slip
history
and
heterogeneity
requires
a
combined
analysis
of
these
data
sets.
introduction
The
17
January
1994
Northridge
(M
.
=
6.7)
eart
hquak
e
produced
the
largest
gro
und
motion
s ever
recor
ded
in
an
urban
environment
a
nd
ca
used the
grea
test d
amage
in
the
Un
it
ed
Stat
es
s
in
ce
the
great
1906
San Francisco
earthquake
(US
GS
and
SCEC,
1994).
Peak
acceleration
and
ve
locit
y val-
ues we
re
among
th
e lar
ges
t ever
recor
ded
in
any
earthquake,
and
th
e large
numb
er
of
strong-m
ot
ion r
ecor
din
gs
is
un-
*Presen
t address:
Di
vision
of
Geological
and
Planetary
Sciences,
Cali
·
fomia
In
stit
ute
of
Technolo
gy, Pasade
na , California
91125.
S49
prece
dente
d . Extensive
portabl
e
in
stru
ment
deployments
following
the
mai nshock
for
recording
aftershocks
will
pro-
vi
de ca
libr
atio
n d
ata
for
co
nstra
inin
g the
regional
velocity
structure
and,
ultimately.
for
better
understanding
the main-
shock
strong
motion
s.
The
exte
nt
of
the
damage
and
th e
abundance
of
recorded
gro
und
m
ot
ion
s nece
ss
it
ate
a system-
atic
analys
is
of
the
source-ruptu
re process
in
ord
er
to
better
und
ersta
nd
the
natur
e
of
the ground
motions
and
resultin
g
damage
patterns.
Wald
and
Heato
n ( 1994a)
examined
an
ear
li
er subset
of
S50
the
stro
ng
-motion
data
described
herein
and
determined
a
rupture
model
based
on
an
inversion
of
those
data.
In
this
analysis,
we
add
stro
ng-motion
data
,
GPS
and
levelin
g-l
ine
displacements,
and
teleseismic
waveforms
to
the
earl
ier,
near-source
strong-motion
data
set and
use
all,
both
sepa-
rately
and
in
unison
, to
invert
for
the
spatia
l and
temporal
variatio
ns
of
slip
on
the
fault.
The
models
resulting
from
indi
vidual
data
sets
were
checked
against
the
other
data in
a
forward
modeling
sense
to
analyze
their
resolution
and
pre-
dictive
capacity.
The
results
presented
here
supersede
the
earlier
work
since
we
have
included
additional
data.
Unlike
the
earlier
studies,
we
use
different
Green
's
functions
for
strong-motion
stations
at
soil
and
rock
sites,
rather
than
us-
ing
a single-velocity
structure
, and
we
use
a layered
earth
model
for
the
geo
detic
displacement
calculations
, as
op-
posed
to
the
homogeneous
half-space
approximation
used
in
ear
lier
work.
Generally,
the
results
of
our
earlier
modeling
are
consistent
with
the
improved
and
updated
resu
lts
pre-
sented
here.
Our
fault
parameterization
involves
a variable-slip,
fi-
nite-fault
model
that
treats
the
diverse
data
sets
in
a self-
consistent
manner
, allowing
them
to
be
inverted
jointly
or
independently
.
By
representing
slip
on
the
fault
with
nu-
merou
s subfaults
and
slip
on
each
subfault
by
the
summation
of
many
point
sources
over
the
subfault
area,
we
can
gen-
erate
near-
source
static,
strong-motion
, or
teleseismic
syn-
thetic
Green
's
functions
with
identical
fault
rupture
models.
There
are
several
important
advantages
in
combining
the
multiple
data
sets.
First,
neither
the
GPS
nor
the
wave-
form
stations
uniformly
cover
the
near-source
region.
As
a
combined
data
s
et
, the
spatial
sampling
is enhanced.
Second
,
the
range
of
frequencies
covered
is
from
DC
to
1.0
Hz
, al-
lowing
comparisons
between
slip
models
that
sam
ple
only
coseismic
slip
(waveform
data)
with
tho
se
that
include
slip
from
early
aftershocks
as
well
as
aseismic
slip
(geodetics).
Finally
, since
the
geodetically
determined
slip
pattern
is
completely
independent
of
the
rupture
timing
, requiring
the
final
slip
in
the
waveform
inversion
s to
fit
the
static
data
provides
an
independent
constraint
on
any
a priori
timing
assumptions
made
in
the
waveform
modeling
. This
has
a
great
advantage
over
band-limited
waveform
studies
alone,
where
there
is
commonly
a trade-off
between
the
rupture
timing
and
the
slip
location.
Other
recent
studie
s have
show
n the
benefit
of
combin-
ing
geodetic
and
waveform
data
in
source
inver
sion
s. Wald
and
Heaton
(1994b)
found
that
the
ad
dition
of
the
geo
detic
data
to
the
strong-motion
and
teleseismic
data
in
the
analysis
of
the 1992
Landers
earthquake
ad
ded
important
constraints
on
the
ruptur
e evol
ution
.
Only
with
the
addition
of
the
geo-
deti
c data
(Hudnut
eta/.,
1994
) could
the temporal
and
spa-
tial
evolution
be
ima
ged
with
confidence.
ln
a study
of
the
hi
storic
data
from
the
19
23
Kanto
, Japan
, earthquake,
Wald
and
Somerville
( 1995
) constrained
the
s lip
on
the
subduc
tin
g
fault
plane
with
the
available
geodetic
data
(Matsu'ura
eta/.,
19
80)
and
pl
aced
constrai
nts
on
the
ruptur
e timing
with
tele
-
seism
ic body
-waveform
data.
D.
J.
Wald
, T.
H. Heaton,
and
K.
W.
Hudnut
Unfortunately,
the
Northridge
inversion
is
more
limited
than
the
Landers
study
for
severa
l reasons.
First.
with
the
Northridge
earthquake,
there
is ambiguity
in
assuming
the
location
and
geomet
ry
of
the
fault
rupture
surface(s)
at
depth.
Geom
etrical
fault
comp
lexity
at
depth
is
difficult
to
interpret
from
the aftershock
locations
alo
ne. In
cont
rast,
the
multiple-fault
segments
of
the
Landers
rupture
were
exposed
at
the
ground
surface
. Although
complex,
they
were
clearly
defined
and
known
to
be
nearly
vertical
in
the
down-dip
direction.
Second,
the
greater
average
depth
extent
of
the
slip
in
the
Northridge
earthquake
reduces
the
effective
res-
olution
of
the
geodetic
observations
, particularly
for
deeper
slip.
Conversely
, the
geodetic
monuments
for
the
Landers
earthquake
were
often
imm
ediatel
y
adjacent
to
shallow,
high-slip
areas
of
the
fault
and
were
thus
very
sensitive
to
the
location
and
amount
of
slip
. Finally,
the
rupture
dimen-
sions
and
source
duration
are
relatively
short
for
the North-
ridge
earthquake;
thu
s, we
are
attempting
to
resolve
short
er
wavelength
features
with
lower
slip
amplitudes
than
for
both
the
Lander
s and
Kanto
earthquakes.
We
first
di
scuss
the
coherency
and
variations
of
the
near-
sourc
e recorded
ground
motion
s and
display
the
ground
motion
s in
a map
view,
allowing
the
waveform
and
ampli-
tude
variations
to
be
examined.
Next
, we
invert
the
band-
passed
(I
to
10
sec)
veloc
ity
ground
motions
alone
to
de-
termine
the
distribution
of
slip
on
the
fault
rupture
plane.
The
teleseismic
and
geodetic
data
are
then
inverted
sepa-
rately
in
the
same
fashion,
allowing
a direct
comparison
be-
tween
the
waveform
and
static
solutions
. A
co
mbined
in-
version
of
all
three
data
se
ts is
then
performed
to find
a
dislocation
model
mo
st compatible
with
all
of
the
observa-
tions
, and
the
so
lution
is
discu
ssed.
Finally
, the
individual
models
are
tested
against
the
other
independent
data
sets,
and
implication
s for
the
resolution
of
our
ana
ly
sis are
dis-
cussed.
Fault
Rupture
Model
In
order
to
model
slip
during
the
Northridge
earthquake,
we
need
to
assume
a fault
geometry
, so
we
choose
a single
fault
plane
that
is
mo
st consistent
with
a broad
range
of
observations.
We
use
a strike
of
122°,
compromising
be-
tween
the
different
so
lution
s found
from
modeling
tele-
seismic
surface
waves
(Harvard
CMn
and
body
waves
(Thio
and
Kanamori
, 1996
) that
indicate
strikes
near
130
°
and
the
first-motion
mechanism
(USGS
and
SCEC,
1994
) that
requires
a strike
between
100
°
and
110
°.
Further,
vertica
l
cross
sections
of
the
aftershock
distribution
(Mori
et
al.
,
1995
) present
the
simple
st
planar
struct
ur
e when
pr
ojected
perpendicular
to
roughly
a
120°
strike
(Fig.
1).
The
fault
plane
dips
40
°
and passes
directly
through
the
relatively
sim-
ple,
planar
aftershock
distribution
(Fig. 1).
We
did
not
at-
tempt
to
model
the
data
with
fault
locations
that
violate
the
afte
rshock
observations.
Th
e dep
th
to
the top
of
our
assumed
fault
is
5.0
km
,
and
the
depth
to
the
bottom
of
the
fault
is
20.4
km,
giving
a
The
Slip
History
of
the
1994
Northridge
Earthquake
Detemzined
from
Strong-Motion.
Teleseismic
,
CPS
,
and
Le1·eling
Data
S51
20'
10'
~
\
..-
..
.
...
.
"-
,
.
~-
........
·
.. .
'
"'-
·
-~
..
.
.
:.
'-
.....
··.
f;.-
:
•.·
20
Klol
I
I
I
I
I
I
7
/
/
50'
40'
30'
20'
A'
.---.
::::E
~-10
I
f-
a..
w
0
-20
A
0
b
%0
.,
.
.,
.
....
.
·:.
..
.
.
...
10
DISTANCE
(KM)
. .
.··
.
·.
0
0
20
30
Figure
I.
Map
view
(top)
and
cross
sec
tion
(bottom)
of
the
af
tershock
distribution
for
the
Northridge
earthquake
from
17
January
to
3 1 November
1994
. Aftershock
locations
shown
are
the
3D
relocations
of
Mori
et
a/
.
(
1995
). Thick
line
s indicate
the
dimen
s ion
s
of
the
surface
projection
of
the
fault
plane
used
in
thi
s study.
Contour
s
(interval
0.4
m)
show
the
slip
pattern
determined
from
the combined
inver
sion
of
wave
-
form
and
geodetic
data
.
MAGNITUDES
0 .
0+
1.0+
2 .
0+
3 .
0+
0
4 .
0+
EJ
5 .
0+
6.
0+
S52
down-dip
width
of
24 km
.
Th
e along-strike
fault
length
is
18 km
. We discretized
the
fault
plane
into
a total
of
196
subfault
s,
each
1.29-krn
wide
and
1.71-km
long down-dip
,
in
order
to
represent
variable
slip
along
the fault.
The
fault
parameterization
and
modelin
g
pr
oced
ure
we
emplo
y is fully
de
sc
ribed
by
Hartzell
and
H
ea
ton ( 1983)
and
is summarized
only
briefly
bel
ow.
Syntheti
c
Green's
Function
s
Each
s
ubf
a ult'
s motion
is obtained
by
summing
there-
spo
nses
of
25
po
int
sources
uniformly
distributed
over
each
su bfault.
Each
point
source
is
lagged
appropriately
in
time
to
include
the
travel-time
difference
due
to
the
varying
so
urce-to-station
position
s and
to
simul
ate
the
propa
ga
ti
on
of
the
ruptur
e front
across
each
subfault.
Thu
s, all
s
ubf
aults
se
parately
include
the
correct
effects
of
dire
ctivit
y.
The
com-
plete
point-
sour
ce
respon
ses
for
th
e s
tro ng- mo
ti
on synth
etic
s
a
nd
the
geo
deti
c static
di splace
me nts
are
computed
for
a
laye
red
ve
locity
model
(Table
I) with
the
discrete
-wave
-
number
, finite-element
(
DWFE
) scheme (Olson
et al.,
1984
)
for
frequencies
up
to
3.0
Hz.
ln
practice
, we
calculate
a
ma
ster
se
t
of
sy nth
etic
s for
1-km
incr
e ments
in
depth
from
4.0
to
22.0
km
and
for
ranges
betw
ee
n
0
and
60
km.
to a
ll
ow
for
the closest
a
nd
farthest
po
ssible
subfa
ult-
station
combi-
nations
. Th
e n for
each
point-
sour
ce
sta
ti
o n p
air, the
requir
ed
response
is derived
by a lin
ear
interpo
la
ti
on
of
the
clo
ses
t
Gr
ee
n
's
functi
o ns ava
ilabl
e in
the
master
se
t.
Th
e lin
ear
in
-
terpolation
of
adjacent
Green'
s function
s is performed
by
alignin
g the waveforms
acco
rdin
g to their
shear-wa
ve
trav
el
time
s.
The
source-reg
ion
velocity
mod
el u
se
d to
compute
the
strong-moti
o n Green's
functi
ons
at
rock
site
s (Table
2)
a
nd
all
the
static
displ
acemen
ts
(G
PS
and
leve
ling
), given
in
Ta
-
ble
I a, is modifi
ed from
Lang
ston
( 1978
, model
C)
.
We have
added
a thin
(0.5
km
), slower
laye
r to
La ng
ston
's
model
to
better
app
roxima
te elas
tic
prop
e rtie
s
just
beneath
the
stro
ng-
motion
rock
-si
te
statio
ns.
Min
or
va
ri
ation
s on
this
model
have
been
used
exte
ns ive
ly
(e.g.,
Dr
ege
r and
Heimb
erger,
19
90)
for
mod
elin
g many local
and
regional
waveforms
in
so
uthern
California.
For
soi
l-si te
stron
g-motion
station
s,
we
replace
the
top
0.3
km
of
th
e rock
-site velocity
mod
el with
slow
e r
P-
and
S-wave
ve
loci
ti
es,
as
sho
wn in
Tabl
e I b .
Sour
ce
Tim
e Function
and
Ruptur
e Velocity
Th
e dislocation
tim
e
hi
story
for
eac
h s
ubf
ault
is repre-
sented
by
the
integral
of
an i
sosce
les
tri angle
with
a duration
of
0.6
sec.
Each
sub
fau
lt
is also
allow
ed
to
slip
in
any
of
thr
ee
identi
cal 0
.6-sec
tim
e windows
following
the pa
sage
of
the
rupture
front,
with
the
initi atio
ns
of
eac
h window
se
p-
arated
by
0.4
sec.
Since
the
windows
overlap
in
time.
they
can
provide
a smooth
overall
sl ip
hi
story
last
ing up
to
1
.4
sec
.
if
neces
sary.
Examples
of the
res
ultin
g
su
bf
au
lt
di
s-
placement
tim
e f
un
ctions
are
show
n in
a later
section.
With
multipl
e tim
e windows,
we
can
approxi
mate
both
spatia
l
va
ri
ations
in
slip
duration
and
rupture
ve
locity
perturb
at
ion
s
from
the
a sumed
uniform
velocity.
D .
J.
Wald
.
T.
H. H
ea
ton.
and
K .
W.
Hudnut
Table
1
Northridge
R
eg
ional
Veloc
it
y Structure
A . R
ock
Stat1o
ns
Vp
Vs
De
nS
II)'
Tlud.ncss
Dep<h
(kmlsec)
(km/sec)
(g/cm)
(
lm
)
(
lm
)
1.
9
1.0
2. 1
0.5
0.0
4.0
2.0
2.4
1.0
0.5
5.5
3.2
2.7
2.5
1.5
6.3
3.6
2.8
23.0
4.0
6.8
3.9
2.9
13
.0
27.0
7.8
4.5
3.3
40.0
B
Sotl
Stauons
Vp
Vs
Den
slly
llud
.ness
Deplh
(kmlsec)
(
km/sec
)
(g/cm)
(l
ml
(k
m)
0.8
0. 3
1.7
0. 1
0.0
1.2
0.5
1.8
0.2
0.1
1.9
1.0
2. 1
0.2
0.3
4.0
2.0
2.4
1.0
0.5
5.5
3.2
2.7
2.5
1.5
6.3
3.6
2.8
23.0
4.0
6.8
3.9
2.9
13.0
27.0
7.8
4.5
3.3
40
.0
Th
e rupture
velocity
is assumed
to
be
a constant
3.0
krn/
sec.
or
about
85
%
of
the
shear-wave
velocity
in
the
source
region
(T abl e I ).
We
iterated
through
a range
of
va
lu
es
from
2.7
to
3.3
km/sec
but
found
that
rupture
veloc
itie
s in
the
rang
e
of
2.8
to
3.0
kmlsec
provide
s the
best
fit
to
the stron
g-
motion
data
.
The
fa
ster
rupture
ve
loc
it
y
(3.0
km/sec),
how-
ever.
provided
a better
mat
c h when
the
geo
de tic
and
wave-
form
da ta are
inverted
jointly.
Rupture
Initiation
Evidence
from
th
e s
trong
-motion
data
indi
cates
that
the
initial
rupture
was
rather
subdued
, remini
sce
nt
of
delaye
d
init
ial g rowth
of
the Lorn
a
Pri
e ta
(W
al
d
et
a/.
,
1991)
and
Landers
eart
hquak
es
(Aberc
ro mbie
a
nd
Mo
ri
, 1994
).
How
-
ever,
ther
e is no
ev
ide n
ce
for
the
unu
sua
l l ong
-peri
od r
ad
i-
ation
th
at
was
observed
in
the
beginning
of
the
Lorna
Prieta
earthquake.
That
is.
th
e begi
nnin
g
of
the
Northridge
main-
shock
was
indi
stin
guishable
fr
o m
the
beginning
of
after
-
shocks
in
the
hypocentr
al r
eg
io n (A
ber
c rombi
e,
1994
).
Th
e
stro
ng-mo
ti
on tri
gger
tim
es.
when
avai
lable
, i ndi
ca
te tha t the
triggering
P
wave
arrived
at least
0.5
sec
late
r than
ex
pected
(W
a
ld
and
Heato
n. 1994a)
, give
n the
pr
edicted
trave
l time
from
the
hypocen
tral
par
amete
rs de te rmined
from
the
hi
gh-
gai
n short
-per
iod record
s f
rom
the
Southern
Ca
liforn
ia
Seis
-
mograp
hi
c Ne
twork
(SCSN).
Further
analysi
s by Ellsworth
and
Beroza
( 1994
) sugges
ts that
a
sma
ll nucleation
ph
ase
of
the
ru
pture
was
fo
ll
owed
by
a seco
ndary
. larger
ruptur
e
ep
-
isode
beginning
near
the hypocenter
approx
im
ate
ly
0.5
sec
later.
consis
tent
with
the
delayed
strong-motion
trigger
times.
We us
ed
the
origin
tim
e (12:30:55.2
GMT),
ep
icenter
(34.2
11
o
orth
latitud
e.
11
8.546
° We
st longit
ude).
and
hy
-
pocentral
dep
th
(17.5
km)
det
ermined
by
relocating
SCS
network
pha
se
data
(J.
M
or
i. written
comm
.. 1994)
. Based
The
Slip
HistorY
of
1he
199-J
Nonhridge
Earthquake
De1ermined
from
Strong-MOl
ion.
Teles
eis
mi
c,
CPS.
and
Le1·eling
Daw
S53
AL
HF
ARL
BLD
CAS
ECC
EI\"R
GRF
HYSB
JFP
:\1NG
i\10R
1'/H
L
!\"H20
PARD
PDM
PIRU
PKC
PTi\1G
RRS
RSE
sec
SCR
scs
SHR
St.1C
SSt:
SVA
SY
L
TPG
L'03
1.:53
S1..ll1on
:"-lame
Alhambra
Freemont
School
Arleta
-
:'-lordhoff
Ave
.
Fire
Station
LA-B
aldwin
Hill
s
Castaic
Old
Ridge
Route
Energ)
Control
Center
Encino
Encino
Rese
rvoir
Dam
Abutment
Griffith
Park
Griffith
Observatory
Lo
s Angele
s
Holl)
wood
Storage
Bldg
.
Granada
Hi
lis
Jenson
Filtr.
Plant
Generator
Bid.
Mon
te Nido
Fire
Station
:\ll
oorpark
::-lewhall
LA
County
Fire
Dept
:'1/orth
Hollywood
20-;,tOr)
Hotel
Santa
Clarita
Pard
ee
Substation
Pacoima
Dam
Downstream
Lake
Piru
Santa
Fe licia
Dam
Down
stream
Pacoima
Kagel
Canyon
Fire
Sta.
#74
Point
:\llu
gu
Laguna
P
eak
Sylmar
Rinaldi
Recei,
·i
ng
Station
San
Fernando
Receiving
Station
Ea:,t
Sepulvada
Canyon
Control
Facility
Stone
Canyon
Re,en
oi r site
Sylmar
Sy
l
mar
Con,·ening
Station
Sherman
Oak
s
13-
story
Commercial
Bldg
.
Santa
Monica
City
Hall
Ground'
Santa
Susanna
D.O.E.
-
Ground
Site
Supulveda
V.A.
Hospital
Sylmar
6-:.tof)
County
H
o,pi
tal
Parking
Lot
Top
anga
Fire
Stat
io n
Canoga
Park
1
7M5
Sat
i
coy
Canoga
Park
7769
Topanga
Canyon
Blvd
Table
2
Strong
Mo
ti
on
Station
l\onh
Lat.
34.070
34.136
3-t.009
3
-t
.5M
3-t.259
3-t.l
5
3-1.118
34.090
34.312
34.078
3-1.288
3-1.387
3
-1
. 138
3-l.-135
34.33-l
34.-160
3
-1
.288
3
-1
.109
34.281
34.17
3-1.097
34.106
3-1.3
12
3-1.154
34.011
3-1.230
3-U49
34.326
34.084
34 .2
09
3-1.212
Wc
...
t
Long
118.150
118.-139
118.361
118.6-12
118.336
118.51
118.299
118.339
118.-196
118.693
11
8.881
11
8.530
118.539
118.582
118.396
118.753
118.375
11
9.065
11
8.-179
118.36
118.-178
118.-154
118.-181
118
.465
118.-190
118.713
118.-175
I
1
8.-14-1
118.600
118.517
118.506
Ep1Central
o,,LanC'C"'
39
9
28
-10
19
7
26
23
12
21
33
20
19
25
19
3-l
17
so
9
17
15
2-l
12
10
24
16
8
15
16
6
Pe
ak
Vclocit~
t
II
18
53
27
2-l
31
26
97
12
29
121
39
92
50
32
59
18
183
36
31
38
135
59
42
23
76
136
20
63
63
RotatiOn
Angle:
97
82
1-12
76
61
10
118
148
160
10
-13
37
16
34
19
163
25
124
31
79
3
-l
91
25
166
91
52
76
13
148
10
4
Code;~
BR
cs
CN
CR
LR
LR
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BN
GS
G:-.1
cs
cs
cs
ES
CR
CR
CR
CN
LS
LS
GR
BR
LR
cs
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GR
c.
cs
GR
cs
cs
(continued)