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A study on Hypocenter Determination of Earthquakes at Izu Tobu District
By
ÇOMOĞLU, Mustafa
Geophysical Engineer, Seismologist
Bogazici University Kandilli Observatory and Earthquake Research Institute
National Earthquake Monitoring Centre,TURKEY
Advisor: Associate Professor Yuichi MORITA
ERI, University of TOKYO
DISASTER RISK MANAGEMENT TECHNOLOGY ON VOLCANIC ERUPTION, DEBRIS FLOW AND LANDSLIDE
INDIVIDUAL PROGRAM REPORT (MAY-AUGUST 29th 2008)
At University Of Tokyo, Earthquake Research Institute
Geology And Petrology Group “Volcano Research Center”
1
Motivation of my individual study
My job in my country (TURKEY)
To locate earthquake hypocenter using zSACWin,
The software based on HYPO71 but I did not
know the process of that software in detail.
Purpose of my individual study
To learn the algorithm of the software.
To learn software programming.
Exercising to make program.
2
3
MY ROUTINE JOB (READING P AND S ONSETS)
RESULTS “THE LAST YEARS SEISMICITY”Hypocenter distribution of from year 2005 to June 2008
Seismic Stations: 119 (BB: 88, SP: 31)
4
(12.636 events is mapped )
5
If we focus on the volcanic areas;
Eastern Part of TurkeyWestern Part Of Turkey
Central Part Of Turkey
• Red triangles indicate
volcanic regions
• White circles indicate
earthquakes.
6In these diagrams , we noticed that there are some seismic anomaly around Suphan Mountain. It s
indicated by orange circles. However due to the lack of seismic station network coverage (look at Map
1.1 and Map 1.2) we cannot get a chance to focus on volcano related seismicity in that area.
The Earthquake Hypocentre coordinates has been turned 32 degree in clockwise
due to the positions of the Volcanic Mountains
Name of
volcanoes
N32E
S32W
SUPHAN
NEMRUT
GIREKOL
TENDUREK
ARARAT
Map 1.2 Stations distribution around volcanic area at eastern part of Turkey
7
SUPHAN
:KOERI SEISMIC STATIONS
400 km0
In this individual program;
•TARGET 1) To understand the processes of hypocenter
determination
2) Programming (Fortran)
3) Effect of the station Correction
•DATA : Earthquake swarm in Izu Tobu district, JAPAN
(2006-03-25 - 07-20) by ERI.
•SOFTWARE : HYPO71 by Lee et al.
•COMPILER : Intel Visual Fortran 10.1 with MKL Library used to revise
program sources due to our necessities. (Provided by JICA)
•PLATFORM : Microsoft Visual Studio 2005
8
9
UNDERSTANDING
HYPO71
EARTHQUAKE
LOCATING
SOFTWARE
HYPO71.for
OPEN THE INPUT AND OUTPUT FILES
DEFINE INPUT AND OUTPUT FILES
INPUT FILES OUTPUT FILES
eg. HYPO71.INP HYPO71.SUM
HYPO71.PUN
HYPO71.BRI
INPUT2.for:
INPUT PHASE LIST
INPUT1.for:
INPUT STATION LIST,CRUSTAL MODEL
SUMOUT.for
END PROGRAM
SINGLE.for: Processes one earthquake at a
time
SET UP A TRIAL HYPOCENTER AZWTOS.fo
r
ARVDRV.
for SWMREG.f
orALIOUT.for
MISING.f
orFPLOT.for
XFMAGS0.f
or
SORT.fo
r
SORT.fo
r
(O
RIG
INA
L H
YP
O7
1)
FL
OW
CH
AR
T
HYPO71
COMPUTE SUMMARY OF TRAVEL TIME RESIDUALS
COMPUTE RMS AT AUXILIARY POINTS
CHECK FOR MULTIPLE SOLUTIONS OF THE SAME EARTHQUAKE
SINGLE.for: This Routine processes one earthquake at a time and involves these steps;
SET UP A TRIAL HYPOCENTER, The first trial epicenter is normally set to be latitude and longtitude of the station with the earliest P
arrival.the first trial focal depth is set equal to that given in the control card, unless specified on the instruction card.The First trial origin time is
set so that the average residual of P and S arrivals is zero….
Compute error estimates
AZWTOS.for
AZIMUTHAL
WEIGHTING OF
STATIONS BY
QUADRANTS
ARVDRV.for
COMPUTE TRAVEL
TIME AND
DERIVATIVES
FROM CRUSTAL
MODEL
SWMREG.for
COMPUTES
GEIGER
ADJUSTMENTS
BY STEP-WISE
MULTIPLE
REGRESSION OF
TRAVEL TIME
RESIDUALS
ALIOUT.for
OUTPUT
HYPOCENTER
MISING.for
CHECK MISSING
STATIONS
FPLOT.for
PLOT
FIRST-MOTION
DIRECTIONS OF
THE LOWER
FOCAL
HEMISPHERE IN
EQUAL AREA
PROJECTION,
WHERE C
DENOTES
COMPRESSION
AND D DENOTES
DILATATION
XFMAGS0.for
COMPUTE
X-MAGNITUDE
AND
F-MAGNITUDE
SORT.for
This is a utility
subroutine to sort
xi,i=1,..N by
increasing value.
ANSWER.for
INTERMEDIATE
RESULTS OF
REGRESSION
ANALYSISSORT.for
This is a utility
subroutine to sort
xi,i=1,..N by
increasing value.
..
…
10
RESET TEST(02)=150.0RESET TEST(03)=0.5RESET TEST(06)=0.25RESET TEST(11)=25.RESET TEST(13)=5.0
YLVX4034.00N 2922.37E 829 -0.18YOZ 3938.30N 3518.92E1422 0.15YSFR4036.37N 2914.51E 115YTSV4037.60N 2905.24E 70YZL 4041.42N 2952.04E 75ZYBG4023.40N 2847.69E 70EARA3458.28N13907.10E-145IOB13452.43N13912.39E-985IOB23456.15N13916.18E-1330IOB33457.70N13913.02E-1170ITHH3456.80N13905.13E-160JIZF3455.00N13859.63E 263KAMA3455.71N13903.65E 175KNIH3505.12N13858.67E-100KWZH3446.99N13858.20E 28NHTS3502.52N13910.01E -84NITO3457.14N13908.30E -84NJIZ3454.97N13859.65E 263NMNZ3508.74N13909.01E-114NNRY3503.79N13857.58E -91NRYH3503.79N13857.58E -91SZJH3458.54N13854.77E 47
4.035 0.0006.104 5.0006.320 20.0007.500 40.000
5. 50. 750. 1.73 4 1 5 2 1 0 1NITOIP 1 060325034846.332 47.74IS 1 ITHHIP 1 060325034846.523 48.01IS 1 EITOIP 1 060325034846.561 48.17IS 1 EKAWEP 2 060325034846.577 48.12IS 1 EFTOEP 2 060325034846.723 48.36IS 1 KAMAEP 3 060325034846.761 48.48IS 1 EOKVEP 3 060325034846.781 48.46IS 1 NJIZEP 3 060325034847.652 49.94IS 1 JIZFEP 3 060325034847.665 EHOKEP 3 060325034848.019 50.50IS 1 EATAEP 3 060325034848.198 NNRYEP 3 060325034848.372 51.12IS 1 EICYEP 3 060325034848.378 NRYHEP 3 060325034848.429 51.17IS 1 SZJHEP 3 060325034848.551 51.66IS 1
Velocity Structure
Station Data
Onset times of each station.
Some control Parameters
11
HYPO71 Input File
12
HYPO71 OUTPUT FILES “*.SUM”
P (Reading )
P (Calculated)
P Residual
S (Reading )
S (Calculated)
S Residual
*In this study *.SUM Files used to calculate Mean Residuals and Re-Location
STATION CORRECTION
The HYPO71 that used in my job does not use
the station correction
Effect of the station correction is distinct in the
case of local earthquakes, because the structure
just beneath the station affects much on
estimated hypocenters.
Using Japanese data I evaluate the effect of the
station correction. (I need data conversion from
Japanese system to HYPO71 system)
13
Tectonic background around the Izu Peninsula
North margin of Philippine Sea Plate. Tectonic stress is P axis : NW-SE T axis : NE-SW.
There are many mono-genetic volcanoes at the Izu Peninsula.
There are many earthquake swarms accompanied by ground deformation.
14
Earthquake swarms at Izu Peninsula
Frequency of observed earthquakes at Kamata (JMA)
(Submarine eruption)
Mo
nth
ly fre
qu
en
cy
Activity declines
since 1998
15
The submarine eruption in 1989.
Oshima et al. (1991)
July 13, 1989
Unique eruptive activity among latest 50 years
16
17
SEISMIC STATIONS NETWORK AROUND IZU AREA
17
18
Velocity Model
Lay
ers
P Wave
Velocity
(Km/s)
Depth
(Km)
1st 2.600 0.000
2nd 4.100 0.300
3rd 5.200 2.100
4th 5.750 6.000
Previous study
This study
19
The following maps show that 4256 Earthquakes at IZU TOBU area which located by
WinSystem (Japanese software) and HYPO71
1- 4256 Earthquakes located by HYPO71* 2- 4256 Earthquakes that located both by
HYPO71* and WinSystem (Dark blue circles are
WinSystem Earthquake Locations
MAPPING OF HYPOCENTRE DETERMINATION RESULTS
19
Residual distributions of some stations in case of the HYPO71
20
0
50
100
150
200
250
-1 -0.5 0 0.5 1
EITO
0
50
100
150
200
250
-1 -0.5 0 0.5 1
NRYH
0
20
40
60
80
100
120
140
160
-1 -0.5 0 0.5 1
KNIH
0
20
40
60
80
100
120
140
160
180
200
-1 -0.5 0 0.5 1
SZJH
0
20
40
60
80
100
120
140
-1 -0.5 0 0.5 1
MNZH
EITO NRYH KNIH
SZJH MNZH
21
Residual distributions of some stations in case of the HYPO71
0
50
100
150
200
250
300
350
400
450
500
-1 -0.5 0 0.5 1
KAMA
0
20
40
60
80
100
120
140
160
180
-1 -0.5 0 0.5 1
EATA
0
20
40
60
80
100
120
140
-1 -0.5 0 0.5 1
EHOK
0
10
20
30
40
50
60
70
-1 -0.5 0 0.5 1
KWZH
KWZH
KAMA EATA EHOK
22
HOW TO ESTIMATE STATION CORRECTION
CALCULATING P-S WAVE “MEAN RESUDIALS”
“resmean” fortran source code helps us to
check each events and each stations
residuals in *.SUM files which produced
by HYPO71 then to calculate mean
residuals for each stations.
ST N
AM
E
LAT LONG ELV.
P M
EAN
RES
.
S M
EAN
RES
.
NU
MB
ER O
F P
REA
DIN
GS
NU
MB
ER O
F S
REA
DIN
GS
EARA 3458.28N 13907.10E -145 0.03 -0.06 1619 813
EATA 3506.95N 13904.36E 290 -0.01 0 2582 0
EFTO 3454.46N 13908.14E 75 0.08 0.13 3259 2083
EHAT 3502.30N 13910.35E 46 0.11 0.11 2499 882
EHOK 3451.18N 13902.18E 890 0.15 0.25 2687 1295
EICY 3454.40N 13855.81E 210 0.02 0 2374 0
EITO 3456.49N 13904.48E 204 -0.38 -0.66 3986 2852
EKAW 3457.29N 13908.54E 5 0.08 0.23 4255 2998
EKWZ 3445.95N 13859.21E 65 -0.13 -0.53 813 437
EOKV 3456.42N 13903.62E 170 0.03 -0.05 4103 3549
IOB1 3452.43N 13912.39E -985 -0.04 0.25 272 86
IOB2 3456.15N 13916.18E -1330 0.07 1.28 329 86
IOB3 3457.70N 13913.02E -1170 -0.17 0.37 634 166
program resmeanreal*8 alat,aloncharacter dtx*80,stnm*4,cla*1,clo*1open(20,file='stname.inp')open(21,file='stname.out')
10 read(20,2000,end=70) stnm,alat,cla,alon,clo,ielvif(stnm.eq.' ') goto 70
2000 format(2x,a4,f7.2,a1,f8.2,a1,i5)np=0ns=0pt=0.0st=0.0
open(10,file='I:\...\jpinp.sum')read(10,1000) dtx
1000 format(a80)30 read(10,1000,end=50) dtx
if(dtx(1:4).ne.stnm) goto 30write(6,'(a80)') dtxread(dtx(25:25),'(i1)') ipif(ip.gt.0) thenread(dtx(38:43),'(f6.2)') pxnp=np+1pt=pt+px
endifread(dtx(54:54),'(i1)') isif(is.gt.0) thenread(dtx(67:72),'(f6.2)') sxns=ns+1st=st+sx
endifgoto 30
50 close(10)if(np.gt.0) thenpt=pt/float(np)
elsept=0.0
endifif(ns.gt.0) thenst=st/float(ns)
elsest=0.0
endifwrite(6,600) stnm,pt,np,st,ns
600 format(a4,2(f8.2,i5))write(21,2100) stnm,alat,cla,alon,clo,ielv,pt,st,np,ns
2100 format(2x,a4,f7.2,a1,f8.2,a1,i5,2f6.2,2i6)goto 10
70 close(20)close(21)stopend
This software is written, for calculating Station corrections for each station by using the P and S wave residuals of each event
Use the HYPO SUMMARY FILE *.SUM
•Sample data produced by resmean.for
RESMEAN
23
What we changed on INPUT2.for Subroutine
ADDING STATION CORRECTIONS
23
24
INPUT2.for:
INPUT PHASE LIST
INPUT1.for:
INPUT STATION LIST,CRUSTAL MODEL
SUMOUT.for
END PROGRAM
HYPO71.for
OPEN THE INPUT AND OUTPUT FILES
DEFINE INPUT AND OUTPUT FILES
INPUT FILES OUTPUT FILES
eg. HYPOMC.INP HYPO71.SUM
HYPOMC.PHS HYPO71.PUN
HYPOMC.STA HYPO71.BRI
SINGLE.for: Processes one earthquake at a time
SET UP A TRIAL HYPOCENTER
AZWTOS.for ARVDRV.for SWMREG.for
ALIOUT.for
MISING.for
FPLOT.for
XFMAGS0.for SORT.for
SORT.for
Station Correction Data
added (for both P and S
waves)
Contains CRUSTAL
MODEL
Contains PHASE
DATAContains STATION
NAME,LON,LAT,EL
EV, STATION
CORRECTIONS
HYPOMC
FLOWCHART
24
HYPOMC
25
NEW *.INP File for HYPOMC
CRUSTAL MODEL
NEW *.STA File for HYPOMC
produced by RESMEAN.for NEW *.PHS File for HYPOMC
NECESSARY FILES TO RUN HYPOMC
Iterative estimation of station correctionHypocenter determination
without station correction
Calculate mean residuals
Hypocenter determination
With station corrections
1st iterationHypocenter determination
With station corrections
Calculate mean residuals
2nd iteration
26
HYPO71
RESMEAN
HYPOMC
RESMEAN
HYPOMC
.
.
.
.
.
.
27
WHY I SEPARATED HYPO71 INPUT FILE 3
PART?
1.The 1st part ( *.inp ) contains some test
variables and Crustal Velocity Model. In this way
we can easily switch to another velocity model by
changing this file if we need to use another
velocity model.
2.The 2nd part ( *.sta ) contains stations
information (latitude, longitude, elevation and
calculated station correction values. For each
iteration this file is produced by RESMEAN.for
again.
3.The last part ( *.phs ) contains events data.
28
0.145
0.15
0.155
0.16
0.165
0 2 4 6 8
EITO P
0
0.1
0.2
0.3
0.4
0 2 4 6 8
EITO S
0
0.2
0.4
0.6
0 2 4 6 8EHOK P
0
0.2
0.4
0.6
0.8
0 2 4 6 8EHOK S
0
0.02
0.04
0.06
0 2 4 6 8KAMA P
0.155
0.16
0.165
0.17
0.175
0.18
0 2 4 6 8
KAMA S
7 ITERATION APLLIED TO SUM FILE
P onsets S onsets
EHOK
EITO
KAMA
Station
X- Axis : Number of iteration Y-Axis : Standart deviation
29
0.076
0.078
0.08
0.082
0.084
0.086
0 2 4 6 8
MNZH P
0
0.05
0.1
0.15
0.2
0.25
0 2 4 6 8
MNZH S
0
0.05
0.1
0.15
0 2 4 6 8KWZH P
0
0.1
0.2
0.3
0.4
0 2 4 6 8KWZH S
0
0.05
0.1
0.15
0.2
0.25
0 2 4 6 8
KNIH S
0
0.02
0.04
0.06
0.08
0 2 4 6 8
KNIH P
MNZH
KWZH
KNIH
P onsets S onsetsStation
X- Axis: Number of iteration Y-Axis : Standart deviation
7 ITERATION APLLIED TO SUM FILE
30
0
0.02
0.04
0.06
0.08
0.1
0 2 4 6 8
NRYH P
0.53
0.54
0.55
0.56
0.57
0.58
0 2 4 6 8
NRYH S
0.124
0.125
0.126
0.127
0.128
0.129
0.13
0.131
0 2 4 6 8
SZJH P
0.106
0.108
0.11
0.112
0.114
0.116
0 2 4 6 8
SZJH S
0.085
0.09
0.095
0.1
0 2 4 6 8
EATA P
EATA
SZJH
NRYH
P onsets S onsetsStation
X- Axis: Number of iteration Y-Axis : Standart deviation
7 ITERATION APLLIED TO SUM FILE
31
Residual distributions of some stations
before and after iteration.
0
50
100
150
200
250
300
-1 -0.5 0 0.5 1
EITO-BEFORE EITO-AFTER
0
100
200
300
400
500
600
-1 -0.5 0 0.5 1
NRYH-BEFORE NRYH-AFTER
0
50
100
150
200
250
300
-1 -0.5 0 0.5 1
KNIH-BEFORE KNIH-AFTERX Axis: Residuals
Y Axis: Number of events
EITO
3986 eventsNRYH
3182 Events
KNIH
2117 Events
32
Residual distributions of some stations
before and after iteration.
0
20
40
60
80
100
120
140
160
180
-1 -0.5 0 0.5 1
MNZH-BEFORE MNZH-AFTER
0
10
20
30
40
50
60
70
80
90
-1 -0.5 0 0.5 1
KWZH-BEFORE KWZH-AFTER
0
100
200
300
400
500
600
700
800
-1 -0.5 0 0.5 1
KAMA-BEFORE KAMA-AFTER
X Axis: Residuals
Y Axis: Number of events
KAMA
4324 Events
MNZH
1441 EventsKWZH
1371 Evens
33
Residual distributions of some stations
before and after iteration.
0
50
100
150
200
250
300
-1 -0.5 0 0.5 1
EHOK-BEFORE EHOK-AFTER
0
50
100
150
200
250
-1 -0.5 0 0.5 1
SZJH-BEFORE SZJH-AFTER
0
50
100
150
200
250
300
-1 -0.5 0 0.5 1
EATA-BEFORE EATA-AFTER
X Axis: Residuals
Y Axis: Number of events
EATA
2582 Events
EHOK
2686 Events
SZJH
1940 Events
34
Seismicity around Izu Tobu district between 2006-03-25 and 07-20
(Without Adding Station Correction)
35
Seismicity around Izu Tobu district between 2006-03-25 and 07-20
(With Station Correction)
Seismicity with Depth around Izu Tobu district between 2006-03-25 and 07-20
(Without Adding Station Corrections)
36
37
Seismicity with Depth around Izu Tobu district between 2006-03-25 and 07-20
(With Station Corrections)
38
CONCLUSIONS
o I understood the processes of HYPO71 completely.
and I can revise the software freely.
o I tried to add the station corrections into the original
HYPO71 source code.
o I understood the effect of the station correction for
earthquake swarms. The scattered hypocenters
concentrate in narrow regions after adding
station correction.
o I will apply this method to the local events in
TURKEY .
39
ありがとうございましたT
EŞ
EK
KÜ
R E
DE
RİM
TH
AN
K Y
OU