21
545 Bulletin of the Seismological Society of America, 90, 3, pp. 545–565, June 2000 Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake by Yoshimitsu Fukushima, Kojiro Irikura, Tomiichi Uetake, and Hisashi Matsumoto Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during the 1995 Hyogo-ken Nanbu (Kobe) earth- quake. We analyzed the attenuation of the peak-ground acceleration and velocity as a function of distance and geological site conditions. The observed peak amplitudes agree well with those predicted by an empirical attenuation relation that was devel- oped for Japanese earthquakes. This demonstrates that on average the peak amplitude of the ground motion generated by this damaging earthquake did not exceed the level predicted by the empirical attenuation relation. We found a significant effect of the surface geology on the observed ground-motion peak amplitude. In particular for soft-soil sites, located near the fault, the peak-horizontal acceleration decreases rap- idly with distance as a result of the nonlinear response of soils. In order to take into account the effect of the site conditions we introduced correction factors to the ex- isting attenuation relation. This resulted in a significant reduction of the residuals between the predicted and observed peak amplitudes. Based on the attenuation re- lation corrected for the site condition effect we generated a map of horizontal peak- ground acceleration in the Kobe and Osaka area for the Kobe earthquake. The area of simulated large ground motion agrees well with the severe damage zone of inten- sity VII, JMA scale. Introduction More than 6,500 people were killed and 170,000 build- ings were destroyed in the Hanshin and Awaji areas as a result of the 17 January 1995 Hyogo-ken Nanbu earthquake. The origin time and hypocenter of the event given by the Japan Meteorological Agency (JMA) were 05h46m52sec (local time) and longitude 1352.6 E, latitude 3436.4 N, respectively, and the focal depth was 14.3 km. The magni- tude was M j 7.2 determined by the JMA, M s 6.8 by the U.S. Geological Survey, and M w 6.9 by Harvard University and Kikuchi (1995) from a seismic moment of 2.5 10 26 dyne cm. The JMA intensity was VII throughout a narrow beltlike area stretching from Awaji Island to Nishinomiya City east of Kobe. The surface fault trace in the southwest part of the source area was in evidence along the Nojima fault in the Hokutan-cho area of Awaji island (Nakata et al., 1995). No clear surface trace was found in the eastern part of the source area around Kobe on Honshu island. Shimamoto (1995) pre- sumed the area of JMA intensity VII corresponding to the faults, which generated the earthquake. On the other hand, aftershocks occurred close to existing Quaternary faults, which are located north of Kobe. Sekiguchi et al. (1996) identified three fault segments along the Rokko fault system using the particle motions of the strong-motion records and the geodetic data in the near-source region. Kamae et al. (1998) and Kamae and Irikura (1998) simulated ground mo- tions from the main shock by an empirical Green’s function method using the asperity distribution on the fault founded by Sekiguchi et al. (1996). Their simulated ground motions agree well with the observed one. Based on simulated near- fault velocity in the frequency range of 0.1–1.0 Hz, Seki- guchi et al. (2000) showed that the eastern end of the source was likely to have branched to the Gosukebashi and Ashiya faults. The precise fault location is still being investigated. In this study we adapted the fault model of Sekiguchi et al. (1996). One of the most important issues is whether the di- saster resulted from unpredictable strong-ground motion or not. We address this issue in this study by analyzing the attenuation of the ground motion as a function of the closest distance to the fault. Over 200 peak amplitudes of ground motion were ob- served during this earthquake. The main purpose of these observations was not to do research work but rather emer- gency response systems. Individual organizations that had strong-motion data kindly made their data available for this work. We investigated the records and the site conditions in detail. The sensors were installed on various ground condi- tions and some were located in seriously damaged areas. The observed peak-horizontal acceleration (PHA) and velocity

Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

545

Bulletin of the Seismological Society of America, 90, 3, pp. 545–565, June 2000

Characteristics of Observed Peak Amplitude for Strong Ground Motion

from the 1995 Hyogoken Nanbu (Kobe) Earthquake

by Yoshimitsu Fukushima, Kojiro Irikura, Tomiichi Uetake, and Hisashi Matsumoto

Abstract Over 200 peak amplitudes of strong motion were observed at distancesof less than 250 km from the fault during the 1995 Hyogo-ken Nanbu (Kobe) earth-quake. We analyzed the attenuation of the peak-ground acceleration and velocity asa function of distance and geological site conditions. The observed peak amplitudesagree well with those predicted by an empirical attenuation relation that was devel-oped for Japanese earthquakes. This demonstrates that on average the peak amplitudeof the ground motion generated by this damaging earthquake did not exceed the levelpredicted by the empirical attenuation relation. We found a significant effect of thesurface geology on the observed ground-motion peak amplitude. In particular forsoft-soil sites, located near the fault, the peak-horizontal acceleration decreases rap-idly with distance as a result of the nonlinear response of soils. In order to take intoaccount the effect of the site conditions we introduced correction factors to the ex-isting attenuation relation. This resulted in a significant reduction of the residualsbetween the predicted and observed peak amplitudes. Based on the attenuation re-lation corrected for the site condition effect we generated a map of horizontal peak-ground acceleration in the Kobe and Osaka area for the Kobe earthquake. The areaof simulated large ground motion agrees well with the severe damage zone of inten-sity VII, JMA scale.

Introduction

More than 6,500 people were killed and 170,000 build-ings were destroyed in the Hanshin and Awaji areas as aresult of the 17 January 1995 Hyogo-ken Nanbu earthquake.The origin time and hypocenter of the event given by theJapan Meteorological Agency (JMA) were 05h46m52sec(local time) and longitude 135�2.6� E, latitude 34�36.4� N,respectively, and the focal depth was 14.3 km. The magni-tude was Mj 7.2 determined by the JMA, Ms 6.8 by the U.S.Geological Survey, and Mw 6.9 by Harvard University andKikuchi (1995) from a seismic moment of 2.5 � 1026 dynecm. The JMA intensity was VII throughout a narrow beltlikearea stretching from Awaji Island to Nishinomiya City eastof Kobe. The surface fault trace in the southwest part of thesource area was in evidence along the Nojima fault in theHokutan-cho area of Awaji island (Nakata et al., 1995). Noclear surface trace was found in the eastern part of the sourcearea around Kobe on Honshu island. Shimamoto (1995) pre-sumed the area of JMA intensity VII corresponding to thefaults, which generated the earthquake. On the other hand,aftershocks occurred close to existing Quaternary faults,which are located north of Kobe. Sekiguchi et al. (1996)identified three fault segments along the Rokko fault systemusing the particle motions of the strong-motion records andthe geodetic data in the near-source region. Kamae et al.

(1998) and Kamae and Irikura (1998) simulated ground mo-tions from the main shock by an empirical Green’s functionmethod using the asperity distribution on the fault foundedby Sekiguchi et al. (1996). Their simulated ground motionsagree well with the observed one. Based on simulated near-fault velocity in the frequency range of 0.1–1.0 Hz, Seki-guchi et al. (2000) showed that the eastern end of the sourcewas likely to have branched to the Gosukebashi and Ashiyafaults. The precise fault location is still being investigated.In this study we adapted the fault model of Sekiguchi et al.(1996). One of the most important issues is whether the di-saster resulted from unpredictable strong-ground motion ornot. We address this issue in this study by analyzing theattenuation of the ground motion as a function of the closestdistance to the fault.

Over 200 peak amplitudes of ground motion were ob-served during this earthquake. The main purpose of theseobservations was not to do research work but rather emer-gency response systems. Individual organizations that hadstrong-motion data kindly made their data available for thiswork. We investigated the records and the site conditions indetail. The sensors were installed on various ground condi-tions and some were located in seriously damaged areas. Theobserved peak-horizontal acceleration (PHA) and velocity

Page 2: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

546 Y. Fukushima, K. Irikura, T. Uetake, and H. Matsumoto

(PHV) were compared with predicted values using attenua-tion relations developed in Japan (Fukushima and Tanaka,1992: modified Fukushima and Tanaka, 1990; Midorikawa,1993). Similar comparisons have been performed in otherstudies (e.g., Irikura and Fukushima, 1995; Ejiri et al. 1996;Midorikawa et al. 1996; Fukushima et al. 1997). In thisstudy, the ratio of predicted to observed peak amplitude isnewly studied for various ground conditions: (1) bedrock;(2) Neogene; (3) diluvium, which is the consolidated allu-vium; (4) alluvium, which is unconsolidated; and (5) re-claimed ground. Further, the ratio of peak vertical acceler-ation (PVA) and velocity (PVV) to horizontal component isevaluated. The PHA/PHV and PVA/PVV ratios for variousground conditions are also studied.

At several sites close to the source, PVA was higher thanPHA on soft soil ground. This phenomenon was previouslyobserved at Array 6 in the 1979 Imperial Valley earthquake,and has been explained in terms of nonlinear behavior (Mo-hammadioun and Pecker, 1984). Clear nonlinear behaviorhas been identified in the Kobe event in vertical array recordsat Port Island, where the PVA at the surface was also largerthan the horizontal component.

The determination of spatial distribution for PHA nearfault is very important to know the strong ground motioncharacteristics in the near-source region. Some iso-PHAmaps were determined from the observation PHAs only.However, these are usually difficult subjects because the de-termination of average function is almost equal to derivinga new attenuation relation, which must be applicable to thenear source region (Stewart et al., 1994; Borcherdt and Hol-zer, 1996). Even if an attenuation relation could be used asthe average function, the distribution of PHA was distortedin sparse observation area (Fukushima et al., 1998). Fortu-nately, the digital geological information furnished as theGIS (the Digital National Land Information compiled by theGeographic Survey Institute and the National Land Agency,Japan) around this area is available. We try to derive cor-rection functions of the geological conditions and determinean iso-PHA map multiplying the predicted value by the at-tenuation relation and the correction function.

Data

Prior to this event, strong-motion data were disclosedby only a few observational organizations in Japan. Afterthe Kobe event, however, all organizations kindly made theirdata available. Peak-ground accelerations and velocitiesfrom the event were announced immediately by the RailwayTechnical Research Institute (RTRI; Nakamura et al., 1995),Osaka Gas Co., Ltd., the Committee of Earthquake Obser-vation and Research in the Kansai Areas (CEORKA), KansaiElectric Power Company (KEPCO), the Port and Harbor Re-search Institute (PHRI), the JMA, and others. A database ofpeak ground accelerations and velocities was compiled fromthese announcements and a prompt report was published byNIED (National Research Institute for Earth Science and Dis-

aster Prevention, Science and Technology Agency, 1995).Digital records of strong-ground motions from this eventwere made available to the public by CEORKA (10 sites),JMA (14 sites), and the Port Island Strong Motion Station ofthe Development Bureau of Kobe city (four sites in a verticalarray) within a few weeks. These data were compared withattenuation relations by Irikura and Fukushima (1995) andlisted in Fukushima and Irikura (1997).

The catalog for strong-motion data of the earthquakewas published by the Architectural Institute of Japan (1996)together with time histories, response spectrum, and particleorbits. The largest number of observation sites belongs tothe Japan Railway Companies (JR), and their details werereported in Nakamura et al. (1996). The Conference on Us-age of Earthquakes (CUE) in RTRI distributed five majorrecords by floppy disks; this study is using the floppy diskwith serial number R-031. The JMA distributed records takenby JMA87 type instruments through the Japan Weather As-sociation. PHRI immediately released their records, and theywere reported by Miyata et al. (1995). Records of the PublicWorks Research Institute (PWRI) of the Ministry of Con-struction, Hanshin Expressway Public Corporation, andHonshu-Shikoku Bridge Authority are announced in theTechnical Note of PWRI (1995), and their digital data aredistributed by floppy disks with the Technical Note. TheBuilding Research Institute (BRI) of the Ministry of Con-struction reported their data in Kashima and Kitagawa(1995). CEORKA reported on observation records just afterthe event (Geo-Research Institute, Osaka, 1995). The JapanSociety for Earthquake Engineering Promotion (1998) com-pleted a database and distributed it on CD with a report. TheCD contains data observed by Obayashi Corporation, Ko-noike Construction Co., Ltd., Maeda Corporation, KEPCO,Osaka Gas Co. Ltd., RWRI, BRI, PHRI, Ministry of Postsand Telecommunications, Hanshin Expressway Public Cor-poration, Kobe City Office, Shiga Prefecture, Laboratory ofStrong Motion Seismology of DPRI, Research Center ofEarthquake Prediction of DPRI of Kyoto University, Re-search Reactor Institute Kyoto University, and Shiga Pre-fecture University. Data from other organizations, such asthe Ohsaka Technical Institute, Kansai University, NTT,Takenaka, Hankyu Railway, the Technical Institute of Mat-sumura-gumi, Kansai Airport and others, are listed by theArchitectural Institute of Japan (1996). Further, HokushinRailway, Nose Railway, and NHK announced their data in-dividually.

These strong-motion instruments have been installed forvarious purposes, so their sensors were set up differently.We investigated the individual site condition of each instru-ment (Matsumoto et al., 1998). The investigated sites arelisted in the appendix.

The peak acceleration and velocity data contain differ-ential values from the velocity records and integral valuesfrom the accelerograms, respectively. Although the fault-normal component is already known to be very large in thenear-fault region (Somerville et al., 1997), the orientation of

Page 3: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake 547

Figure 1. Comparison between observed peak-horizontal accelerations and the pre-dicted values using empirical attenuation equation (1). Individual marks indicate dif-ferent ground conditions at the observation site. The solid line indicates the predictedpeak-horizontal acceleration. Broken lines indicate the standard error of the equation.

Table 1Number of Data

Category PHA PHV PVA PVV

Bedrock 22 21 22 19Neogene 5 ↑ 4 —Diluvium 18 13 16 10Alluvium 76 45 68 39Reclaimed 21 17 20 15All data 142 96 130 83

some sites is unknown; therefore, the mean peaks of twohorizontal components are taken to be PHA and PHV. Dataof only one horizontal component is rejected.

These mean values are more stable and only 10%smaller than the maximum values of the two correspondinghorizontal components on average. A total of 142 PHA and96 PHV observations were selected on the basis of the fol-lowing conditions:

1. The sensor should be installed on free surface. Sensorlocated in structures such as buildings were excludedfrom the study.

2. Borehole instruments installed at a depth greater than 1

m for soil site and greater than few tens of meters forrock site are excluded in order to avoid the effect of thedowngoing waves reflected at the ground surface.

3. Only large records are observed at far distance and biasedon the average characteristics (Fukushima, 1997). There-fore the records at the distances less than 220 km areaccepted. This is the reliability limit of the attenuationrelation (Fukushima and Tanaka, 1990) for this magni-tude.

The number of PVA and PVV records are 130 and 83,respectively; this number is smaller than the one for PHA,because the absence of vertical sensors at some sites. Nosurface trace was found in the eastern part of the fault, so itis difficult to precisely locate the fault plane. We assumed asingle plane, simplifying the three-segment-fault model ofSekiguchi et al. (1996). The length, width, strike angle, anddip angle of the fault plane are assumed to be 45 km, 15 km,235 degrees, and 85 degrees, respectively. The shortest dis-tance from the simplified fault model to the observation siteis used for empirical predictions of peak amplitude in thisstudy. Because fault distance errors are up to several hundredmeters, estimated distances of less than 500 m were takento be 500 m. Ground conditions at individual observation

Page 4: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

548 Y. Fukushima, K. Irikura, T. Uetake, and H. Matsumoto

Figure 2. Relation between ratio of observed to predicted peak-horizontal acceler-ation and closest distance to the fault plane. Individual marks indicate different groundconditions at the observation site. Regression lines on the logarithmic scale are alsoindicated for the individual ground conditions.

Table 2Ratios of Peak Amplitudes

Average in linear scale

CategoryObserved/Predicted

PHAObserved/Predicted

PHV PVA/PHA PVV/PHV PHA/PHV(PVA/PVV)/(PHA/PHV)

Bedrock 0.55 0.59 0.59 0.49 9.6 1.3Neogene few data ↑ 0.30 — — —Diluvium 0.94 0.78 0.46 0.38 13.5 1.3Alluvium distance dependent 1.16 0.45 0.33 10.4 1.5Reclaimed distance dependent 0.86 0.77 0.40 8.4 2.3

All data 1.03 0.93 0.53 0.39 10.4 1.6

sites were investigated from geological maps and loggingdata in the site vicinity and confirmed by visits to the site.Geological site conditions are classified into five types: (1)seismic bedrock, e.g., sedimentary rock predating the Neo-gene, and volcanic or plutonic rock; (2) Neogene strata; (3)diluvium; (4) alluvium; and (5) reclaimed ground. The num-ber of data points in each category is indicated in Table 1.There is only one observation of PHV on the Neogene, there-fore, this data is included in the bedrock category.

Attenuation Relations

Fukushima and Tanaka (1990) collected 686 PHAs from28 earthquakes in Japan and 15 earthquakes in the UnitedStates and other countries and used them to develop an at-tenuation relation by a two-step regression analysis. Later,

new data of 147 PHAs were added and the attenuation re-lation was revised. The new result was almost the same asthe previous one (Fukushima and Tanaka, 1992). This in-dicates that the derived empirical attenuation relation is verystable. The relation is given in the form of the followingequation:

logPHA � 0.42M � log(Rw0.42Mw� 0.025 � 10 ) � 0.0033R � 1.22 (1)

where, PHA is in cm/sec2, MW is the moment magnitude, andR is the distance from the fault plane to the site in km.Ground conditions at the individual observation sites werenot classified; therefore, this equation may be taken as cor-responding to average ground conditions in Japan.

Page 5: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake 549

Figure 3. Relation between ratio of observed topredicted peak-horizontal acceleration and the pre-dicted peak-horizontal acceleration for (a) reclaimedground and (b) alluvium. Solid lines indicate regres-sion lines for the data points.

Recently, a nonlinear scaling between earthquakeground motion and MW has been recognized (Fukushima,1996), particularly in the predominant period of several sec-onds, which is effective to PHV. In addition, a strong de-pendence on average S-wave velocity near the ground sur-face can be seen in PHV. Taking this nonlinear scaling andthe dependence on S-wave velocity into account, Midori-kawa (1993) developed the following attenuation relation forPHV:

2logPHV � �0.22M � 3.94M � log(Rw w0.43Mw� 0.01 � 10 ) (2)

� 0.002R � 11.9� 0.71 � logVs

where, PHV is in cm/sec and VS is the average S-wave ve-locity from the surface to 30 m deep in m/sec.

Amplitude Ratios

Observed/Predicted

Predicted PHA values from equation (1) are comparedwith the observed values in Figure 1. Most of the observeddata points fall within the standard error of the attenuationrelation, even if errors of several hundred meters in evalu-ating the distance from the fault are considered. The ratiosof observed/predicted PHA are shown in Figure 2 with dif-ferent marks for individual geological conditions. As shownin Table 2, the average ratios for bedrock and diluvium are0.55 and 0.94. At distance ranges over 100 km, the ratiosfor alluvium and reclaimed ground are larger than 1.0 onaverage. On the contrary, the ratios for reclaimed groundand alluvium decrease with decreasing distance due to thenonlinear behavior of soils described in the next section. Thefollowing equations are adopted as the distance dependentratios for the reclaimed ground and alluvium:

0.241O/P(reclaimed) � 0.362 � R (3)

0.165O/P(alluvium) � 0.549 � R (4)

where O/P is observed/predicted PHA ratio. Using these cor-rection factors, the standard error decreases from 0.247 to0.193 in base-ten logarithms. Further, if these distance de-pendencies are caused by nonlinear behavior, the level ofPHA may affect the ratio. Figure 3 shows the relation be-tween the ratio of observed to predicted PHA and the pre-dicted PHA. The following relations between predicted PHAand the ratio are determined for reclaimed ground and al-luvium:

�0.383O/P(reclaimed) � 5.476 � PHA (5)

�0.239O/P(alluvium) � 3.113 � PHA (6)

Using these correction factors, the standard error decreasesto 0.180. Although it is limited to the case of the Hyogo-kenNanbu event, this residual corresponds to a standard devia-tion from 66% to 151% for predicted PHA.

The comparison between observed and predicted PHVsis shown in Figure 4. In this figure, the prediction curves forthe reference S-wave velocity (hereafter VS) of 400 m/sec,which is an average VS of the database of Midorikawa(1993), as well as those for 200 and 700 m/sec are indicatedfor a comparison of different values of VS. Equation (2)agrees well with the data. The ratios of observed/predictedPHV for the individual geological conditions are shown inFigure 5. As shown in Table 2, the ratios for stiff ground onaverage are small, for example, about 0.59 for bedrock and

Page 6: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

550 Y. Fukushima, K. Irikura, T. Uetake, and H. Matsumoto

Figure 4. Comparison between observed peak-horizontal velocities and predictedlevels using empirical attenuation equation (2). Individual marks indicate differentground conditions at the observation site. The predicted peak horizontal velocity for areference VS of 400 m/sec is indicated by the solid line. The predicted velocities forother VS of 200 and 700 m/sec are also indicated by broken and chained lines, respec-tively.

0.78 for diluvium. The distance dependence seen in the caseof PHA for soft soils cannot be seen in the case of PHV.

Vertical/Horizontal

The ratios of PVA/PHA are shown in Figure 6. In thisfigure, the dispersion in the data is too large to allow a sys-tematic discussion. The average ratio is 0.53 as shown inTable 2. Most cases where the ratio is larger than 1.0 cor-respond with reclaimed ground or alluvium. All of thesepoints are located near the seashore. This may be due to theeffects of the nonlinear behavior, which was similarly ob-served during the 1979 Imperial Valley, California, earth-quake (Mohammadioun and Pecker, 1984). Kawase et al.(1995) interpreted the remarkable decay of the horizontalcomponents at the surface using effective stress analysis forthe vertical array records at Port Island. Namely, the high-frequency horizontal component propagating as a shearwave was isolated by the liquefied soil. On the contrary, thehigh-frequency vertical component propagating as a com-pressional wave was amplified by the large contrast in P-wave velocity at the ground water level.

The ratios of PVV/PHV are shown in Figure 7. All ratios

are less than 1.0 and their average is 0.39. The ratios forbedrock seem to be larger than those for the other categories.This might be due to the large incident angle of SV wave tothe bedrock. However, even for bedrock, the average ratiois less than 0.5. The peak acceleration correlates with theresponse spectral intensity of the predominant period from0.2 to 0.8 seconds, whereas the peak velocity correlates witha relatively long period range from 0.5 to 1.5 seconds (Nak-azawa et al., 1998). Therefore, the nonlinear behavior hasless effect on the peak velocity than on acceleration.

Acceleration/Velocity

The average ratio of PHA/PHV for the observed datashown in Table 2 is 10. As shown in Figure 8, the individualratios have a remarkable dependence on distance. The ratiopeaks at around 50 km. Values of PHA/PHV predicted fromequations (1) and (2) are also shown in this figure. The curveof the predicted ratio has a similar characteristic. This factindicates that the bend of attenuation curve for PHA issharper than that for PHV around 50 km. The observed ratiosfor soft soil in the distance range less than 10 km are smalldue to the decrease in PHA caused by the nonlinear behavior

Page 7: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake 551

Figure 5. Relation between ratio of observed to predicted peak horizontal velocityfor VS 400 m/sec and closest distance to the fault plane. Individual marks indicatedifferent ground conditions at the observation site. Regression lines on the logarithmicscale are also indicated for the individual ground conditions.

Figure 6. Relation between ratio of observed peak vertical per horizontal acceler-ation and distance. Individual marks indicate different ground conditions at the obser-vation site.

Page 8: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

552 Y. Fukushima, K. Irikura, T. Uetake, and H. Matsumoto

Figure 7. Relation between ratio of observed peak vertical to horizontal velocityand distance. Individual marks indicate different ground conditions at the observationsite.

Figure 8. Ratio of peak-horizontal acceleration to velocity. Individual marks indi-cate different ground conditions at the observation site. Ratio predicted by the empiricalattenuation relations of equations (1) and (2) is indicated by a solid line.

Page 9: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake 553

Figure 9. Distribution of classified geological conditions into bedrock, diluvium,alluvium, and reclaimed ground.

Figure 10. The PHA (cm/sec2) distribution considering geological correction factorsfor reclaimed, alluvium, diluvium, and bedrock. Long rectangle indicates assumed faultplane. Cross indicates epicenter. Areas indicated by red line depict the area of JMAintensity VII.

Page 10: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

554 Y. Fukushima, K. Irikura, T. Uetake, and H. Matsumoto

of soils. On the other hand, PVA does not decrease as a resultof the nonlinearity, so the ratios of PVA/PVV at short dis-tances are larger than the PHA/PHV ratios, and the ratio of(PVA/PVV)/(PHA/PHV) for reclaimed ground is the largestin Table 2. If a frequency f 0 Hz predominated in the peakamplitude, at a first order approximation, the PHA can beexpressed by 2pf 0 PHV. Therefore the mean value of 10corresponds to the frequency of 1.6 Hz. In the near-faultregion, the ratio is about 7 and this corresponds to about 1Hz, which is consistent with predominant frequencies re-corded at many sites near the causative faults. The ratio,which is related to the predominant frequency, for soft soilsnear the faults tends to further decrease due to the nonlinearbehavior. On the contrary, sites of high ratio, for exampleHigashiyama and Kyoto, belong to areas of forward rupturedirectivity. Only Gobo is belonging to sideward directivity,but this site is located on thin reclaimed ground over bed-rock, and high-frequency phases corresponding to reclaimedlayers were predominant. At distances longer than 100 km,the ratio falls off, perhaps due to the contamination causedby the low-frequency surface waves.

Isoseismal Map

The distribution of peak acceleration at the ground sur-face is very interesting, in particular the characteristics ofstrong-ground motion at near-fault sites where the numberof observations was very limited. On the basis of the findingsdescribed in the previous section, we consider that equation(1) represents the average value of the PHA. We used GISdata on a fine grid points with the longitudinal and latitudinalinterval of 0.0125 and 0.0083 degree around this area. Theground condition distribution is shown in Figure 9. This alsoincludes the newly reclaimed area. The correction factorsare estimated using equations (5) and (6) for the reclaimedand alluvial soil, and multiplying the average value by 55%and 94% for the bedrock and diluvium (Table 2). The surfacePHA distribution was estimated by multiplying the predictedvalue of equation (1) and the correction factors for the com-pleted distribution. In Figure 10, the estimated PHA is com-pared with the region of JMA intensity VII. Around the eastend of the assumed fault plane, the area of the JMA intensityVII is located relatively south of the large PHA area. Thisdivergence might be due to the basin edge effect that prob-ably amplified the ground motion at sites along the basinedge, south of the fault (Kawase, 1996; Pitarka et al., 1998).However in general, the severe damage belt of the JMA in-tensity VII corresponds to the estimated high amplitudezone.

Conclusions

1. The 1995 Kobe earthquake caused severe structural dam-age in a modern metropolitan area. However, the ob-served peak amplitudes agree well with amplitudes pre-

dicted by the empirical attenuation equations developedfor Japanese earthquakes (Fukushima and Tanaka, 1992;Midorikawa, 1993), suggesting that on average the peakamplitude of the ground motion generated by the dam-aging earthquake did not exceed the level predicted bythe empirical attenuation equation.

2. The ratio of the observed/predicted peak amplitudes forthe average horizontal component significantly dependson the local ground conditions. The ratio is larger for softsoils, except for PHA at short distances, where the PHAdecreases due to nonlinear behavior of soils. The residualbetween the observed and predicted PHA is considerablyreduced if corrections for the site effect are applied.

3. The ratios of the PVA to PHA for soft soils are greaterthan 1.0 when PHA decreases as a result of the nonlinearbehavior of soils. On the other hand, all of the PVV/PHVare less than 1.0, and are 0.4 on average.

4. The ratio of the PHA to PHV has a peak at around 50 km.This demonstrates that the saturation of the PHA withdecreasing distance in the near-source region is more no-table than that of the PHV, in particular for soft soils.

5. The average correction factors for the individual geolog-ical conditions were derived from the ratio of the ob-served/predicted PHA. Multiplying the predicted PHAvalues by the attenuation relation and the correction fac-tors, the PHA distribution reflecting also the effect of thesurface geology can be derived for the near-fault region.The estimated high PHA area agrees well with the severedamage belt of the JMA intensity VII.

Acknowledgments

We wish to express our gratitude to all organizations that announcedpeak amplitudes and made observations available. Most kindly made theirsites available to us. We also wish to express gratitude to Dr. MotofumiWatanabe of Shimizu Corp. for his suggestions in the writing of this manu-script and to Dr. Toshio Yamashita of TEPCO for his help in this researchproject. This manuscript was much improved by the rewriting of Dr. ArbenPitarka of URS Greiner Woodward Clyde Federal Services.

References

Architectural Institute of Japan (1996). 1995nen Hyogoken-Nanbu JishinKyoushin Kiroku Shiryousyu, January 1996, Special Working Groupfor Hyogoken-Nanbu Jishin, AIJ (in Japanese).

Borcherdt, R., and T. Holzer (1996). The January 17, 1995 Hyogoken-Nanbu (Kobe) earthquake, performance of structures, lifelines, andfire protection systems, in Seismology, Geology, and GeotechnicalIssues, Natl. Inst. Stand. Technol. Spec. Publ. 901, (Editor), R. Chung.

Eriji, J., S. Sawada, Y. Goto, and K. Toki (1996). Peak ground motioncharacteristics, Special Issue of Soils and Foundations, JapaneseGeotechnical Soc., 7–13.

Fukushima, Y., and T. Tanaka (1990). A new attenuation relation for peak

Page 11: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

Characteristics of Observed Peak Amplitude for Strong Ground Motion from the 1995 Hyogoken Nanbu (Kobe) Earthquake 555

horizontal acceleration of strong earthquake ground motion in Japan,Bull. Seism. Soc. Am. 80, 757–783.

Fukushima, Y., and T. Tanaka (1992). Revised attenuation relation of peakhorizontal acceleration by using a new data base, Programme andAbstracts of the Seism. Soc. Japan, No. 2, 116 (in Japanese).

Fukushima, Y. (1996). Scaling relations for strong ground motion predic-tion models with M2 terms, Bull. Seism. Soc. Am. 86, 329–336.

Fukushima, Y. (1997). Comment on “Ground motion attenuation relationsfor subduction zones,” Seism. Res. Lett. 68, 947–949.

Fukushima, Y., T. Watanabe, T. Uetake, and H. Matsumoto (1997). Atten-uation characteristics of observed peak amplitude from 1995 Hyogo-ken Nanbu event, 14th SMiRT K02/5, 83–90.

Fukushima, Y., and K. Irikura (1997). Attenuation characteristics of peakground motions in the 1995 Hyogo-ken Nanbu earthquake, J. Phys.Earth 45, 135–146.

Fukushima, Y., T. Watanabe, T. Uetake, and H. Matsumoto (1998). Char-acteristics of peak amplitude for strong ground motion from 1995Hyogoken nanbu earthquake, in Proc of the 2nd International Sym-posium on the Effects of Surface Geology on Seismic Motion, 1155–1162.

Geo-Research Institute, Osaka (1995). Heisei 7-nen Hyogoken NanbuJishin Sokuhou, February, 1995 (in Japanese).

Irikura, K., and Y. Fukushima (1995). Attenuation characteristics of peakamplitude in the Hyogoken-Nambu earthquake, J. Natural DisasterSciences, 16,(3), 39–46.

Japan Society for Earthquake Engineering Promotion (1998). Strong Mo-tion Array Observation No. 3 (in Japanese).

Kamae, K., K. Irikura, and A. Pitarka (1998). A technique for simulatingstrong ground motion using hybrid Green’s function, Bull. Seism. Soc.Am. 88, 357–367.

Kamae, K., and K. Irikura (1998). Source model of the 1995 Hyogo-kenNanbu earthquake and simulation of near-source ground motion, Bull.Seism. Soc. Am. 88, 400–412.

Kashima, T., and Y. Kitagawa (1995). The 1995 Hyogo-ken-nanbu Earth-quake, Prompt Report on Strong Motion Records, 4, Building Res.Inst., Ministry of Construction, Japan (in Japanese).

Kawase, H., T. Satoh, K. Fukutake, and K. Irikura (1995). Borehole recordsobserved at the Port Island in Kobe during the Hyogo-ken Nanbuearthquake of 1995 and its simulation, J. Struct. Constr. Eng., AIJ,No. 475, 83–92 (in Japanese).

Kawase, H. (1996). The cause of the damage belt in Kobe: “the basin-edgeeffect”, constructive interference of the direct S-wave with the basin-induced diffracted/Rayleigh wave, Seism. Res. Lett. 67, 25–34.

Kikuchi, M. (1995). Teleseismic analysis of the Southern Hyogo (Kobe),Japan, earthquake of January 17, 1995, Yokohama City Univ. Seis-mological Note 38.

Matsumoto, H., T. Uetake, Y. Fukushima, and T. Watanabe (1998). Siteeffect for the attenuation characteristics of observed peak amplitudefrom 1995 Hyogo-ken Nanbu event, Proc. of the 10th Japan Earth-quake Engineering Symposium 1, 541–546 (in Japanese).

Midorikawa, S. (1993). Preliminary analysis for attenuation of peak groundvelocity on stiff site, Proc. of the International Workshop on StrongMotion Data, 2, 39–48.

Midorikawa, S., H. Si, and M. Matsuoka (1996). Empirical analysis of peakhorizontal velocity for the Hyogo-ken Nanbu, Japan earthquake ofJanuary 17, 1995, Proc. of the 11th World Conference on EarthquakeEngineering 1564, disk 3 of 4.

Miyata, M., Y. Satho, and S. Iai (1995). Mechanism of damage to portfacilities during 1995 Hyogo-ken Nanbu earthquake (Part 1)—strong-motion earthquake records in port areas, Technical Note, The Portand Harbour Research Institute, Ministry of Transport, Japan, 813(in Japanese).

Mohammadioun, B., and A. Pecker (1984). Low-frequency transfer of seis-mic energy by superficial soil deposits and soft rocks, EarthquakeEng. Struct. Dyn. 12, 537–564.

Nakamura, Y., K. Hidaka, J. Saita, and S. Sato (1995). Strong accelerations

and damage of the 1995 Hyogoken-Nanbu earthquake, JR EarthquakeInformation No. 23b, Railway Technical Research Institute.

Nakamura, Y., F. Uehan, and H. Inoue (1996). Waveform and its analysisof the 1995 Hyogo-Ken-Nanbu earthquake (II), JR Earthquake Infor-mation No. 23d, Railway Technical Research Institute (in Japanese).

Nakata, T., K. Yomogida, J. Odaka, T. Sakamoto, K. Asahi, and N. Chida(1995). Surface fault ruptures associated with the 1995 Hyogoken-Nanbu earthquake, J. Geography 104, 127–142.

Nakazawa, M., T. Uetake, H. Inada, T. Watanabe, and Y. Fukushima(1998). Relation between peak amplitude and response spectrum ofstrong ground motion from Hyogo-ken Nanbu earthquake, Summariesof Technical Papers of the Annual Meeting of the Architectural In-stitute of Japan B-2, 129–130 (in Japanese).

National Research Institute for Earth Science and Disaster Prevention,Science and Technology Agency (1995). Prompt Report on Strong-Motion Accelerograms No. 46, January 17, 1995, Southern HyogoPrefecture, Japan (in Japanese).

Pitarka, A., K. Irikura, T. Iwata, and H. Sekiguchi (1998). Three-dimen-sional simulation of the near-fault ground motion for the 1995 Hyogo-ken Nanbu (Kobe), Japan, earthquake, Bull. Seism. Soc. Am. 88, 428–440.

Public Works Research Institute (1995). Strong-motion acceleration re-cords from public works in Japan (No. 21), Technical Note of PublicWorks Research Institute, Ministry of Construction, Japan, 64.

Sekiguchi, H., K. Irikura, T. Iwata, Y. Kakehi, and M. Hoshiba (1996).Minute locating of faulting beneath Kobe and waveform inversion ofthe source process during the 1995 Hyogo-ken Nanbu, Japan, earth-quake using strong ground motion records, J. Phys. Earth 44, 473–448.

Sekiguchi, H., K. Irikura, and T. Iwata (2000). Fault Geometry at the 1995Hyogo-ken Nanbu earthquake, Bull. Seism. Soc. Am. 90, 117–133.

Shimamoto, T. (1995). Mystery of “damage belt” during Kobe earthquake,Iwanami-Kagaku 65, No. 4, 195–198 (in Japanese).

Somerville, P. G., N. F. Smith, R. W. Graves, and N. A. Abrahamson(1997). Modification of empirical strong ground motion attenuationrelations to include the amplitude and duration effects of rupture di-rectivity, Seism. Res. Lett. 68, 199–222.

Stewart, J. P., J. D. Bray, R. G. Seed, and N. Sitar (1994). Preliminaryreport on the principal geotechnical aspects of the January 17, 1994,Northridge earthquake, Earthquake Engineering Research Center Re-port No. UCB/EERC 94/08, University of California, Berkeley.

Ohsaki Research InstituteFukoku-seimei BLDG 27F2-2-2, Uchisaiwai-choChiyoda-ku, 1000011, [email protected]

(Y. F.)

Disaster Prevention Research InstituteKyoto UniversityGokasho, Uji, 6110011Japan

(K. I.)

Power Eng. R&D CenterTokyo Electric Power Company4-1 Egasaki-cho, Tsurumi-kuYokohama, 2308510Japan

(T. U., H. M.)

Manuscript received 24 May 1999.

Page 12: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

556

App

endi

xL

ist

ofSt

rong

Mot

ion

Obs

erva

tion

Site

sof

Kob

eE

arth

quak

e

No.

Site

Org

aniz

atio

nL

ong.

d,m

,s(E

)L

at.d

,m,s

(N)

Lev

el*

Acc

/Vel

H1

(cm

/sec

/sec

)H

2(c

m/s

ec/s

ec)

UD

(cm

/sec

/sec

)H

1(c

m/s

ec)

H2

(cm

/sec

)U

D(c

m/s

ec)

H1

com

p.†

H2

com

p.

1Ta

kato

riJR

135

0811

3438

53G

LA

cc60

665

727

912

7.0

127.

017

.3N

SE

W2

Shin

-Kob

eJR

135

1149

3442

08G

LA

cc53

026

734

4N

SE

W3

Taka

razu

kaJR

135

2037

3448

37G

LA

cc68

460

141

871

.981

.533

.7N

SE

W4

Nis

hi-A

kash

iJR

134

5750

3439

50G

LA

cc47

445

538

046

.840

.221

.4N

SE

W5

Shin

-Osa

kaJR

135

3001

3443

43G

LA

cc18

121

617

641

.036

.311

.3N

SE

W6

Shin

-Osa

kaT

rans

JR13

530

5834

4449

GL

Acc

221

229

6234

.325

.26.

3N

SE

W7

Kak

ogaw

aJR

134

5035

3445

50G

LA

cc23

531

816

821

.427

.210

.2N

SE

W8

Kan

kuu

Tra

nsJR

135

1534

3426

17G

LA

cc16

714

112

219

.623

.210

.7N

SE

W9

Hig

ashi

kish

iwad

aJR

135

2317

3426

42G

LA

cc18

220

979

18.2

12.4

8.0

NS

EW

10Sh

in-T

akat

suki

Tra

nsJR

135

3914

3451

32G

LA

cc29

723

112

1N

SE

W11

Sasa

yam

aguc

hiJR

135

1048

3503

11G

LA

cc20

027

557

10.5

13.4

2.8

NS

EW

12H

imej

iJR

134

4140

3449

16G

LA

cc82

125

48N

SE

W13

Sono

beJR

135

2913

3506

00G

LA

cc13

525

454

10.8

12.6

5.1

NS

EW

14W

akay

ama

JR13

511

3834

1347

GL

Acc

174

126

5814

.411

.85.

4N

SE

W15

Nar

aJR

135

4918

3440

34G

LA

cc11

210

436

NS

EW

16N

ijoJR

135

4441

3500

27G

LA

cc84

max

17H

igas

hiya

ma

Tra

nsJR

135

4750

3458

41G

LA

cc18

220

978

9.5

7.0

3.4

NS

EW

18A

ioi

JR13

428

2934

4854

GL

Acc

6252

28N

SE

W19

Has

him

ato

JR13

537

0234

1854

GL

Acc

2118

13N

SE

W20

Toku

shim

aJR

134

3304

3404

19G

LA

cc82

larg

er21

Fuku

chiy

ama

JR13

507

1635

1735

GL

Acc

108

134

264.

98.

32.

5N

SE

W22

Ikun

oJR

134

4752

3509

36G

LA

cc36

5320

NS

EW

23Ir

iT

rans

JR13

413

3734

4500

GL

Acc

9777

64N

SE

W24

Ritt

oT

rans

JR13

559

4535

0141

GL

Acc

6068

25N

SE

W25

Gob

oJR

135

0947

3354

14G

LA

cc12

816

639

7.7

10.3

3.6

NS

EW

26N

ishi

mai

zuru

JR13

519

5935

2617

GL

Acc

6079

20N

SE

W27

Taka

mat

suJR

134

0255

3420

49G

LA

cc94

larg

er28

Tsug

eJR

136

1532

3450

35G

LA

cc77

6733

NS

EW

29G

okas

you

JR13

611

0235

0820

GL

Acc

133

140

4711

.18.

24.

2N

SE

W30

Oba

ma

JR13

544

5635

2917

GL

Acc

7461

26N

SE

W31

Oka

yam

aJR

133

5507

3439

371F

Acc

8558

30N

SE

W32

Toyo

oka

JR13

448

5935

3231

GL

Acc

103

9027

NS

EW

33Sh

injo

Tra

nsJR

133

4903

3438

38G

LA

cc66

4620

NS

EW

34B

anno

suT

rans

JR13

349

5334

2059

GL

Acc

3624

17N

SE

W35

Hits

uish

i-Ji

ma

JR13

348

2434

2508

GL

Acc

3817

13N

SE

W36

Shin

-Mai

bara

Tra

nsJR

136

1735

3518

58G

LA

cc21

513

829

18.7

8.6

2.3

NS

EW

37Ta

dots

uJR

133

4528

3415

531F

Acc

49la

rger

38K

iiN

agas

him

aJR

136

2033

3412

21G

LA

cc46

max

39M

atsu

zaka

JR13

632

1834

3426

GL

Acc

49m

ax40

Kaz

umi

JR13

437

3135

3800

GL

Acc

3851

21N

SE

W41

Kin

omot

oJR

136

1326

3530

18G

LA

cc50

5313

NS

EW

42A

wa

Iked

aJR

133

4825

3401

241F

Acc

35la

rger

43Ts

urug

aJR

136

0455

3538

31G

LA

cc59

4116

NS

EW

44K

uman

oshi

JR13

606

0933

5311

GL

Acc

52m

ax

Page 13: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

557

45Su

sam

iJR

135

2954

3332

34G

LA

cc23

2912

NS

EW

46Y

okka

ichi

JR13

637

5934

5736

GL

Acc

65m

ax47

Seki

gaha

raJR

136

2819

3521

36G

LA

cc95

max

48Sh

in-S

ekig

ahar

aT

rans

JR13

628

5635

2129

GL

Acc

106

7229

NS

EW

49Sh

in-K

amog

ata

JR13

333

2334

3158

GL

Acc

1416

12N

SE

W50

Kii

Kat

suur

aJR

135

5638

3337

26G

LA

cc38

3813

NS

EW

51H

ajim

aT

rans

JR13

640

2035

1934

GL

Acc

5832

12N

SE

W52

Osu

giJR

133

4000

3345

27G

LA

cc20

larg

er53

Take

fuJR

136

1024

3554

02G

LA

cc16

1919

NS

EW

54K

isog

awa

JR13

647

0235

2046

GL

Acc

67m

ax55

Shin

-Biw

ajim

aT

rans

JR13

652

0135

1142

GL

Acc

2118

7N

SE

W56

Oda

kaT

rans

JR13

657

1035

0252

GL

Acc

1914

8N

SE

W57

Anj

oT

rans

JR13

705

5634

5544

GL

Acc

2220

7N

SE

W58

Fuku

iJR

136

1334

3603

29G

LA

cc38

2318

NS

EW

59K

ochi

JR13

332

5833

3348

GL

Acc

40la

rger

60M

ihar

aJR

133

0506

3423

51G

LA

cc30

max

61O

kaza

kiJR

137

0936

3455

12G

LA

cc9

max

62E

chiz

enO

noJR

136

2957

3558

46G

LA

cc20

2411

NS

EW

63M

ino

Ota

JR13

701

2835

2631

GL

Acc

50m

ax64

Shin

Mih

ara

Tra

nsJR

133

0236

3423

43G

LA

cc16

167

NS

EW

65Iy

oSa

ijoJR

133

1130

3354

33G

LA

cc20

max

66Ta

jimi

JR13

707

1935

1948

GL

Acc

15m

ax67

Ots

uka

JR13

716

4834

4840

GL

Acc

109

4N

SE

W68

Toyo

hash

iJR

137

2313

3445

26G

LA

cc12

max

69M

iyos

hiJR

132

5131

3447

58G

LA

cc9

max

70D

aisy

ouji

JR13

618

5836

1752

GL

Acc

5863

20N

SE

W71

Suza

kiJR

133

1748

3323

14G

LA

cc12

larg

er72

Shin

-Sai

joT

rans

JR13

246

4134

2343

GL

Acc

2214

5N

SE

W73

Ger

oJR

137

1432

3548

07G

LA

cc12

max

74N

akat

suga

wa

JR13

730

1835

2942

GL

Acc

14m

ax75

Mik

awa

JR13

629

3536

2902

GL

Acc

4028

11N

SE

W76

Kob

eJM

A13

510

4634

4118

GL

Acc

818

617

332

91.0

75.0

40.0

NS

EW

77O

saka

JMA

135

3118

3440

42B

3FA

cc81

6665

19.4

15.6

7.1

NS

EW

78K

yoto

JMA

135

4408

3500

43G

LA

cc16

019

736

15.0

11.0

4.7

NS

EW

79To

kush

ima

JMA

134

3436

3403

53G

LA

cc94

9035

12.0

10.0

3.5

NS

EW

80M

aizu

ruJM

A13

519

1335

2649

GL

Acc

6752

394.

64.

92.

1N

SE

W81

Taka

mat

suJM

A13

403

2634

1853

GL

Acc

6887

346.

39.

82.

6N

SE

W82

Oka

yam

aJM

A13

355

0834

3927

B1F

Acc

7759

365.

33.

82.

7N

SE

W83

Toyo

oka

JMA

134

4931

3531

59G

LA

cc87

138

5015

.010

.03.

5N

SE

W84

Hik

one

JMA

136

1448

3516

23G

LA

cc13

714

739

16.0

15.0

3.1

NS

EW

85Ts

uJM

A13

631

2534

4353

B1F

Acc

7160

266.

46.

73.

0N

SE

W86

Totto

riJM

A13

414

2835

2906

GL

Acc

7774

159.

99.

21.

0N

SE

W87

Shio

nom

isak

iJM

A13

545

5033

2652

GL

Acc

1924

91.

91.

61.

4N

SE

W88

Gif

uJM

A13

645

5635

2349

1FA

cc32

229

3.1

3.4

1.1

NS

EW

89N

agoy

aJM

A13

658

0535

0952

GL

Acc

1614

103.

32.

50.

92N

SE

W90

Mur

oto

JMA

134

1048

3314

53G

LA

cc23

139

2.2

3.6

1.5

NS

EW

91Fu

kui

JMA

136

1332

3603

11G

LA

cc33

4210

4.0

5.3

1.5

NS

EW

92Y

onag

oJM

A13

320

3035

2535

GL

Acc

1921

82.

52.

10.

90N

SE

W

Page 14: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

558

No.

Site

Org

aniz

atio

nL

ong.

d,m

,s(E

)L

at.d

,m,s

(N)

Lev

el*

Acc

/Vel

H1

(cm

/sec

/sec

)H

2(c

m/s

ec/s

ec)

UD

(cm

/sec

/sec

)H

1(c

m/s

ec)

H2

(cm

/sec

)U

D(c

m/s

ec)

H1

com

p.†

H2

com

p.

93M

atsu

yam

aJM

A13

246

5033

5024

GL

Acc

1421

62.

41.

20.

92N

SE

W94

Kob

ePo

rtPH

RI

135

1231

3441

10G

LA

cc50

220

528

310

0.0

35.0

32.0

N43

WN

47E

95Pi

er8

PHR

I13

513

0234

4115

pier

Acc

683

394

334

185.

061

.038

.0N

42W

N48

E96

Am

agas

aki

PHR

I13

524

1434

4243

GL

Acc

321

472

311

52.0

57.0

27.0

N06

WN

84E

97O

saka

PHR

I13

526

4034

3846

GL

Acc

178

125

103

S24E

E24

N98

Wak

ayam

aPH

RI

135

0854

3412

51G

LA

cc15

710

967

N12

EE

12S

99K

omat

sujim

aPH

RI

134

3517

3402

50G

LA

cc89

9632

NS

EW

100

Tsur

uga

PHR

I13

603

5535

3914

GL

Acc

5651

20N

SE

W10

1Y

okka

ichi

PHR

I13

638

2634

5700

GL

Acc

5441

11N

SE

W10

2N

agoy

aPH

RI

136

5206

3504

22pi

erA

cc30

3212

S20W

E20

S10

3K

inuu

raPH

RI

136

5648

3452

41G

LA

cc27

259

NS

EW

104

Koc

hiPH

RI

133

3410

3330

18G

LA

cc28

2610

NS

EW

105

Saka

imin

ato

PHR

I13

315

0435

3232

GL

Acc

4433

16N

SE

W10

6M

atsu

yam

aPH

RI

132

4252

3351

17G

LA

cc40

3510

NS

EW

107

Am

agas

aki

Bri

dge

PWR

I13

525

2034

4235

GL

Acc

265

294

324

52.0

51.0

23.0

N15

0EN

240E

108

Oyo

doPW

RI

135

2911

3442

18G

LA

cc20

322

123

934

.031

.08.

2N

68E

N15

8E10

9Y

odog

awa

EM

B.

PWR

I13

531

1334

4254

GL

Acc

138

119

101

16.0

14.0

5.3

LG

TR

110

Kak

ogaw

aPW

RI

134

5330

3447

30ba

nkA

cc14

421

126

4L

GT

R11

1H

irak

ata

PWR

I13

538

5034

4852

GL

Acc

293

397

140

17.0

20.0

5.1

N45

EN

135E

112

Yam

atog

awa

PWR

I13

535

3234

3519

GL

Acc

156

199

568.

917

.05.

2E

WN

S11

3K

inok

awa

PWR

I13

509

1234

1332

GL

Acc

129

105

6522

.014

.05.

4N

62E

N15

2E11

4K

inok

awa

Bri

dge

PWR

I13

509

5934

1250

GL

Acc

106

145

5213

.09.

54.

8N

120E

N21

0E11

5A

mag

ase

PWR

I13

549

4934

5236

tunn

elA

cc10

756

285.

93.

02.

4L

GT

R11

6To

kush

ima

PWR

I13

433

2734

0511

GL

Acc

133

119

5014

.08.

94.

5L

GT

R11

7Is

hii

PWR

I13

427

1734

0554

GL

Acc

119

9197

10.0

8.8

6.7

LG

TR

118

Saru

tani

Dam

PWR

I13

544

4234

1035

GL

Acc

3918

121.

91.

41.

2E

WN

S11

9M

inat

oB

ridg

ePW

RI

134

4941

3538

25G

LA

cc73

6639

6.6

7.8

4.1

N13

0EN

220E

120

Aka

giB

ridg

ePW

RI

135

5115

3346

24G

LA

cc60

439

121

Hig

ashi

Kob

eB

ridg

ePW

RI

135

1745

3442

24G

LA

cc28

132

739

582

.087

.036

.0N

78E

N16

8E12

2In

agaw

aPW

RI

135

2537

3449

44G

LA

cc42

241

736

140

.040

.020

.0N

SE

W12

3Y

otsu

bash

iPW

RI

135

3000

3440

08G

LA

cc25

233

022

329

.021

.08.

4N

SE

W12

4M

atsu

noha

ma

p32

PWR

I13

524

2434

3023

GL

Acc

145

135

116

15.0

13.0

4.7

N59

EN

149E

125

Mat

suno

ham

ap2

3PW

RI

135

2439

3430

31G

LA

cc16

910

710

620

.09.

84.

5N

59E

N14

9E12

6Su

itaSh

imiz

uPW

RI

135

3247

3448

041F

Acc

485

127

Nar

uto

Hon

-Shi

B.A

.13

439

4934

1415

tunn

elA

cc13

611

948

16.0

13.0

4.0

TR

LG

128

Kob

eU

niv.

CE

OR

KA

135

1426

3443

30tu

nnel

Vel

305

270

51.0

31.0

33.2

NS

EW

129

Fuku

shim

aC

EO

RK

A13

528

2634

4113

1FV

el18

021

219

530

.929

.89.

6N

SE

W13

0A

beno

CE

OR

KA

135

3108

3438

10G

LV

el21

722

613

621

.324

.96.

3N

SE

W13

1M

orik

awac

hiC

EO

RK

A13

534

1934

4048

1FV

el21

012

315

927

.124

.76.

1N

SE

W13

2Sa

kai

CE

OR

KA

135

2808

3433

501F

Vel

150

125

100

15.9

15.7

6.6

NS

EW

133

Yae

CE

OR

KA

135

3643

3440

481F

Vel

155

145

127

21.2

21.8

7.0

NS

EW

134

Tada

oka

CE

OR

KA

135

2429

3428

481F

Vel

290

190

137

24.4

14.7

6.9

NS

EW

135

Chi

haya

CE

OR

KA

135

3732

3426

20ba

seV

el91

109

745.

24.

92.

4N

SE

W13

6Fu

kiai

Ohs

aka

Gas

135

1239

3441

42G

LA

cc68

780

258

.012

3.0

N12

0WN

030W

137

Nis

hino

miy

aO

hsak

aG

as13

521

0434

4317

GL

Vel

792

max

138

Hok

kou

Ohs

aka

Gas

135

2547

3440

03G

LV

el26

6m

ax13

9Iw

asak

iO

hsak

aG

as13

528

5034

3955

GL

Vel

169

139

24.0

19.0

NS

EW

Page 15: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

559

140

Senr

iO

hsak

aG

as13

531

1334

4815

GL

Acc

299

185

28.0

17.0

N20

EN

110E

141

Saka

iO

hsak

aG

as13

526

5334

3605

1FV

el17

332

.0m

ax14

2Se

npok

u2O

hsak

aG

as13

524

3034

3226

1FV

el24

0m

ax14

3H

ashi

ram

oto

Ohs

aka

Gas

135

3610

3446

57G

LV

el25

131

.0m

ax14

4K

awac

hiO

hsak

aG

as13

535

3634

4132

GL

Vel

177

34.0

max

145

Senp

oku1

Ohs

aka

Gas

135

2616

3432

261F

Acc

178

max

146

Shijo

unaw

ate

Ohs

aka

Gas

135

3755

3444

21G

LA

cc22

125

624

.028

.0N

90W

NS

147

Toub

ushi

sya

Ohs

aka

Gas

135

3712

3440

05G

LV

el18

013

023

.019

.0N

SE

W14

8H

imej

iO

hsak

aG

as13

441

5234

4539

1FV

el18

9m

ax14

9O

nji

Ohs

aka

Gas

135

3734

3436

191F

Vel

169

22.0

max

150

Fujid

era

Ohs

aka

Gas

135

3633

3433

52G

LV

el19

814

812

.07.

1N

SE

W15

1Sa

yam

aO

hsak

aG

as13

532

4734

2946

GL

Vel

160

186

9.0

11.0

NS

EW

152

Shik

ama

Ohs

aka

Gas

134

4035

3447

28G

LA

cc25

3m

ax15

3M

atsu

eO

hsak

aG

as13

508

2734

1420

GL

Vel

160

157

22.0

20.0

NS

EW

154

Hei

jou

Ohs

aka

Gas

135

4523

3443

32G

LA

cc11

114

07.

89.

1N

60E

N15

0E15

5N

akan

oshi

ma

Ohs

aka

Gas

135

1101

3414

04G

LA

&V

107

106

15.0

12.0

NS

EW

156

Fush

imi

Ohs

aka

Gas

135

4435

3455

35G

LA

&V

178

152

18.0

7.3

N13

5WN

45W

157

Kyo

toO

hsak

aG

as13

544

2834

5931

GL

Vel

294

145

13.0

9.1

NS

EW

158

Shin

-Kob

eT

rans

KE

PCO

135

1500

3443

50G

LA

cc51

158

449

563

.077

.026

.0N

SE

W15

9A

mag

asak

iK

EPC

O13

523

2734

4124

GL

Acc

227

354

373

45.0

50.0

20.0

NS

EW

160

Soug

ougi

ken

KE

PCO

135

2630

3444

35G

LA

cc29

964

820

537

.048

.021

.0N

SE

W16

1N

anko

uK

EPC

O13

524

3034

3650

GL

Acc

107

126

199

21.0

20.0

12.0

NS

EW

162

Taka

sago

KE

PCO

134

4552

3445

17G

LA

cc19

119

818

234

.044

.012

.0N

SE

W16

3Y

aoK

EPC

O13

536

4034

3610

GL

Vel

148

139

8213

.013

.04.

8N

SE

W16

4M

inam

iO

saka

KE

PCO

135

2830

3427

50G

LV

el14

414

593

14.0

12.0

3.9

NS

EW

165

Shig

iK

EPC

O13

539

0734

3546

GL

Acc

4246

283.

42.

90.

94N

SE

W16

6N

ishi

-Kyo

toK

EPC

O13

537

2034

5800

GL

Acc

114

129

8314

.011

.06.

2N

SE

W16

7K

aina

nK

EPC

O13

511

2234

0904

GL

Acc

9812

892

8.4

9.4

3.7

NS

EW

168

Ako

uK

EPC

O13

422

4534

4405

GL

Acc

104

8412

211

.011

.03.

8N

50E

N14

0E16

9Y

amaz

aki

KE

PCO

134

3610

3503

35G

LA

cc13

192

3.6

4.8

NS

EW

170

Gob

oK

EPC

O13

509

1033

5122

GL

Acc

6074

262.

43.

70.

94N

12W

N78

E17

1Ta

kaha

ma

KE

PCO

135

3030

3531

10ba

seA

cc17

2316

N14

0WN

050W

172

Miy

azu

KE

PCO

135

1520

3533

15G

LA

cc57

7057

3.2

4.1

1.7

N03

0EN

120E

173

Oi

KE

PCO

135

3917

3532

15ba

seA

cc12

1213

N04

0WN

050E

174

Yuz

aki

KE

PCO

135

2112

3340

24G

LV

el16

198

2.3

2.9

1.3

NS

EW

175

Mih

ama

KE

PCO

135

5747

3542

04ba

seA

cc16

146

N10

5WN

015W

176

Ous

akay

ama

Shig

aPr

ef.

135

5140

3459

53tu

nnel

Vel

4543

406.

64.

03.

5N

SE

W17

7K

usat

suSh

iga

Pref

.13

557

2935

0040

GL

Vel

145

8937

11.5

7.8

4.9

NS

EW

178

Kuz

ugaw

aSh

iga

Pref

.13

551

0435

1332

GL

Vel

2937

206.

24.

02.

8N

SE

W17

9M

inag

uchi

Shig

aPr

ef.

136

1012

3458

05G

LV

el43

4123

4.1

3.0

2.5

NS

EW

180

Imaz

uSh

iga

Pref

.13

602

0635

2411

GL

Vel

4743

224.

23.

92.

0N

SE

W18

1To

rahi

me

Shig

aPr

ef.

136

1554

3524

58G

LV

el70

6521

6.9

6.4

2.1

NS

EW

182

Shig

aTa

ndai

Shig

aPr

ef.J

.Col

lege

136

1341

3515

33G

LA

cc78

2824

10.0

5.0

2.6

NS

EW

183

Abu

yam

aR

CE

P,K

yoto

Uni

v.13

534

2534

5136

tunn

elV

el78

8157

10.0

9.1

7.6

NS

EW

184

Wac

hiR

CE

P,K

yoto

Uni

v.13

524

0535

1657

tunn

elV

el18

2117

2.4

3.2

2.9

NS

EW

Page 16: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

560

No.

Site

Org

aniz

atio

nL

ong.

d,m

,s(E

)L

at.d

,m,s

(N)

Lev

el*

Acc

/Vel

H1

(cm

/sec

/sec

)H

2(c

m/s

ec/s

ec)

UD

(cm

/sec

/sec

)H

1(c

m/s

ec)

H2

(cm

/sec

)U

D(c

m/s

ec)

H1

com

p.†

H2

com

p.

185

Oya

RC

EP,

Kyo

toU

niv.

134

3957

3519

18tu

nnel

Vel

3825

253.

93.

22.

4N

SE

W18

6K

ume

RC

EP,

Kyo

toU

niv.

133

5057

3505

19tu

nnel

Vel

1413

133.

21.

51.

0N

SE

W18

7A

zai

RC

EP,

Kyo

toU

niv.

136

1910

3528

38G

LV

el25

2311

2.6

2.1

1.1

NS

EW

188

Res

.Rea

ctor

RR

I,K

yoto

Uni

v.13

520

5834

2258

base

Acc

218

166

151

189

DPR

IO

saka

JMA

DPR

I,K

yoto

Uni

v.13

532

1334

4041

B2F

Acc

8168

7919

0N

Ohs

aka

Inst

.Tec

h.13

525

4334

3754

GL

Acc

7677

NS

EW

191

DO

hsak

aIn

st.T

ech.

135

3245

3443

39G

LA

cc18

915

512

6N

SE

W19

2A

Ohs

aka

Inst

.Tec

h.13

530

5034

3831

GL

Acc

7626

NS

EW

193

PO

hsak

aIn

st.T

ech.

135

3804

3439

00G

LA

cc15

214

510

1N

SE

W19

4U

Ohs

aka

Inst

.Tec

h.13

539

1534

3906

GL

Acc

110

104

55N

SE

W19

5R

AO

hsak

aIn

st.T

ech.

135

2134

3422

42G

LA

cc57

56N

SE

W19

6H

Ohs

aka

Inst

.Tec

h.13

547

5634

3530

GL

Acc

108

104

44N

SE

W19

7K

ansa

iU

niv.

Kan

sal

Uni

v.13

534

4734

5227

GL

Acc

6761

369.

48.

24.

9N

SE

W19

8O

saka

BR

I13

531

0834

4117

B3F

Acc

9083

109

199

Mai

zuru

BR

I13

523

2035

2823

1FA

cc85

7019

200

Mat

suza

kaB

RI

136

3658

3436

361F

Acc

7064

3420

1Y

onag

oB

RI

133

1959

3525

37B

1FA

cc26

227

202

Ban

paku

NT

T13

531

5434

4805

1FA

cc26

612

510

320

3H

imej

iN

TT

134

4152

3449

451F

Acc

8850

3820

4K

omat

suN

TT

136

2650

3623

441F

Acc

3822

620

5O

baya

shi

Bld

g.O

baya

shi

135

3007

3441

20B

2FA

cc13

987

210

21.2

21.2

9.2

SNW

E20

6Ta

isho

Oba

yash

i13

528

4234

3859

GL

Vel

202

155

168

27.6

26.6

11.1

NS

EW

207

MO

baya

shi

135

3121

3442

14B

2FA

cc60

8642

14.6

13.1

7.4

SNW

E20

8A

biko

Oba

yash

i13

530

0634

3551

1FV

el10

811

511

316

.713

.67.

9N

SE

W20

9B

Take

naka

135

3017

3442

10G

LA

cc18

226

730

223

.02.

910

.0N

140E

N13

0E21

0Y

Take

naka

135

3109

3441

51G

LA

cc43

5049

4.3

7.7

2.1

NS

EW

211

TTa

kena

ka13

534

5534

3047

GL

Acc

5350

46N

SE

W21

2R

okko

uH

anky

uR

W13

514

1534

4259

1FA

cc49

9m

ax21

3N

akat

suH

anky

uR

W13

529

3534

4225

GL

Acc

206

max

214

Saiin

Han

kyu

RW

135

4352

3459

52G

LA

cc19

9m

ax21

5K

itash

iro

Han

shin

RW

135

2519

3442

511F

Acc

303

max

216

Tani

gam

iH

okus

hin

RW

135

1025

3445

321F

Acc

356

max

217

Hir

ano

Nos

eR

W13

525

0934

5154

1FA

cc27

621

8Po

rtIs

land

Kob

eC

ity13

512

2934

4011

GL

Acc

341

284

556

85.0

51.0

63.0

NS

EW

219

Mat

sum

ura

RI

Mat

sum

ura

gum

i13

513

0034

5121

GL

Acc

268

265

239

23.0

35.0

9.2

N33

4EN

064E

220

WE

STM

inis

try

Post

Tel.

135

1306

3451

36G

LA

cc26

330

021

325

.036

.013

.0N

SE

W22

1Ta

kam

iJu

toK

ouda

n13

527

4334

4125

GL

Acc

222

267

255

31.0

33.0

11.0

NS

EW

222

Kan

sai

Air

port

Kan

sai

Air

port

135

1521

3426

15G

LV

el16

910

424

718

.023

.08.

3N

57E

N14

7E22

3N

HK

Kob

eN

HK

135

1128

3441

291F

Acc

680

368

NS

EW

Page 17: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

561

No.

Dis

tanc

e(k

m)

Situ

atio

nIn

stru

men

tPe

riod

Ran

geW

ave

Satu

rate

Bor

ing

PSlo

gG

eolo

gyTo

pogr

aphy

Ref

eren

ce

10.

6no

ise

inte

rfer

ence

SM-1

0A0.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d2

1.4

next

totu

nnel

NE

WS-

II�

dilu

vium

clif

fJR

,Ear

thq.

Info

.,23

d3

5.9

nois

ein

terf

eren

cein

EW

SM-1

0A0.

1–�

EW

�di

luvi

umge

ntle

slop

eJR

,Ear

thq.

Info

.,23

d4

10.0

unde

rel

evat

edR

WN

EW

S-II

0.1–

��

dilu

vium

flat

JR,E

arth

q.In

fo.,

23d

516

.7ne

xtto

elev

ated

RW

SM-1

0A0.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d6

17.8

NE

WS-

II0.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d7

25.4

SM-1

0A0.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d8

25.8

Lon

g.&

Lat

.had

erro

rof

abou

t1�

NE

WS-

R89

0.1–

�re

clai

med

flat

JR,E

arth

q.In

fo.,

23d

932

.1so

uthw

est

ofst

atio

nN

EW

S-R

840.

1–�

�di

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d10

32.3

NE

WS-

IIal

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d11

34.9

onpl

atfo

rmN

EW

S-R

840.

1–�

dilu

vium

flat

JR,E

arth

q.In

fo.,

23d

1238

.4un

der

elev

ated

RW

NE

WS-

II�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

1340

.5N

EW

S-R

840.

1–�

dilu

vium

flat

JR,E

arth

q.In

fo.,

23d

1442

.3no

rth

end

ofst

atio

nN

EW

S-R

890.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d15

46.7

sout

heas

ten

dof

stat

ion

NE

WS-

R84

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d16

47.4

NE

WS-

R89

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d17

49.7

next

totu

nnel

NE

WS-

II0.

1–�

�di

luvi

umm

ount

ain

skir

tsJR

,Ear

thq.

Info

.,23

d18

51.6

unde

rel

evat

edR

WN

EW

S-II

�al

luvi

umge

ntle

slop

eJR

,Ear

thq.

Info

.,23

d19

56.1

wes

tof

stat

ion

NE

WS-

R84

�be

droc

kfla

tPr

ompt

Rep

ort

46,N

IED

2060

.9re

mov

edH

GA

-2B

�be

droc

kfla

tJR

,Ear

thq.

Info

.,23

d21

61.7

next

tost

atio

nbu

ildin

gN

EW

S-R

840.

1–�

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d22

63.6

unkn

own

NE

WS-

R84

BR

orA

Lfla

tJR

,Ear

thq.

Info

.,23

d23

67.9

NE

WS-

IIal

luvi

umfla

tm

ount

ain

skir

tsJR

,Ear

thq.

Info

.,23

d24

68.4

NE

WS-

II0.

2–�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

2572

.7so

uthe

ast

ofst

atio

nN

EW

S-R

890.

1–�

�B

Ror

AL

flat

JR,E

arth

q.In

fo.,

23d

2675

.0ne

xtto

Kita

tang

oR

Wst

atio

nN

EW

S-R

84�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

2782

.5re

mov

edH

GA

-2B

�re

clai

med

flat

JR,E

arth

q.In

fo.,

23d

2886

.3ce

nter

ofst

atio

nN

EW

S-R

84di

luvi

umge

ntle

slop

eJR

,Ear

thq.

Info

.,23

d29

89.2

NE

WS-

II0.

1–�

allu

vium

flat

but

near

mou

ntai

nJR

,Ear

thq.

Info

.,23

d30

89.5

NE

WS-

R84

0.2–

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d31

92.8

unde

rel

evat

edR

WN

EW

S-II

��

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

3297

.9N

EW

S-R

84�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

3310

1.7

NE

WS-

IIal

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d34

101.

9ne

xtto

brid

gepi

erN

EW

S-II

recl

aim

edfla

tJR

,Ear

thq.

Info

.,23

d35

102.

9N

EW

S-II

bedr

ock

slop

eJR

,Ear

thq.

Info

.,23

d36

107.

9un

know

nN

EW

S-II

0.1–

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d37

110.

7un

der

stai

rsSM

AC

-B2

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d38

112.

2no

rthw

est

onth

epl

atfo

rmN

EW

S-R

84al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d39

113.

5no

rth

ofst

atio

nN

EW

S-R

84�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4011

5.4

NE

WS-

R84

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4111

6.5

NE

WS-

R84

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4211

6.8

1Fof

2-st

ory

build

ing

SMA

C-B

2di

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d43

119.

7L

ong.

had

erro

rof

abou

t3�

.N

EW

S-R

840.

2–�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4412

0.7

unde

rbr

idge

NE

WS-

R84

BR

orA

Lfla

tJR

,Ear

thq.

Info

.,23

d

Page 18: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

562

No.

Dis

tanc

e(k

m)

Situ

atio

nIn

stru

men

tPe

riod

Ran

geW

ave

Satu

rate

Bor

ing

PSlo

gG

eolo

gyTo

pogr

aphy

Ref

eren

ce

4512

1.5

wes

tof

stat

ion

NE

WS-

R89

�be

droc

kfla

tJR

,Ear

thq.

Info

.,23

d46

122.

0un

der

brid

geN

EW

S-R

84�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4712

4.2

NE

WS-

R84

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

4812

4.9

NE

WS-

IIN

eoge

nefla

tm

ount

ain

skir

tsJR

,Ear

thq.

Info

.,23

d49

125.

0N

EW

S-II

allu

vium

gent

lesl

ope

JR,E

arth

q.In

fo.,

23d

5013

6.0

sout

heas

tof

stat

ion

NE

WS-

R89

�N

eoge

nefla

tJR

,Ear

thq.

Info

.,23

d51

138.

3N

EW

S-II

0.2–

allu

vium

flat,

bank

JR,E

arth

q.In

fo.,

23d

5214

3.8

SMA

C-B

2be

droc

kst

eep

slop

eJR

,Ear

thq.

Info

l.,23

d53

148.

2ne

xtto

plat

form

NE

WS-

R84

0.2–

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d54

148.

4ce

nter

ofst

atio

nN

EW

S-R

84�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

5514

9.1

NE

WS-

II�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

5615

2.5

NE

WS-

II0.

2–N

eoge

nefla

tJR

,Ear

thq.

Info

.,23

d57

163.

7on

bank

NE

WS-

II0.

2–di

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d58

165.

6no

rth

ofst

atio

nN

EW

S-R

840.

2–�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

5916

5.7

nort

heas

tof

stat

ion

SMA

C-B

2�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

6016

8.9

unde

rel

evat

edR

WH

GA

-2�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

6116

9.1

sout

heas

tne

xtto

RW

NE

WS-

R84

�di

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d62

172.

3ne

xtto

stat

ion

build

ing

NE

WS-

R84

0.2–

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d63

172.

7ne

xtto

build

ing

SM-1

0A�

dilu

vium

flat

JR,E

arth

.Inf

o.,2

3d64

172.

8N

EW

S-II

BR

orA

Lva

lley

JR,E

arth

q.In

fo.,

23d

6517

3.4

200

mw

est

ofst

atio

nH

GA

-2B

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

6617

6.0

sout

hof

stat

ion

NE

WS-

R84

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

6717

9.4

NE

WS

II0.

2–di

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d68

189.

2so

uthe

ast

end

NE

WS-

R84

dilu

vium

flat

JR,E

arth

q.In

fo.,

23d

6919

0.8

east

ofst

atio

nH

GA

-2�

Neo

gene

flat

JR,E

arth

q.In

fo.,

23d

7019

2.7

onpl

atfo

rmN

EW

S-R

840.

2–�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

7119

6.3

SMA

C-B

2�

allu

vium

flat

JR,E

arth

q.In

fo.,

23d

7219

7.0

next

totu

nnel

NE

WS-

IIbe

droc

kfla

tJR

,Ear

thq.

Info

.,23

d73

209.

4no

rthw

est

end

NE

WS-

R84

dilu

vium

onsu

ppor

tw

all

of5

mJR

,Ear

thq.

Info

.,23

d74

215.

1ce

nter

ofst

atio

nN

EW

S-R

84al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d75

218.

5ne

xtto

plat

form

NE

WS-

R84

0.2–

�al

luvi

umfla

tJR

,Ear

thq.

Info

.,23

d76

1.0

onsm

all

sens

orta

ble

JMA

870.

02–1

0�

�di

luvi

umon

smal

lhi

ll77

20.4

onsm

all

sens

orta

ble,

rem

oved

JMA

870.

02–1

0�

�fla

t78

47.0

onsm

all

sens

orta

ble

KI-

03A

0.02

–10

��

allu

vium

flat

7960

.3on

smal

lse

nsor

tabl

eK

I-03

A0.

02–1

0�

�re

clai

med

flat

8076

.0on

smal

lse

nsor

tabl

eJM

A87

0.02

–10

�re

clai

med

flat

8182

.7on

smal

lse

nsor

tabl

eK

I-03

A0.

02–1

0�

allu

vium

flat

8292

.7on

smal

lse

nsor

tabl

eJM

A87

0.02

–10

��

allu

vium

flat

8396

.6on

smal

lse

nsor

tabl

eK

I-03

A0.

02–1

0�

�al

luvi

umfla

t84

101.

8on

smal

lse

nsor

tabl

eJM

A87

0.02

–10

��

allu

vium

flat

8511

0.1

onsm

all

sens

orta

ble,

B1F

of5-

stor

ybu

ildin

gJM

A87

0.02

–10

��

allu

vium

flat

8612

2.0

onsm

all

sens

orta

ble

in3-

stor

ybu

ildin

gJM

A87

0.02

–10

��

allu

vium

flat

8714

2.8

onsm

all

sens

orta

ble

JMA

870.

02–1

0�

�be

droc

kfla

t88

149.

4m

oved

Apr

il19

95K

I-03

A0.

02–1

0�

dilu

vium

flat,

next

tori

ver

8915

6.9

onsm

all

sens

orta

ble

JMA

870.

02–1

0�

�di

luvi

umhi

lltop

,flat

9015

7.6

onse

nsor

tabl

eth

roug

h1

stor

yJM

A87

0.02

–10

��

bedr

ock

hillt

op91

165.

1on

smal

lse

nsor

tabl

eJM

A87

0.02

–10

��

allu

vium

flat

9217

4.9

onsm

all

sens

orta

ble

JMA

870.

02–1

0�

allu

vium

flat

Page 19: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

563

9321

1.4

onsm

all

sens

orta

ble

JMA

870.

02–1

0�

�al

luvi

umfla

t94

0.8

hut

SMA

C-B

2�

��

recl

aim

edfla

tTe

ch.N

ote,

813,

PHR

I95

1.1

pier

sust

aine

dm

ajor

dam

age

ER

S-G

��

�on

pier

Tech

.Not

e,81

3,PH

RI

969.

2hu

t,un

der

wat

erle

vel

ER

S-G

��

recl

aim

edfla

tTe

ch.N

ote,

813,

PHR

I97

16.9

hut,

sens

orw

asch

ange

dto

ER

SSM

AC

-B2

��

recl

aim

edfla

tTe

ch.N

ote,

813,

PHR

I98

40.6

hut

ER

S-G

��

allu

vium

flat

Tech

.Not

e,81

3,PH

RI

9961

.5hu

t,re

mov

edE

RS-

G�

�re

clai

med

flat

Tech

.Not

e,81

3,PH

RI

100

119.

9w

areh

ouse

ER

S-G

��

allu

vium

flat

Tech

.Not

e,81

3,PH

RI

101

122.

5w

areh

ouse

SMA

C-B

2�

�al

luvi

umfla

tTe

ch.N

ote,

813,

PHR

I10

214

5.5

pier

SMA

C-B

2�

�re

clai

med

onpi

erTe

ch.N

ote,

813,

PHR

I10

314

9.3

SMA

C-B

2�

�re

clai

med

flat

Tech

.Not

e,81

3,PH

RI

104

168.

6hu

tE

RS-

G�

�al

luvi

umfla

tTe

ch.N

ote,

813,

PHR

I10

518

8.5

hut

ER

S-G

��

recl

aim

edfla

tTe

ch.N

ote,

813,

PHR

I10

621

6.5

hut

ER

S-G

��

recl

aim

edfla

tTe

ch.N

ote,

813,

PHR

I10

710

.8so

uthw

est

end

ofsc

hool

SMA

C-Q

0.1–

3.0

��

allu

vium

flat

Tech

.Not

e,64

,PW

RI

108

16.3

SMA

C-Q

0.1–

3.0

�al

luvi

umfla

tTe

ch.N

ote,

64,P

WR

I10

918

.8fe

wm

eter

sfr

omri

ver

SM-1

0A0.

1–3.

0�

�di

luvi

umne

xtto

rive

rTe

ch.N

ote,

64,P

WR

I11

025

.4in

bank

SM-1

0A0.

1–3.

0�

allu

vium

inba

nkTe

ch.N

ote,

64,P

WR

I11

130

.4hu

tSM

AC

-B2

0.1–

3.0

��

allu

vium

flat

Tech

.Not

e,64

,PW

RI

112

31.3

hut

SMA

C-Q

0.1–

3.0

��

allu

vium

flat

Tech

.Not

e,64

,PW

RI

113

39.8

next

toba

nkSM

AC

-MD

0.1–

3.0

�al

luvi

umun

der

bank

Tech

.Not

e,64

,PW

RI

114

41.4

SMA

C-B

20.

1–3.

0�

�al

luvi

umfla

tTe

ch.N

ote,

64,P

WR

I11

548

.3an

othe

rse

nsor

was

inst

alle

don

aflo

orof

build

ing

SM-1

00.

1–3.

0�

bedr

ock

clif

fTe

ch.N

ote,

64,P

WR

I11

659

.3hu

tSM

AC

-Q0.

1–3.

0�

�al

luvi

umfla

tTe

ch.N

ote,

64,P

WR

I11

764

.1hu

tSM

AC

-Q0.

1–3.

0�

�al

luvi

umfla

tTe

ch.N

ote,

64,P

WR

I11

875

.417

2,15

4,59

Gal

inpr

ompt

repo

rtw

ere

erro

r.SM

-10A

0.1–

3.0

�be

droc

kst

eep

slop

eTe

ch.N

ote,

64PW

RI

119

107.

2ne

xtto

rive

r,L

Gdi

rect

ion

65�

40�

SMA

C-B

20.

1–3.

0�

allu

vium

flat

Tech

.Not

e,64

PWR

I12

011

7.9

rem

oved

from

Tech

nica

lN

ote

ofPW

RI

SMA

C-B

2N

eoge

nege

ntle

slop

eTe

ch.N

ote,

64,P

WR

I12

13.

5bo

reho

leG

L-3

5m,H

1:42

5.4,

H2:

282.

0SA

-355

CT

0.03

–10

��

recl

aim

edre

clai

med

Tech

.Not

e,64

,PW

RI

122

12.2

bore

hole

GL

-30m

,NS

200,

EW

186,

UD

152

SA-3

55C

T0.

03–1

0�

�al

luvi

umne

xtto

rive

rTe

ch.N

ote,

64,P

WR

I12

319

.2un

der

over

pass

SA-3

55C

T0.

03–1

0�

�al

luvi

umfla

tTe

ch.N

ote,

64,P

WR

I12

427

.5un

der

over

pass

,nex

tto

bank

,lon

gco

daSA

-355

CT

0.03

–10

��

allu

vium

next

toba

nkTe

ch.N

ote,

64,P

WR

I12

527

.6un

der

over

pass

,lon

gco

daSA

-355

CT

0.03

–10

��

recl

aim

edpr

otec

ting

wor

ksTe

ch.N

ote,

64,P

WR

I12

621

.01F

of5-

stor

ybu

ildin

gSM

-23

dilu

vium

flat

Tech

.Not

e,64

,PW

RI

127

39.9

abou

tG

L-2

5m(G

1),i

nan

chor

and

othe

rsi

deof

brid

geSA

-355

�be

droc

kin

clif

f12

81.

1tr

oubl

ew

ithU

Dco

mpo

nent

VSE

-11/

120.

014–

40�

UD

��

bedr

ock

gent

lesl

ope

129

16.1

mac

hine

hous

ene

xtto

scho

olV

SE-1

1/12

0.01

4–40

��

allu

vium

flat

130

22.7

VSE

-11/

120.

014–

40�

�al

luvi

umpl

atea

u,fla

t13

124

.61F

of3-

stor

ybu

ildin

gV

SE-1

1/12

0.01

4–40

�al

luvi

umfla

t13

225

.61F

of2-

stor

ybu

ildin

gV

SE-1

1/12

0.01

4–40

��

allu

vium

flat

133

28.0

1Fof

2-st

ory

build

ing

VSE

-11/

120.

014–

40�

�al

luvi

umfla

t13

430

.01F

of3-

stor

ybu

ildin

gV

SE-1

1/12

0.01

4–40

��

dilu

vium

flat

135

45.3

onfo

otin

gof

gym

nasi

umlo

cate

don

ahi

llto

pV

SE-1

1/12

0.01

4–40

�be

droc

kst

eep

slop

e13

60.

1T

G63

1�

�al

luvi

umfla

t13

75.

1liq

uefie

dgr

ound

DA

S320

AV

�al

luvi

umfla

t13

814

.3D

AS3

20A

Vre

clai

med

139

18.0

unde

rst

epne

xtto

hous

eD

AS3

20A

V�

�re

clai

med

Page 20: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

564

No.

Dis

tanc

e(k

m)

Situ

atio

nIn

stru

men

tPe

riod

Ran

geW

ave

Satu

rate

Bor

ing

PSlo

gG

eolo

gyTo

pogr

aphy

Ref

eren

ce

140

18.8

insm

all

mac

hine

hous

eT

G63

1�

�di

luvi

umpl

atea

u,fla

t14

121

.11F

of1-

stor

ybu

ildin

gD

AS3

20A

Vre

clai

med

142

24.5

1Fof

1-st

ory

build

ing

DA

S320

AV

�re

clai

med

143

25.8

DA

S320

AV

�al

luvi

umfla

t,ne

arri

ver

144

26.0

DA

S320

AV

�al

luvi

umfla

t14

526

.11F

of2-

stor

ybu

ildin

gD

AS3

14C

�re

clai

med

146

28.5

Dir

ectio

nof

TG

631

isro

tate

d90

degr

ees.

TG

631

��

allu

vium

flat

147

29.2

DA

S320

AV

�al

luvi

umfla

t14

832

.81F

of1-

stor

ybu

ildin

gD

AS3

20A

V�

recl

aim

ed14

932

.81F

of1-

stor

ybu

ildin

gD

AS3

20A

V�

dilu

vium

flat

150

34.2

sens

orta

ble

isis

olat

edflo

orof

build

ing

DA

S320

AV

��

dilu

vium

flat

151

35.8

NS

com

pone

ntsl

ight

lyro

tate

s.D

AS3

20A

V�

dilu

vium

gent

lesl

ope

152

36.6

TG

631

�al

luvi

umfla

t15

337

.8D

AS3

20A

V�

allu

vium

flat

154

40.0

Dir

ectio

nof

TG

631

isro

tatin

g.T

G63

1�

Neo

gene

gent

lesl

ope

155

40.5

The

rear

ese

nsor

sof

acc

and

vel.

DA

S320

AV

&T

G63

1�

allu

vium

flat

156

42.7

dire

ctio

nof

TG

631

isro

tatin

g.D

AS3

20A

V&

TG

631

�al

luvi

umfla

t15

746

.1D

AS3

20A

V�

allu

vium

flat

158

1.1

onw

eath

ered

rock

VP-

9462

HH

V�

��

bedr

ock

bank

betw

een

faul

ts15

910

.0V

P-94

62H

HV

��

�re

clai

med

flat

160

11.1

othe

rse

nsor

ofbo

reho

leG

L-2

5m,-

97m

SDA

-240

0.03

–10

��

�al

luvi

umfla

t16

117

.9ot

her

sens

orof

bore

hole

GL

-1m

and

-70m

V40

1�

��

recl

aim

edfla

t16

228

.7L

ong

has

erro

rof

1�.

SD-2

400.

03–3

.3�

�re

clai

med

flat

163

31.8

hori

zont

altr

iang

lear

ray,

Bpo

int

isop

ened

VSE

-11/

12�

�al

luvi

umfla

t16

435

.0ho

rizo

ntal

tria

ngle

arra

y,B

poin

tis

open

edV

SE-1

1/12

��

dilu

vium

flat

165

35.3

othe

rse

nsor

inst

alle

din

bore

hole

and

velo

city

type

PK-1

30H

��

�be

droc

ksl

ope

166

35.7

hori

zont

alop

encu

tof

rock

SD20

3G.3

��

bedr

ock

flat

167

48.8

othe

rse

nsor

inbo

reho

leof

GL

-25m

and

-100

mSD

-240

0.03

–3.3

��

�re

clai

med

flat

168

54.5

othe

rse

nsor

inbo

reho

leof

GL

-20m

V-2

41FB

��

�re

clai

med

flat

169

64.7

SD-2

40-3

G�

�ba

nkst

eep

slop

e17

078

.1G

L-0

,10,

20m

(GL

�T

P�

3.8m

)V

-241

FB�

�re

clai

med

1m

bank

171

85.7

onm

atof

reac

tor

SDA

-240

��

�be

droc

kfla

tcu

t17

288

.0V

-946

2A�

��

bank

onpr

otec

tion

wal

lof

20m

173

91.3

onm

atof

reac

tor

SD-2

40�

�be

droc

kfla

t17

410

2.8

VSE

-11/

120.

014–

40�

bedr

ock

slop

e17

511

9.5

betw

een

turb

ine

and

reac

tor

PK-1

30�

�be

droc

kfla

t17

655

.9on

tunn

elflo

orbu

tis

olat

edby

sand

VSE

-11/

120.

02–6

0�

bedr

ock

slop

e17

764

.5V

SE-1

1/12

0.02

–60

��

allu

vium

flat

178

70.7

VSE

-11/

120.

02–6

0�

bedr

ock

slop

e17

980

.9V

SE-1

1/12

0.02

–60

��

allu

vium

flat

180

96.5

VSE

-11/

120.

02–6

0�

�al

luvi

umfla

t18

111

2.6

VSE

-11/

120.

02–6

0�

�al

luvi

umfla

t18

299

.5be

twee

nsc

hool

build

ing

SA-3

550.

03–1

0�

�al

luvi

umfla

t18

325

.5in

tunn

elun

der

60m

from

surf

ace

VSE

-11/

12�

bedr

ock

stee

psl

ope

184

58.3

VSE

11/1

2�

bedr

ock

stee

psl

ope

Page 21: Characteristics of Observed Peak Amplitude for Strong ... · Abstract Over 200 peak amplitudes of strong motion were observed at distances of less than 250 km from the fault during

565

185

85.1

VSE

11/1

2�

bedr

ock

stee

psl

ope

186

115.

6V

SE11

/12

�be

droc

kst

eep

slop

e18

712

0.8

VSE

11/1

2�

dilu

vium

stee

psl

ope

188

35.8

VSE

11/1

2�

flat

189

21.7

VS3

190

17.3

unkn

own

beca

use

unde

rgro

und

PTK

130

HS/

VS

�E

W�

allu

vium

gard

en19

120

.8D

AT

OL

-100

��

allu

vium

flat

192

22.0

dry

area

next

to5-

stor

ybu

ildin

gPT

K13

0H

S/V

S�

�di

luvi

umG

L-4

m19

331

.2un

know

nbe

caus

eun

derg

roun

dD

AT

OL

-100

�al

luvi

umfla

t19

432

.8un

know

nbe

caus

eun

derg

roun

dD

AT

OL

-100

�di

luvi

umsl

ope

195

36.7

inho

use

but

onro

ckou

tcro

pSD

240-

3�

EW

bedr

ock

gent

lesl

ope

196

47.6

�al

luvi

um19

726

.73

sens

ors

onro

ckou

tcro

p,on

bank

and

unde

rba

nkSM

AC

-MD

0.03

–50

��

�be

droc

ksl

ope

198

19.8

SMA

C-M

D�

��

199

80.3

SMA

C-M

��

allu

vium

200

111.

7SM

AC

-MD

�al

luvi

um20

117

6.8

SMA

C-M

D�

202

19.8

SMA

C-B

2�

��

dilu

vium

flat

Prom

ptR

epor

t46

,NIE

D20

338

.9�

flat

204

208.

5al

luvi

um20

518

.3se

nsor

inst

alle

d1,

15,3

1FSA

-375

CT

�di

luvi

umfla

t20

618

.9G

L0m

and

�58

mV

SE-1

1/12

��

allu

vium

flat

207

19.4

Gl-

70.4

,�28

,�4m

,1,2

0,30

,41F

SA-1

56C

T�

�al

luvi

umfla

t20

824

.51F

of5-

stor

ybu

ildin

gV

SE-1

1/12

�di

luvi

umfla

t20

917

.9SA

-355

CT

�al

luvi

umbe

side

open

cut

210

19.4

othe

rse

nsor

isG

L-6

0m,c

apac

ityis

max

50ga

lPT

K-1

30H

/V�

EW

�di

luvi

umfla

t21

136

.4ot

her

sens

oris

GL

-100

m,c

apac

ityis

max

50ga

lPT

K-1

30H

/V�

NS,

EW

�di

luvi

umge

ntle

slop

e21

20.

51F

inse

riou

sly

dam

aged

build

ing

DA

S-31

4�

dilu

vium

gent

lesl

ope

213

16.8

unde

rel

evat

edR

WD

AS-

314

�al

luvi

umfla

t21

445

.7in

mac

hine

hous

eD

AS-

314

�al

luvi

umfla

t21

510

.51F

to4-

stor

ybu

ildin

gSD

A-2

40�

allu

vium

recl

aim

ed21

67.

7un

der

elev

ated

RW

SDA

-203

�di

luvi

umge

ntle

slop

e21

714

.6ne

xtto

4-st

ory

build

ing

SM-4

0be

droc

kon

prot

ectio

nw

orks

218

2.2

onliq

uefie

dso

ilSD

-240

��

recl

aim

edfla

t21

914

.2on

base

ofba

seis

olat

ion

build

ing

SDA

-203

��

�be

droc

kfla

t22

014

.5SM

-12V

��

bedr

ock

flat

221

15.0

buri

edSD

A-2

030.

03–1

0�

��

allu

vium

flat

222

26.1

4in

runw

ay,1

atG

L-5

0mD

AT

OL

-200

0.02

–40

��

recl

aim

edfla

t22

30.

71F

ofse

riou

sly

dam

aged

4-st

ory

build

ing

GT

A40

dilu

vium

gent

lesl

ope

*Jap

anes

e-st

yle

leve

lde

sign

atio

ns:

e.g.

,1F,

grou

ndle

vel;

BIF

ison

ele

vel

belo

wgr

ound

.GL

isfr

eesu

rfac

e.†m

ax,c

ompo

site

oftw

oho

rizo

ntal

com

pone

nts;

LG

and

TR

are

para

llel

and

orth

ogon

alto

stru

ctur

alap

selin

e.