2010 CHILE EARTHQUAKE AND TSUNAMITECHNICAL REPORT

By
JST-JICA SATREPS PERU PROJECTCHILE EARTHQUAKE FIELD INVESTIGATION TEAMDECEMBER 2010

This report was sponsored by
Japan Science and Technology Agency (JST) thoroughthe project of Science and Technology Research Partnership for
Sustainable Development (SATREPS)

Forward
This technical report contains five individual papers written by the members of the 2010
Maule, Chile, earthquake/tsunami survey teams sponsored by Japan Science Technology
Agency (JST). The 2010 Chile earthquake occurred off the coast of the Maule Region ofChile on February 27, 2010, at 03:34 local time (06:34 UTC) with moment magnitude of 8.8.
As a part of an international research project “Enhancement of earthquake and tsunami
disaster mitigation technology in Peru”, which is under the research program “Science andTechnology Research Partnership for Sustainable Development (SATREPS)” supported by theJapan Science and Technology Agency (JST) and the Japan International Cooperation Agency(JICA), three survey teams consisting of Japanese and Peruvian researchers were dispatchedto the affected areas from early April to early May, 2010. The reason why such aninternational group conducted field survey is that the lessons learned from the 2010 Chile
earthquake are expected to apply to earthquake/tsunami disaster mitigation technologies in
Peru also because the two countries have common regional tectonics and similar
natural/social environments.
The first survey team performed quick damage data collection with the aid of GPS andhigh-resolution satellite images. Geo-referenced photos and videos were taken in the hard-hit
areas. The results of the field survey and data analysis are presented in the paper by Yamazaki
et al. (2010).
The second survey team, consisting of tsunami scientists, focused on the measurements oftsunami inundation/run-up height, flow depth, extent of inundation zone, structural damage
inspection, and collecting eyewitness accounts. The paper by Koshimura et al. (2010)
summarized the tsunami data collected in their survey.
The third survey team, consisting of structural engineers, geotechnical engineers, andseismologists, conducted the field investigation from the view points of strong motion, local
site effects, and building damage. The paper by Pulido et al. (2010) provides the informationon the source process and the results of microtremor measurement at seismic recording sites.
The paper by Shoji et al. (2010) summarized the damage observation of houses andinfrastructures, affected by both strong motion and tsunami. The paper by Saito et al. (2010)
presents the detailed information of damaged buildings due the earthquake.
Although our investigation is still preliminary, we want to share the observations and lessons
learned from the event internationally. During the field survey, the team members wereassisted by many Chilean government officers, researchers and engineers. We express sincere
appreciation to all these supports.
Fumio Yamazaki
Principal Investigator, JST-JICA SATREPS Peru project
Professor, Chiba University, JapanTABLE OF CONTENTS

Earthquake Source Process and Site Effects of Strong Motion Stations of the2010 Chile Mega-Earthquake .............................................................................. 1
Nelson Pulido, Toru Sekiguchi, Gaku Shoji, Jorge Alba, Fernando Lazares, andTaiki Saito

Field Survey of the 2010 Tsunami in Chile ...................................................... 10
Shunichi Koshimura, Masashi Matsuoka, Masafumi Matsuyama, Takumi Yoshii,
Erick Mas, Cesar Jimenez and Fumio Yamazaki

Damage Investigation of the 2010 Chile Earthquake and Tsunami Consideration to the Damage of a Structure subjected to a Seismic Excitation
and a Following Tsunami Wave Load - ............................................................ 27
Gaku Shoji, Nelson Pulido, Toru Sekiguchi, Jorge Alva, Fernando Lazares andTaiki Saito

Building Damage Investigation of the 2010 Chile Earthquake and Tsunami
Disaster .............................................................................................................. 32
Taiki Saito, Susumu Kono, Koichi Kusunoki, Yousok Kim, Tomoya Matsui,
Masanori Tani, Yo Hibino, Carlos Zavala and Patricia Gibu

Development of Spatial Information Database of Building Damage and Tsunami
Inundation Areas following the 2010 Chile Earthquake ................................... 41
Fumio Yamazaki, Yoshihisa Maruyama, Hiroyuki Miura, Shizuko Matsuzaki
and Miguel Estrada

Earthquake Source Process and Site effects of Strong
Motion stations of the 2010 Chile Mega-Earthquake
Nelson PULIDO1, Toru SEKIGUCHI2, Gaku SHOJI3 , Jorge ALBA4, Fernando
LAZARES5, and Taiki SAITO6
1Researcher, National Research Institute for Earth Science and Disaster Prevention(3-1 Tennodai, Tsukuba, Ibaraki, 305-0006, Japan)
E-mail:nelson@bosai.go.jp
2 Assistant Professor, Chiba University(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail: tsekiguc@faculty.chiba-u.jp
3 Associate Professor, University of Tsukuba(1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan)
E-mail: gshoji@kz.tsukuba.ac.jp
4 Professor, Universidad Nacional de Ingenieria, Peru
(Av. Tupac Amaru 1150, Lima 25, Peru)
E-mail: jalvah@terra.com.pe
4 Researcher, Universidad Nacional de Ingenieria, CISMID, Peru
(Av. Tupac Amaru 1150, Lima 25, Peru)
E-mail: f_lazares@uni.edu.pe
6Chief Research Engineer, IISEE, Building Research Institute(1 Tachihara, Tsukuba-shi, Ibaraki-ken 305-0802, Japan)
E-mail:taiki@kenken.go.jp

We report on a reconnaissance survey on the seismological and geotechnical aspects of the 27 February,
2010 Maule mega-earthquake, Chile, carried out between April 27 and May 1, 2010. The survey wassponsored by the Japan Science and Technology Agency and JICA (SATREPS). In this study we surveyed
the cities of Concepción Viña del Mar and Santiago. We also performed microtremors measurements atstrong motion stations that recorded the earthquake. We will give an outline of the fault rupture process
and strong motion characteristics of the earthquake and the site effects estimated from microtremor measurement.
Key Words : 2010 Chile earthquake, strong motion, source process, permanent displacement, site effects,
microtremors H/V

1. INTRODUCTION
The 2010/2/27 Maule (Chile) mega-earthquake, the fifth largest earthquake in instrumental history, waslocated in the subduction of the Nazca plate in Meridional Andes beneath the South American plate. This
earthquake fills a well studied seismic gap between the source areas of the largest ever recorded 1960 Great
Valdivia earthquake (M 9.5), and the 1985 Valparaiso earthquake (M7.8) 1). In this study we report on a reconnaissance survey on the seismological and geotechnical aspects of the 27 February, 2010 Maule
mega-earthquake, Chile, carried out between April 27 and May 1, 2010. The survey was sponsored by theJapan Science and Technology Agency and JICA (SATREPS), under the framework of a newly launched 5
years SATREPS project entitled “Enhancement of Earthquake and Tsunami Disaster Mitigation Technology inPeru” 2). In this study we surveyed the heavily damaged city of Concepción, as well as moderately damaged
cities of Viña del Mar and Santiago (Figure1). We performed microtremor measurements at strong motion
stations that recorded the earthquake in order to evaluate their site characteristics. We also surveyed thedamage to buildings due to tsunami effects in Dichato and Talcahuano among other areas but these results arereported elsewhere3).
1

Figure 1. Location of sites for field survey

Figure 2. Intensity distribution of the Maule earthquake
based on questionnaire survey4).

2. SOURCE PROCESS OF THE MAULE EARTHQUAKEThe Maule earthquake ruptured a source area of nearly 450 km extending from southern Santiago in the
North, down to the Arauco Peninsula south of Concepción city. The intensity distribution obtained from aquestionnaire survey soon after the earthquake4), indicates that a region of nearly 350 km above the fault plane
experienced an intensity larger than 5 upper in the JMA intensity scale (Figure 2). This earthquake was aninter-plate mega-subduction event with a pure reverse mechanism, and had a seismic moment magnitude of 8.8(Figure 3). The source rupture model of this earthquake was obtained by inversion of 38 P-wave teleseismic
waveforms of the FDSN and GSN global seismic networks and using an inversion technique that incorporates
an error component in Green’s function calculation and the Akaike’s Bayesian Information Criteria (ABIC) 5).
The source process is characterized by two asperities with a peak slip of more than 10 m and a rupture area ofapproximately 450 by 200 km2 6). The first asperity is located at the hypocenter and the second is locatedapproximately 150 km north-east of the hypocenter. The rupture propagated bilaterally starting slightly southof Constitución and with an average rupture velocity of 2.8 km/s, however the main moment release was located towards the North in the Pichilemu region. The source moment function has a total source duration of
150 s and display two sub-events separated by 30s (Figure 3). The average rake angle of this earthquake is 93
degrees which approximately corresponds to the oblique convergence of the Nazca plate beneath the SouthAmerican plate.

3. STRONG MOTION CHARACTERISTICS
The Maule earthquake was recorded by 30 strong motion stations belonging to Universidad de Chile (Servicio Sismológico Nacional SSN, Geophysics department, 10 stations, and Red Nacional de acelerógrafos,
RENADIC, Civil Engineering department, 20 stations). Instruments are mostly digital (21), and a large
number of them is localized in Santiago (10) (Table 1). Published maximum PGA and PGV values reached2

Figure 3. Source model of the 2010/02/27 Maule mega-earthquake (Chile)6).

Figure 4. Source model and strong ground motion recordings of the 2010/02/27
Maule mega-earthquake (Chile)6).

909 cm/s2 at the Angol station south of Concepción, and 69 cm/s at Constitución (Table 1, Figure 4). Strong
ground motions recorded in the northern region of the source area such as Curicó, Santiago and Viña del Mar
display two clear sub-events separated by 15s to 30s, which is consistent with a rupture propagation velocity
value of 2.8 km/s (Figure 4). Stations towards the central and southern regions of the source area such as
Constitución, Concepción and Angol do not diplay distinct sub-events, as the rupture propagation of thenorthern asperity gradually runs away from southern stations. Angol station displays the largest PGA which

3

Table 1. Strong ground motion stations that recorded the 2010/02/27 Maule mega-earthquake

Longitude

Latitude

PGA(cm/s2)PGV(cm/s)-73.1087-36.8443

637

44-70.6335-33.5691

267

25-71.0156-32.9759

184

21-70.5369-33.3961

220

29

QDR

-71.2138-33.6874

762

46

SSN
SSN2
SSN2

QDR
QDR
Makalu-71.1730-71.4108-70.3510-32.9940-33.3208-33.6440

347
322
471

28
44
63

SSN2
SSN2
RENADIC3

MakaluMakaluSMA-1-70.5308-70.6428-71.4440-33.4518-33.4405-32.5090

302
332
413

34
46
25

RENADIC3

ETNA-71.5099-33.0482

344

45

-

RENADIC3

QDR-71.5508-33.0253

327

33

-

3

SMA-1

-71.5956-33.0346

261

16

3

RENADICRENADIC3
RENADIC3

SMA-1
SMA-1
ETNA

-71.6130-71.6150-70.6617-33.0560-33.6130-33.4572

298
553
162

29
31
22

RENADIC3

SSA-2-70.6520-33.4670

303

26

RENADIC3

QDR-70.7719-33.5087

550

44

RENADIC3

QDR-70.5792-33.5006

289

29

RENADIC3

QDR-70.5811-33.5769

260

31

RENADIC3

K2-70.6060-33.5135

231

19

StationCode

Organization

CCSP

SSN2

Santiago (Campus Antumapu)

ANTU

2

SSN

Cerro El Roble

ROC1

SSN2

Santiago (Cerro Galán)

CLCH

SSN2

Melipilla

MELP

SSN2

Olmué (10 km West of El Roble)
Casablanca, Teatro municipal
San José de Maipó1

OLMU
CSCH
SJCH

2

Santiago (Colegio las Américas)
Santiago (Cerro Santa Lucía)
Papudo (V Región)1
Viña del Mar Marga-marga (VRegión)

LACH
STL
-

Viña del Mar Centro (V Región)

Station Location
Concepción-

Valparaíso UTFSM (V Región)1

Valparaíso Almendral (V Región)
Llolleo (V Región)1
Santiago FCFM RM
Santiago centro RM (Based Isolated building Comunidad Andalucia)1

Santiago Maipú RM (CRS Maipú)
Santiago Peñalolen RM (Hospital
Luis Tisne)
Santiago Puente Alto RM (Hospital Sotero del Rio)
Santiago La Florida RM (Linea 5,
Mirador)--RENADIC

Instrument
Type
ETNA
Episensor,
Earth data
Episensor,
Q330 digitizer
SSA-120SLN,
Terra Techn.

Matanzas (VI Región)-

RENADIC3

SMA-1-71.8734-33.9604

335

43

Hualañe (VII Región)
Curico (VII Región)
Talca (VII Región)-

RENADIC3
RENADIC3
RENADIC3

SMA-1
QDR
SMA-1

-71.8053-71.2364-71.6649-34.9765-34.9808-35.4299

452
461
467

39
33
33

Constitución (VII Región)
Concepción (VIII Región),
Colegio Inmaculada Concepción-

RENADIC3

SMA-1-72.4057-35.3401

627

69

-

3

RENADIC

SMA-1-73.0483-36.8281

394

68

Angol (IX Región)
Valdivia (XV Región)-

RENADIC3
RENADIC3

QDR
QDR-72.7081-73.2133-37.7947-39.8244

909
135

38
18

Notes
1
approximate station coordinates from Google Earth2
Servicio Sismológico Nacional, Universidad de Chile
3
Red Nacional de Acelerógrafos, Universidad de Chile
4
Most infomation for this table was compiled from 7,8,9,10)

4

Figure 5. Attenuation of PGA and PGV for observed strong motions Maule mega-earthquake

indicates the possibility of large slip below the Arauco peninsula (around latitude -37.5 degrees), that is not
sufficiently simulated in our current slip model. In fact a recent study indicates that the Arauco peninsula
experienced a maximum coseismic uplift of 2.5m along the coast, suggesting that the source area could havereached a latitude as far as -38 degrees11), which approximately corresponds the northern end of the 1960
Valdivia earthquake.
In Figure 5 we plotted the PGA and PGV attenuation characteristics of observed strong ground motions of
the Maule earthquake, for all the sites described in Table 1. We plot the data together with an empirical relationship of PGA and PGV for inter-plate subduction earthquakes (Mw=8.8, depth 35 km) for soil, stiff soil androck site conditions12). We may observe that all observed data falls within one sigma (+/-0.3) around thevalues for a stiff soil. This result implies that the observed peak ground motions characteristics from the Maule
earthquake can be satisfactorily explained by a typical empirical attenuation relationship for inter-plate subduction earthquakes.

4. COSEISMIC PERMANENT DISPLACEMENTS
GPS measurements from the Maule earthquake in South America indicate a coseismic displacement to theWest as large as 3m at the CONZ station in Concepción (Figure 6). CONZ is a high sampling GPS (cGPS)
station located at the Transportable Integrated Geodetic Observatory (TIGO), which recorded in real time theMaule earthquake 13). We attempted to calculate the permanent displacement at Concepción by using a strong
motion recording of the earthquake at the CCSP station, which is closely located to the TIGO observatory. For
that purpose we double integrated and de-trended the unfiltered acceleration data. Our results show nearly 3mof permanent displacement to the West, which is in very good agreement with the results by the cGPS recording at TIGO (Figure 7). Displacement time series obtained from this strong ground motion recording arealso in close agreement with the observed cGPS from the arrival of the rupture up the static displacement value.
We also calculated the coseismic vertical displacements along the coastline by using our source model of theMaule earthquake (Figure 3) and analytical expressions for strains and displacements in a half space due toshear dislocations15) (Figure 8). Our simulation results show in general a good aggreement with the observed
uplift/subsidence values along the coast, estimated from changes in coral algae11) as well as high sampling GPS
measurements at the TIGO geodetic observatory [CONZ] (Figure 8). However our simulated vertical displacements underestimate the observed values at the Arauco peninsula, suggestting larger values of coseismic
fault slip beneath the Peninsula (Figure 8).

5Figure 6. Coseismic displacements at South American GPS stations during the 2010/02/27 Maule
mega-earthquake (Chile). Displacements at Concepción are as large as 3 m to the West14).

Figure 7. Strong ground motion recording of the 2010/02/27 Maule
mega-earthquake (Chile) at the Colegio San Pedro (Concepción),
strong motion site. Upper panel shows the unfiltered acceleration,
middle panel the unfiltered and de-trended velocity, and the lower
panel the calculation of the permanent displacement at this station 6).

Figure 8. Comparison between observed (red) and simulated (blue) permanent coseismic vertical displacement along
the coast during the 2010 Maule earthquake (left figure). Observed vertical uplifts where measured from observation ofchanges in coral algae along the coast 11). Right figure shows the location of vertical displacement measurement points.

5. MICROTREMORS MEASUREMENS AT STRONG MOTION SITESIn order to estimate the site characteristics at strong motion sites that recorded the mainshock we performed
microtremors measurements in Santiago, Concepción and Viña del Mar cities. The microtremors measurements where performed by using a velocity sensor with predominant period of 2s and a sampling frequency of
200 Hz. Measurement time at each site was set to 300s.
(1) Measurements at Santiago city
We surveyed two areas in Santiago city. The first area (MPS) is the RENADIC Santiago Maipú RM strong
6

Figure9. H/V of microtremors measurements near strong motion station Maipu [MPS], andChile university [CLU] in Santiago city

motion station located in the western region of the city (Figure 9). We found sevearl heavy damaged buildings
around this area. We also surveyed the area near Chile university in the center of Santiago city (CLU). In thiscase our survey indicates no building damage around this area. Our H/V measurements at MPS indicate a clear
peak around 0.4s. This site experienced a PGA value of 550 cm/s2 and a PGV of 44 cm/s respectively. On theother hand H/V measurements at CLU don’t show a clear peak. These measurements suggest that the site
effects may have had a contribution to the building damage near MPS.
(2) Measurements at Concepción city
In Figure 10 we show the microtremors measurements sites as well as other survey sites on a microzonation
map of Concepción city17). This microzozonation is based on H/V measurements as well as other geologicaland geotechnical information. A yellow region on the map (Z-I) corresponds to H/V peaks of 1.0-1.4s. We canobserve that the dowtown area is largely characterized by a predominant peak around 1s. On the other hand in
the South-West area of downtown runs the Bio-Bio river which suggest that the soil condition in this region

Figure 10. Microzonation map of Concepción city16). Survey
sites are shown within the figure

Figure 11. H/V ratios of microtremors in downtown
Concepción city7

might be characterized by thick alluvial deposits. We performed microtremors measurements at four sites
including two schools in down-town; Colegio inmaculada Concepción (CIG), Colegio María Inmaculada(CMI), a heavily damaged (to be demolished) 12 stories reinforced concrete building (Edificio Salas 1334,
SLS), and another school located in the opposite shore of the Bio-Bio river in a mountain footslope area
(Colegio San Pedro) (Figure 10). Our H/V measurements at CIG and SLS show a predominant peak larger
than 1s, and a peak of 0.7s at CMI (Figure 11). The heavy damage sustained at SLS might be related with thelarge H/V peak at this site. The underground floor of the CIG building accomodates a RENADIC analogueacelerograph that recorded a PGA value of 394 cm/s2 and a PGV of 68 cm/s. This building sustained a moderate damage and according to the shool principal an older section of the school also experienced the 1960
Valdivia earthquake. Our H/V measurements at Colegio San Pedro where located near the CCSP strong motion
station within the school premises. This site recorded a PGA value of 637 cm/s2 and a PGV of 44 cm/s. The
school is built on a sandy soil area within a small valley, and the CCSP is located at the egde of the valley neara slope. A 1 story classroom located close to the strong motion station sustained significant damage
produced by subsidence of the ground. Although H/V measurements close to the CCSP station do not show
significant peaks (Figure 10), another H/V measurement at the school ground in the middle of the valley show
a clear peak around 0.3s. This indicates that the CCSP station is located at the edge of the valley sandy soil
deposits18).
(3) Measurements at Viña del Mar city
We surveyed two areas in down town Viña del Mar. The first area (VMS) is located in the southern region of
the Marga Marga river close to the RENADIC Viña del Mar Centro strong motion station (Figure 12). Our
survey indicates no building damage around this area. We also surveyed the area to the north of Marga-Margariver (VMB). In this case we found a heavy concentration of damage to medium rise apartment buildings. Our
H/V measurements at VMS indicate a clear peak around 0.4s. This site experienced a PGA value of 327 cm/s2
and a PGV of 33 cm/s respectively. On the other hand H/V measurements at VMB show a clear peak at 1s.
These measurements suggest that the site effects may have had a big contribution to the building damage at
VMB, and indicate the ground motion might have been stronger at the Nothern part of Marga-Marga rivercompared to the Southern area.

6. CONCLUSIONS
We performed a field survey of the 2010 Chile earthquake which included visits to several universities inSantiago, Concepción and Viña del Mar, as well as microtremor measurements near strong motion stations atthese cities. Near-source strong ground motions characteristics of the mainshock are largely influenced bycomplexity in source rupture process. On the other hand ground motion attenuation characteristics of thisearthquake can be satisfactorily explained with a typical empirical law for inter-plate subduction earthquakes.
Based on a strong motion recording of the mainshock we obtained a 3m permanent displacement to the west atConcepción city, which is in very good agreement with the results obtained by a 1Hz GPS recording of the earth-Figure12. H/V of microtremors measurements near strong motion station Viña del mar Centro[VMS], and within the building damage area [VMB] in Viña del mar

8quake at the TIGO observatory in Concepción. Our theoretical calculations of coseismic displacements along thecoast are also in good agreement with the observed data. Our microtremors measurements and field survey
indicates a clear relationship between site effects and building damage. Future research work includes the
improvement of our source model using constraints from near-source data as well as the strong motion simulation of this earthquake.

ACKNOWLEDGMENT: We would like to thank Sergio Barrientos, Jaime Campos, Ruben Boroschek aswell as other members of Universidad de Chile, Universidad de Concepción, and Universidad de Valparaiso.
Strong motion data used in this study belongs to Servicio Sismológico Nacional, Universidad de Chile.

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Shunichi Koshimura1, Masashi Matsuoka2 , Masafumi Matsuyama3,
Takumi Yoshii4, Erick Mas5, Cesar Jimenez6 and Fumio Yamazaki7
1Disaster Control Research Center, Graduate School of Engineering, Tohoku University, Japan(Aoba 6-6-11-1104, Aramaki, Aoba-ku, Sendai, 980-8579 Japan)
E-mail:koshimura@tsunami2.civil.tohoku.ac.jp
2 Geoinformation Center, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Japan(Central 7, 1-1-1 Higashi, Tsukuba 305-8567, Japan)
E-mail: m.matsuoka@aist.go.jp
3Civil Engineering Research Laboratory, Central Research Institute of Electric Power Industry, Japan(1646 Abiko , Abiko-shi , Chiba 270-1194 Japan)
E-mail: matsu@criepi.denken.or.jp
4Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Japan(1646 Abiko , Abiko-shi , Chiba 270-1194 Japan)
E-mail: takumi@criepi.denken.or.jp
5Graduate School of Engineering, Tohoku University, Japan(Aoba 6-6-11-1106, Aramaki, Aoba-ku, Sendai, 980-8579 Japan)
E-mail: erick@tsunami2.civil.tohoku.ac.jp
6Direccion de Hidrografia y Navegacion, Peru
(Jr. Roca 2da. Cuadra con Av. Gamarra - Chucuito – Callao, Peru)
E-mail: cesarsud86@hotmail.com
7Department of Urban Environment Systems, Graduate School of Engineering, Chiba University, Japan(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail: fumio.yamazaki@faculty.chiba-u.jp

We conducted the field survey of the tsunami generated by the M8.8 great earthquake in Chile triggeredon 27 February 2010 (UTC). The survey focused on the measurements of tsunami inundation/run-up
height, flow depth, extent of inundation zone, structural damage inspection, and collecting eyewitness
accounts. In total, tsunami heights and flow depths at approximately 155 points were measured along thecoast of Biobio region, Chile, to understand the tsunami features during this event.
Key Words :The 2010 Maule earthquake, tsunami, field survey

1. INTRODUCTION
On 27 February 2010, a megathrust earthquake of M8.8 (Fig.1) generated a destructive tsunami. It struck notonly Chilean coast but propagated all the way to Japan. After the event occurred, the post-tsunami survey team
was assembled, funded by JST, to survey the area of severely affected by the tsunami. The main purpose of thesurvey was to examine the damage, measure the tsunami run-up and inundation height, flow depth and extent
of inundation, and interview the eyewitnesses of the tsunami. A joint survey team was consisted of themembers from SATREPS and the researchers from Central Research Institute of Electric Power Industry (5researchers from Japan and two researchers from Peru).
The following report aims to describe the findings and knowledge from the survey.

10Fig.1 (a) Significant earthquakes of more than M8 since 1700 and the epicenter of the 27 February 2010 Chile
earthquake. (b) Mainshock (red star) and aftershocks of the 2010 Chilean earthquake (gray dots) during one
day since the mainshock occurred.

2. POST TSUNAMI FIELD SURVEY(1) Logistics
Because the tsunami hit quite long extent of Chilean coast, the survey area needed to be prioritized. We decided
to deploy the most severely affected area in Biobio region. The survey team was deployed along the central
coast of Chile from 18 to 25 April 2010. Fig.2 shows the route of the survey team. Setting the base lodging in
Concepcion, we started the survey on 18 April from Talcahuano to visit eight coastal communities using a car.
(2) Methods
Conventionally, the post-tsunami survey measures tsunami inundation and run-up height, flow depth, andextent of inundation zone. The inundation height is measured as the height of watermarks on structures ordebris on trees above sea level (after tide correction), and the run-up height as the altitude of the inland limit oftsunami penetration. Flow depth is the thickness of tsunami inundation flow measured as the height of thewatermark from the local ground level. Measurements were conducted using the laser range finder (Laser
Technology Inc.) with survey rods and digital cameras with GPS and compass. During the survey, we interviewed witnesses to collect the information of tsunami features (time of the tsunami arrival, polarity of the firstwave, timing of maximum wave). In total, we obtained 155 points along the coast as the measurement oftsunami inundation and run-up heights, and flow depths. Figs. 3 and 4 show the longshore distribution of themeasured tsunami heights and depths. The complete dataset is provided in Appendix. We made the tide correction for all the data by using tide table at Talcahuano.
Along with the field measurements, we used high-resolution optical satellite images to inspect the impact oftsunami disaster. Table 1 is the list of high-resolution satellite images used in the inspection of tsunami-affected area.
11

Fig. 2 The route and area of the post-tsunami field survey in Biobio region.
Table 1 Acquired satellite images for the use of inspection in the tsunami- affected area.
Acquired area
Talcahuano
Talcahuano
DichatoDichato
Llico

Sensor or [Source]
WorldView-2
QuickBird [Google]
QuickBird [Google]
QuickBird [Google]
GeoEye-1 [Google]

Acquisition date
6 March, 201013 April, 2009
5 March, 201026 April, 2006
8 October, 2009

3. RESULTS(1) Talcahuano
Talcahuano is the port city in Biobio Region, which contains the naval base, and has approximately 250,000
inhabitants as a population (2002 census). According to the tide gauge record (NOAA, 2010), the first wave oftsunami reached Talcahuano at 3:30 (Local time) with receded wave. After the arrival of first wave, the tidegauge at Talcahuano did not successfully record the tsunami and stopped transmitting data. CATOE (Centro
12

de Alertamiento Temprano y Oficina de Emergencia) reported that the tsunami attacked the coast at least fourtimes with its period of 45 to 60 minutes, and the fourth wave was the largest.
Fig. 5 represents the result of tsunami inundation height measurement in Talcahuano. The tsunami penetrated approximately 300 m inland in the port-town area and more than 1 km in the southern coastal marsh.
Tsunami inundation reached to 6-8 m in port-town area and 10 m in the coastal marsh. This figure also shows
the comparison of pre and post event satellite images in Talcahuano port (Figs. 5(b), (c)). Significant amount ofcontainers and fishing boats were left as tsunami debris, which caused long duration of failure of port andharbor facilities. While the tsunami left considerable damage to the town of Talcahuano (eastern bottom of thebay), no damage was found in the western port area (San Vicente). The measured tsunami run-up height in San
Vicente was 3.4 m (Fig. 5(a)).

Fig.3 Longshore distribution of inundation and run-up height above the astronomical tide level when thetsunami arrived. Tide correction was made by using tide table in Talcahuano.

13

Fig.4 Longshore distribution of measured flow depths, which were measured as a height of watermark oftsunami penetration above the ground level.

14

Fig. 5 (a) Result of tsunami height measurement in Talcahuano. The red line indicates the extent of inundation
zone which was obtained by the interview with CATOE (Centro de Alertamiento Temprano y Oficina deEmergencia). (b) Damage in Talcahuano found in the post-event satellite image (WorldView-2). (c) Satellite
image of Talcahuano before the tsunami attack (13 April 2009, from Google) (d) Close-up view of port of
Talcahuano. Grounded fishing boats and drifted containers were seen.

15

Fig. 6 Result of tsunami flow depth measurement in the town of Talcahuano. The tsunami penetrated approximately 100 m inland with the flow depth of up to 2-3 m.

Fig. 7 Pre and post event satellite images in Talcahuano. Points A to D represent the position of ground photos
taken by the authors (Fig. 8). White arrow is approximate direction of the camera focus. (a) Overview of
Talcahuano port. (b) and (b') A 70m-long tumbled ship found the east of waterway. (c) and (c') Considerable
change of coastline and drifted containers in the coastal marsh.
16

Fig. 8 Ground photos in Talcahuano taken by the authors. Each point is identified in Fig. 7. A : Tsunami debris
and drifted containers in the coastal marsh. B : Erosion by the tsunami inundation found at the underpass. C :Overview of the coastal marsh inundated by the tsunami. D : Panoramic view of the coastal marsh from the hill.
According to the interview with eyewitness, the tsunami slightly overtopped the dock of the harbor but did
not inundate out of the port. Possible causes of this discrepancy may be local effect of tsunami source mechanisms and the condition of harbor oscillation related to the size and shape of the bay.
In the town of Talcahuano, the tsunami penetrated with up to 2-3 m of flow depth (Fig. 6). After inspecting
the structural damage in the town, some washed-away structures were found, but it was limited within the port
facilities (north-west) and industrial area (south-west). Most of the structural damage in the town was likely to
be caused by ground shaking, but minor damage, e.g. bending shutters of commercial buildings and broken
windows.
(2) Inspection of satellite images
Inspecting pre and post event satellite images and ground photos helps to understand multi aspects of tsunami
disaster. Fig. 7 is the comparison of pre and post event satellite images in Talcahuano. We acquired thepre-tsunami image from GoogleEarth (QuickBird image taken on 13 April, 2009), and used WorldView-2
pan-sharpened composite image as post-tsunami image. From post-tsunami image and field survey, we foundthe tumbled ship at the west of waterway in Tulcahuano bay that has been stably stood in the bay (even though
it was not in use). In the coastal marsh, considerable changes of shoreline and tsunami debris are seen in thesatellite images, and it was found from the ground photos (Fig. 8) that the coastal sand were eroded by inland
penetration of tsunami.
(3) Detection of salt-water penetration
Since salt-water penetration causes death of vegetation, sometimes it is used as a clear indicator of tsunami
inundation. Using a specific feature of vegetation, i.e. strong absorption of visible red-band and strong reflection of nir-band, NDVI is defined by Equation (1) using the reflectance of near infrared and visible redbands.
NDVI = (Near infrared – Red)/ (Near infrared + Red)

17

(1)

Fig. 9 (a) Inspection area of salt-water penetration, (b) Pan-sharpened multi-spectral image of WorldView-2
acquired on 6 March 2010. A, B and C is the point of ground photos, White arrow is approximate direction ofcamera focus. (c) Spatial distribution of NDVI Western. A and B : Ground photos taken on the western andeastern bank of the canal respectively. C1 is the ground photo for inspecting vegetation activity (Same positionas B). C2 and C3 : False color composite image and NDVI taken by the multi spectral camera (Tetracam
ADC3). White plate is the reflector used for calibration.
Here, we focused on the eastern bank of the canal in Talcahuano. Fig. 9 indicates the area of investigationand illustrates the result of detecting tsunami penetration by the analysis of WorldView-2 pan-sharpened
multi-spectral image and the multi spectral camera (Tetracam ADC3). As shown in the ground photos (Figs. 9
A and B), considerable inundation was found on the western bank of the canal while the eyewitness testified
that the tsunami slightly overtopped the eastern bank (no inundation in houses). Using the multi spectral
camera that takes visible red, green and near infrared bands, we first calculated NDVI at the top of the bankwhere the tsunami did not overtop (Fig. 9B). As a result, we found that NDVI of the dead vegetation becomesless than 0.3. Using the threshold value determined by the spectral camera, we discuss the salt-water penetration on the eastern bank of the canal. Fig. 9 (c) shows the distribution of NDVI calculated from thepost-tsunami WorldView-2 image (pan-sharpened). NDVI indicates lower value on the western bank (inundated) while relatively higher value on eastern bank (not inundated), and these features are quite consistent
with the ground photos A and B.

18

(4) Tumbes, Puerto Ingles and Llico
Tumbes locates and Puerto Ingles are the coastal communities, which were isolated by the limited road access.
Fig.10 represents the overview of tsunami height measurements. Tsunami attacked these communities with up
to 11 m height and caused significant damage. Along the coast from Tumbes to Puerto Ingles, the tsunami wasparticularly devastating to demolish the houses of isolated villages (Fig.11). Some survivors mentioned thatthe first wave was withdrawal and the 2nd wave was the largest. Having the experience and lessons from the1960 Chilean tsunami, most of the village people evacuated to the hill immediately after the ground shaking.
They mentioned that the tsunami in 1960 was witnessed only as receded sea and did not cause inundation.

Fig. 10 (a) Overview of tsunami measurements (inundation and run-up heights) in Tumbes and Puerto Ingles.
(b) Detailed features of the measurements and the damage in Tumbes. (c) Devastated damage in Puerto Ingles.
Point A to D is the position of ground photos in Fig. 11 respectively with the arrow of focus direction.

Fig. 11 Ground photos from Tumbes (A, B) and from Puerto Ingles (C, D). A : Watermark on school building.
B : Watermark on the house of Tumbes, C and D : Completely devastated village of Puerto Ingles.

19Fig 12. Result of tsunami height measurement in Llico. Point A to D are the position of ground photos with thearrow of focus direction shown in Fig. 13.

Fig. 13 Ground photos from Llico. A : Completely devastated village. In the village, there were around 60
houses before tsunami. Almost all the houses were washed-away. B : Inland limit of tsunami inundation that is
approximately 400 m from the shoreline. C : Tsunami run-up along the river. D : Tsunami debris line above
14.8 m pre-tsunami sea level.
(5) Dichato
Dichato is a coastal village of approximately 3,000 inhabitants (Census 2002), which belongs to the municipality of Tome, located 37 km north of the city of Concepcion. Having a beautiful sandy beach, Dichato wasvery popular in summer for water sports and recreation. Attacked by the tsunami, Dichato became one of themost devastated towns. According to Dichato-Tome Emergency office, 405 families living in camps, and 1223
families were affected on their properties Fig. 14 represents the measured tsunami run-up height and flow
depths. The tsunami penetrated approximately 800 m inland to 10 m altitude. Figs. 15 and 16 illustrates thedevastating damage in Dichato. In this area, most of the houses were washed away and the tsunami left con20

siderable amount of debris. According to the eyewitness who watched the tsunami from 8-story building, thefirst wave of tsunami hit at 5:00 (AM) after most of the people evacuated. In addition, he said that the tsunami
attack was at least 3 times and the 3rd wave was the largest. The other eyewitness said that the tsunami did notcome first from the sea, but from the backside with not so much power (first wave).
Number of fatality and missing reported is 66 and the surviving resident believe that most of the victims are
not from Dichato but tourists or different regions, also heart attack elders or drunken people. This is mainly
because the residents of Dichato knew about the possible tsunami after the earthquake and had evacuation
drills.

6. SUMMARY
In summary, the results of our survey provide a dataset of tsunami run-up and inundation heights, flow
depths and extent of inundation at approximately 150 points. The survey extent was from Dichato to Llico, theareas mostly devastated by the tsunami. The tsunami inundation heights and flow depths were well recorded
and will be used as a constraint in developing tsunami source model to comprehend the features of tsunami
propagation and coastal inundation. Also, we collected the eyewitness accounts to describe the picture oftsunami attack. Most of the eyewitnesses said that the largest tsunami did not occur in the first wave.
Throughout the trip, we found that many of survivors knew the past event 1960 and evacuated immediately
after the ground shaking. Again we found that education and passing the lessons from the past event is highly
valued to mitigate the tsunami fatalities.

ACKNOWLEDGMENT: This research was funded by JST-JICA’s Science and Technology ResearchPartnership for Sustainable Development (SATREPS) and the NEDO Industrial Technology Research Grant
Program (Project ID: 08E52010a).

REFERENCES
1)

2)
3)

Ruegg, J.C., A. Rudloff, C. Vigny, R. Madariaga, J.B. de Chabalier, J. Campos, E. Kausel, S. Barrientos, D. Dimitrov, Interseismic strain accumulation measured by GPS in the seismic gap between Constitucion and Concepcion in Chile, Physics of the
Earth and Planetary Interiors, 175, pp.78-85, 2009.
U.S. Geological Survey, <http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010tfan/>West Coast/Alaska Tsunami Warning Center, NOAA,<http://wcatwc.arh.noaa.gov/previous.events/Chile_02-27-10/Tsunami-02-27-10.htm>

21

Fig. 14 Tsunami height, flow depth and extent of inundation in Dichato.

Fig. 15 Pre and post event satellite images of the most devastated area in Dichato. Points A to G represent theposition of ground photos taken by the authors (Fig. 16). White arrow is approximate direction of the camera
focus.

22

Fig. 16 Ground photos from Dichato. A and B : Most devastated area. Only the unit of bathroom is remained.
C : Damage on a bridge and erosion by tsunami inundation. D: Withstanding house, but significant damage. E :Drifted boat. F : Watermark on the house (approximately 2 m of flow depth). G : Panoramic view of the townof Dichato.

23

APPENDIX A

Tsunami measurement data

Attribution : I : inundation height/depth, R : run-up height
Point Number

ID

Place

Latitude[dd]

Longitude[dd]

Attribution

Depth
[m]

Height
[m]

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50

JST-CRIEPI-1
JST-CRIEPI-2
JST-CRIEPI-3
JST-CRIEPI-4
JST-CRIEPI-5
JST-CRIEPI-6
JST-CRIEPI-7
JST-CRIEPI-8
JST-CRIEPI-9
JST-CRIEPI-10
JST-CRIEPI-11
JST-CRIEPI-12
JST-CRIEPI-13
JST-CRIEPI-14
JST-CRIEPI-15
JST-CRIEPI-16
JST-CRIEPI-17
JST-CRIEPI-18
JST-CRIEPI-19
JST-CRIEPI-20
JST-CRIEPI-21
JST-CRIEPI-22
JST-CRIEPI-23
JST-CRIEPI-24
JST-CRIEPI-25
JST-CRIEPI-26
JST-CRIEPI-27
JST-CRIEPI-28
JST-CRIEPI-29
JST-CRIEPI-30
JST-CRIEPI-31
JST-CRIEPI-32
JST-CRIEPI-33
JST-CRIEPI-34
JST-CRIEPI-35
JST-CRIEPI-36
JST-CRIEPI-37
JST-CRIEPI-38
JST-CRIEPI-39
JST-CRIEPI-40
JST-CRIEPI-41
JST-CRIEPI-42
JST-CRIEPI-43
JST-CRIEPI-44
JST-CRIEPI-45
JST-CRIEPI-46
JST-CRIEPI-47
JST-CRIEPI-48
JST-CRIEPI-49
JST-CRIEPI-50

Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
TumbesTumbesTumbesTumbes-36.712167-36.712500-36.712278-36.712667-36.712750-36.713000-36.713694-36.714056-36.712778-36.733583-36.721333-36.707970-36.710417-36.714613-36.714299-36.714028-36.713872-36.713654-36.713643-36.713600-36.713600-36.714070-36.714840-36.715120-36.715240-36.715160-36.714830-36.714440-36.714210-36.713980-36.713560-36.713020-36.712800-36.712230-36.711660-36.712230-36.712680-36.713770-36.714090-36.714640-36.714090-36.714470-36.713860-36.713540-36.712790-36.712040-36.640278-36.639528-36.641778-36.642278-73.114861-73.114500-73.114806-73.114361-73.114111-73.113750-73.114139-73.114444-73.113556-73.074778-73.109056-73.113667-73.114133-73.113778-73.113456-73.113197-73.113211-73.112961-73.110922-73.112130-73.112130-73.110450-73.110650-73.110740-73.110790-73.111270-73.111250-73.111610-73.112070-73.112530-73.113080-73.113530-73.114060-73.113890-73.114730-73.114920-73.114400-73.114150-73.113990-73.112920-73.114380-73.114760-73.115880-73.115640-73.115410-73.115270-73.094083-73.094444-73.093528-73.094250

I
I
I
I
I
I
I
I
I
R
I
I
I
R
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
R
I
I
R

2.30
2.44
2.29
2.34
2.34
2.35
1.27
0.74
2.67
1.53
2.88
0.95
0.09
1.80
1.72
1.66
2.15
2.48
2.52
1.45
2.55
1.81
1.67
0.92
0.33
1.49
1.59
1.73
2.09
1.94
2.19
2.33
1.87
1.70
2.46
2.49
1.50
1.15
0.41
0.79
0.30
0.66
1.07
1.22
1.85
1.20
3.77
-

6.52
6.58
6.54
6.53
6.43
6.61
6.59
6.25
7.03
8.16
6.72
6.13
6.35
6.37
6.73
6.92
6.96
6.90
6.70
10.00
5.34
8.28
8.87

24

51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104

JST-CRIEPI-51
JST-CRIEPI-52
JST-CRIEPI-53
JST-CRIEPI-54
JST-CRIEPI-55
JST-CRIEPI-56
JST-CRIEPI-57
JST-CRIEPI-58
JST-CRIEPI-59
JST-CRIEPI-60
JST-CRIEPI-61
JST-CRIEPI-62
JST-CRIEPI-63
JST-CRIEPI-64
JST-CRIEPI-65
JST-CRIEPI-66
JST-CRIEPI-67
JST-CRIEPI-68
JST-CRIEPI-69
JST-CRIEPI-70
JST-CRIEPI-71
JST-CRIEPI-72
JST-CRIEPI-73
JST-CRIEPI-74
JST-CRIEPI-75
JST-CRIEPI-76
JST-CRIEPI-77
JST-CRIEPI-78
JST-CRIEPI-79
JST-CRIEPI-80
JST-CRIEPI-81
JST-CRIEPI-82
JST-CRIEPI-83
JST-CRIEPI-84
JST-CRIEPI-85
JST-CRIEPI-86
JST-CRIEPI-87
JST-CRIEPI-88
JST-CRIEPI-89
JST-CRIEPI-90
JST-CRIEPI-91
JST-CRIEPI-92
JST-CRIEPI-93
JST-CRIEPI-94
JST-CRIEPI-95
JST-CRIEPI-96
JST-CRIEPI-97
JST-CRIEPI-98
JST-CRIEPI-99
JST-CRIEPI-100
JST-CRIEPI-101
JST-CRIEPI-102
JST-CRIEPI-103
JST-CRIEPI-104

Tumbes
Talcahuano
TumbesTumbesTumbesTumbesTumbesTumbesTumbesTumbesTumbesSan Marcos
TumbesTumbesTumbesPlaya Blanca
Playa Blanca
Playa Blanca
Arauco
Llico
Llico
Llico
Curaquilla
Llico
Llico
Llico
Llico
Llico
Llico
Llico
Llico
Llico
Curaquilla
Curaquilla
Curaquilla
Candelaria
CanteraPuerto Ingles
Puerto Ingles
San Vicente
Lenga
Lenga
Lenga
Lenga
Lenga
Tome
DichatoDichatoDichatoDichatoDichatoDichatoDichatoDichato-36.641194-36.722083-36.636269-36.635472-36.635583-36.635944-36.636378-36.636539-36.637019-36.638336-36.638617-36.746880-36.636580-36.637400-36.638810-37.061389-37.061889-37.061450-37.237611-37.197167-37.197000-37.195750-37.246806-37.190528-37.194020-37.196660-37.196640-37.196770-37.197050-37.196950-37.195980-37.195640-37.245660-37.243910-37.246780-36.628500-36.627758-36.622778-36.622028-36.725111-36.766361-36.768361-36.768028-36.767333-36.764083-36.622111-36.548583-36.548417-36.546194-36.545583-36.547306-36.547306-36.547472-36.547583
25-73.093806-73.107972-73.092089-73.091417-73.091389-73.091861-73.092119-73.092194-73.092583-73.092253-73.092336-73.084256-73.092170-73.092380-73.092730-73.141944-73.141389-73.142070-73.321389-73.564583-73.564389-73.564389-73.418917-73.566944-73.563660-73.565470-73.565010-73.565360-73.564710-73.564340-73.563630-73.564270-73.401740-73.396810-73.397450-73.091472-73.092372-73.094556-73.095972-73.131944-73.173972-73.174833-73.175639-73.176389-73.175639-72.957528-72.930028-72.930306-72.930806-72.932500-72.939278-72.939278-72.939306-72.940361

R
I
R
R
R
R
R
R
R
R
I
I
I
I
I
I
R
I
R
R
I
I
R
R
I
I
I
I
I
I
I
I
I
I
I
R
I
R
R
R
I
R
R
R
R
I
R
I
R
I
I
I
I
I

1.80
0.32
1.06
3.00
3.20
1.15
1.10
1.10
0.60
2.12
3.00
2.70
0.67
0.61
0.60
0.53
1.70
1.96
1.40
2.50
1.08
1.00
0.50
0.35
2.00
4.10
3.71
1.87
1.75
1.80

8.97
8.41
6.83
7.45
7.03
8.90
11.04
11.12
8.96
10.90
5.40
5.00
5.06
3.01
6.14
6.10
7.17
6.22
14.78
9.39
8.60
9.04
9.41
3.41
4.98
2.06
2.52
3.94
7.54
4.76
9.44
8.44
8.79
6.56
-

105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
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135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155

JST-CRIEPI-105
JST-CRIEPI-106
JST-CRIEPI-107
JST-CRIEPI-108
JST-CRIEPI-109
JST-CRIEPI-110
JST-CRIEPI-111
JST-CRIEPI-112
JST-CRIEPI-113
JST-CRIEPI-114
JST-CRIEPI-115
JST-CRIEPI-116
JST-CRIEPI-117
JST-CRIEPI-118
JST-CRIEPI-119
JST-CRIEPI-120
JST-CRIEPI-121
JST-1
JST-2
JST-3
JST-4
JST-5
JST-6
JST-7
JST-8
JST-9
JST-10
JST-11
JST-12
JST-13
JST-14
JST-15
JST-16
JST-17
JST-18
JST-19JST-20
JST-21
JST-22
JST-23
JST-24
JST-25
JST-26
JST-27
JST-28
JST-29JST-30
JST-31
JST-32
JST-33JST-34

DichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoDichatoTalcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
Talcahuano
TomeDichatoDichatoDichatoDichatoConstitucion
Constitucion
Constitucion
Constitucion
Constitucion
Constitucion
Constitucion
Constitucion
Constitucion-36.548028-36.548472-36.548750-36.548639-36.548639-36.548333-36.548028-36.548222-36.548680-36.548370-36.547950-36.547730-36.547620-36.547050-36.546490-36.545800-36.545890-36.731702-36.732127-36.732127-36.731015-36.730803-36.718993-36.718207-36.718072-36.717693-36.717687-36.716822-36.716688-36.716688-36.716722-36.716722-36.716720-36.716770-36.716805-36.717238-36.717415-36.619962-36.549433-36.549782-36.548377-36.548117-35.328178-35.328078-35.331180-35.331378-35.328343-35.328510-35.328467-35.324527-35.324703

26-72.940028-72.941139-72.941333-72.939528-72.939222-72.939222-72.938667-72.938361-72.937080-72.936070-72.935530-72.935030-72.934890-72.934420-72.934220-72.934430-72.934510-73.108907-73.108920-73.108920-73.109097-73.109310-73.108610-73.108715-73.108925-73.109075-73.109215-73.109195-73.109030-73.109030-73.109058-73.109058-73.109107-73.109397-73.109702-73.109867-73.109757-72.958023-72.934448-72.933927-72.930255-72.938658-72.410415-72.410192-72.408433-72.408313-72.407100-72.407483-72.407605-72.410187-72.410562

I
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1.78
2.55
1.03
2.85
0.58
1.96
1.48
1.97
1.22
1.01
1.95
2.38
2.05
4.00
2.73
2.12
2.54
0.68
1.26
1.18
1.59
1.48
1.68
1.51
2.17
1.52
1.78
1.53
2.12
1.70
2.05
1.60
2.00
1.98
2.03
1.32
0.55
0.20
1.76
2.24
1.94
1.48
1.13
1.12
0.89
0.89
1.83
2.33
2.35
2.00
2.20

-

Damage Investigation of the 2010 Chile Earthquake
and Tsunami - Consideration to the Damage of a
Structure subjected to a Seismic Excitation and a Following Tsunami Wave Load Gaku SHOJI1, Nelson PULIDO2, Toru SEKIGUCHI3,
Jorge ALVA4, Fernando LAZARES 4 and Taiki SAITO5
1 Associate Professor, Graduate School of Systems and Information Engineering, University of Tsukuba(1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan)
E-mail:gshoji@kz.tsukuba.ac.jp
2 Chief Researcher, National Research Institute for Earth Science and Disaster Prevention(3-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan)
E-mail: nelson@bosai.go.jp
3 Assistant Professor, Graduate School of Engineering, Chiba University(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail: tsekiguc@faculty.chiba-u.jp
4 Japan-Peru Center for Earthquake Engineering and Disaster Mitigation, National University of Engineering(P.O. Box 31-250, Lima 31, Peru)
E-mail: jalvah@terra.com.pe, f_lazares@uni.edu.pe
5 Chief Research Engineer, IISEE, Building Research Institute(Tachihara 1, Tsukuba, Ibaraki 305-0802, Japan)
E-mail: tsaito@kenken.go.jp

We show the investigation results on the tsunami-induced damage of houses and infrastructures after
subjected to a seismic excitation in the 2010 Chile earthquake and tsunami, from the field survey from 26
April to 3 May, 2010 for the affected areas.
Key Words : 2010 Chile earthquake and tsunami, damage of houses and infrastructures, combination ofseismic and tsunami wave loads

1. INTRODUCTION
The tsunami-induced damage of houses and infrastructures after subjected to a seismic excitation is observed in affected areas by the 2010 Chile earthquake and tsunami. Reports on the related damage have notbeen shown sufficiently enough for previous earthquake and tsunami disasters, although we can guess easily
that there existed many houses and infrastructures suffered by combination of seismic and tsunami wave loads.
From the reason above we focused on field survey to investigate the tsunami-induced damage of houses andinfrastructures after subjected to a seismic excitation in the 2010 Chile earthquake and tsunami. This investigation was carried out based on the framework of research project on “Enhancement of earthquake andtsunami disaster mitigation technology in Peru” sponsored by the JST- JICA SATREPS project (leader, Professor F. Yamazaki at Chiba University) 1).

2. DAMAGE OF HOUSES AND INFRASTRUCTURES(1) Survey areas
The following tsunami-induced damage of houses and infrastructures after subjected to a seismic excitation
is observed obviously in two areas: first area is the east part of Talcahuano and second one is Coliumu which islocated at the opposite shore of Dichato (Fig. 1). In the former area the damage of a bridge, sewerage pipelines27and houses is shown and in the latter area the damage of houses is shown (Fig. 2).

Viña del Mar
Valparaíso
Santiago
Damage of a bridge(Figure 3)
Damage of houses(Figure 5)

Epicenter

Talcahuano

Damage of houses atColiumu (Figure 6
and Figure 7)

Damage of sewerage
pipelines (Figure 4)

DichatoConcepcíon

Fig.1 Subject areas in the related regionswith the 2010 Chile earthquake.

Fig.2 Locations of the occurrence of the damage (left figure shows the locations
at the east part of Talcahuano and right one at Coliumu).

(2) Damage of a bridge
Figure 3 show the damage of a bridge at the east part of Talcahuano. The bridge is located at the river mouth
and it is a six-spanned bridge with prestressed concrete girders. The span length is about 10m long and the total
width of a deck is about 20m long. Significant liquefaction occurs along both riversides in the direction fromthe location of the bridge to the 30m - 50m upstream. Consequently, subsidence of both abutments and thesebackfill occurs although we can not observe significant physical damage of bridge girders and piers. We guessthat severer subsidence of the abutment at the left bank of the river by scouring of the backfill subjected totsunami compression and tensile waves, follows the subsidence by the liquefaction subjected to ground motions, than that at the right bank.

Fig.3 Damage of a bridge

Fig.4 Damage of sewerage systems(3) Damage of sewerage pipelines
Figure 4 show the damage of sewerage systems buried in adjacent road with the river at the east part of
Talcahuano. Manholes of the systems are uplifted about 15cm to 25cm high from the road surface, and subsidence of buried pipelines and gaps between those spans occur at the side of the road in front of houses. It is28

inferred from the damage above that liquefaction of the ground with sewerage systems subjected to a groundshaking is a dominant influence factor of the damage. In addition to this, the tsunami-induced flow runs extensively into the suffered sewerage pipelines by the liquefaction, and causes the interruption of flowing ofwastewater through the pipelines.
(4) Damage of houses at the east part of Talcahuano
Figure 5 show the damage of houses at the east part of Talcahuano, which are RC masonry ones.
The house in the upper part of Fig. 5 seems to be suffered by about 1m inundation after the occurrence ofsubsidence and declination equivalent to about 40cm to 50cm height of the house due to ground motions. The
subsidence and declination cause dominant shear crack between bricks and motor in the sidewall of the house.
We can measure the inundation height at the site by the inundation horizontal marks remained in the 1st floorof the house.
Similarly, the house in the lower part of Fig. 5 seems to be suffered by about 20cm subsidence of the ground,which is due to the liquefaction of surrounding soil subjected to ground motions. Consequently, it causes that
the RC-framed beam is pulled down locally about 40cm at the joint corner between a column and a beam. The
failure of the upper beam causes the failure of the sidewall in the house. These structural damage of the houseis due to the forced displacement due to the liquefaction.
It is inferred that the houses in the areas are subjected more dominantly to the forced displacement due to theliquefaction, than to the inundation after the tsunami run-up along the river.

Fig.5 Damage of houses at the east part of Talcahuano(5) Damage of houses at Coliumu
The houses in the areas at Coliumu, which is located at the opposite shore of Dichato, seem to be suffered by
combination of forced vibration due to ground motions and direct tsunami wave pressure due to tsunami wave
propagation. The structural type of houses suffered by the combination loads is a RC masonry one.
Figure 6 show the damage of the house by the combination loads. The minor horizontal cracks in the sidewall of the house occur at the height from the bottom of the wall to about 1m high, and furthermore the major
one crack occurs in the diagonal direction from the joint corner between upper beam and a column. The former
cracks seem to be due to the forced vibration of the house subjected to ground motions and the latter crack
seems to be due to the tsunami wave pressure, which is modeled as a triangle load to a wall located in parallelwith the direction of tsunami wave propagation 2), 3). Based on the results by previous research 2),3), the occurrence of above diagonal major crack in the wall can be explained by the loading to a wall of tsunami wave
pressure with a 3m - 4m inundation height.
Figure 7 show the damage of the house, which is suffered by no damage by ground motions, however issuffered by minor functional damage by tsunami inundation. Functional damage means that the residents can
not use their own house for dairy life due to the inundation although the house is not suffered by the physicaldamage due to the combination of seismic and tsunami loads. One of residents says that the inundation reaches
29the height of the upper beam at the second floor of the house. It is inferred from his evidence that the inundation
height at the house is about 7m - 8m from the ground level, which can be interpreted as very high inundation
height to a house. The guideline on the tsunami-proof design for a building offered by Japanese Cabinet Office4)
describes how to design a building resisting the tsunami wave load of about 8m inundation height. The
damage of this house should be further analyzed based on the evaluation framework of a tsunami wave load toa structural component by the guideline.

Fig.6 Damage of a house by combination of seismic and tsunami wave loads at Coliumu

Fig.7 Minor functional damage of a house by combination of seismic and tsunami wave loads at Coliumu

3. CONCLUDING REMARKS
We focused on field survey to investigate the tsunami-induced damage of houses and infrastructures after
subjected to a seismic excitation in the 2010 Chile earthquake and tsunami. The following tsunami-induced
damage of houses and infrastructures after subjected to ground motions is observed obviously in two areas:
first area is the east part of Talcahuano and second one is Coliumu which is located at the opposite shore of
Dichato. In the former area the damage of a bridge, sewerage pipelines and houses is shown and in the latterarea the damage of houses is shown. The former damage of a bridge, sewerage pipelines and houses in the areas
seems to be subjected more dominantly to the forced displacement due to the liquefaction by ground motions,than to the tsunami inundation after the tsunami run-up along the river. The latter damage of houses seems to be
subjected to combination of forced vibration due to ground motions and direct tsunami wave pressure due totsunami wave propagation.

ACKNOWLEDGMENT: The authors deeply appreciate research information and valuable assistance associated with the field survey provided by the related professors and researchers at Universidad de Chile, Universidad de Concepción and Universidad de Valparaiso.

REFERENCES
1)

Yamazaki, F., Nakai, S., Koshimura, S., Saito, T., Midorikawa, S., Zavala, C., Aguilar, Z. and Estrada, M. : Start-up of a
JST-JICA SATREPS project : Enhancement of earthquake and tsunami disaster mitigation technology in Peru, Procs of the 13th
Japan Earthquake Engineering Symposium (CD-ROM), pp. 683- 690, 2010.
30

2)
3)
4)

Nakano, Y. : Design load evaluation for tsunami shelters based on damage observations after Indian Ocean tsunami disaster due tothe 2004 Sumatra earthquake, AIJ J. Technol. Des., Vol. 13, No. 25, pp. 337-340, 2007.
Shoji, G., Moriyama, T., Kosa, K., Matsutomi, H., Shigihara, Y., and Murashima, Y. : Damage assessment of structures due to the2006 Java tsunami, Journal of Coastal Engineering, Japan Society of Civil Engineers, Vol. 54, pp. 861-865, 2007.
Cabinet Office, Government of Japan : The guideline for tsunami shelters, http://www.bousai.go.jp/oshirase/h17/050610/guideline.pdf, 2005.

31

Building Damage Investigation of
the 2010 Chile Earthquake and Tsunami Disaster
Taiki SAITO1, Susumu KONO2, Koichi KUSUNOKI3, Yousok KIM4, Tomoya MATSUI5,
Masanori TANI6, Yo HIBINO7, Carlos ZAVALA8 and Patricia GIBU8
1Chief Research Engineer, IISEE, Building Research Institute(Tatehara 1, Tsukuba 305-0802, Japan)
E-mail:tsaito@kenken.go.jp
2Associate Professor, Kyoto University(Yoshida Honmachi, Sakyo-ku, Kyoto 606-8501, Japan)
E-mail: kono@archi.kyoto-u.ac.jp
3Associate Professor, Yokohama National University(79-1, Tokiwadai, Hodogayaku, Yokohama 240-8501. Japan)
E-mail: kusunoki@ynu.ac.jp
4Research Associate, Earthquake Research Institute, The University of Tokyo
(7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan)
E-mail: yskim@eri.u-tokyo.ac.jp
5Research Associate, Toyohashi University of Technology(1-1 Hibarigaoka Tenpaku-cho, Toyohashi 441-8580, Japan)
E-mail: matsui@ace.tut.ac.jp
6Research Associate, Kobe University(1-1 Rokkodai, Nada-ku, Kobe, 657-8501. Japan)
E-mail: mtani@port.kobe-u.ac.jp
7Research Associate, Materials and Structures Laboratory, Tokyo Institute of Technology(4259 Nagatsuda, Midori-ku, Yokohama 226-8503, Japan)
E-mail: hibino@serc.titech.ac.jp
8Japan-Peru Center for Earthquake Engineering and Disaster Mitigation, National University of Engineering(Martin of Porres 161, San Isidro, Lima 27, Peru)
E-mail:czavala@uni.edu.pe, pgibu@uni.edu.pe

A great earthquake of magnitude 8.8 struck on the Pacific coast of Chile, at 3:34a.m. local time on
February 27, 2010, and the earthquake and Tsunami caused widespread damage in Chile. The group ofJapanese and Peruvian researchers conducted disaster investigation especially for buildings from 26 April
to 3 May, 2010.
Key Words : Chile Earthquake, building damage, reinforced concrete, RC quake resisting wall

1. INSTRUCTION
A great earthquake of Mw8.8 occurred at 3:34 A.M. on February 27, 2010 local time with the Pacific coastof Chile as the hypocenter. This earthquake collapsed or destroyed more than 810,000 buildings etc., resulting
in more than 1.8 million victims including 432 deaths (as of March 27). When the earthquake occurred, in Peru,
which a neighboring country of Chile, the Japan-Peru international joint research project, “Project for Enhancement of Earthquake and Tsunami Disaster Mitigation Technology in Peru” (JST-JICA Science andTechnology Research Partnership for Sustainable Development Project, representative researcher: Fumio
Yamazaki, professor at Chiba University, 2009-2014) was under way. Given that Peru and Chile are closely
related to each other in terms of the seismotectonic and natural/social environments, and hence the findings
obtained from the study on the great earthquake of Chile are expected to be mostly applied to Peru, withconsiderable ripple effects on other Latin-American countries, it was decided to perform investigation andinformation gathering on the damage caused by the earthquake and Tsunami that hit Chile, jointly with thecounterpart from Peru. In addition, it was also decided that the second investigation team (team leader: Susumu
32

Kawano) would be dispatched from the Architectural Institute of Japan to the site around the same period to
perform a joint investigation.
The investigation was performed from April 26 to May 3, approximately two months after the earthquake.
Given the JICA Study Team (March 13 to 23) and a joint study team comprised of four societies (Japan Association for Earthquake Engineering, Japan Society of Civil Engineers, Japanese Geotechnical Society, andArchitectural Institute of Japan) (March 27 to April 8) already dispatched from Japan and the limited investigation days, this investigation was devoted chiefly to performing on-the-spot inspection of disaster-stricken
buildings, acquisition of design documents, hearing with relevant parties, and so on, with the objective ofelaborately investigating reinforced concrete buildings. While our activities included the investigation ofbuildings equipped with a base isolation or seismic control structures, we would like to report in this paper ourinvestigation results on the damage to reinforced concrete structures.

2. OUTLINE OF INVESTIGATION
The investigation was performed chiefly in principal cities (Santiago, Concepcion, and Viña del Mar) of
Chile and the surroundings. Figure 1 was the investigation points and the locations of faults. Table 1 shows thelist of the investigated buildings. The results of our detailed investigation on the underlined buildings of thoselisted in the table are as follows.
Table 1

(Santiago)
B1. Torre Titanium (vibration control)
B2. Ciudad Empresarial
B3. Edificio Leones 1300
B4. Sol Oriente 1 and 2
B5. Edificio Don Luis
B6. Edificio Don Tristan
B7. Edificio Don Luis
B8. Hall Arnoldo Hax (Catolica Univ., seismic isolation)
B9. Comunidad Andalucia (seismic isolation)

(4)
(1)

Fault

(2)

(Concepcion)
B10. Torre O'Higgins 241
B11. LINCOYAN 440 (Torre Livertad)
B12. CAUPOLICAN 518
B13. Alto Rio
B14. SALAS 1343
B15. LOS CARRERAS 1535
B16. ROZAS 1145 (Edificio Don Feodra)
B17. FREIRE 1965 (Edificio Centro Mayor)
B18. Plaza Mayor
B19. BARROS ARANA 272

(3)

4/27
4/28
4/29
4/30
5/1

Figure 1

(1)
(1)
(2)
(2)
(4)

Investigated buildings

Santiago
Santiago
Concepcion
Concepcion, (3) Talcahuano
Viña Del Mar(Talcahuano)
B20.Edificio de Biblioteca Municipal de Talcahuano(Viña del Mar)
B21. Building Festival
B22. ACHS (Asociacion Chilena de Seguridad)(seismic isolation)
B23. Efidicio Rio Petrohue

Investigation points and locations of fault

3. INVESTIGATION RESULTS OF BUILDING DAMAGE(1) Damaged buildings in Santiago Citya) B4. Sol Oriente 1 and 2
It is an apartment complex constructed of box-frame-type reinforced concrete in 2007 with 18 stories above33

ground (2 stories underground) (Photo 1). The building was damaged particularly on the first basement level ofthe underground self parking lot (Photos 2, 3). The structural features and the summary of damage are follows:- Multi-story shear wall structure connected by flat slabs.
- Flexural tension failure occurred in three structure planes out of five 4-span ones on the first basement. An
end main reinforcement ruptured.
- The height of the north side multi-story shear wall on the basement is shorter by 1200 mm than on higher
floors. In addition, only the northern end of the north side multi-story shear wall lacks an orthogonal wall
(Figures 2, 3). Accordingly, the flexural strength of the north side multi-story shear wall is low on the first
basement, likely resulting in the flexural tension failure in the south direction on the north side multi-story
shear wall.

Photo 1
Appearance of the building

Figure 2

Photo 2
Underground parking lot

Basement plan view

Figure 3

Photo 3
Shear wall on the first basement

Building section view (sketch)(2) Damaged buildings in Concepcion City
Concepcion City is a city located approximately 105 km away from the hypocenter with a population of
approximately 220 thousand. The earthquake brought eight buildings into serious damage, of which one wascompletely collapsed. We could obtain entry permits to and design documents of several buildings thanks tothe cooperation of the Urban Development Bureau and the Police Bureau of Concepcion City.
a) B11. LINCOYAN 440 (Torre Livertad)
It is an RC wall flat slab structure constructed in 1973. The building has 17 stories above ground and one
basement (with no underground car park), of which the three lower floors are occupied by commercial tenants
and the fourth and above floors are used for housing (Photo 4). The machine room on the first basement was
hardly damaged. The non-structural brick wall collapsed more seriously on upper floors. The walls on the first34

and second floors failed in flexural tension with the wall-end main reinforcement fractured or buckled (Photo5). While the building was damaged particularly on the walls in the northeast and southwest directions, little
damage was observed on the walls in the orthogonal direction. The damage concentrated on the wall footing islikely attributable to the lack of flexural strength of the T section web resulting from the respective bending
deformation of two multi-story shear walls arranged in parallel due to the limited floor slab area in the staircase(Figures 4, 5, 6).

Figure 4
Building plan view
Photo 4
Appearance of the building

Figure 5
X-X' section view

2nd floor

Main Rebar

Figure 6
Failure mechanism of T-shaped section wall

Photo 5Wall fracture35b) B13. Alto Rio
It is a reinforced concrete apartment complex constructed in 2008 with 15 stories above ground and twostories underground (parking lot). The building completely fell down from the base on the first floor (Photo 6,
7). Photo 7 shows the appearance of all the reinforcing bars on the first floor having been pulled out or cut
down from the wall pillars and load-bearing walls on the first floor during the overturning of the building.
Conversely, little damage was observed on the underground end plane walls. As shown in the plan view of
Figure 7, the walls on the first floor and the basements (parking lot) are smaller than those on the second andabove floors in both length and volume. This fact may have resulted in the damage particularly on the wall
footing on the basements.

Photo 6
Photo of the building before collapsed(excerpted from the Web Page)

Photo 7
Collapsed building

B1F

1F

1F

2520
3060
2520

2F
Figure 7 Difference in wall volume and layout among basement, first floor, and second floor

36c) B14. SALAS 1343
It is an apartment complex constructed in 2007 with 13 stories above ground and an underground car parkprovided beside the building. It consists of two buildings arranged in L shape and connected with an expansion
joint (Photo 8, Figure 8). It is constructed with a middle corridor in planar shape with more wall volume in theridge direction. While the south side building was seriously damaged, the north side building was slightly
damaged. The south side building seems to have suffered torsional vibration caused by stiffness eccentricity
resulting from the many walls in the surrounding of elevators and staircases.

地下

駐車場
Undergroundparking lot
5620

4270

4270

2860

4120

2860

4270

4270

5620

810

3360

3020

3020

3580 520

810

階段

N

EV

Exp. joint

4270

4270

2860

2900

3440

3690

エキスパンションジョイント部
階段

5620

Photo 8
Appearance of the building

810

1F
730 3360

3020

3020

3360

730

Figure 8

Plan view and damage(3) Damaged buildings in Viña del Mar City
Viña del Mar City is a city with a population of approximately 300 thousand. The 1985 Chile Earthquake(magnitude 7.8, 150 deaths) damaged many high-rise RC buildings within the city.
a) B21. Building Festival
It is an apartment complex (wall-type flat slab structure) with 14 stories above ground and one basement. It
was severely damaged (Photo 9). The building had undergone seismic retrofitting such as the placement ofadditional concrete for walls and beams and the additional installation of walls in response to the earthquake in
1985, but suffered damage in the recent earthquake such as flexural tension failure and separation of concreteadded walls in the wall footing (Photo 10, Figure 9).

37

Photo 9
Appearance of the building

Photo 10
Appearance of the building

Wall damage
at B1FNo damage at
floor beam

damage at floor
beam at 1F

damage at stair

too much bars

crack to 2F level

damageat
retrofitted wall

Not examined

Figure 9

Plan view and damage

38

4. SUMMARY
The characteristics of the damaged buildings are as summarized below.
Many of the damaged buildings are flat slab structures with no beam or frame column on the wall.
x
The standard size of wall reinforcement is D10@250-D.
x
At the wall end, confinement steel (or supplementary cross ties) is installed as well as bending reinx
forcement.
The wall pillars, which are provided in place of pillars, are arranged longitudinally in the span directionx
for reasons of the layout of the parking lot. This fact may result in lower flexural strength and stiffness in
the ridge direction.
The length of a multi-story shear wall may be reduced in the underground parking lot space for the sake ofxvehicular traffic.
A parking lot in the underground of the building may be constructed in a shape protruded in one direction.
x
In this case, the parking lot is enclosed only by the three-side retaining walls immediately below thebuilding, with the other side of wall set back in the ridge direction.
Some walls or wall pillars in the span direction are not connected to orthogonal walls. Such walls include
x
a wall extending in the span direction on the side without a retaining wall and a piloti-type wall pillar(ground parking lot). They were damaged probably due to the low flexural strength when the tensile load
was exerted to the side with no orthogonal wall.
The buildings have a relatively large number of stories and a high slenderness ratio. As a result, the wallsxof such buildings mostly underwent flexural tension failure. In addition, lack of enough strength to bear
the story shear force on the compression side may result in collapse of the building.
Most of the severely damaged or collapsed buildings were high-rise constructions with 13 or more stories
and damage concentrated on the footing of the multi-story shear wall observed as a common characteristic.
Conversely, most buildings in cities appeared to be sound and few buildings suffered intermediate damage, e.g.
slight or medium damage. This may be a characteristic of damage to box frame constructions without plastic
deformability. The damage can be considered generally minor, in view of the great magnitude of the recent
earthquake at 8.8. While elaborate analysis is still required as to the extent of the seismic force applied to thebuildings, given the fact that the damage remained so modest after the great earthquake, the Chilean Seismic
Code seems to have functioned extremely well. One of the factors behind the major lack of damage to buildingsin the recent earthquake was the positive introduction of the load-bearing wall.
The Chilean Seismic Code includes a provision likely encouraging the positive introduction of theload-bearing wall such as a strict restriction of deformation and reduction of the design seismic force according
to the load ratio of the load-bearing wall. In Japan, the height of wall-type rigid-frame structures is limited to 15
stories. Given the modest damage to buildings in the recent Chile Earthquake and the continuous usability of
post-earthquake buildings, Japan may also need to recognize anew the benefits of box frame constructions.
From the research perspective, a design method needs to be established to prevent such brittle failure after
flexural yielding as observed in the recent seismic damage. Structural testing on flexural failure of load-bearing
walls is not common in Japan and future research and development is awaited.

ACKNOWLEDGMENT
This damage investigation was performed as a part of the international joint research project “Project forEnhancement of Earthquake and Tsunami Disaster Mitigation Technology in Peru” (JST-JICA Science andTechnology Research Partnership for Sustainable Development Project, representative researcher: Fumio
Yamazaki, professor at Chiba University, 2009-2014) and an earthquake disaster investigation of the Architectural Institute of Japan. In conducting this investigation, we obtained cooperation from many people including Professor Boroschek and Mr. Tomas of the University of Chile; Professor Cruz of the PontificalCatholic University; an ex-trainee, Mr. Raul; and the JICA Chile Office. We wish to express our gratitude to
them.

39

REFERENCES
1) Hiroto Kato, Seitarou Tajiri, Tomohisa Mukai: 2010 Chile Earthquake Field Survey Report (Flash Report), Building ResearchInstitute, April 2010
2) A study team from the Japan Association for Earthquake Engineering and the Architectural Institute of Japan: Damage Investigation
Report for Maule, Chile, Earthquake of 27 February 2010 dated May 20103) ‘Learning from Earthquake, The Mw 8.8 Chile Earthquake of February 27, 2010,’ EERI Special Earthquake Report, 2010.6.
4) Riddle, R., Wood, S.L. and De La Liera, J.C.: ‘The 1985 Chile Earthquake,’ A Report to the National Science Foundation, Research
Grants ECE 86—03789, Univ. of Illinois, 1987.

40

Development of Spatial Information Database of
Building Damage and Tsunami Inundation Areas
following the 2010 Chile Earthquake
Fumio YAMAZAKI1, Yoshihisa MARUYAMA2, Hiroyuki MIURA3, Shizuko
MATSUZAKI4 and Miguel ESTRADA5
1Professor, Dept. of Urban Environment Systems, Chiba University(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail:yamazaki@tu.chiba-u.ac.jp
2Associate Professor, Dept. of Urban Environment Systems, Chiba University(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail:ymaruyam@ tu.chiba-u.ac.jp
3Assistent Professor, Dept. of Built Environment, Tokyo Instisute of Technology(4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan)
E-mail: hmiura@enveng.titech.ac.jp
4Graduate Student, Dept. of Urban Environment Systems, Chiba University(1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan)
E-mail: 10td0309@graduate.chiba-u.jp
5Associate Professor, Japan-Peru Center for Earthquake Engineering and Disaster Mitigation, National University ofEngineering, Peru (Av. Túpac Amaru 1150, Lima 25, Peru)
E-mail: estrada@uni.edu.pe

This paper presents the results of a field survey conducted by the authors after the 2010 Chile earthquake.
The authors visited the affected area about a month after the earthquake. The GIS datasets for the damagelevels of buildings in Talca and the tsunami-inundated areas in Talcahuano, Dichato, and Constitución are
constructed in this study, and a series of fundamental analyses are performed using a digital elevation
model (DEM). Further, the usefulness of satellite images captured after the earthquake to detect damagedbuildings in Talca is discussed using the GIS datasets constructed in this study.
Key Words : 2010 Chile earthquake, GIS, building damage, tsunami-inundated area, digital elevation
model (DEM)

1. INTRODUCTION
The 2010 Chile earthquake occurred off the coast of the Maule Region of Chile on February 27, 2010, at
03:34 local time (06:34 UTC) with a magnitude of 8.8 on the moment magnitude scale. The epicenter was
offshore from the Maule Region, approximately 335 km southwest of Santiago, the capital of Chile, and 105
km north-northeast of Chile’s second largest city, Concepción. It is reported that a severe ground motion with
the Modified Mercalli Intensity (MMI) scale of VII was felt widely in Chile and that the extensive damage wascaused by the ground shaking and tsunami1). The total economic loss estimates range from USD 15 to 30
billion, which correspond to 10% to 15% of Chile’s real GDP2). According to the report on the scene, the actual
death toll was 486 as of March 8, 2010, and approximately 370,000 homes were damaged2).
The authors visited the affected area about a month after the event as part of an international research project“Enhancement of earthquake and tsunami disaster mitigation technology in Peru”3), which is under the research program “Science and Technology Research Partnership for Sustainable Development (SATREPS)”4)
supported by the Japan Science and Technology Agency (JST) and the Japan International Cooperation
Agency (JICA). The lessons learned from the 2010 Chile earthquake are expected to apply to the earthquake
disaster mitigation technologies in Peru because the two countries have common regional tectonics and social
surroundings.
41

Fig. 1 Locations of cities visited by the authors and outline of field survey by the authors.

Fig. 2 Survey route and field photos in Santiago—April 2, 2010

Three teams of Japanese and Peruvian researchers were dispatched by the SATREPS project to carry out
field surveys. In this paper, the results of the field survey performed by Damage Assessment Group and Disaster Mitigation Plan Group are presented. The spatial damage data, topographical maps, and satellite images
provided by different institutions are compiled by the geographical information system (GIS), and the primitive analyses are conducted to reveal the characteristics of the tsunami-inundated areas in view of elevations
and damage incidents to adobe and unreinforced masonry buildings, which are also widely seen in Peru.

2. OUTLINE OF FIELD SURVEY
The authors arrived in Santiago on April 2, 2010. We drove to Concepcíon the next day and visited thetsunami-affected areas of Talcahuano, Dichato, and Constitución. We moved to Talca on April 7 and left
Santiago on April 8. Before leaving, we visited Valparaíso and Viña del Mar. Figure 1 shows the locations of
the cities that we visited during the survey.
Figure 2 shows the route of our field survey in Santiago and some field photographs. The route was recorded by a portable GPS device during the survey and the location of the photo shooting could be identified as
the location data were embedded in the Exchangeable Image File Format (EXIF). An RC building with 20
stories constructed in 2003 suffered from shear failures in columns and walls at the first and the second stories.
A collapsed highway bridge and an RC building with the collapsed first floor were found. The locations ofthese sites are also shown in the survey route in Fig. 2.
42

Fig. 3 Survey route and field photos in Concepcíon—April 4, 2010

Fig. 4 Survey route and field photos in Dichato—April 5, 2010

Figure 3 shows the survey route in Concepcíon. An RC building with the damaged middle floor was foundat the site numbered 1. An RC building with 15 stories had collapsed completely at the site numbered 2. The
road bridges collapsed at sites 3 and 4. The temporary bridge girder was constructed two days after theearthquake at site 3. Although the photos are not shown in this paper, the adobe and unreinforced masonry
constructions were severely damaged in the urban area.
Figure 4 shows the survey route in Dichato. It is reported that more than 80% of the built-up area in Dichato
suffered from tsunami5). As shown in the field photos, the buildings collapsed because of the tsunami waves. A
ship was conveyed against the river flow because of the tsunami and eventually found at site 3.

3. CONSTRUCTION OF GIS FOR BUILDING DAMAGE AND TSUNAMI-INUNDATED
AREA(1) Building damage GIS in Talca
Talca is the capital of both Talca Province and Maule Region. Its population is approximately 200,000, and
it is approximately 250 km south of Santiago and 60 km northwest of the epicenter of the 2010 Chile Earthquake5). According to USGS1), Talca was affected with a severe ground motion with the MMI scale of VII.
During our survey, we interviewed officials from Maule Regional Office to investigate the damage ofbuildings. As a result of our interview, an image file that shows the damage levels of buildings was provided.
The polygons, which indicate the building lots, are classified into four levels, namely, to be removed, to be
repaired, no damage, and under investigation. It should be noted that the image file was compiled with thedamage dataset as of March 31, 2010.
In this study, the location of the image file was established in terms of map projections. The satellite image
and road data presented in Google Earth were employed as a base map to georeference the image file. Then, the43Fig. 5 GIS file to show the damage levels of buildings in Talca and locations of field photos

Fig. 6 Cumulative frequencies of the areas of building lots with respect to the damage level

Fig. 7 Comparison between pre- and post-event satellite images to detect affected buildings

image file was converted to a GIS file with polygons to identify the damage levels of buildings. Figure 5
shows the developed GIS file presented by Google Earth and some field photos to show the examples ofdamaged buildings.
In all, 5617 polygons were projected to the map coordinate system. 1559 (27.8%), 1872 (33.3%), and 1864
(33.2%) buildings were classified as to be removed, to be repaired, and no damage, respectively. The typicalconstruction types in Talca are adobe and unreinforced masonry buildings, which are primarily used for older
constructions with 2–4 stories (dating back to before the 1960s–70s). Modern buildings that were designed
according to the current codes suffered minor, repairable damage, while a large number of adobe and unreinforced masonry constructions suffered significant damage6).
Figure 6 shows the cumulative frequencies of the areas of building lots with respect to the damage level.
44

Fig. 8 Tsunami-inundated areas in Talcahuano, Dichato, and Constitución

The mean of all the georeferenced areas was approximately 430 m2 and was almost equal to that of the areas
associated with the buildings to be repaired. The mean of the lot areas of the buildings to be non-damaged wasapproximately 340 m2, which was considerably smaller than that of the buildings to be removed. On the basisof the results, it has been speculated that the newer buildings are constructed in relatively small lots; however,the construction periods are not available at this moment.
Recent advancements in remote sensing technologies and their applications have made it possible to use
remotely sensed imagery for estimating the damage distribution due to natural disasters. Among them,high-resolution optical satellite imagery, which has become available in the last decade, has made satellite
remote sensing more useful in disaster management since even the damage status of individual buildings can be
identified7), 8). Figure 7 compares the pre- and post-event high-resolution optical satellite images with the GIS
dataset shown in Fig. 5. As for the pre- and post-event images, the image captured by QuickBird9) on January
1, 2008, which is presented in Google Earth, and that captured by WorldView-210) on March 10, 2010, areemployed in this study. A comparison of the pre- and post-event images revealed that some of the affectedbuildings could be visually detected, but not all the damaged ones could be identified appropriately. Since thepost-event image was captured with the large off-Nadia angle (40.3°), the quality of image is not sufficient forvisual damage inspection. Moreover, the number of affected buildings whose roofs had completely collapsed issmall in Talca. Hence, it can be concluded that the damaged buildings in Talca are difficult to be detected
through visual damage inspection using satellite images.
(2) Development of GIS for tsunami-inundated area
Various institutions released the maps to show the damage distribution at their Web sites after the 2010 Chile
earthquake. The tsunami-inundated areas interpreted from satellite and aerial images were published by National Office of Emergency of the Interior Ministry (ONEMI) of Chile11). On the basis of the maps, the number
of affected buildings and that of causalities were estimated.
In this study, the tsunami-inundated areas were projected onto a map coordinate system, and the topographical conditions were evaluated in terms of the elevation. The inundated areas in Talcahuano, Dichato, andConstitución were converted to the GIS data and compared with the digital elevation model (DEM). The DEM
employed in this study is the ASTER Global Digital Elevation Model (GDEM) developed by the Ministry of
Economy, Trade, and Industry (METI) of Japan and the United States National Aeronautics and Space Administration (NASA)12). The ASTER GDEM is a highly accurate DEM covering all the land on earth with the45

Fig. 9 Elevations along the transverse lines set in Fig. 8

Fig. 10 Measurement of tsunami inundation depth in Talcahuano

spatial resolution of 30 m.
Figure 8 shows the tsunami-inundated areas in Talcahuano, Dichato, and Constitución and the distributionsof the elevation derived from the ASTER GDEM. The elevations in the inundated areas are lower than 20 m on
the whole except for a certain area in Constitución. As shown in the figure, we set the two traverse lines in each
inundated area. The elevations were extracted along the two lines. The extracted elevations are illustrated interms of the distance from the coastline in Fig. 9. As for Line 2 in Constitución, the elevations are presented
with respect to the distance from the Maule River. The relatively low elevations and slow grades result in long
travel distances of the tsunami wave. According to Line 2 in Talcahuano, the tsunami wave could travel approximately 2000 m from the coastline. Line 1 in Constitución was assigned to identify the surveyed site by
Imamura et al.13). According to their report, the tsunami runup height was 28.3 m at the site. Since the DEM
used in this study is a global dataset that consists of 30-m grid cells, the elevation at the site is estimated to beapproximately 23 m. The slope is estimated to be approximately 67% and is almost equivalent to that reported
by Imamura et al., which is 63.5%13).
As shown in Fig. 10, the inundation depth was measured at several sites in the three cities. The inundation
depth along the beachfront street in Talcahuano was larger than 150 cm, but a depth of 55 cm was observed inits bystreet (site 4). Figure 11 summarizes the measurements in the three cities. The inundation depth is presented with respect to the elevation and the distance from the coastline. As for the results in Constitución, therecords are shown with respect to the distance from the Maule River. A clear tendency is not seen in the rela46

Fig. 11 Summary of the measurement of tsunami inundation depth

tionship between the tsunami inundation depth and the elevation. The recorded depth in Talcahuano andConstitución decreased with an increase in the distance from the coastline or the river; however, this tendency
is not seen from the records in Dichato because of the insufficient number of measurements.

4. CONCLUSIONSIn this paper, the results of a field survey conducted after the 2010 Chile earthquake by the authors during
April 2–8, 2010, are presented. The GIS dataset for the building damage in Talca was developed by establishing the location of the image file in terms of map projections. The usefulness of high-resolution satellite
images to detect the building damage in Talca was investigated with the aid of the constructed GIS dataset.
Moreover, the tsunami inundation maps published by ONEMI were georeferenced, and the characteristics of
the inundated areas were evaluated in view of the elevation.
According to the relationship between the building damage levels and the lot areas, the mean of the areas
associated with the non-damaged buildings was the smallest, while the mean of the areas associated with thebuildings to be removed was the largest. In Talca, modern buildings that were designed according to the current codes suffered minor, repairable damage, while a large number of adobe and unreinforced masonry constructions, which were built in the 1960s–70s, suffered significant damage. On the basis of these circumstances, it has been speculated that the newer buildings may be constructed in relatively small lots; however, theconstruction periods are not available at this moment. According to the results of a visual damage inspection
using pre- and post-event satellite images, it was concluded that the damaged buildings in Talca could not beappropriately detected because of their damage patterns and the quality of the post-event satellite image.
A comparison of the georeferenced tsunami-inundated areas with the elevations obtained from the ASTER
GDEM revealed that the elevations in the inundated areas were lower than 20 m on the whole except for acertain area. A clear tendency was not seen in the relationship between the tsunami inundation depth and theelevation. The recorded inundation depth in Talcahuano and Constitución decreased with an increase in the
distance from the coastline or the river.
These findings of our field survey after the 2010 Chile earthquake will be expanded in the earthquake andtsunami disaster mitigation technology in Peru through the SATREPS project.

ACKNOWLEDGMENT: The authors would like to express their sincere gratitude to the Japan Science andTechnology Agency (JST) for the financial support in conducting the field survey under the SATREPS project“Enhancement of earthquake and tsunami disaster mitigation technology in Peru” (Principal Investigator: Prof.
Fumio Yamazaki, Chiba University).

REFERENCES
1)
2)
3)

U.S. Geological Survey : http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/2010tfan/.
Bray, J. and Frost, D. : Geo-engineering Reconnaissance of the 2010 Maule, Chile Earthquake, 2010.
Yamazaki, F., Zavala, C., Nakai, S., Koshimura, S., Saito, T., and Midorikawa, S. : Enhancement of Earthquake and Tsunami
Disaster Mitigation Technology in Peru: A SATREPS Project, Proceedings of the 7th International Conference on Urban
47

Earthquake Engineering, pp. 1501-1506, 2010.
Japan Science and Technology Agency : http://www.jst.go.jp/global/english/index.html.
Humboldt State University Preliminary Tsunami Survey Team : http://www.eqclearinghouse.org/20100227-chile/.
MCEER,
Preliminary
DamageReports
from
the
Chile
Earthquake:February27,
2010:
http://mceer.buffalo.edu/research/Reconnaissance/Chile2-27-10/damage-reports.asp.
7) Saito, K., Spence, R., Going, C., and Markus, M. : Using High-Resolution Satellite Images for Post-Earthquake Building Damage
Assessment: A Study Following the 26 January 2001 Gujarat Earthquake, Earthquake Spectra, Vol. 20, No. 1, pp. 145-169, 2004.
8) Yamazaki, F., Yano, Y., and Matsuoka, M : Visual Damage Interpretation of Buildings in Bam City Using QuickBird Images
Following the 2003 Bam, Iran, Earthquake, Earthquake Spectra, Vol. 21, No. S1, pp. 329-336, 2005.
9) Digitalglobe : http://www.digitalglobe.com/index.php/85/QuickBird.
10) Digitalglobe : http://worldview2.digitalglobe.com/.
11) Sistema Nacinal De Informacion Territorial : http://hosting.snit.cl/terremoto2010/.
12) Aster Gdem : http://www.gdem.aster.ersdac.or.jp/.
13) Imamura, F., Fujima, K., and Arikawa, T. : Field Survey of the 2010 Chilean Tsunami,
http://www.jsce.or.jp/committee/eec2/eq_report/201003Chile/Imamura.pdf.
4)
5)
6)

48