Earthquake EngineeringEarthquake Engineering
Research InstituteResearch Institute
An illustrated description of their causes and effects
The Great Sumatra Earthquake and The Great Sumatra Earthquake and
Indian Ocean Tsunami Indian Ocean Tsunami
of December 26, 2004of December 26, 2004
This presentation was developed to explain the origins of the This presentation was developed to explain the origins of the Sumatra earthquake of December 26, 2004 and the ensuing Sumatra earthquake of December 26, 2004 and the ensuing tsunami, and to document the damages caused by the tsunami, and to document the damages caused by the earthquake and tsunami in so many countries around the earthquake and tsunami in so many countries around the Indian Ocean.Indian Ocean.
This project was supported by funds from the National Science FoThis project was supported by funds from the National Science Foundation through undation through
EERIEERI’’ss Learning From Earthquakes Program under grant # CMSLearning From Earthquakes Program under grant # CMS--01318950131895
�� The presentation was created The presentation was created largely by largely by WidiantoWidianto, a doctoral , a doctoral candidate in civil engineering candidate in civil engineering and president of the EERI and president of the EERI student chapter at the student chapter at the University of Texas at Austin. University of Texas at Austin.
�� Other contributors include Other contributors include Sarah Nathe, Craig Comartin, Sarah Nathe, Craig Comartin, and Heidi Faison.and Heidi Faison.
PrefacePreface
United States Geological Survey (USGS)
“The tsunami that struck Southeast Asia on
December 26, 2004 has been confirmed as the most
devastating in modern history.”
Guinness Book of World Records
“The 26th December 2004 Sumatra-Andaman
earthquake is the fourth largest earthquake in the
world since 1900 and is the largest since the 1964
Prince William Sound, Alaska earthquake.”
Contents� Introduction: Plate tectonics, earthquakes
� Sumatra Earthquake
- Tectonic activity
- Observations
- Damage
� Indian Ocean Tsunami
- Basic mechanism
- Videos: before and after giant wave arrival
- Damage
� Tsunamis in the USA
� Tsunami Risk Reduction
� The Earthquake Engineering Research Institute
Introduction – Plate Tectonics� The Earth is characterized by a small number of lithospheric plates that
float on a viscous underlayer called the asthenosphere.
� Geological evidence shows that plates undergo constant, gradual
change. Magma is continually upwelling at the mid-oceanic ridges and rises
as the seafloor spreads apart.
� In some areas, large sections of plates are forced to move beneath other
plates (surface layers of rocks are absorbed into the earth’s interior). These
areas are called subduction zones.
���� A plate being subducted beneath another
Introduction – Plate Tectonics
95% of earthquakes occur along the edges of the interacting plates
Source: Earthquakes by Bruce A. Bolt
World’s Largest Magnitude Earthquakes
Approx. casualtiesApprox. casualtiesYearYearMagnitudeMagnitudeEarthquakeEarthquake
>283,100 >283,100
(>173,000 in Indonesia)(>173,000 in Indonesia)
200420049.09.05. Sumatra5. Sumatra
Not reportedNot reported195219529.09.04.4. KamchatkaKamchatka
PeninsulaPeninsula
Not reportedNot reported195719579.19.13.3. AndreanofAndreanof
Islands, AlaskaIslands, Alaska
≅≅≅≅≅≅≅≅ 125125196419649.29.22. Prince William 2. Prince William
Sound, AlaskaSound, Alaska
>2000>2000196019609.59.51. Chile1. Chile
Source: United States Geological Survey (USGS)
Sumatra Earthquake
Magnitude: 9.0
Date-time: Sunday, December 26,
2004 at 7:58:53 AM (local time)
Depth: 30 km (18.6 miles)
Distances:
* 250 km (155 miles) SSE of Aceh,
Sumatra, Indonesia
* 310 km (195 miles) W of Medan,
Sumatra, Indonesia
* 1260 km (780 miles) SSW of
Bangkok, Thailand
* 1605 km (990 miles) NW of
Jakarta, Java, Indonesia
Source: United States Geological Survey (USGS)
Tectonic Summary
� It occurred on the interface of
the India and Burma plates: an
interplate earthquake.
� India plate subducts beneath
the overriding Burma plate at
the Sunda Trench.
� In the region of the earthquake,
the India plate moves toward the
northeast at a rate of about
6 cm/year relative to the Burma
plate.
� Thrust faulting caused the
earthquake (slip directed
perpendicular to the trench).
� Fault rupture propagated to
the northwest from the epicenter
with a width ≅ 100 km and an
average displacement on the fault
plane ≅ 20 meters.
6 cm/yr
Source: United States Geological Survey (USGS)
Felt Shaking Reports�Modified Mercalli Intensity Scale:
� Banda Aceh, Sumatra: IX
� Medan, Sumatra: IV
� Port Blair, Andaman Islands: VII
� Subsidence and landslides
were observed in Sumatra.
� A mud volcano near Baratang,
Andaman Islands began erupting
on December 28, 2004.
� Intensity vs. Distance from
Epicenter Plot :
Source: United States Geological Survey (USGS)
AftershockAftershock
ZoneZone
� Extends from
Northern Sumatra to
the Andaman Islands,
~ 1300 km to the north.
� Largest aftershock
directly following the
main shock was M =
7.1 in the Nicobar
Islands.
�On March 28, 2005, a
M = 8.7 earthquake
occurred in a region of
the fault southeast of
the Dec 26th mainshock
and its rupture zone.
Epicenter of mainshock,
28 Mar 2005
Earthquake Damage Earthquake Damage
Structural damage to concrete frame building.
epicenter
Banda Aceh
epicenter
Banda Aceh
Location: Banda Aceh,
Sumatra, Indonesia
Photo: Jose Borrero
Earthquake DamageEarthquake Damage
Partial collapse of concrete frame building due to column failure.
epicenter
Banda Aceh
epicenter
Banda Aceh
Location: Banda Aceh,
Sumatra, Indonesia
Photo: Murat Saatcioglu, Ahmed
Ghobarah, Ioan Nistor
Partial collapse of concrete frame building due inadequate column reinforcement.
epicenter
Banda Aceh
epicenter
Banda Aceh
Location: Banda Aceh
Sumatra, Indonesia
Photos: Murat Saatcioglu, Ahmed
Ghobarah, Ioan Nistor
Earthquake DamageEarthquake Damage
Earthquake Damage Earthquake Damage
Architectural damage to the
Grand Mosque tower.
epicenter
Banda Aceh
epicenter
Banda Aceh
Location: Banda Aceh,
Sumatra, Indonesia
Photo: Jose Borrero
Earthquake Damage Earthquake Damage
Source: Geological Survey of India
Location: Port Blair,
Andaman Islands
epicenter
Port Blair
epicenter
Port Blair
Column of residential building damaged by ground motion.
Earthquake Damage Earthquake Damage
Source: Geological Survey of India
Location: Port Blair,
Andaman Islands
epicenter
Port Blair
epicenter
Port Blair
Longitudinal (50 m long)
crack on Kamraj Road after
the earthquake
Major crack showing a rupture width of
15 cm on Kamraj Road after the
earthquake
Earthquake and Tsunami
Not all earthquakes generate tsunamis.
An earthquake must have certain characteristics in order to
generate a tsunami:
Source: Earthquakes by Bruce A. Bolt
1. Epicenter is underneath or near the ocean.
2. Fault causes vertical movement of the sea floor (up to
several meters) over a large area (up to 100,000 km2).
3. Large magnitude ( > 7.5 ) AND shallow focus ( < 70 km).
Basic Tsunami Mechanism
� An earthquake causes a
vertical movement of the
seafloor, which displaces the
sea water.
� Large waves then
radiate from the epicenter
in all directions.
Tsunami Explained� A tsunami is series of traveling ocean waves of extremely long length
generated primarily by earthquakes occurring below or near the ocean floor.
� Tsunami waves propagate across the deep ocean with a speed exceeding
800 km/h (≅ 500 mph) and a wave height of only a few tens of centimeters or
less.
� As they reach the shallow waters of the coast, the waves slow down and
their height increases up to tens of meters (30 ft) or more.
Source: NOAA
Tsunami Translated
� “Tidal wave” is a misnomer because the cause
is unrelated to tides.
� “Seismic sea wave” is misleading because a
tsunami can be caused by non-seismic events,
and it is not dangerous in the open ocean.
Japanese word:
“Tsu“ means
“harbor”
“Nami“ means
“wave”
English translation:
“Harbor wave”
Water Recession: A Precursor
From: Nature Publishing GroupFrom: Nature Publishing Group
Wave Generation Draw Down Effect
From: Digital Globe
Kalutara Beach, Sri Lanka
Tsunami Wave AppearanceTsunami Wave Appearance
�� A tsunami wave crest has A tsunami wave crest has three general appearances three general appearances from shore:from shore:�� FastFast--rising tiderising tide
�� Cresting waveCresting wave
�� A stepA step--like change in the like change in the water level that advances water level that advances rapidly (called a rapidly (called a borebore))
�� Series of wavesSeries of waves�� Most tsunamis come in a series of waves that may last for severaMost tsunamis come in a series of waves that may last for severall
hourshours
�� The outflow of water back to the sea between waves can cause The outflow of water back to the sea between waves can cause more damage than the original incoming wave frontsmore damage than the original incoming wave fronts
�� The first wave is rarely the largestThe first wave is rarely the largest
A bore on the Qian Tang Jiang River, China
Source: www.waveofdestruction.org
Tsunami Damage Tsunami Damage
Before Tsunami
January 10, 2003
After Tsunami
December 29, 2004
Source: National University of Singapore
Location: Lhoknga, Indonesia
epicenter
Lhoknga
epicenter
Lhoknga
Tsunami DamageTsunami DamageLocation: Lhoknga, Indonesia
epicenter
Lhoknga
epicenter
Lhoknga
Exposed
bridge piers of
road that
washed away.
Damage zone showing an
overturned tanker, trees
snapped in half, and the
high water mark on islands
where vegetation was
stripped away.
Overturned
ship
High Water Mark
Broken Trees
Photo: Jose Borrero
Photo: Jose Borrero
Tsunami Damage Tsunami Damage
Before Tsunami
April 12, 2004
After Tsunami
January 2, 2005
Source: Digital Globe
Location: Gleebruk, Indonesia
epicenter
Gleebruk
epicenter
Gleebruk
Tsunami Damage Tsunami Damage
Before Tsunami
April 12, 2004
After Tsunami
January 2, 2005
Source: Digital Globe
epicenter
Gleebruk
epicenter
Gleebruk
Tsunami Damage Tsunami Damage
Before Tsunami
June 23, 2004
After Tsunami
December 28, 2004
Source: Digital Globe
Location: Banda Aceh, Indonesia
epicenter
Banda Aceh
epicenter
Banda Aceh
Tsunami DamageTsunami DamageLocation: Banda Aceh, Indonesia
epicenter
Banda Aceh
epicenter
Banda Aceh
Damage was caused by
both water and water-borne
debris.
A boat was
lifted on top
of houses
by the
waves.
Photo: Jose Borrero
Photo: Jose Borrero
Tsunami DamageTsunami Damage
Location: Banda Aceh & Lhoknga,
Indonesia
epicenter
Banda Aceh
epicenter
Banda Aceh
The tsunami waves came
from many directions and
flowed across the tip of
northeastern Sumatra.
Graphic: Jose Borrero
epicenter
Kerala Coast
epicenter
Kerala Coast
Tsunami DamageTsunami Damage
Location: Thailand
Damage to Kao
Lak Resort from
tsunami waves.
Despite the presence of debris,
this naval base building had
little structural damage due to a
retaining wall at its frontage.
Photo: Curt Edwards
Photo: Chitr Lilavivat
Thailand
Tsunami DamageTsunami Damage
Location: Sri Lanka
epicenter
Kerala Coast
epicenter
Kerala CoastSri Lanka
Damage to house in Tangala.
Flow depths were
about 4.5 m at Yala
Safari Resort, where
water levels were
determined by debris
in the trees (see door
impaled on branch).
Tsunami Damage Tsunami Damage
Location: Kerala, India
Source: Geological Survey of India
epicenter
Kerala Coast
epicenter
Kerala Coast
The collapsed front
portion of a concrete
house.
In the village of Alappad, the foundations and
the soil beneath many of the houses were
scoured out.
Tsunamis in the U.S.A.Tsunamis in the U.S.A.�� TheThe west coastwest coast, from California to Alaska, is vulnerable to , from California to Alaska, is vulnerable to
tsunamis from nearby or distant earthquakes. tsunamis from nearby or distant earthquakes.
�� HawaiiHawaii is extremely vulnerable to all tsunamis in the Pacific is extremely vulnerable to all tsunamis in the Pacific Ocean.Ocean.
�� California, Oregon, Washington, Alaska and Hawaii all have California, Oregon, Washington, Alaska and Hawaii all have tsunami education programstsunami education programs for residents and visitors, for residents and visitors, coastal signagecoastal signage, and , and warning response planswarning response plans..
Photo: Eugene Schader, NISEE Collection
Warped pier in Crescent City, CA caused by
1964 Alaska earthquake tsunami
Photo: Kirkpatrick, NISEE Collection
Tsunami induced damage in Seward, Alaska
from 1964 Alaska earthquake
Historical Tsunamis in the U.S.A.Historical Tsunamis in the U.S.A.
unknownunknownWest coast West coast 17001700CascadiaCascadia FaultFault
EarthquakeEarthquake
Tsunami CasualtiesTsunami CasualtiesAffected StatesAffected StatesYearYearTsunami SourceTsunami Source
120120 (total)(total)AK, HI , WA, CAAK, HI , WA, CA19641964Alaska EarthquakeAlaska Earthquake
(Mw = 9.3)(Mw = 9.3)
6161 (Hilo, Hawaii)(Hilo, Hawaii)CA, HICA, HI19601960Chile EarthquakeChile Earthquake
(Mw = 9.5)(Mw = 9.5)
22AKAK19581958LituyaLituya Bay, AlaskaBay, Alaska
LandslideLandslide
159 (Hilo, Hawaii)159 (Hilo, Hawaii)
165165 (total)(total)
AK, HI , WA, OR, CAAK, HI , WA, OR, CA19461946Aleutian EarthquakeAleutian Earthquake
(Mw = 8.3)(Mw = 8.3)
Sources: NOVA; International Tsunami Information Center (ITIC)
Tsunami Risk ReductionTsunami Risk Reduction
1.1. Determine & understand community tsunami riskDetermine & understand community tsunami risk�� Hazard: Hazard:
� Study the shape of the sea floor and the coastal topography
� Run simulations of tsunamis
�� Vulnerability:Vulnerability:
�� DevelopDevelop mapsmaps of potential risk areas of potential risk areas
�� Exposure:Exposure:
�� Costal communities, especially with tsunami historyCostal communities, especially with tsunami history
2.2. Avoid new development in tsunami runAvoid new development in tsunami run--up areasup areas
1.1. Designate risk areas as Designate risk areas as openopen--spacespace, i.e., parks and agriculture, i.e., parks and agriculture
2.2. Zone to minimize human riskZone to minimize human risk
1.1. Low density residential zoningLow density residential zoning
2.2. Large singleLarge single--residence lotsresidence lots
Tsunami Risk ReductionTsunami Risk Reduction
3.3. Locate and configure new development in the runLocate and configure new development in the run--upup
areas to minimize future tsunami lossesareas to minimize future tsunami losses
� Avoid inundation areas
i.e. build on high ground
� Slowing water currents
i.e. Conserve or replant coastal belts
of forest and mangrove swamps
� Steering water forces
i.e. angled, by-pass walls
� Blocking water forces
i.e. Build sea walls
SLOWING
STEERING
BLOCKINGSource: National Tsunami Hazard Mitigation Program (NTHMP)
Tsunami Risk ReductionTsunami Risk Reduction
Elevated restaurant in Hilo, Hawaii. Lower level is designed
to allow waves to pass through.
Source: National Tsunami Hazard Mitigation Program
4.4. Design and construct new buildings to minimize Design and construct new buildings to minimize tsunami damagetsunami damage
� Heavy and rigid structure
� Raise building on stilts*
� Many openings on the
ground floor *
� Orient perpendicular to the
shoreline:
*Use caution with this design in areas
with high earthquake-shaking risk.
Tsunami Risk ReductionTsunami Risk Reduction
WAVE
Overturning
Sliding
Scouring
Buoyancy
Water pressure
& debris impact
WAVE
Overturning
Sliding
Scouring
Buoyancy
Water pressure
& debris impact
4. Tsunami-resistant buildings (cont.)
Tsunami forces on
structures
Lowest
horizontal
structure
above wave-
crest
Horizontal
member
perpendicular to
the wave
Lateral bracing
Deep protected piles
Rigid connection
Lowest
horizontal
structure
above wave-
crest
Horizontal
member
perpendicular to
the wave
Lateral bracing
Deep protected piles
Rigid connection
Structure designed to resist
tsunami forces
Source: National Tsunami Hazard Mitigation Program (NTHMP)
Caveat: Remember EarthquakeCaveat: Remember Earthquake--
Resistant Design Principles Resistant Design Principles
�� Most communities at risk from tsunamis are also at risk from Most communities at risk from tsunamis are also at risk from
damaging earthquakesdamaging earthquakes
�� Buildings designed well for earthquakes typically perform Buildings designed well for earthquakes typically perform
well in tsunamiswell in tsunamis
Well-designed building withstood tsunami forces
without collapse in Banda Aceh, Indonesia
Photo: Jose Borrero
Well-designed building standing amidst the
rubble in Banda Aceh, Indonesia
Photo: Jose Borrero
Tsunami Risk ReductionTsunami Risk Reduction
5.5. Protect existing developmentProtect existing development throughthroughredevelopment, retrofit, and land reuse plans and redevelopment, retrofit, and land reuse plans and projectsprojects
6.6. Take special precautions in locating and designing Take special precautions in locating and designing infrastructureinfrastructure andand critical facilitiescritical facilities
� Locate critical infrastructure (water plants, hospitals, etc) outside the tsunami danger zone
�� Relocate or protect critical infrastructureRelocate or protect critical infrastructure
�� Plan for emergency and recovery Plan for emergency and recovery
Tsunami Risk ReductionTsunami Risk Reduction
�� Plan for EvacuationPlan for Evacuation
�� IdentifyIdentify vertical evacuation buildingsvertical evacuation buildings
�� Create horizontal Create horizontal evacuation routesevacuation routes
�� DevelopDevelop early warning systemsearly warning systems
�� EducateEducate and inform publicand inform public
Tsunami Risk Reduction Tsunami Risk Reduction Tsunami early warning system:
� Pressure sensors sit on the ocean
bottom and measure the weight of
water column above them.
� If a tsunami passes overhead, the
pressure increases and the sensor
sends a signal to a buoy sitting on the
sea surface.
� The buoy then sends a signal to a
satellite, which in turn alerts a staffed
early warning center.
Tsunami Risk ReductionTsunami Risk Reduction
The least expensive and the most important mitigation effort is …
"Even without a warning system, even in places where they
didn't feel the earthquake, if people had simply
understood that when you see the water go down, when
you hear a rumble from the coast, you don't go down to
investigate, you grab your babies and run for your life,
many lives would have been saved."
Lori Dengler, Humboldt State UniversityNew Scientist MagazineNew Scientist Magazine
January 15, 2005January 15, 2005
The power of knowledge:The power of knowledge:
�� VictorVictor DesosaDesosa saved the saved the villagevillage ofof GalbokkaGalbokka in Sri in Sri Lanka because Lanka because he knew he knew what to dowhat to do when the water when the water receded.receded.
�� Only one inhabitant in his Only one inhabitant in his village was killed.village was killed.
�� Casualty rates in nearby Casualty rates in nearby villages were 70 villages were 70 –– 90 %90 %
“Natural hazards are inevitable.“Natural hazards are inevitable.
Natural disasters are not.”Natural disasters are not.”
John John FilsonFilson, USGS retired, USGS retired
New York TimesNew York Times
December 27, 2004December 27, 2004
Earthquake EngineeringEarthquake Engineering
Research InstituteResearch Institute
�� EERI is a professional, association dedicated to EERI is a professional, association dedicated to
reducing earthquake risk. reducing earthquake risk.
�� Members of EERI work in the many different Members of EERI work in the many different
fields of research and professional practice fields of research and professional practice
dedicated to reducing earthquake losses. dedicated to reducing earthquake losses.
EERI ProgramsEERI Programs
�� PublicationsPublications –– Website, Monthly Newsletter and Website, Monthly Newsletter and
Quarterly Technical JournalQuarterly Technical Journal----Earthquake SpectraEarthquake Spectra
�� TechnicalTechnical SeminarsSeminars & National & National ConferencesConferences
�� Web based Web based World Housing EncyclopediaWorld Housing Encyclopedia
�� 55 Regional ChaptersRegional Chapters ---- Political AdvocacyPolitical Advocacy
�� 2020 Student ChaptersStudent Chapters
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lessons for research and practicelessons for research and practice
To contact us or become a member of EERI, visit our website: To contact us or become a member of EERI, visit our website:
www.eeri.orgwww.eeri.org
ReferencesReferences� United States Geological Survey (USGS)
� U.S. National Oceanic and Atmospheric Administration (NOAA)
� UNESCO / Intergovernmental Oceanographic Commission (IOC)
� International Tsunami Information Center (ITIC)
� Laboratoire de Geophysique, France (LDG)
� Earthquakes: A Primer, Bruce A . Bolt, W.H. Freeman, 1978
� Digital Globe
� Geological Survey of India
� National University of Singapore
� New Scientist magazine, Issue #2482, January 15, 2005
� BBC News
� Nature, Vol. 433, January 27, 2005, Nature Publishing Group
� Sri Lanka Reconnaissance Teams: http://walrus.wr.usgs.gov/tsunami/srilanka05/ &
http://www.gtsav.gatech.edu/cee/groups/tsunami/index.html
ReferencesReferences (cont.)(cont.)
� Natural Tsunami Hazard Mitigation Program (NTHMP), Designing for
Tsunamis, March 2001
� National Information Service for Earthquake Engineering (NISEE),
Earthquake Image Database, Karl Steinbrugge Collection
� www.wavesofdestruction.org
� “Field Survey of Northern Sumatra,” Jose Borrero, EERI Newsletter,
March 2005
� Pacific Tsunami Museum
� NOVA: “The Wave that Shook the World,” PBS http://www.pbs.org/wgbh/nova/tsunami/
� Metro TV, Surabaya Citra Televisi Indonesia (SCTV), Rajawali Citra
Televisi Indonesia (RCTI)
� Prof. Wiratman Wangsadinata, Wiratman & Associates Consulting
Company, Indonesia
� EERI’s Virtual Clearinghouse: http://www.eeri.org/lfe/clearinghouse/sumatra_tsunami/overview.html