The Great Sumatra Earthquake and Indian Ocean Tsunami of December 26, 2004

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 Foundation through This project was supported by funds from the National Science Foundation through EERI’s Learning From Earthquakes Program under grant # CMS-0131895EERI’s Learning From Earthquakes Program under grant # CMS-0131895

The presentation was created The presentation was created largely by Widianto, a doctoral largely by Widianto, 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

Source: Earthquakes by Bruce A. Bolt

Introduction – Plate Tectonics95% of earthquakes occur along the edges of the interacting plates


World’s Largest Magnitude Earthquakes

EarthquakeEarthquake MagnitudeMagnitude YearYear Approx. casualtiesApprox. casualties

1. Chile1. Chile 9.59.5 19601960 >2000>2000

2. Prince William 2. Prince William Sound, AlaskaSound, Alaska

9.29.2 19641964 125125

3. Andreanof 3. Andreanof Islands, AlaskaIslands, Alaska

9.19.1 19571957 Not reportedNot reported

4. Kamchatka 4. Kamchatka PeninsulaPeninsula

9.09.0 19521952 Not reportedNot reported

5. Sumatra5. Sumatra 9.09.0 20042004 >283,100 >283,100

(>173,000 in Indonesia)(>173,000 in Indonesia)

Source: United States Geological Survey (USGS)

Earthquake Energy


Sumatra-Andaman (2004)

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


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


Felt Shaking ReportsModified 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 :


Aftershock Aftershock 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


Photo: Murat Saatcioglu, Ahmed Ghobarah, Ioan Nistor

Partial collapse of concrete frame building due inadequate column reinforcement.

epicenter

Banda Aceh

epicenter

Banda Aceh


Photos: Murat Saatcioglu, Ahmed Ghobarah, Ioan Nistor

Earthquake DamageEarthquake Damage


Architectural damage to the Grand Mosque tower.

epicenter

Banda Aceh

epicenter

Banda Aceh


Photo: Jose Borrero


Source: Geological Survey of India

Location: Port Blair, Andaman Islands

epicenter

Port Blair

epicenter

Port Blair

Column of residential building damaged by ground motion.



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:


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: Fast-rising tideFast-rising tide Cresting waveCresting wave A step-like change in the A step-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 several Most tsunamis come in a series of waves that may last for several

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 Propagation

National Institute of Advanced Industrial Science and Technology, Japan

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


Before Tsunami

April 12, 2004

After Tsunami

January 2, 2005

Source: Digital Globe

Location: Gleebruk, Indonesia

epicenter

Gleebruk

epicenter

Gleebruk


Before Tsunami

April 12, 2004

After Tsunami

January 2, 2005


epicenter

Gleebruk

epicenter

Gleebruk


Before Tsunami

June 23, 2004

After Tsunami

December 28, 2004


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 DamageLocation: 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 DamageLocation: 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


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. The The 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.

Tsunami SourceTsunami Source YearYear Affected StatesAffected States Tsunami CasualtiesTsunami Casualties

Cascadia FaultCascadia Fault EarthquakeEarthquake

17001700 West coast West coast unknownunknown

Aleutian EarthquakeAleutian Earthquake

(Mw = 8.3)(Mw = 8.3)

19461946 AK, HI , WA, OR, CAAK, HI , WA, OR, CA 159 (Hilo, Hawaii)159 (Hilo, Hawaii)

165165 (total) (total)

Lituya Bay, AlaskaLituya Bay, Alaska LandslideLandslide

19581958 AKAK 22

Chile EarthquakeChile Earthquake

(Mw = 9.5)(Mw = 9.5)

19601960 CA, HICA, HI 6161 (Hilo, Hawaii) (Hilo, Hawaii)

Alaska EarthquakeAlaska Earthquake

(Mw = 9.3)(Mw = 9.3)

19641964 AK, HI , WA, CAAK, HI , WA, CA 120120 (total) (total)

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 maps maps 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 run-up areasAvoid new development in tsunami run-up areas 1.1. Designate risk areas as Designate risk areas as open-spaceopen-space, i.e., parks and , i.e., parks and

agricultureagriculture2.2. Zone to minimize human riskZone to minimize human risk

1.1. Low density residential zoningLow density residential zoning

2.2. Large single-residence lotsLarge single-residence lots


3.3. Locate and configure new development in the run-up Locate and configure new development in the run-up 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)


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 theshoreline:

*Use caution with this design in areas with high earthquake-shaking risk.


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 Earthquake-Caveat: 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


5.5. Protect existing developmentProtect existing development through through redevelopment, 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 and and 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


Plan for EvacuationPlan for Evacuation Identify Identify vertical evacuation buildingsvertical evacuation buildings Create horizontal Create horizontal evacuation routesevacuation routes Develop Develop early warning systemsearly warning systems EducateEducate and inform public and 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.


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:

Victor Desosa Victor Desosa saved the saved the villagevillage of Galbokka in Sri of Galbokka 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 – 90 %villages were 70 – 90 %

““Natural hazards are inevitable.Natural hazards are inevitable. Natural disasters are not.” Natural disasters are not.”

John Filson, USGS retiredJohn Filson, USGS retired

New York TimesNew York TimesDecember 27, 2004December 27, 2004

Earthquake EngineeringEarthquake EngineeringResearch 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 Journal--Quarterly Technical Journal--Earthquake SpectraEarthquake Spectra

Technical Technical SeminarsSeminars & National & National ConferencesConferences Web based Web based World Housing EncyclopediaWorld Housing Encyclopedia 5 5 Regional ChaptersRegional Chapters -- Political Advocacy -- Political Advocacy 20 20 Student ChaptersStudent Chapters Learning From Earthquakes ProgramLearning From Earthquakes Program

Field reconnaissanceField reconnaissance of earthquake impacts to learn of earthquake impacts to learn 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

References References 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

The Great Sumatra Earthquake and Indian Ocean Tsunami of December 26, 2004

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