Sumatra earthquake 2004

SUMATRA EARTHQUAKEAR4051 DISASTER MANAGEMENT & EARTHQUAKE RESISTANT BUILDINGS

SUBMITTED BY:LAKSHMI RAVI CHANDU KOLUSUB130397AR

GUIDED BY:AR SINDHUJA KASTHALA

NATIONAL INSTITUTE OF TECHNOLOGY CALICUT

INTRODUCTION▪ The 2004 Indian Ocean earthquake occurred at 00:58:53 UTC on 26

December with the epicentre off the west coast of Sumatra, Indonesia. ▪ The shock had a moment magnitude of 9.1–9.3 and a maximum Mercalli

intensity of IX (Violent). ▪ The undersea megathrust earthquake was caused when the Indian Plate

was subducted by the Burma Plate and triggered a series of devastating tsunamis along the coasts of most landmasses bordering the Indian Ocean.

▪ It cause a killing of 230,000–280,000 people in 14 countries, and inundating coastal communities with waves up to 30 metres high.

▪ It was one of the deadliest natural disaster recorded in history. ▪ Indonesia was the hardest-hit country, followed by Sri Lanka, India, and

Thailand.

INTRODUCTION

▪ It is the third largest earthquake ever recorded on a seismograph and had the longest duration of faulting ever observed between 8.3 and 10 minutes.

▪ It caused the entire planet to vibrate as much as 1 centimetre (0.4 inches) and triggered other earthquakes as far away as Alaska. 

▪ Its epicentre was between Simeulue and mainland Indonesia. ▪ The resulting tsunami was given various names, including

the 2004 Indian Ocean tsunami, South Asian tsunami, Indonesian tsunami, the Christmas tsunami and the Boxing Day tsunami.

FORESHOCK:

▪ The 2002 Sumatra earthquake occurred at 01:26 UTC on 2 November.

▪ It had a magnitude of 7.3 on the moment magnitude scale with an epicentre just north of Simulue island and caused three deaths.

▪ This earthquake is regarded as a foreshock of the 2004 Sumatra earthquake, which had an epicentre about 60 km to the northwest.

INTERSEISMIC:• India subducts

beneath Burma microplateat about 50 mm/yr.

• Fault interface is locked.

EARTHQUAKE (COSEISMIC):• Fault interface

slips, overriding plate rebounds, releasing accumulated motion.

TECTONIC PLATES:

N• 26th December 2004 00h 58min 51s UT

• Western COAST OF NORTHERN SUMATRA

• Epicentre latitude : 3.298° longitude : 95.778°

• Magnitude = 9.2

• 3rd largest Earthquake since ever recorded on a seismograph.

TECTONIC PLATES:

Seismograms of the day: Global Seismic Displacement Wavefield, December 26, 2004.

AFTERSHOCKS & OTHER EARTHQUAKES

▪ Numerous aftershocks were reported off the Andaman and Nicobar islands and the region of the original epicentre in the hours and days that followed.

▪ The magnitude 8.7 2005 Nias – Simulue earthquake, which originated off the coast of the Sumatran island of Nias, is not considered an aftershock, despite its proximity to the epicentre, and was most likely triggered by stress changes associated with the 2004 event.

▪ This earthquake was so large that it produced its own aftershocks (some registering a magnitude of as great as 6.1) and presently ranks as the 7th largest earthquake on record since 1900.

▪ Other aftershocks of up to magnitude 6.6 continued to shake the region daily for up to three or four months. 

▪ As well as continuing aftershocks, the energy released by the original earthquake continued to make its presence felt well after the event.

▪ A week after the earthquake, its reverberations could still be measured, providing valuable scientific data about the Earth's interior.

AFTERSHOCKS & OTHER EARTHQUAKES

ENERGY RELEASED

▪ The energy released on the Earth's surface only (ME, which is the seismic potential for damage) by the 2004 Indian Ocean earthquake and tsunami was estimated at 1.1×1017 joules or 26 megatons of TNT.

▪ This energy is equivalent to over 1,500 times that of the Hiroshima atomic bomb, but less than that of Tsar Bomba, the largest nuclear weapon ever detonated.

▪ However, the total work done MW (and thus energy) by this quake was 4.0×1022 joules (4.0×1029 ergs), the vast majority underground.

▪ This is over 360,000 times more than its ME, equivalent to 9,600 giga tons of  TNT equivalent (550 million times that of Hiroshima) or about 370 years of energy use in United States.

TSUNAMI

• All along the rupture the seafloor was shunted vertically by about 10 meters.

• This movement displaced the overlying water, generating a massive tsunami, or tidal wave.

• The wave then fanned out across the Indian Ocean at enormous speed.

▪ The tsunami, like all others, behaved very differently in deep water than in shallow water.

▪ In deep ocean water, tsunami waves form only a small hump, barely noticeable and harmless, which generally travels at a very high speed of 500 to 1,000 km/h (310 to 620 mph).

▪ In shallow water near coastlines, a tsunami slows down to only tens of kilometres per hour but, in doing so, forms large destructive waves.

▪ Scientists investigating the damage in Aceh found evidence that the wave reached a height of 24 metres (80 ft) when coming ashore along large stretches of the coastline, rising to 30 metres (100 ft) in some areas when traveling inland.

TSUNAMI

Scale showing size of tsunami waves that hit

Indonesia

IN DEEP OCEAN tsunami has long wavelength, travels fast, small amplitude - doesn’t affect ships.

AS IT APPROACHES SHORE, it slows. Since energy is conserved, amplitude builds up - very damaging.

TSUNAMI

TSUNAMI

Animation of tsunami caused by the earthquake showing how it radiated from the entire length of the 1,600 km (990 mi) rupture.

Damage map of Banda Aceh city showing the impact of tsunamis wave fronts from two directions. The numerals indicate the tsunami elevation in meters near the beach (white) and flow depth inland (black).

Banda Aceh City, Sumarta

BEFORE

AFTER

A three story house damaged by the tsunami showing the tsunami inundation height in downtown Banda Aceh.

THE DESTRUCTION CAUSED:

Scale of devastation Thousands are reported to have been killed, but there has been little news from the worst-hit areas where all transport and communication links were destroyed.

• Low lying coastal areas were left obliterated and flooded as here in Aceh province in Sumatra, Indonesia.

• Current reports indicate that the north and west coasts of Sumatra have experienced the worst destruction.

• Low lying areas have been left flooded with seawater which quickly becomes contaminated with sewage and decomposing bodies.

THE DESTRUCTION CAUSED:

▪ In Aceh, Indonesia, so many doctors have been killed that there are few trained medical workers to assist the injured.

THE DESTRUCTION CAUSED:

• Increasing numbers of homeless people needing shelter, food and water.

• Clean drinking water is required to avoid the spread of disease.

THE DESTRUCTION CAUSED:

PROBLEMS FACED

• In all affected areas survivors are hungry as food supplies run out.

• The threat of disease increases.• Medicines are needed desperately.• In some areas relief supplies are piling up.• Disruption of communications means that emergency supplies

cannot be distributed efficiently.• Co-ordination of relief efforts from throughout the world is

proving to be a major challenge.• Four days after the tsunami many of the worst affected areas

cannot be reached.

EVACUATION

• The evacuation of foreign tourists from the beach resorts begins.

• Other survivors, such as these women and children from the Nicobar Islands, leave to a more uncertain future.

• Relief efforts, which have been slow to start, gather pace as the enormity of the disaster begins to be appreciated.

Effects on other countries

• Whole villages were flattened as here in Sri Lanka

Scenes which were repeated across the Indian Ocean

Sri Lanka Phuket, Thailand

Millions of people have been left homeless

Cuddalore, south of Madras, India Penang, Malaysia

Thankyou