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Indonesia. Weighted by frequency. Weighted by mortality. Weighted by Mortality. Interesting Table . Weighted by GDP. Weighted by GDP. * ) Data collecting still in progress. A snap shot of Indonesia’s hazard problem.
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Weighted by frequency Weighted by mortality
Weighted by Mortality Interesting Table Weighted by GDP
A snap shot of Indonesia’s hazard problem • March 6: An earthquake strikes Sumatra Island, killing at least 52 people and damaging hundreds of buildings. • _ March 3: Landslides triggered by days of heavy rain kill at least 40 people in eastern Indonesia. • _ Feb. 1: Rivers in the capital, Jakarta, burst their banks, submerging parts of the city in water up to 12 feet deep, killing 57 and displacing 450,000. • _ Dec. 29, 2006: A ferry sinks in a storm, killing more than 400 people in the Java Sea. • _ Dec. 23, 2006: Heavy rain touches off floods that kill more than 100 people and displace over 400,000 on Sumatra. • _ July 17, 2006: An earthquake triggers a tsunami off Java island's southern coast, killing at least 600 people. • _ June 19, 2006: Floods and mud flows kill up to 300 people in southern Sulawesi province. • _ May 27, 2006: An earthquake in central Java kills at least 5,800 people and injures more than 36,000. • _ May 2006: A series of explosions spew hot ash down the slopes of Mount Merapi, forcing 15,000 villagers to flee. • _ May 2006: A mud eruption at a drilling shaft on Java displaces more than 11,000 people and inundates villages and factories, spewing a million oil drums of muck a day. • _ Jan. 4, 2006: Some 200 people are killed in a landslide on Java. • _ March 28, 2005: More than 900 people are killed and tens of thousands are left homeless when an earthquake hits Nias, Banyak and Simeulue islands off the coast of Sumatra. • _ Dec. 26, 2004: An earthquake sets off a tsunami that kills more than 160,000 people in Indonesia, mostly in Aceh province on Sumatra.
Hazards in Indonesia • The tectonic hazard: • Volcanoes • Earthquakes • Tsunami • The landsliding hazard • The flooding hazard • The fire hazard • The storm hazard
Tsunami • Indonesia is a region of inherent tectonic instability as it forms an integral part of the Pacific Ring of Fire and is dominated by Subduction processes and associated transform faults. • Some active transforms faults are well known: The Great Sumatra Fault (Sumatra Island), Palu-Koro (Central Sulawesi/Celebes) Fault and Sorong Fault (Papua Island). • The displacement of crustal material around this area has caused a great many tsunami events.
Drought • Drought is another serious problem faces in the dry season between April and September. • It is associated mainly with El Nino but also interruption to the migration of the ITCZ.
Landsliding • Persistent heavy rains in December and January can cause devastating mudslides. • This is encouraged by rapid rates of deforestation decreasing the shear strength of the hillsides. • La Nina often compounds the rains.
Fires • Biomass burning, particularly on Sumatra, often gets out of control and in the dry season can spread. • Carbon Monoxide is a good tracer of pollution as it is a by-product of the combustion associated with wild and agricultural fires.
Storms • A ferry carrying 600 passengers sank in the Java Sea between the islands of Borneo and Java on 29th December, 2006. This is not uncommon. • Similarly, many plane crashes occur due to the unsettled atmospheric conditions. • Winter monsoons from the Asian continent, large thermals, El Nino and cyclones are all causes.
Flooding • Flooding in Indonesia occurs due to the reasons already discussed. • Often accelerated in La Nina years, the main sources of rain are from convectional storms, cyclones and ITCZ migration. • Removal of the forest canopy accelerates rates of overland flow and causes rivers to swell and burst there banks. • Flooding can also be causes from the sea by tsunami and storm surges.
Indonesia is well known as active tectonic region. It consists of three major active tectonics plates which are Eurasia in the north, Indian Ocean-Australia in the south and pacific plate in the east. The plate movements generate subduction boundaries which are responsible for volcanic arc building and produces Sumatra, Java Island, Nusa Tenggara and maluku, amongst others. The subduction process encourages particularly violent and explosive volcanic behaviour. Tectonic Hazards
Volcanic Hazards • Indonesia consists of more than 500 young volcanoes including 128 active volcanoes. • It is represents 15 % of the active volcanoes in the world. • The most active volcano in Indonesia is Merapi which is situated 20 kilometers to the north of Yogyakarta.
Earthquakes • Besides island arc building, the subduction processes also generate seismic active belt along the volcanic arc. • Fortunately, shallow epicenter earthquakes usually occur in the remote areas with less number of populations. • However in some cases major earthquake stroke dense populated region such as Bengkulu, Liwa, bali and Nusa Tenggara (Flores Island).
