Prambanan Temple – Effect of 2006 Earthquake

Prambanan temple – Unesco world cultural heritage

Background – With over 240 Hindu temples located near Piyungan, Prambanan is a Unesco World Cultural Heritage site and is more than 1100 years old. Earthquake resulted in extensive damage to this beautiful place.

Wreckage in Prambanan, after the 2006 earthquake devastated the area.

Yogyakarata Prambanan – Geological settings

Geology – Situated at the flat land between two hilly areas (West Progo Mountain and Southern Mountain), Prambanan is located at the foot of Mt Merapi and at the end of Opak River Fault, a 40 km secondary fault perpendicular to the main fault at the subduction zone where the Indo-australian plate descend beneath the Eurasian place. The left and right side of the fault moved at different speeds.

2006 Earthquake – Mag 6.3

More than 5000 dead, 83000 homes damaged and 1.5 million homeless in the densely populated Yogyakarta. Prambanan temple was also in a wreckage, with most of the shrines and temples being destroyed.

There used to be more than 240 temples and shrines. But only a few remained after the 2006 earthquake.

Why is the 2006 Earth so devastating, especially the area near Prambanan?

1.     The Earthquake in 2006 produced tremors along the Secondary fault (Opak river fault). Tremors along secondary fault lines are often shallow, less than 10km away from the surface. The impact of shallow earthquake can be quite severe despite the lower magnitude because the energy from the quake would have less time to dissipate, resulting in great damage to the area.

2.      Prambanan is located at the end of the secondary fault as seen in the figure. As such, Prambanan received the greatest impact as the seismic energy is concentrated at the end of the secondary fault.

3.      Prambanan is on the soft volcanic rocks of the deposits from Mt Merapi, which amplify and prolong shaking when there is earthquake. Half of the Prambana temple built on swamp filled with reclaimed soft soil, the other half on solid ground. As such, the earth resulted in a long crack in the middle, causing much devastation to the temple.   
4.   Wrong restoration of the Siva Temple before 2006 resulted in more harm – Before the 2006 earthquake, clay and cement were used to join the stone blocks, which is different from the ancient way of construction using interlock system. This proved to be a mistake as  the cement and clay are too rigid and does not allow flexibility in the structure, as such many temples crumbled and collapsed during the 2006 earthquake.

Interlock system used in the past, which proved to be more earthquake resistant since it allow the stones more flexibility and movement to counter the tremors from the earthquake.

Secondary impact on tourism.

Tourism is a key economic sector for Yogyakarta, providing employment and income directly and indirectly to thousands of people. Hundreds of craft villages that make souvenirs, arts and crafts were greatly affected. (Bali tourism board)

Locals walking around to pick up metal cans and
sell them to make a living.