July 17, 2006 Tsunami: South of Java, Indonesia

Four-hundred and thirteen people killed, 2,741 injured and 15 missing in Ciamis; 62 people killed, 6,124 injured and 2 missing in Tasikmalaya; 15 people killed and 244 injured at Banjar; 1 person killed and 30 injured in Garut; 157 people killed, 104 injured and 15 missing in Cilacap; 10 people killed, 22 injured and 33 missing in Kebumen; 1 person killed in Banyumas; 3 people killed and 10 injured in Gunung Kidul; 3 people killed in Bantul. At least 1,540 buildings damaged or destroyed, 176 boats destroyed and many roads damaged in Jawa Barat. At least 83 buildings damaged and 698 boats damaged or destroyed in Jawa Tengah. Felt (IV) at Bandung, Jakarta, Pangandaran and Tasikmalaya; (III) at Cianjur; (II) at Karangkates, Sawahan and Yogyakarta. Felt at Banda Aceh, Sukabumi and Surabaya. Also felt at Broome, Australia; Subang Jaya, Malaysia and in Singapore. All deaths and damage were a result of a tsunami with maximum runup heights of 4.6 m at Widarapayung, 3.6 m at Cikembulan, 3.4 m at Parang Kusumo and 1.8 m at Pangandaran. Inundation was at least 457 m at Buntong, 422 m at Cikembulan and 304 m at Suwuk. Wave heights in centimeters (peak-to-trough) were recorded at the following selected tide stations: 82.7 at Christmas Island, 28.8 at Hillarys, 19.5 at Esperance, 11.9 at Cocos Island and 4.5 at Broome, Australia; 24.3 at Benoa and 11.9 at Sabang, Indonesia; 21.4 at Hanimaadhoo, Maldives; 73.8 at Rodriguez, Mauritius. (ref #1053)

This was a 'slow earthquake', meaning that the rupture occurred more slowly and took longer than in a normal earthquake. Slow earthquakes usually occur at very shallow depths and produce greater displacements than normal earthquakes. As a consequence, they are more likely to significantly displace the seabed and generate tsunamis. In addition, the magnitude of slow earthquakes may be underestimated by traditional magnitude calculations because the energy they radiate is deficient in high frequencies due to the slower rupture speed. Further, the strongest energy release of the earthquake may occur minutes after the initial rupture and thus not be captured by the initial magnitude calculation. This event was also called a 'tsunami earthquake,' which is an earthquake that generates a tsunami much larger than expected given the earthquake magnitude. 'Tsunami earthquakes' are often caused by 'slow earthquakes'. According to a ReliefWeb report, on 19 July, Indonesian Vice President Jusuf Kalla announced that the death toll had reached 525 with 273 people missing. Most damage centred on the town of Pangandaran. More than 50,000 people were evacuated. (ref #9200)

802 killed, 35,543 affected, $55 million damage. (ref #1250)

A large tsunami occurred over more than 250 km of the south Java coast from Garut prefecture in the west to Yogyakarta prefecture in the east. In the heavily damaged area of Pangandaran, the estimated run-up heights from eyewitness accounts is 4 to 6 m. Along the southwest shore of Pangandaran National Park, which is a small spit that extends about a kilometer to the south, the tsunami was relatively small. From observations of markers consisting of lines of sands and leaves, the tsunami did not appear very high-about 1 to 2 m. Measurements of runup heights (Indonesia Ministry of Marine Affairs and Fisheries et al. 2006 and Kongko et al. 2006) show variable inundations ranging from 1 to 8 m across the region[...]Eyewitness accounts consistently mentioned two large waves with the second wave larger and about 10 to 20 minutes after the first[...]The largest loss of life was in the resort area of Pangandaran, where more than 200 people were killed. (ref #12565)