January 2, 2002 Tsunami: Vanuatu Islands

On January 3, 2002 (UTC 2002/01/02 17:22:50, 04:22 am local time), a magnitude Mw 7.1 earthquake, the largest recorded so far in the vicinity, struck Port Vila, Efate, Vanuatu. It was located only 50 km west of Port Vila and at the shallow depth of 21 km below the sea floor. Fifteen minutes after the main shock, a tsunami struck Port Vila Harbour. The event was followed that same night by a large aftershock (Mw 6.4) which also produced a tsunami, though much smaller in size. A tsunami of appreciable size was generated with the earthquake, but was fortunately small enough, given the extremely low tide at the time, not to cause any significant flooding above Highest Astronomical Tide (HAT) level. Had it struck at high tide, much flooding, damage and perhaps loss of life could have resulted. Although the tsunami only registered on the tide gauge as having a crest to trough amplitude of 0.8 m, eyewitness accounts in different parts of the harbour put the maximum effect at around 3.0 m, nearly four times that of the height recorded on the water level gauge. (reference #2660)

3 January 2002 LT (2 January 2002 UTC) Efate A significant event of magnitude Mw 7.2, located west of Efate Island and felt on the whole island, caused some damage in the capital city of Port Vila and generated a tsunami that arrived 15 min after the shock in the bay of Port Vila. A maximum amplitude of 32 cm is recorded at the Port Vila tide gauge. However, eyewitnesses reported a much larger effect at different places around the harbour, with maximum wave heights around 3m from trough to crest; Shorten, 2002). According to the same reference, a small tsunami following a large Mw 6.4 aftershock is also reported, although nothing can be seen on the tide gauge record. (reference #13893)