The 2002 Port Vila earthquake occurred in the early dawn of January 3, 2002, 04:22 a.m. local time (UTC+11) northwest of Port Vila, the capital of Vanuatu. It had a magnitude of 7.2 and a maximum intensity of X (Extreme) west of the island on the Modified Mercalli intensity scale. There are no exact estimates on the number of injured individuals, but the majority of accounts say there were "several" amounts of injured civilians. the event also caused a minor tsunami of about 0.4−0.8 m just 11 minutes after the quake.

Tectonic setting

The tremor was caused by the convergence of the Australian Plate and the New Hebrides microplate. Different rates of convergence are present in different regions, in the southern Tanna regions the relative movement is oriented at around N244 ±4 and has a uniform rate of 11.7±0.8 cm/yr. The rate in Efaté, near the epicenter, was at around 0.3±0.9 cm/yr, oriented N242 ±4. Both azimuths very well compare with slip vectors of the last major earthquakes. Lastly, in the North, the rate at Santo is only 3.6 ±1.2 cm/yr, oriented N253 ± 26. The difference in the convergence rates between Santo on the one hand and Efaté and Tanna in the other hand points to a right lateral shear zone between Santo and Efaté. At Santo where the plate coupling is very high, the very low convergence rate might be related to the absence of recent strong earthquakes. No significant variations are detected for the baselines within the Australia plate. Relatively to a western North Fiji basin (WNFB) reference, the northern and southern segments rotate in opposite directions, consistently with the extension observed in the troughs east of both segments. Both rotations combine in Central Vanuatu into an eastward translation that "bulldozes" the central segment into the WNFB at ~55 mm/yr. That model suggests that the motion of the central segment, forced by the subduction/collision of the D'Entrecasteaux ridge, influences the motion of the adjoining segments. The New Caledonia archipelago is motionless with respect to the rest of the Australia plate despite the incipient interaction between the Loyalty ridge and the NH margin. Southeast of the interaction area, convergence is partitioned into a ~50 mm/yr trench-normal component accommodated at the trench and a ~90 mm/yr trench-parallel component, close to the A/P convergence, and presumably accommodated by a transform boundary at the rear of the NH arc.

2002 Port Vila earthquake

Earthquake

Preliminary magnitudes for the earthquake were between 7.1−7.4 in magnitude. Later, the United States Geological Survey settled on a magnitude of 7.2 . The entirety of the populace of Efate were shaken, added by several aftershocks that continued to rock the area. According to the local authorities, the seismic intensities were recorded as high as X (Extreme) or for comparison similar to the strength of a much larger 8.2 magnitude earthquake.

2002 Port Vila earthquake

Tsunami

About 500 people had fled to higher ground in fear of a tsunami. Eyewitnesses had reportedly seen 3 meter waves approaching the shores, however the maximum run-up crest height of the tsunami recorded by gauges were only 30-40 cm.

2002 Port Vila earthquake

Damage

There were no immediate reports of serious casualties but the earthquake caused major damage to buildings and infrastructure such as numerous schools, as well as factories and shops that were deemed unsafe. The Teuma bridge, which links the southern coast of Efate to the capital, was badly damaged. Three bridges other bridges that connect other parts of the island, as well as other infrastructure from other small communities within Mele Bay, sustained heavy damage. Landslides blocked and buried many roads, most notably one that links to the main wharf in Klems Hill. The condition of agriculture in the area was dire and would be even more crippled adding to which more possibly strong aftershocks as well as heavy rains that may hit the areas.