2006 Tonga earthquake
|Date||4 May 2006|
|Origin time||04:26:35 local |
|Magnitude||8.0 Mw |
|Depth||15 km (9 mi) |
|Max. intensity||VII (Very strong) |
|Tsunami||.54 m (1 ft 9 in) |
|Casualties||1 injured |
The 2006 Tonga earthquake occurred on 4 May at 04:26:35 local time with a moment magnitude of 8.0 and a maximum Mercalli intensity of VII (Very strong). One injury occurred and a non-destructive tsunami was observed.
CNN and BBC reports showed that the town of Gisborne, New Zealand was being evacuated. Civil Defence in New Zealand had issued no statements, and there was no information inside New Zealand about Gisborne being evacuated. The National Oceanic and Atmospheric Administration's Pacific Tsunami Warning Center in Hawaii issued a warning 17 minutes after the earthquake for coastal areas around the Pacific. An hour later, the center downgraded the warning to only the region within 600 miles of the epicenter, and an hour after that, it canceled the alert.
The event caused very limited damage. The previous large earthquake in Tonga, in 1977, was of inferior magnitude but resulted in more severe damage. A likely cause is that the 2006 quake generated other frequencies that only resulted in resonance in small items. It was striking to see, especially in the supermarkets, all the cans and bottles which contained fluids turned upside down or fallen to the ground, while the bigger items or those containing dry goods were largely unaffected. There was very little damage reported in Tonga apart from pictures fallen from the walls or items tumbled down from cupboards and shelves.
- The century old, Catholic church in Lapaha had new cracks in the tower and several stones fell down, leaving the steeple in a somewhat unstable position.
- The tower of a 60-year-old church, of the Free church of Tonga in Veitongo, collapsed, the steeple came down and several walls cracked beyond repair. As in Lapaha, the faithful continued their services inside.
- A Korean business man jumped in panic from his second floor hotel room and was hurt in the fall. He was brought to the hospital where he had to wait a long time for any help as power was off and most staff off duty (as that day was a public holiday).
- The American wharf in Nukuʻalofa sustained cracks in addition to those caused by the 1977 earthquake.
- A ship, sunk in 1949 near Toula, Vavaʻu apparently burst open and its load of copra came floating to the ocean surface.
- A landslide occurred at Hunga island in Vavaʻu, when the ground at a steep cliff along the shore began gliding into the sea.
- In Haʻapai, the islands closest to the epicentre, the wharf was damaged and a number of water-pipes and telephone lines were broken. Niuʻui hospital suffered severe damage beyond repair.
Since the earthquake occurred underwater, tsunami warnings were issued, but then lifted.
- ISC (2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009), Version 2.0, International Seismological Centre
- USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey
- USGS. "M8.0 - Tonga". United States Geological Survey.
- Chang, Kenneth (4 May 2006). "Quake Causes Tsunami Alert, But No Damage". The New York Times.
- Tonga struck by strong earthquake – BBC News
- Aftershocks rattle South Pacific nation – MSN
- Poster of the Tonga Earthquake of 3 May 2006 - Magnitude 7.9 – United States Geological Survey
- Earthquake and tsunami of May 3, 2006 in Tonga – George Pararas-Carayannis
- Tonga quake not conducive to tsunami – Phys.org