Where: Wellington, New Zealand

July 16, 2009 : A powerful 7.8-magnitude earthquake occurred in New Zealand’s South Island, near the city of Invercargill. No one was injured, nor was there any major damage. The region, South Westland, is almost uninhabited, and the quake was centred 35 kilometres under the sea off its coast. An earthquake of this intensity could have caused destruction on a massive scale had it struck near the heavily populated capital city of Wellington.

Radio New Zealand reported that people living hundreds of kilometres away from the epicentre felt the tremors. The Pacific Tsunami Warning Centre in Hawaii, USA, warned that there might be a tsunami after it recorded a slight rise in sea levels. The warning was later cancelled. The quake was felt as far away as Sydney, Australia. A performance at Bondi Pavilion there was cancelled and theatregoers rushed home fearing a tsunami strike. Some people were also evacuated from residences on Lord Howe Island between Australia and New Zealand.

More than 16 hours after the initial quake, four strong aftershocks struck South Island’s Fiordland. New Zealand authorities have warned people against entering the remote national park in the area. An extensive aerial search of the South Westland region continued. Ground parties were checking on hikers who were known to be in the area.

More than 14,000 earthquakes are recorded annually in New Zealand, and this was the biggest since February, 1931, when a 7.8 quake killed 250 people in North Island’s city of Napier. The biggest quake ever recorded in the country was of 8.2 magnitude in 1855. That destroyed most of the present day capital city of Wellington.

Note: The magnitude of earthquakes is usually measured on what is called the Richter scale. The Richter scale measures the largest seismic wave recorded for the earthquake. These magnitudes are based on a logarithmic scale, or base 10. This means that for each whole number you go up on the scale, the intensity of the earthquake goes up ten times.