Canadian Underwriter

Little damage from 6.5 magnitude quake on New Zealand’s South Island

August 19, 2013   by Canadian Underwriter

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There were no serious injuries, but some damage to homes and roads when a 6.5-magnitude earthquake hit central New Zealand in the early afternoon of Aug. 16, reports catastrophe modeller AIR Worldwide.

Little damage after 6.5 magnitude quake in New Zealand

With New Zealand’s stringent building codes, the moderate magnitude of the event and the quake’s epicenter – on land about 10 km southeast of the South Island town of Seddon – AIR Worldwide notes that it does not expect significant losses from the earthquake.

A local media report from Aug. 19 noted that more than 400 claims had been filed with New Zealand’s Earthquake Commission by noon that day. Most of the buildings in Sedden received some damage, with a handful being rendered uninhabitable, added the report from New Zealand Newswire.

The quake, at a depth of 8 km, was felt widely across the country and damage has been reported, particularly in Seddon, New Zeland’s Earthquake Commission (EQC) noted in a statement following the event. Severe aftershocks have followed, EQC added.

“The earthquake caused light damage, but triggered many fears. Businesses evacuated properties for the safety of their personnel while building safety assessments were carried out,” notes a statement from catastrophe modeller RMS.

The earthquake follows a July 21 quake of the same magnitude “and is creating concern that a new sequence is under way, similar to the Canterbury Earthquake Sequence in 2010/2011,” RMS reports.

Wellington remains as the region with the greatest concentration of exposure at risk from the highest earthquake hazard, notes the RMS statement. “In addition to the expected ground shaking impacts from a significant earthquake, Wellington would likely have localized areas of liquefaction. Landslide is also a potentially significant contributor to loss,” it adds.

The region has experienced several small- to-moderate earthquakes in recent weeks, AIR Worldwide notes in a statement, all of which have occurred in the Cook Strait, which separates New Zealand’s North and South Islands.

“The (Seddon) earthquake was felt as far away as Christchurch, 240 km southwest, and Auckland, 404 km north,” notes Arash Nasseri, senior research engineer at AIR Worldwide.

About 80 km from Sedden in Wellington, AIR Worldwide reports the event was felt strongly. Items jiggled off shelves and some buildings were evacuated.

In Seddon, several homes suffered cracks, fallen chimneys, and collapsed roofs. An earth dam near the town, cracked during an earlier quake and in the process of being emptied over concerns about its safety, was further damaged.

Through Geonet, the New Zealand government reported several other weak or light quakes on the morning of Aug. 19, measuring magnitudes of 2.1 to 2.5.

Just days before the Seddon quake, EQC confirmed that the assessment following the Cook Strait earthquake cluster in late July was to begin Aug. 19.

Twenty assessment teams were to be split between the lower North and upper South Island to start assessing damage to homes, land and contents. All have completed an event-specific training and induction period, EQC reports.

An assessment of all claims is expected to take three to six months, the commission statement says, adding that a little more than 4,400 claims had been lodged as of Aug. 14. Of these, roughly three-quarters were in the lower North Island and one-quarter in the upper South Island.