M7.8 New Zealand South Island Earthquake

Update 2 | Summary
Posting Date: November 17, 2016, 12:15:00 PM

More than 80,000 landslides and 2,600 aftershocks have been recorded following the massive earthquake that struck New Zealand’s South Island early this week. The temblor was the largest experienced by the country since the 2009 M7.8 Dusky Sound earthquake and one of the four most powerful since 1855. Recovery efforts in the region have been additionally hampered by gale-force winds, heavy rainfall, and flooded roads.

Reported Damage

The epicenter of the M7.8 earthquake was near the small tourist town of Kaikoura, which lies halfway between Christchurch and the capital, Wellington. Kaikoura was cut off by landslides and lost its power, water supply, and sewage system. More than 134 buildings have been inspected in Kaikoura, resulting in 13 red tags denoting unsafe for use as well as 39 yellow tags denoting restricted use. About 1,200 visitors and residents have been evacuated, and a local state of emergency has been declared. The seabed in the area has been raised by up to two meters in places, likely impacting the local fishing industry and the operation of the whale watching boats for which the town is noted.

Christchurch appears to have experienced far less damage than it did in the devastating earthquakes that struck the area in late 2010 and early 2011—but has not escaped unscathed. Damage in the Canterbury area may account for up to 30% of the total losses. Near Canterbury the historic Cobb Cottage in Waiau, built in the 1860s from clay, straw, and tussock, and now a museum, is one of the casualties.

Much of the region impacted by the November 14 event is rural and sparsely populated, but significant damage accounting for at least half of the losses from this event is reported in Wellington on the southern tip of North Island. Throughout the impacted region, glass has been broken in buildings, chimneys have collapsed, and some structural damage has occurred. Building contents breakage has occurred widely, and power outages, disruption of water and sewer services, and interruption of phone service are reported. Some highways and rail lines in the affected region have been damaged, and many bridges and tunnels were closed after the initial quake pending inspection. State Highway 1, which runs through Kaikoura, has been badly damaged and is blocked by a massive landslide; it is not clear if it will be repaired.

In Wellington some multi-story buildings experienced broken windows and contents damage, and the capital initially appeared to have escaped serious loss. Inspections, however, raised concerns about 60 or so buildings in the center. Adjacent buildings were evacuated when a movie theater parking garage was judged to be at imminent risk of collapse; it will likely be demolished. One of Wellington’s first high-rise structures, an office building on Molesworth St., experienced structural damage in the initial quake and incremental additional damage in aftershocks; it too is deemed to be in danger of collapsing. While parts of the central business district have been cordoned off because of damage to buildings, there is no “Red Zone” like the 859-day exclusion zone controversially established five years ago in Christchurch.

Much of the central business district and waterfront of New Zealand’s capital is underlain by soft sediments, which amplify ground shaking; liquefaction damage has been reported there and on the Picton foreshore. The waterfront area building that houses Statistics New Zealand and other government offices, for example, has experienced substantial damage and may remain closed for a considerable time. The floor of the Greater Wellington Regional Council building has reportedly sunk by around six inches. Port operations have been suspended until further notice by CentrePort because of shake and liquefaction damage to buildings and facilities.

New Zealand is well placed economically to rebound from the earthquake. Most residential damage will be covered by the government-owned insurer, the Earthquake Commission (EQC), which is backed by NZD 4.7 billion (USD 3.3 billion) in reinsurance. Businesses of 20 employees or fewer impacted by the earthquake can benefit from up to eight weeks of wage subsidies through a relief package announced by the government.

Loss Estimates

AIR Worldwide estimates that industry insured losses from the Mw 7.8 earthquake that struck New Zealand’s South Island near Hanmer Springs on November 14 will be between NZD 1.15 billion (USD 762 million) and NZD 5.2 billion (USD 3.5 billion). AIR’s insured loss estimates reflect take-up rates that vary by line of business.

ALERT^TM subscribers can download scenarios for the event, in addition to similar stochastic event IDs and a Touchstone®-ready shapefile of the estimated ground motion (peak ground acceleration) or the median scenario.

AIR's modeled insured loss estimates include:

• Insured physical damage to property (residential, commercial/ industrial), both structures and their contents from ground shaking
• Demand surge—the increase in costs of materials, services, and labor due to increased demand following a catastrophic event—although not triggered by this event.
• Direct business interruption losses

AIR’s modeled insured loss estimates do not include:

• Losses to uninsured properties
• Losses to land
• Losses to automobiles
• Losses to infrastructure
• Indirect business interruption losses
• Loss adjustment expenses
• Losses from non-modeled perils, such as tsunami, liquefaction, fire-following, and landslide

Update 2 | Downloads
Posting Date: November 17, 2016, 12:15:00 PM