Sep 4 2008 - August roundup

Last month's progress and news within the GeoNet project.

Operations
The newly-operational Angora Road seismic site in southern Hawke's Bay.

The newly-operational Angora Road seismic site in southern Hawke's Bay.

  • A new seismic site near Wimbledon, Hawke's Bay, Angora Road (ANWZ) was made operational.
  • A new strong-motion recorder was installed at Eastbourne, near Wellington, Point Howard (PHHS).

Earthquakes

  • The most significant earthquake of the month occurred on August 25, magnitude 5.9, 10 km south-west of Hastings, 30 km deep. It was felt throughout the North Island (south of Auckland) and the top of the South Island, with damaging intensities of MM 7 and 8 in Napier and Hastings.
  • The preliminary locations of July's earthquakes are shown below.

Reported Landslides

  • Shotover River Landslide Response (161.26Kb)
    The GNS Science terrestrial laser scanner was again taken down to the Shotover River landslide (upstream of Arthur’s Point) to carry out a second scan of the landslide.

Friday August 1 to Tuesday August 5

  • Railway closed by slips between Christchurch and Picton. Road also affected.
  • Portobello Road and Sandymount, Dunedin, roads closed by slips.

Sunday August 3

  • Aro Valley, Wellington house evacuated after landslide beneath it. Slips also reported from Miramar, Kilbirnie, Mt Cook, Kelburn, Houghton Bay, Northland, Karori and Khandallah.

Monday August 4

  • Slip below house in Palliser Road, Roseneath, Wellington.

Tuesday August 5

  • Wellington: new landslides on Tinakori Road near Thorndon Quay intersection blocking one lane. Ohiro Rd, Brooklyn, one lane blocked by a slip near Penthouse cinema.

Wednesday August 6

  • Road to Eastbourne completely blocked by a slip at Point Howard about 9 pm. Open for one lane by midnight. A house above the slip was evacuated.

Monday August 11

  • Two slips below road SH 31, Hauturu placing road at risk.
  • SH 35 Tikitiki-Ruatoria blocked by subsidence at Kemps Hill.

Wednesday August 13

  • SH 1 affected by slip at Bombay.
  • SH 35 Tikitiki-Ruatoria dropout at Kemps Hill.

Friday August 15

  • Slip destroyed 100 m of water supply line at Redoubt Road, cutting off water for 3,000 Manukau houses.
  • First signs of instability noted at Kawakawa Bay.

Monday August 18

  • Slip closed one lane of Hunua Road, Papakura.

Tuesday August 19

  • Slip blocked access to Lyttelton Tunnel for 1 hour, Tunnel Road, Heathcote Valley.

Wednesday August 20

  • Northbound lane of SH 1 closed by slip at Waiwera, north of Auckland.

Monday August 25

  • Four houses evacuated in Unsworth Heights, North Shore, Auckland. Albany Highway and Condor Place cordoned off. A house in St Mary’s Bay was also affected by a fallen tree on a slip (a large pohutukawa) on the cliff below Ring Terrace.
  • Numerous slips reported in North Canterbury: SH 1 Christchurch to Blenheim affected by slips. Large slip affecting railway near Kaikoura reactivated (line was blocked 3 weeks earlier). Leslie Street blocked between SH 1 and Whales Back, and the railway was closed at Billy Goat Bay due to a slip. The inland road from Waiau to Kaikoura was blocked by several slips at both ends.
  • Petone Overbridge, SH 2 blocked by slip during the evening.
  • Slips reported on SH 35 between Tikitiki and Ruatoria (Kemps Hill), SH 31 near Ngutunui , SH 37 near Waitomo and SH 4 near Mapiu, but none of these roads were closed.

Tuesday August 26

  • SH 2, Rimutaka Hill – one lane blocked by slip halfway between summit and Featherston.
  • SH 1 near Oaro (south of Kaikoura) blocked by slip, Also SH 1 blocked by a slip at Weld Pass near Blenheim. SH 1 blocked by slips between Cheviot and Seddon.
  • SH 7 blocked by slips between Waipara and Hanmer Springs turnoff.

Wednesday August 27

  • Heavy rain causes 15 slips in Wellington large enough to block road lanes. Oban St (Wadestown), Seatoun Tunnel, Upland Road and Ngaio Gorge experienced the largest. 32 mm rainfall recorded at Kelburn.
  • SH 1 either side of Kaikoura now open for one lane in places.
  • Parnell baths closed by slip – carpark and walkway to Point Resolution closed. Slip behind the swimming complex left cracks at the top of the cliff through paved viewing area.

Friday August 29

  • Near Eastbourne, a Sunshine Bay house was damaged by a rock falling from the cliff above. Boulders and debris blocked one lane of the road, causing morning traffic chaos, and Eastbourne residents were advised to stay home. Note: no rain had fallen in previous 24 hours.
Felt earthquakes of July 2008.

Felt earthquakes of
July 2008.

Shallow earthquakes of July 2008.

Shallow earthquakes of
July 2008.

Deep earthquakes of July 2008.

Deep earthquakes of
July 2008.