Nov 12 2009 - October roundup
Last month's progress and news within the GeoNet project.
Operations
View of White Island crater lake, October 14 2009.
View of White Island crater lake, October 14 2009.
- A new communications hub was installed at Eltham in Taranaki to support the upgrade and expansion of the monitoring networks for Egmont Volcano.
- The camera located at the factory ruins on White Island was upgraded and installed at a new location, along with Dino the White Island monitoring mascot.
- A new seismic vault was built at the National Seismograph Network site Waipu Caves (WCZ), near Whangarei, and the equipment upgraded.
Earthquakes
- The most significant earthquake of the month occurred on October 10, magnitude 4.8, 20 km north-west of Wellington, 40 km deep. It was felt strongly in the Wellington region.
- The preliminary locations of September's earthquakes are shown below.
Volcano Surveillance
Wednesday October 14 - Gas flight over White Island
Flying conditions were good with the presence of high clouds. The wind speed was about 7 m/s. The SO2 flux increased but CO2 flux decreased since the last survey (September 8).
|
White Island Gas |
14/10/2009 |
08/09/2009 |
|---|---|---|
| SO2 emission (Cospec) | 197 ± 24 | 133 ± 7 |
| SO2 emission (Flyspec) | 265 ± 40 | 159 ± 11 |
| CO2 emission (Contouring) | 1141 ± 37 | 1579 ± 40 |
| H2S emission (Contouring) | 2.4 ± 0.1 | 2.4 ± 0.04 |
| SO2 emission (Contouring) | 87 ± 2.1 | 64 ± 1.1 |
Wednesday October 21 - Gas flight over Ruapehu and Ngauruhoe
The wind speed was about 12.6 m/s with clouds present at low altitude. SO2 was not detected on the Cospec and Flyspec, but measured on interscan, and H2S and SO2 were detected on the interscan meter.
|
Ruapehu Gas |
21/10/2009 |
07/09/2009 |
28/07/2009 |
|---|---|---|---|
| SO2 emission (Cospec) | ND | 10.5 ± 1.3 | 22.2 ± 2.1 |
| SO2 emission (Flyspec) | ND | 12.1 ± 2.9 | ND |
| CO2 emission (Contouring) | 405.2 ± 19.4 | 387.7 ± 42 | 398.6 ± 21 |
| H2S emission (Contouring) | 0.5 ± 0.1 | 0.075 ± 0.008 | 0.088 ± 0.006 |
| SO2 emission (Contouring) | 12.4 ± 0.5 | 3.3 ± 0.35 | 3.6 ± 0.18 |
Saturday October 31 - Ruapehu Crater Lake sampling
The lake was sampled both for headspace gases and water in the central vent area only. It was very windy at the summit (20 knots), proving difficult for water sampling by the helicopter. Upwelling was visible in the central vent area. The lake was well mixed and with a more green colour. Temperature measured was 22.9 °C in the central vent area, but as there was a time lag transferring the sample to the sampling site due to the high wind speed, this temperature is likely to have been higher.
There is an overflow occurring at the lake outlet.
Reported Landslides
Sunday October 4
- Heavy rain caused reactivation of the slip on Ohope Road between Cliff Road and Brown Road, Ohope Beach, blocking one lane for several hours.
Monday October 5
- Heavy rain caused a slip near a school at Welcome Bay, Tauranga, but the road remained partially open.
Friday October 9
- Heavy rain at Matata caused flooding and numerous slips on the road.
Saturday October 10
- A slip came down behind a house on Mowhanau Drive near Kai Iwi Beach, Wanganui.
- Slips affected SH 3 north of New Plymouth and SH 2, the Rimutaka Hill Road.
- Heavy rain at Matata caused flooding and numerous slips on the road.
Thursday October 15
- SH 6 between Renwick and Richmond was closed by a slip, but opened to one lane over the weekend. An initial slip of 500 cubic metres increased to 2,500 cubic metres as a result of further rain.
Sunday October 18
- SH 1 between Cheviot and Kaikoura was affected by debris on the road as a result of heavy rain.
Monday October 19
- A slip blocked Akatarawa Road between Upper Hutt and Waikanae near Staglands Wildlife Reserve. It was cleared the following morning.
Thursday October 29
- Heavy rain caused a slip on Tangahoe Valley Road north-east of Hawera, isolating 12 residents and cutting power to 5 rural properties. The slip was 80 m long and 6 m deep according to a council spokesman. It was expected to take 4 days to clear.
Felt earthquakes of
September 2009.
Shallow earthquakes of
September 2009.
Deep earthquakes of
September 2009.
