Archive for March, 2006

Earthquakes Near Wanganui

Saturday, March 11th, 2006

Three earthquakes of increasing strength occurred near Wanganui during the early hours of this morning. The earthquakes, which occurred at the same location off-shore 30 km south-west of Wanganui, were all 30 km deep.

The first tremor of magnitude 4.1 was felt at 55 minutes after midnight, and followed 8 minutes later by a magnitude 4.3 event at 1:04 a.m. A slightly larger magnitude 4.5 shake was felt at 3:17 a.m. according to Geonet.

Geonet’s seismic drums indicate that a smaller quake occurred at 5:28 a.m. but they have yet to publish data on this event.

Swarms of earthquakes have occurred in the area in the past. In 2005, a swarm of 5 earthquakes occurred 30 km south of Wanganui between May 20th and July 4th, the largest event being magnitude 3.9. Earthquakes located near Otaki and Levin occurred at the same time.

A few weeks later, a swarm of 4 earthquakes up to magnitude 3.7 occurred – again in conjunction with a swarm of 6 events off the coast near Levin. On this occasion the Wanganui quakes were located 20 km south of the city between July 20th and August 5th.

Later in 2005, 3 earthquakes up to magnitude 4 occurred 30 km south of Wanganui between November 4th and 10th. This sequence of shakes occurred at the same time as a swarm of 12 earthquakes occurred near Seddon.

February 2006 Windier Than Previous Three Years

Tuesday, March 7th, 2006

Manual weather data has been collected at Tawa since 2003 and in 2005 it was augmented by the installation of an automatic weather station. This report blends the historical data from both sources to provide a 4-year climate overview.

The manual readings are obviously subjective, and represent the microclimate where the observations were made. The weather station is sheltered from the south owing to local topography.

Tawa’s climate during February 2006 was windier than the previous three years. In other respects, it was a mixed bag, being wetter and slightly cooler than 2005 while avoiding the flood episodes of 2004.

Readings taken at Tawa:
The lowest February temperatures were 5°C (2003), 6°C (2004), 9.2°C (2005) and 9.8°C (2006).
The average daily low temperatures were 13°C (2003), 14°C (2004), 16°C (2005) and 14°C (2006).
The highest February temperatures were 28°C (2003), 23°C (2004), 32.0°C (2005) and 27.4°C (2006).
The average daily high temperatures were 22°C (2003), 20°C (2004), 24°C (2005) and 23°C (2006).

Average February temperature: 19.6°C (2005), 18.2°C(2006).
Average February humidity: 81% (2005), 79% (2006)

Days with frost: none (2003), none (2004), none (2005) none (2006).
Days with rain: 6 (2003), 19 (2004), 5 (2005), 11 (2006).
Days with thunderstorms: none (2003), 1 (2004), none (2005), 1 (2006).
Days with hail: none (2003), none (2004), none (2005), none (2006).
Days with strong winds: 6 (2003), 7 (2004), 3 (2005), 13 (2006).
Flood events: none (2003) 2 (2004), none (2005), none (2006).
February Rainfall: 32 mm (2005), 69 mm (2006).

February 2004 was memorable as a stormy month, with heavy rain events on the 1st, 14th, 15th, 16th, and 19th. Whilst it had fewer days with strong winds, there were gales on several days and a near record-breaking gust of 180 km/h at Mt Kaukau on the 21st. The thunderstorm on the 19th was impressively noisy and lasted for over 2 hours.

February 2005 was a welcome return to warmer, calmer summer weather. Daily maximums began rising steadily from 23°C on the first, to a welcome 32°C on the 5th, after which they began settling back due to cloudy weather. My weather notes show that the cicadas celebrated the hot weather by striking up a symphony. 🙂

February 2006 had 13 days on which strong winds blew, according to manual records. This was almost double the next windiest year, 2004, and continued January’s windy trend. Otherwise the month was unremarkable apart from a downpour of 9 mm during which rain rates reached 72 mm/hr on the 10th. The short nature of the event meant that surface flooding was limited.

Whilst the maximum temperature failed to reach the giddy heights of 2005, most of the month was pleasantly warm.

The Gisborne Earthquake of 1966. Part 4: Fractious Times

Monday, March 6th, 2006

As Gisbornites set about sweeping up the rubble, repairing damage and returning to a normal life, a fractious interlude occurred during the week after the earthquake.


The Gisborne Earthquake of 1966. Part 3: The Aftermath

Sunday, March 5th, 2006

The scientific and engineering collaboration which resulted in a joint publication about the Gisborne earthquake of the 5th of March 1966 provides a valuable insight into the causes of, effects of, and restorative work required as a result of a large earthquake. Unlike a modern day report which would probably be toned down so as not to offend anyone, the conclusions and recommendations were clear and to the point.


The Gisborne Earthquake of 1966. Part 2: Facts & Figures

Saturday, March 4th, 2006

The magnitude 6.2 earthquake which caused considerable damage in Gisborne on the 5th of March 1966 was centred within 20 km of the city at a depth of 25 km. It struck at 11h 58m 57s on a Saturday morning.


The Gisborne Earthquake of 1966. Part 1: The Experience

Friday, March 3rd, 2006

Saturday the 5th of March 1966 started like any other late summer Saturday morning. Dairies were open for their weekend trade, but in Gisborne the town shops and offices remained closed as they always did in the days before the liberalisation of weekend trading.


Blown to Smithereens

Wednesday, March 1st, 2006

During February 1918, wreckage began to drift ashore between Cape Runaway and Wairoa. A ship’s boat bearing the name Bertha Dolbeer made the coast at Whakaki, parts of a ship’s hull drifted onto the beaches at Te Araroa, Tolaga Bay and Pouawa. Portions of benzine cases were found on Kaiti Beach.

The mystery deepened when a hat amongst wreckage at Te Araroa contained a pad made from a San Francisco newspaper dated 17/6/1917.

It soon emerged that a terrible fate had befallen the master and crew of the American-owned schooner Bertha Dolbeer, en route from San Francisco to Wellington. A fire had broken out among her cargo of 9,000 cases of benzine, and she had been blown to pieces off the East Coast.

[source: Historic Poverty Bay and the East Coast, N.I., N.Z. J.A. Mackay, 1949]