Archive for December, 2005

Local earthquake noisy, but light

Tuesday, December 13th, 2005

This evening’s magnitude 4.5 earthquake near Porirua at a depth of 30 km was noisy, but light. The earthquake had a noticeable P component, the initial jolt that is felt when the faster P-wave passes through, followed about 5 seconds later by a noisy S-wave which had a distinct vertical component that made roofing iron rattle and could be felt through the floor as the rumble was heard.

The absence of goods rattling in cupboards has been remarked upon here in Tawa, owing to the absence of horizontal shaking on firmer ground. Lights and other suspended objects hardly moved.

As the Pacific Plate slides under the Australian Plate, it has to be expected that these events will occur under our feet. Tonight’s earthquake follows a magnitude 5.0 earthquake at 25 km depth further east (to the south-west of Weber) near the subduction interface at 2:55 this morning.

On a pleasant still evening in early summer, many people would have noticed this quake, as it was rumbly and the vertical movement would have made house components emit noises, rather than contents like crockery, glassware and cutlery rattle.

Further north, on the soft soils of the Kapiti Coast, a more pronounced swaying may have been evident.

Here at Tawa the birds, who were packing up for the evening and heading off to their nests, sang throughout the event, and seemed unconcerned.

Site Guide added

Tuesday, December 13th, 2005

A new page with tips on how to navigate this site has been added today.
You can access it by clicking on the “Site Guide” link on the upper right of the main page.

Additional tips will be added over the coming weeks.

Taking Stock

Monday, December 12th, 2005

No, this isn’t a post about shoplifting, even though that’s a topical “sport” that attracts more practitioners at this time of year. I guess they missed the point in the “goodwill to ALL men” phrase that applies to shopkeepers as well as the rest of us. Anyway, shops are heavy things, and lifting one might cause a hernia.

This blog has been running since November 21st, so I thought it was about time that I took stock and considered where it was going.

I have usually managed to post something new every day, but yesterday I was too busy. Blow me down, the number of visits doubled. I really must make an effort to not write more often! 🙂

Despite humid conditions yesterday, the sun managed to appear for lengthy periods and a welcoming draught of rain passed through in the late afternoon. There was a neighbour who needed some help with a project. Then a pleasant hour was spent leaning on a fence “jaw-boning” with other neighbours and looking across our nice leafy part of the suburb, being serenaded by a tui sitting atop the tallest tree in my garden. I suspect the tui was telling me to stay over at the neighbour’s and leave my garden to him. He and his wife were a bit grumpy when I disturbed them shredding a flax bush on Saturday. Tui don’t seem to fear humans and will quite happily fly noisily past your head if disturbed – the bird equivalent of road rage?

Another pleasant hour was spent catching up with a friend over an ale, listening to the birds singing away in the garden. Later the birds patiently queued up for a cooling dip in the bird bath – well the smaller ones did the queueing, while the bigger ones like blackbirds simply dropped straight in with a splash. SHIP rules – Size Has Its Privileges.

A couple of hours in the workshop drilling holes in things was next on the agenda. Another project nearing completion.

A bit of gossiping on the phone. A toothsome repast to be dealt to. Dishes to be scrubbed, some radio to be listened to – “Sounds Historical” on National Radio. It’s one of the few programmes that the dweebs managing National Radio haven’t managed to “dumb down” as part of the current revamp. I suspect that the assorted dispsticks, dorks and dingbats that are responsible for the new “format” don’t actually listen to the station on Sundays. The first-rate morning show with Chris Laidlaw and Jim Sullivan’s historical programme have survived intact. But I bet they flinch every time a shadow passes over them in the studio just in case it’s the grim reaper from the management team popping in “for a wee chat.”

I sometimes wonder if National Radio’s management are lacing the tea in the “caf” with grumpy pills the way “Moaning Report” and “Checkpoint” have headed down the gurgler in recent months. The tendency toward aggressive interviews and pushing a point of view despite the interviewee’s best attempts to get a word in seems to be the order of the day. This technique may suit those listeners with a short attention span, but is a stark contrast to the other presenters who provide a steady diet of “brain food” in the form of thoughtful interviews, interesting snippets, and panel discussions with people who actually have something useful to say.

But back to the blog. I’ve had a surprising amount of feedback on the blog – mostly about what people don’t like which is a surprisingly good result. Kiwis, like many people, usually vote with their feet when they don’t like something – its unusual for them to take the time to constructively criticise something. Perhaps we don’t like to run the risk of hurting someone.

“That’s NOT a blog.” “Sometimes the articles are too long to read.” “No pictures.” “Too many different topics.” “Sometimes I can’t work out what you are on about without reading the whole thing, and my time is sometimes limited.”

Hmmm. Food for thought there. Watch for a new page called “Site Guide” or somesuch which will give you an overview of how this blog works. Just as blogging was new to me when I started this malarkey, I suspect it is also new to some of the readers. There are shortcuts and most items have a precis – finding them may be the challenge.

As to the comments about what people like – well I won’t mention them here, but the feedback has been appreciated.

To mention the good stuff would be too much like blowing my own trumpet and, in my case, I’d probably get it wrong and suck when I should blow, and end up with a trumpet in me throat. Then you’d have to put up with me “parping on” instead of harping on.

‘Tis the Season to be … confused

Saturday, December 10th, 2005

With the first week of December bringing warm, humid and often foggy weather, thoughts turn to the prospect of a nice summer. NIWA seem to be forecasting a dry summer for many, and several areas already have drought conditions in effect.

After a dry November with only 12 mm of rain, December has already served up 24 mm of rain in Tawa under warmer conditions. This is not unusual, as I can remember several Christmas weeks over the years when the weather was humid and foggy with days of misty rain. But what of the other signs of summer arriving?

One of the miniature Christmas lilies was overzealous this year and, having opened a nice burgundy-coloured bloom, bravely shivered through November’s return to cooler temperatures. Its mates have now put forth flower bracts, but seem to be holding off for the moment, casting smug looks at their now shrivelled mate. One of the potted curiosities that I inherited with the house, I am presuming that these are Christmas miniatures, simply because they look like miniature burgundy versions of the pink and white, but larger, Christmas lilies I remember from days long ago.

The annual migration of stick insects and wetas into the house to escape the dry conditions outside has suddenly stopped. It will start again soon, no doubt. Of all the local wildlife, these are the fiddliest to deal with. Stick insects freeze when you try to move them and grip tightly to the surface that they’ve settled upon. Over-zealous intervention with a fastidiously held sheet of cardboard results in their fragile legs falling off. The best method is to get a short sprig of something green and gently encouraging them to hop on board for a free trip outside. Patience is required, although it only takes a minute or two. Provided its not too spicy like a piece of pepper tree or a sprig of rosemary, just slowly bring the greenery up against the stick insect’s feet in a very slow sweeping motion and they’ll eventually step onboard. They think and move slowly, but a good indication that they are going to co-operate is when they start swaying back and forth on their legs as if playing a game of “I will, I won’t…”

Wetas can be more problematic as they jump when surprised, and generally react like this to sudden bumps or if touched. Quick action with a wide-mouthed jar works, but again don’t get them excited by bumping the surface that they’re on or else they’ll be off with you in hot pursuit. Pop the jar over the top of the weta, and slide a thin sheet of cardboard across the opening, by lifting one edge. They’ll usually obligingly jump as the cardboard touches a foot and you can then complete sliding the cardboard across the opening. Its then a simple matter of taking the whole contraption outside and leaving the jar lying on its side in the garden so that they can move on at their leisure. Wetas may be a bit gruesome to look at, but they’re one of our unique insects and are superb predators in the vege garden, I’m told.

Some early wasps are about, but I haven’t seen a honeybee recently. Bimbly bees are about, but in lower numbers than early November which is alarming.

The cicadas struck up a raucous garden symphony on Wednesday, when we had a warm, still day. Since then, they’ve packed up and moved to drier climes, I suspect.

People are starting to decorate their houses with Christmas lights – this isn’t much help in predicting summer weather, but it does confirm that the theoretical summer season is upon us. For a great display of over-zealousness in Ross-on-Wye in Herefordshire, take a look at the latest edition of Wyenot News on the ‘net (can be found with a Google search). Obviously the UK doesn’t have a winter-time power crisis of the sort that we might be facing next year!

The last word in summer prediction has to be left to the pohutukawa trees – many allege that early flowering is the precursor to a long hot summer. My three large specimens are hedging their bets, I’m afraid. One has no sign of bloom, the middle one has a few small flowers, the third has many flower buds but hasn’t cranked them open yet. The surest indication of nature having “a bob each way” (???)

In the meantime, as I wrote this, Tawa again disappeared. My normally pleasant view across the valley is currently one of a few indistinct shapes in the fog. Could whoever stole Tawa bring it back, please?

A brief history of telegraphy in New Zealand

Friday, December 9th, 2005

Musing on the old telegraph network reminded me that it had an interesting evolution. Telegraphy was basically a messaging service, and therefore quite distinct from telephony which is so universally embraced by the public.

Initially, New Zealand operated a fixed-line telegraph service, employing mostly men to send messages via morse code. Small private links were established at first, slowly forming a network that covered much of the South Island and linked into Wellington with the commissioning of a Cook Strait telegraph cable in 1866.

Progress was slower in the North Island owing to dense bush cover, land disputes and rough terrain. A telegraph cable to Australia was commissioned in the late 1870s, not long after a link between Wellington and Auckland had finally been established. The network slowly expanded into the regions during the 1870s and 1880s.

Even as late as World War II, it seems that much of the telegraph traffic was sent by morse code, but via multiplexed circuits. The first telegraph machines were introduced in the 1920s but they still worked alongside morse until the early 1960s.

The Telex service, which offered users of teleprinters the ability to dial other customer’s machines, was commissioned in 1964. The service used step-by-step switching specially adapted from the telephone exchanges to switch the 80 volt telegraph circuits. By the 1970s, from memory, there were telex exchanges at Auckland, Wellington, Christchurch and Dunedin. Subscribers had 4 or 5 digit telex numbers. Telegraph systems allowed customers in the regions to receive a telex connection via a long-line connection to one of the city exchanges.

Inward international calls were automatically switched at Auckland, but outgoing international calls required the intervention of an operator in order to manage billing. Making an international telex call involved calling the international telex operator at INTELEX and typing in the call requirements. The international circuit would be established, right through to the remote answerback being triggered before the operator exited the circuit with a GA+ (Go Ahead). On call completion, the intelex operator called back with a message detailing billed minutes etc. As far as I know, all outward international calls were made on the “price required” basis, which involved a follow-up call with billing charges.

It was early in the 1980s that the step-by-step telex exchanges were replaced with a stored programme controlled (SPC) exchange located in Wellington. However, by this time, telex growth was minimal, with the 300 bps Datex service offering an enhanced service. This was the beginning of packet switching, and the days of Telex were numbered.

Telegraph Service Remembered

Thursday, December 8th, 2005

The sound of a message unrolling before your very eyes as it arrived on the 50 baud teleprinter or telex machine, is something that is hard to forget. It might have been a news story arriving from NZPA at one of the local newspaper offices, or a much anticipated order for goods arriving from overseas, or an imperious message arriving from Head Office instructing that something be done IMMEDIATELY.

All in upper case. Text in black to show it was an incoming message. The thrill of seeing the words being written at a constant rate across the page, the printhead rising and rotating to position each character to be struck against the ribbon to print a letter or number on the paper held in place by the platen. And, as the printhead reached the right-hand edge of the page, the sickening lurch to the left that shook the printer and table as it prepared to print the next line.

The whine of the motor starting was the sound that alerted you to an incoming message. Then the familiar sound of the answerback code RADPHON NZ31010 being printed in red to identify it as local text as your machine identified itself to the caller. A slight pause as the sender obligingly transmitted their answerback code before sending the message.

Another pause, and the message started. Haltingly, if the sender was typing, rhythmically, if they were sending a pre-typed message from a paper tape. At the end of the message the caller could activate a bell on your terminal if they wanted a response immediately by pressing the BELL key. “Ting!” or ” ting, ting, tinga, ting!” if they were impatient or jittery.

Otherwise the caller could simply disconnect after following the etiquette of pressing the IAM key and printing their answerback code at the bottom of the message, followed by the WRU (for “who are you”) key to trigger your machine’s answerback code.

And then silence. “Rrrrrrrrrrr!” As you pulled the top of the message to bring all the text from under the glass. “Thriiiiiip!” as the paper was pulled forward and along the cutting edge to separate it from the roll.

Sounds of the past. Sights of the past. The early teleprinters (like the Creeds and Olivettis) came supplied with metal tables to carry their immense weight – many went on to have long careers in the garages and workshops of the blokes who maintained the telegraph networks and equipment – long after the printers had been laid to rest.

New Zealand operated an 80 volt telegraph network for much of the 20th century. Signals between the machines and the network used a bi-polar +/- 80 volt baudot code which was the bane of any technician who had the misfortune to come into contact with the 160 volts of a telegraph signal in full flight. It felt as if a nest of rats was trying to eat its way out of your arm!

There were several private point-to-point and broadcast telegraph networks for press, large companies and the public telegraph service. There were switched networks too. The better known telex network which allowed business and government to exchange messages and, of course, the gentex service which made telex facilities available to those without a telex machine.

Remember those yellow forms with terse messages (sometimes contrived using incomprehensible shorthand) trying to convey as much information within the chargeable limit? These telegrams could be sent by completing a special form at any Post Office and were usually addressed to a person at a particular telephone number. The teller at the Post Office would stamp the form with a “thock!” and the messages were despatched in batches to the nearest telegraph office.

Telegraph operators would type the messages into the network, and their counterpart at the receiving end would cut and glue the message onto one of the ubiquitous yellow “inland telegram” forms. The message would be telephoned to the recipient, and the form annotated “telephoned.” If the recipient couldn’t be contacted, the form was marked “NR” for no reply and set aside for another attempt. The contact was usually attempted at half-hourly intervals and a “NO REPLY” stamp was applied to the reverse of the form providing a history of attempts to telephone the message through, showing times and the initials of the operator at each attempt. Once the telegram had successfully been delivered by telephone, it was (in the 1970s and 1980s) placed in one of those distinctive brown window envelopes marked TELEGRAM in blue and delivered in the post.

Charging for telegrams was simple, although I’m a bit vague as to the initial word count limit. It was a flat rate for a minimum of 12 words, with an additional fee for each word thereafter. The minimum included the recipients details, so these were usually brief such as “Bruce Kawerau 54321.” It was unnecessary to include the word “phone” in front of the telephone number or a salutation in front of the name, although many inexperienced users of the service did so, thereby reducing the number of words available to convey the message.

New Zealand’s telegraph network was decommissioned a few years back, after more than 120 years of service. It had become redundant as people used cheaper telephone calling rates, facsimile and email to convey their important news.

Earthquake Pre-detection

Wednesday, December 7th, 2005

Earthquake prediction or perhaps more precisely earthquake forecasting is something that still eludes scientists. Despite some well-known successes, the failure rate of earthquake forecasts is still extremely high – even from the clairvoyants who claim knowledge of an event from time to time.

The groundwork which will enable more accurate scientific earthquake forecasts is being carried out by seismologists worldwide. They are already able to indicate that certain areas are at a higher or lower risk of experiencing an earthquake, based on studies of previous events.

Earthquake catalogues for New Zealand have been compiled from historical records, studies of known earthquake faults and, in more recent times, instrument recordings. Seismologists are now studying these catalogues, looking for patterns such as foreshocks which might give warning of a coming larger event and the cyclic nature of previous earthquakes. The significance of earthquake swarms, periods of frequent earthquakes and the role of quiet periods is also being studied. Scientists are also monitoring the build-up of stress in the earth as plate and fault movements occur, in the hope that they can detect when the strain has to be released in an earthquake.

A news item in a programme for radio buffs broadcast on WorldFM caught my attention yesterday. The briefly mentioned item on “This Week in Amateur Radio” reported that radio signals had been detected prior to some of the larger recent earthquakes. This alerted me to two recent studies.

The first involved the study of Very Low Frequency pulse (VLF) signals in the 1-10 kHz range that were emitted days prior to earthquake events. The challenge facing the Japanese scientists studying this effect, is that lightning also causes pulsed radio transmissions in this frequency range and at a far higher rate.

The second study involved a drop in the background level of radio frequencies (RF) days prior to an earthquake. A device which converted the RF signal from an aerial to direct current was connected to a monitor. The device was effectively measuring the combined effect of signals from broadcast and other radio stations as well as noise generated by vehicle ignition systems, computers, TV sets etc. For some reason, it appeared that radio propagation was reduced by some effect days prior to an earthquake.

Several explanations for these effects have been put forward, but further research is required. It is known that the compression of rock as the strain builds up prior to an earthquake causes small anomalies in the local magnetic field and this may affect radio propagation. It is also known that crushing of rock causes energy to be released in the form of heat and electricity, and perhaps RF signals are emitted at some point in the process.

So. Why a couple of days before an earthquake? Completely separate studies back in the 1960s detected an effect called dilatancy which occurs as rock is squeezed when strain in a region builds up. As pressure builds toward a rupture, the rock becomes temporarily stronger as cracks form and fluid content changes. Propagation rates for vibration from distant earthquakes also change in the region affected until things return to “normal” after the rock fails and an earthquake occurs.

All of these observed effects occur at different times before an earthquake, but seem to be different parts of the process.

This work in detecting events leading to an earthquake is effectively pre-detection, and is an essential step on the way to more accurate forecasting.

Summer Storm

Tuesday, December 6th, 2005

We were treated to one of those refreshing summer storms this morning, and commuters stuck in their cars during an accident-induced snarl-up had an entertaining diversion – watching nature “do her thing.”

The day started normally, with sunrise at 6 a.m. and commuters began taking to their cars for the commute into Wellington. At about 7 a.m. a truck accident occurred in the northbound lanes of the urban motorway, north of the Aotea Quay onramp, and the truck ended up crossing the median barrier and blocking some of the southbound lanes.

City-bound traffic began to build up and, by just after 8 a.m., traffic was backed up to Melling on SH2 and north of Tawa on SH1. Tawa commuters found traffic at a standstill trying to access both the motorway and the direct route to Johnsonville, Middleton Road, and were forced to join in as Main Road became a virtual carpark. Light levels began dropping as cloud lowered and thunderstorms rolled in while the rain started. By 9 a.m. it was very gloomy, and commuters in their halted vehicles were treated to a free fireworks display, as nature presented her pyrotechnics to the accompaniment of booms and rumbles.

In Tawa the wind changed to the east and thunder and lightning activity increased as the rain rate passed up from 3 mm/hr through 13 mm/hr to 19 mm/hr. At 9:35 the wind rose and began gusting from all points northward of west and east, the rain rate dropped and the sky began lightening again.

By 10 a.m. rain had eased still further and the traffic tailback began to slowly clear as the offending truck was cut away from the motorway barrier. One local commuter reported a one and three-quarter hour commute to work.

The Tawa weather station recorded 11 mm of rain between 8 and 10 this morning, 1 mm less than November’s total.

Other figures from around the region – Mana 6 mm, Whiby 7.8 mm and Lower Hutt 9 mm between 8 and 10 a.m. Lightning strikes reported at Whitby between 8 and 11 a.m. were 41, with 68 strikes reported at Lower Hutt.

Welcome to summer!

Seven Minutes’ Warning

Monday, December 5th, 2005

There has been increased and timely attention to the matter of tsunami since the Boxing Day earthquake and tsunami that struck in Asian waters. The seismically quiet conditions in New Zealand in recent decades have made us more complacent about such things.

On the 26th of March 1947, a fairly heavy earthquake near the North Island’s East Coast at 8:33 a.m. was followed by two seismic waves which affected the coastline between Tokomaru Bay and Mahia.

The first surge swept ashore seven minutes later at 8:40 a.m. with the waters rising 25 feet above normal at Pouawa. “Mr and Mrs A.F. Hall, who had a beach cottage at Turihaua Point, had an alarming experience. They were in the kitchen with a lady visitor when the first outsize wave rolled in. With the water up to his neck, Mr Hall held onto the mantelpiece, and the women clung to him.” They reached a safe spot before the second wave came ashore a few minutes later.

The larger wave reached up to the windows of the hotel at Tatapouri (known as the “Tata” in my day), carried furniture from the bar and swept away some small buildings. The superstructure of the 36-year-old wooden bridge over the Pouawa River was carried half a mile upstream.

A sobering reminder to be aware of the risk of tsunami when earthquakes are felt on the coast. Currently, there is no hard-and-fast rule as to whether an earthquake will or will not produce a tsunami in a specific area. However, much work is now being done to identify areas at risk. The real challenge will be how to alert people to a tsunami that is generated close to shore.

Achieving a balance between our desire to live a normal life in these desirable coastal areas whilst limiting the risk that tsunami impose is a sensible aim.

[Some data from “Historic Poverty Bay and the East Coast, N.I., N.Z.” J.A. MacKay second edition, 1966]

Summer food crops

Sunday, December 4th, 2005

As summer approaches, my mind turns to the wonderfully toothsome New Zealand produce that will become available as the months roll by.

The organic asparagus that appears in honesty boxes at Marahau is the first of the spring crops to kick my taste buds into gear, if I’m in the Nelson region. Commercial asparagus was in good supply this year and very tasty indeed. Chopped raw into a salad or lightly steamed and dressed with a bit of garlic and parmesan, it’s hard to beat.

The hass and hayes avocadoes have been in good supply lately, unlike last year’s crop. Avocado on toast with shavings of tomato and a crackling of pepper is a breakfast favourite, while chicken and avocado sandwiches make a refreshing lunchtime snack. Firm avocado gives a great lift to a salad, and there’s always guacamole dip which can be whipped up in a jiffy for unexpected guests.

Looking ahead, jersey benne potatoes from Oamaru make great potato salad to accompany the Christmas holiday barbecues. Chopped fresh green-skinned onions add real zing to the recipe which demands some of that tasty Nelson mustard. The banquet can then be finished with lip-smacking black cherries which are grown, along with the later red varieties, in both the North and South Island.

Gisborne’s juicy tomatoes such as the beefsteak variety are a welcome accompaniment to summer steaks, and look great snuggled up against a steaming fillet dressed with a sliver of a light blue cheese. Then there’s the little taste bombs – the cherry tomatoes – that explode as you crunch on them.

Early in the New Year the tree-ripened summer fruit starts arriving – sweet apricots, juicy nectarines, peaches and grapes. A nice summer treat is frozen grapes straight from the freezer that can be sucked like sweets on a hot day.

Not to forget peas, scooped out of the pod, still warm from the sun if you’re lucky enough to know someone who grows them.

The news of Gisborne’s second flood in just over a month made me wonder how things were going for crop growers around the country. It’s a mixed bag – some are smiling, some are facing ruin – owing to the southerly conditions that dropped temperatures, hurled hailstones in some places and dumped 200 mm of rain on Gisborne’s hastily replanted crops.

Despite the rain and large hailstones that fell north of Auckland and piled up like snow on November 26th, part of Northland is experiencing a drought, as is Taranaki. Cooler temperatures have slowed the onion crops in the upper North Island, but there’s still hope that warmer weather will move things along.

Many of Gisborne’s crops have suffered, and tomato, squash and maize were hardest hit. Many crop growers worked frantically to clear silt from the Labour Weekend floods and replanted, but the downpour on November 28th destroyed the replanted crops. There is now insufficient time to prepare the land again, then plant and harvest another crop this season. Expect tomatoes and tomato-based products to be more expensive and less available this summer.

Hawkes Bay got a swipe from the weather with lower temperatures slowing grape crops and hail damaged some of the early cherry fruit. No news yet on the grape set, but fingers are crossed for a good vintage – especially in Gimblett Road where John and Brigid Forrest grow their cabernet for their tasty Cornerstone. Further south, Wairarapa is dry which is encouraging for some of the wine grapes.

Locals in Horowhenua tell me they escaped most of the chilly weather at the end of November, so I’m hoping that the market gardens around Otaki will be churning out great lettuce and capsicum crops soon.

News from Nelson and Marlborough is generally positive, the only sour note was a slowing of the grape crops while cherries and other pip fruit seem to be doing well. I’m hoping that Forrest Estate’s chardonnay crop in Marlborough is on target. Talk is of a drought this summer, so irrigation will be at a premium. The region is also well-known for its olives, and growers with irrigation will be looking forward to a long hot summer. Some of the oils produced have nearly as much flavour as the locally produced wines, and many wineries sell lip-smacking marinated olives by the jar and with lunch.

The biggest delight last year was a chance call at Stafford Lane winery near Nelson which featured a large range of local produce. Their lively sauvignon blanc and rich chardonnay were instantly added to the cellar (where they didn’t last very long) as were several jars of their marinated olives. Further along the road the well-established Seifried Estate run by Hermann and Agnes Seifried had a surprise in store too. The Seifrieds have pioneered many different grapes and wine styles since they started in the 1970s, from the long-lamented Refosca to the innovative ice wines. Last year their Sylvia was a star addition to their range of reds.

Irrigation has been an issue in Canterbury in recent months, with drier rivers and hints that authorities are tightening up irrigation permits. Oddly enough the issue is with moisture at deeper levels, which is allowing crops to develop for the moment. The South Island, in general, has concerns over this year’s low run-off from snow-melt, which raises concerns over low river levels for irrigation and low lake levels for hydro storage. It seems that electricity might be a winter “crop” in short supply.

Otago is dry, so I’m hoping that Sue and Verdun Burgess at Blackridge can anticipate good grape growth this year. That also bodes well for Felton Road Pinot Noir which is a champion in my book, as is Peregrine’s.

But back to food to accompany the tipple, warmer soils in the south fill me with hope for Oamaru’s jersey benne crop. C’mon guys, grow, grow! The Christmas potato salads beckon.

Geological Summary for New Zealand area, November 2005

Saturday, December 3rd, 2005

Geonet, the USGS (NEIC) and IGNS reported 41 earthquakes in the New Zealand area between Raoul Island in the north, and the Auckland Islands to the south during November 2005. The magnitude distributions were as follows:
M5 to 5.9 (3), M4 to 4.9 (15) M3 to 3.9 (23).
An additional 4 events in the magnitude 2 range were deemed worthy of mention.

Four earthquake swarms, one in conjunction with a cluster of earthquakes, were reported during the month. A loose cluster of 8 earthquakes which had occurred in southern Wairarapa near Eketahuna and Martinborough since August 31st came to an end on November 11th.

A swarm of 9 earthquakes centred 10 km east of Seddon started on November 1st and ended its run on the 11th. An associated cluster of 7 earthquakes in the nearby area commenced on the 3rd and was represented by a magnitude 4.2 event on the 29th. Minor damage was reported following some of these earthquakes.

A swarm of 4 earthquakes between magnitude 3.3 and 4.0 occurred 30 km South of Wanganui between November 4th and 27th. Initially the first two events appeared to be a normal earthquake and aftershock sequence, but the continuing activity disproved this. A similar swarm of 5 earthquakes with a largest magnitude of 3.9 occurred in the same area between May 20th and July 4th this year. Two weeks later a swarm of 4 earthquakes with a largest magnitude of 3.7 occurred 20 km South of Wanganui between July 20th and August 5th.

The Mahia Peninsula hosted a short swarm of 3 earthquakes within 15 minutes, with magnitudes between 3.7 and 3.9 on November 16th. This area too had earlier experienced a similar sequence of 3 reported events (magnitudes 3.5, 3.9 and 3.2) on May 6th, 8th and June 10th.

Waiheke Island residents in the Hauraki Gulf near Auckland had the novel experience of feeling and hearing earthquakes on the 29th and 30th. Initial reports mentioned 3 events with magnitudes between 2.5 and 3.3 within 12 hours of each other in this area near to the Auckland volcanic field. Geonet issued a news release on 30th November, showing 6 small earthquakes within a period of 2 days near Waiheke, and described the events as “rare, but not unexpected.” Adding, “If magma started rising from deep within the earth, we would expect it to start causing earthquakes much deeper than 8 kilometres.”

The three largest earthquakes during November were:
A magnitude 5.3 quake, 33 km deep between The Snares and the Auckland Islands on November 7th, reported by Geonet. This was felt on Stewart Island.
A magnitude 5.6 earthquake 290 km deep located 10 km east of Tauranga on November 9th, reported by Geonet. This was felt in Napier, Palmerston North, Wellington and Nelson.
A magnitude 5.1 quake, 46 km deep located 400 km SSW of Raoul Island on November 25th, reported by USGS National Earthquake Information Centre.

Vulcanologists report the nation’s volcanoes to be quiet during November, with only two at Alert Level 1 (some signs of volcano unrest). Their status can be summarised as follows:
Mt Ruapehu (Alert Level 1). Seismic activity low, crater lake temperature rose 6 degrees to 36 degrees C in the last weeks of October.
White Island (Alert Level 1). Seismic activity continues at a low level, crater lake remains at 1 metre below overflow, as it has for the past few months.
Mt Tongariro (Alert Level 0). An increase in the usual number of small volcanic earthquakes was detected early in the month. The increased incidence continues.

On a lighter note –
Against the odds, Dino the pink dinosaur who took up sentry duty in front of the crater camera at White Island in May 2004, has survived the acidic conditions at the volcano. Initially it was expected that he would go the way of his ancestors within a few months. However, though he has started to lose his brilliant pink sheen, his hide has remained intact, and he still makes his hourly appearance on the Geonet website.

Dino, who is not on the GNS payroll, has done a wonderful job as an ambassador for the work being carried out by the scientists who regularly visit the island.

November 2005 drier than previous two years

Friday, December 2nd, 2005

With the proliferation of automatic weather stations, manual weather recordings for Tawa will cease at year’s end. Summaries of the readings taken over the 3 years to 2005 will be progressively published to provide background data for the recently installed automatic weather station.

These manual readings are obviously subjective, and represent the microclimate where the observations were made. However, gardeners might find the data of use in understanding germination, flowering and other crop problems.

Tawa’s climate during November 2005 was drier than the same month in the previous two years, but otherwise on par.

Readings taken at Tawa:
The lowest November temperatures were 3 (2003), 7 (2004) and 5 (2005).
The average daily low temperatures were 10 (2003), 11 (2004) and 11 (2005).
The highest November temperatures were 21 (2003), 24 (2004) and 25 (2005).
The average daily high temperatures were 18 (2003), 19 (2004) and 19 (2005).

Days with frost: none in any of the three years.
Days with rain: 11 (2003), 10 (2004), 7 (2005).
Days with thunderstorms: none in any of the three years.
Days with hail: none (2003), 1 (2004), none (2005).
Days with strong winds: 9 (2003), 13 (2004), 10 (2005).

No local flood events were recorded in the three years being summarised.

November is often one of our windier months, with the spring gales alternating between north and south, as the temperatures rise to their spring values. It’s a crucial month for vegetable gardeners, who generally plant their home vege gardens as close to Labour Weekend as possible, and then hope for a warm, calm November.

Northerly winds dominated November 2003, with nor’west gales and showers setting the scene on the 2nd. Calmer conditions set in on the 3rd until unusual strong easterlies arose on the 10th. The wind then turned nor’west and gusted to gale strength intermittently until calm misty conditions settled in on the 16th and the temperature dropped. Nor’west gales returned on the 20th and 21st and again on the 29th.

Northerly winds also dominated the beginning of November 2004, stripping home vegetable gardens of their crops. Gardeners were then treated to the sight of their missing garden plants returning briefly en route northward under strong southerlies at the month’s end. 😉

Calm, sunny conditions applied until gusty nor’westers arose on the 4th. The wind swung to the north and continued blowing until conditions briefly eased on the 6th. A gusty nor’easter arose late on the 7th, swinging to the north on the 8th from where it blew until early on the 10th.

Muggy humid conditions on the 14th heralded the arrival of nor’west gales on the 15th with gusts to severe gale until the 16th. Gusty northerlies on the 20th rose to nor’west gales later in the day. Still, sunny conditions set in on the 21st, with a brief spell of showers overnight on the 23rd. Strong southerly winds arose on the 26th driving temperatures down for two days as they eased amid foggy conditions on the 29th.

Sunny still conditions at the beginning of November 2005 raised hopes of a warm, calm spring. Maximum daily temperatures steadily rose to reach 25 degrees on the 8th, with only one brief period of gusty northerlies on the 5th. Daily maximums began a slow decline thereafter, remaining below 19 from the 10th. Cooler conditions applied until gusty north and northwest conditions set in on the 19th. The winds swung to the south on the 22nd, becoming gusty on the 26th bringing even cooler conditions which applied until still conditions set in on the 29th, allowing temperatures to rise again.

Local gardeners have reported trouble with bean crops since October, and the cool conditions have checked tomato and capsicum plants which were growing well at the beginning of November. Despite rain or drizzle occurring on 7 days, only 12mm of rain has been recorded this November, and soil moisture levels are very low. Homeowners have been irrigating for much of the month.