Earthquake and Volcano Safety

I wonder how many earthquakes in the Auckland area would be considered a worry?

The reason I mention this is that Auckland has recently had four small earthquakes about 30 miles east in the Waiheke Island area. Then, on Saturday, a newspaper has a front page picture and story about what the next eruption could look like, and how it would be shown at a display at the Auckland museum. Where is this imaginery volcanic eruption? Out at sea on the east side of Auckland. Bit of a coincidence.

Bet the local vulcanologists are keeping an eye on things.

Tsunami risk 'worse than quakes, floods'
20.12.05 1.00pm
By Kent Atkinson

The risk of a tsunami killing large numbers of people in New Zealand's coastal communities is high, compared with other hazards such as flooding, volcanic eruptions and earthquakes, a new report says. A serious earthquake on the Wellington Fault was expected to kill 1000 people at most, but a similar frequency one-in-500-years tsunami would kill over 5000 people, said the review of risk and preparedness compiled by GNS Science.

"The risk of multiple tsunami fatalities is high compared to other natural hazards. Many regions have intolerable and unacceptable levels of risk at regional level, as well as at individual level," researchers said in the report, released today by Civil Defence Minister Rick Barker. Many at-risk regions were poorly prepared for a tsunami.

The report on what can be done to improve New Zealand's tsunami-readiness systems was commissioned after last year's Boxing Day tsunami in Asia. The Indian Ocean catastrophe raised concerns about whether there would be enough warning to New Zealand of a tsunami from the Southern Ocean, the southwest Pacific or one generated close to NZ shores. Mr Barker was told a scientific review had shown relatively high levels of risk at a national level and in some regions, compared to other natural hazards, where warning systems were in place.

"Tsunami risk has not been paid sufficient attention," the report on preparedness said. Current warning systems provided barely enough time to issue a simple warning for a tsunami originating off the New Zealand coast.

Warning sirens are already going up on some beaches. In the Bay of Plenty, the first of 11 sirens that will cover the coast from Waihi Beach to Pukehina has already been installed by district councils, which fast-tracked their plans after the tsunami killed more than 231,000 people around the Indian Ocean's shores. The sirens - due to be in place by Christmas -- will be tested and a publicity campaign started to tell people how to react in an emergency.

Hugh Cowan, A geological scientist responsible for national hazard monitoring and warning systems has warned that coastal communities at risk of tsunami need to review their planning requirements for low-lying areas. Dr Cowan led New Zealand scientists in an assessment of tsunami damage in Thailand earlier this year and warned, before today's report was written, that planning requirements for low-lying areas should be reviewed. Prudent leaders in coastal communities would avoid development in high-risk zones, he said. In some cases low-lying beach suburbs might need to build refuges for people to climb above the waves.

Interesting to see a reference of the game "LEISURE SUIT LARRY" James.

I remember playing that game on my PC many years ago, pretty good too!

I never did complete it due to the fact that it was a damaged boot leg copy.
Gosh, that takes me back.

__________
Julian

As y'all may or may not have heard, the 100th anniversary of the Great San Francisco Earthquake just passed on April 18. Among all the commemorative articles, the SF Chronicle mentioned a booklet available on line, called 'Putting Down Roots in Earthquake Country', accessible via http://www.earthquakecountry.info/. Although the two versions are aimed at people living in the SF Bay area or Southern California, the information is useful for anyone living near an active fault.

Personally, I don't think NZ does suffer from earthquakes. I think it's rabbit breeders spread around NZ that are producing monster bunnies like our Easter Bunny, posted a few days ago. They often refer to rabbits as 'Thumper' because of the thumping action of their back feet when alarmed. Judging by the size of these monsters, I think the earth must shake pretty badly when they get going, enough to spark off concerns about earthquakes.

Chained to quakes and eruptions
TUESDAY , 30 MAY 2006
By MATTHEW TORBIT

Don't panic: an apparent surge in earthquakes and eruptions in the southwestern Pacific is par for the course in Earth's most explosive zone. The 40,000-kilometre Pacific Rim of Fire begins in New Zealand and curls its way northward around the edge of the Pacific Ocean to South America, with about 90 per cent of the world's earthquakes and 75 per cent of known volcanoes on its boundary.

Nearly 5000 people were killed in Indonesia after a 6.3-magnitude quake struck near Yogyakarta on Saturday morning. Volcanic activity has resumed at nearby Mt Merapi. Two powerful quakes – even stronger than that which rocked Yogyakarta – struck within 15 minutes of each other near Papua New Guinea and Tonga on Sunday. In Vanuatu, four volcanoes are being monitored after three began spitting rocks, ash and steam.

A magnitude-5.5 quake struck the north Philippines on Sunday night. But GNS Science geologist Cornel de Ronde said the apparent surge of activity in the Pacific Rim of Fire was 'perfectly normal'. 'Geological history tells us that these sorts of events have been going all the time in the past,' he said. 'Ultimately all these recent events are linked by virtue; they are all on the ring of fire but you cannot directly connect them as being triggered by one another, or being a precursor to other events.'

Dr de Ronde said the Rim of Fire was marked by the boundary between the Pacific Plate and some smaller adjoining tectonic plates. The Pacific Plate was being slowly shunted under adjoining plates on its western edge, causing earthquakes and chains of volcanic activity. 'As the plate goes down it gets to a point, about 200 kilometres deep, where it melts into magma. As a consequence we get all these earthquakes and volcanoes popping up.'

Dr de Ronde said New Zealand intersected a plate boundary and was part of the explosive chain. 'Lower Hutt is in the Pacific Plate and Wellington is on the Australian Plate.''

According to the United States Geological Survey, there have been an average of 19.4 quakes of magnitude 7.0-plus in the rim each year, which means the seismic activity of the past few days is comparatively slight. Earlier this month, a 7.8-magnitude jolt off Tonga sparked a Pacific tsunami warning. In March, Conservation Department worker Mark Kearney was killed when Raoul Island erupted.

Dr de Ronde said it was likely a lot of seismic and volcanic activity went unnoticed in the many chains of deep- sea volcanoes – known as arcs – that skirt the Pacific. New Zealand's volcanoes and earthquakes are monitored by the GNS Science GeoNet division, which is funded by the Earthquake Commission.

GNS Science seismologist Mark Chadwick said 40 monitoring stations 100km apart fed nonstop seismic information to laboratories in Wellington. New Zealand's volcanoes were also monitored by GPS, which detected subtle movements, and regular checks on crater temperatures.

Though the recent swarm of shakes and volcanic activity in the Rim of Fire was not an indication that disaster was pending, Dr Chadwick said the threat of a powerful quake or an eruption in New Zealand was ever present.

South Islanders, sleep soundly in your beds at night.

Deadly alpine quake predicted
Thursday August 24, 2006
By Jarrod Booker

An overdue alpine fault earthquake will strike 'out of the blue' and cause widespread death, shut down power generators, create tsunami within New Zealand and overwhelm emergency services, experts warn.  The major quake will cause intense shaking and rupturing along hundreds of kilometres of the fault line bisecting the South Island, geology experts Tim Davies and Mauri McSaveney predict.

'The most likely time [for the quake] is now. The next most likely time for it to happen is tomorrow,' Associate Professor Davies, of Canterbury University, told the Natural Hazards Management Conference in Christchurch.  'The longer the delay, the bigger it will be. It will occur with no recognisable warning. We can't manage it - we have to adapt to it.'

The pair have outlined a nightmarish scenario in the aftermath of the quake and are urging people to be prepared as best they can. Overseas help would be needed when the quake struck.  'There will be death and injuries, especially in the [Southern] Alps and West Coast. Rescue services and medical services will be overwhelmed, and remain so for weeks in places.'

'Shaking damage and land instability will disrupt surface transport for months, tourists will be trapped, and distribution of vital supplies (eg, food, fuel) will be limited. Hydro stations will shut down immediately and may be slow to restart, power reticulation will be damaged. Only satellite phones will remain in use.  No services will be as normal.'

The intense shaking would cause landslides of millions of cubic metres, damming rivers and later causing floods. Aftershocks could continue for months.  'Landslides into lakes and fiords may cause tsunami, as may the collapse of river deltas in lakes or the sea. Queenstown, Milford and Wanaka are likely sites of tsunami damage.'

The pair say the Alpine fault quake is a certainty. It is only a matter of when.  'The interval since the last event (in 1717) is longer than any interval between known earlier events'.

Plans needed to be developed now for the worst-case scenarios, with relocation of 'obviously perilous' facilities, buildings and infrastructure, with spare equipment and supplies stored in safe locations.  Tour bus operators were urged to stock up on food and supplies for their customers who could likely be trapped for days in isolated locations.

Experts at the conference have also warned of the risk of a deadly ocean tsunami striking New Zealand.  The country had experienced tsunamis in the past, but modern shoreline development has made it much more vulnerable, according to GNS expert Kelvin Berryman.  If warnings and evacuations were not carried out in time, an estimated 5000 people would be killed by waves up to 8m high on the east coasts of New Zealand.

That article came out two years ago and it keeps coming back when news is scarce or they feel they ought to remind people. It was that story that put husband off moving to the South Island, though the North Island can have its fair share of quakes ... with volcanic eruptions thrown in.

I think Kiwis are a bit too relaxed about the subject, probably hoping it will not happen in their lifetime, or to them personally. Indeed, the years do go by without any serious disaster. I certainly would not live anywhere at sea level near the coast, and do prefer single-storey houses in case a quake hits.

Even if the 'big one' does hit tomorrow, I still would not be persuaded to go back to the UK.

:icon_biggrin:

Our own little bit of earthquake excitement ... and we didn't feel it. :(

Apparently we had a 3.5 earthquake last Sunday morning, epicentre just 20km from here. Bit of excitement as it is the first since 1963. Guess we will have to go further south to experience the 'real thing'. ::)

More scaremongering.

Natural disaster due - expert
01 October 2006
By GREG MEYLAN

New Zealand is a country coming apart at the seams. Or, more accurately, subducting at the seams of two continental plates, making it periodically shake, crumble, explode and prone to tsunamis.

As part of Te Papa's Earth Rocks event on Labour Weekend the museum has organised a panel of experts to answer the public's questions about how best to survive the earthquakes, tsunamis, volcanoes or landslides that come with our geology.

Panel leader Dr Hamish Campbell of GNS Science said New Zealand was one of the most geologically active places on earth. Our farms, homes and forests are perched on an unusually thin skin of the earth's crust at the boundary of two tectonic plates.

The panel expects questions such as the best place to find cover in an earthquake, where the most dangerous place to live is, which volcano is likely to erupt next, who provides insurance cover in a landslide and how to escape a tsunami.

The natural threats to New Zealand were widespread and, statistically at least, several of the most dangerous were due to go, Campbell said. "A full-scale Taupo eruption would literally take out all of the North Island," he said.

Lake Taupo erupted an average of once every 950 years but has not erupted since 181AD. Its largest known eruption left half a metre of volcanic debris on the Chatham Islands 1000km away. The Alpine fault, which runs the length of the Southern Alps, is due a major move that would shake every city in the South Island, Campbell said, flattening many houses.

Evidence of the last time the Alpine fault moved include a large area of southern beech forest in which every standing tree was snapped off at the trunk.

Landslides were less apocalyptic but more frequent and were the most common cause of destruction to property. In Auckland, it was only a matter of time before a new volcano appeared and began oozing molten lava.

"There is ample evidence to show there is plenty of activity going on under Auckland. Auckland is built on a hot spot that is deeply rooted; the magma is coming from very, very deep down."

But that would be fairly benign compared to what scientists believed was in store for Wanganui. The ground beneath the city was regularly experiencing tiny tremors, indicating something big was building up. "We think there will be another volcano like Ruapehu smack on Wanganui," Campbell said.

To the west Mt Taranaki - with an eruption average of every 100 to 200 years - was also overdue. "It is like Mt St Helens (which erupted in 1980 in the US, killing 57 people), so you get very big blowouts and big bits collapsing."

Campbell said a report commissioned after the 2004 Boxing Day tsunami concluded the risk to New Zealand from a tsunami was probably as great as from earthquakes.

"And there is no part of New Zealand that is immune to earthquakes."