Researchers find New Zealand more seismically unstable than previously thought

May 23, 2012 NEW ZEALANDResearchers have discovered New Zealand’s earthquake-prone landscape is even more unstable than previously thought, recording deep tremors lasting up to 30 minutes on its biggest fault line. Scientists measured the so-called “creeping earthquakes” when they investigated a puzzling lack of major seismic jolts along a section of the Alpine Fault, which runs the length of the South Island. The quakes, which caused no surface damage, occurred 20-45 kilometres (12-28 miles) beneath the Earth’s crust and continued for as long as half an hour, much longer than ordinary earthquakes. In contrast, the 6.3-magnitude quake that killed 185 people in the South island city of Christchurch in February last year lasted just 37 seconds and struck at a depth of about five kilometres. The quakes could not be measured by regular seismic monitoring devices and researchers from Wellington’s Victoria University had to place sensors in boreholes 100 metres deep to pick them up. Seismologist Aaron Wech said the research showed the Alpine Fault, regarded as New Zealand’s most hazardous, did not remain still between major earthquakes but was constantly shifting. Wech said the implications for future earthquakes were unclear. “It could be that constant tremor builds up stress and may trigger a major fault movement (earthquake) or, alternatively, the activity may decrease the likelihood of a major quake by acting as a release valve for stress,” he said. “What’s important is that we find out more about these tremor events, such as where they happen and how often, so we can better predict the hazard the Alpine Fault poses.” The research was published this week in the U.S. journal Geophysical Research Letters. The government’s GNS Science agency estimates the Alpine Fault has generated four quakes of magnitude 8.0 or higher in the past 900 years, most recently in the early 1700s, and another is overdue. It says there is a high probability one will occur in the next 40 years, producing “one of the biggest earthquakes since European settlement of New Zealand (which) will have a major impact on the lives of many people.” The Christchurch earthquake was not caused by the Alpine Fault but a previously unknown fault line, part of a network of seismic fractures criss-crossing New Zealand, which lies on the junction of two tectonic plates. -AFP
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This entry was posted in Earth Changes, Earth Watch, Earthquake Omens?, High-risk potential hazard zone, Potential Earthchange hotspot, Seismic tremors. Bookmark the permalink.

5 Responses to Researchers find New Zealand more seismically unstable than previously thought

  1. prayntongues says:

    On Jan 8,2012 I had a vision that Australia had a major EQ, then it suddenly split up so powerfully that it actually dropped/sunk into the ocean causing the water to angrily surge. I posted the vision on my youtube channel prayntongues. It is called the Destruction Vision.

  2. Dennis E. says:

    WELL, there has been posted on a couple of sites that alleged UFO observations were rather high during this period of seismic activity………

    • Donna says:

      Haha…I live here and haven’t seen anything sus. Some flashing lighs in the night sky around the large ones but that’s apparently normal and are called earquake lights.

      Just had a 5.2 recently….waiting to see if another follows.

  3. Dan Sherwood says:

    “Researchers have discovered New Zealand’s earthquake-prone landscape is even more unstable than previously thought” Why don’t they just admit that the whole planet is even more unstable then they previously thought and get it over with already.

  4. Joseph t. Repas says:

    What I don’t understand are ” scientists” that are always SURPRISED to find new developments such as seeing fault lines that were not there before, I mean really,do they actually think that no other cracks would develop than the ones they happened to see when they first looked ? I shake my head in amazement at the so called educated and enlightened.

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