Otago has a rich history of establishing firsts, leading
the way in many fields. University of Otago researchers are
attracting international attention, with some granted
millions of dollars for cutting-edge projects. So what are
they up to? Reporter John Gibb does his own research on the
University of Otago geologist Dr Virginia Toy is keen to shed
new light on the likely effects of a predicted huge
earthquake on the Southern Alps fault system.
Dr Toy, a senior lecturer in structural geology, is one of
three co-leaders in a major international scientific venture,
the Deep Fault Drilling Project, at the Southern Alps.
This innovative project aims to drill 1.3km into the Alpine
Fault, on the West Coast, partly to learn more about when the
predicted devastating magnitude 8 quake - sometimes known as
the ''Big One'' - is coming.
''The Alpine Fault is late in its earthquake cycle,'' Dr Toy
''We are quite likely to experience this earthquake in our
Scientists believe the Alpine Fault last ruptured in 1717 in
a huge earthquake which generated about 8m of sideways
movement, and uplifted the land by up to 2m along the fault.
Researchers believe such a major quake is likely to recur
about every 330 years.
The next could happen by the middle of this century.
''If the Alpine Fault fails it will probably shake both
Christchurch and Dunedin as much as the Christchurch
earthquakes did,'' Dr Toy says.
But the ''likely effects''of a huge quake remain unclear,
including if it will generate ''high peak ground
accelerations'' as in the recent big Christchurch quakes.
''My research aims to help us make much more realistic
predictions of the likely ground-shaking hazard.''
Gaining a better understanding of such effects is ''really
important if we are to properly design our buildings and
infrastructure to accommodate the next event''.
And in striving to understand such effects, Dr Toy is
thinking not only of the magnitude 6.3 quake which killed 185
people in Christchurch and heavily damaged thousands of
buildings, on February 22, 2011.
She is also drawing on geological insights gleaned from an
earlier international drilling project undertaken in a
deep-sea trench area off the Japanese coast in 2012.
That was when she spent two months aboard the Japanese
research vessel Chikyu, helping undertake a
record-breaking international drilling initiative, in the
aftermath of a massive 50m movement of a Japanese subduction
That movement, linked to a magnitude 9 quake, generated a
tsunami that killed more than 20,000 Japanese people in March
At the drilling site, about 200km east of the Japanese coast,
in northeast Honshu, researchers and technicians drilled to
about 7740m below sea level and about 850m into underlying
rock in a deep-sea trench area, about 6910m deep.
Extensive research showed the composition of the fault plane
in the Japanese event was ''very, very rich in a clay mineral
''The presence of this clay mineral allowed the Japanese
fault to be really weak [slippery] during the earthquake,''
''This weakness allowed the huge displacement that occurred,
generating the much larger than expected earthquake.
''We're really keen to analyse more Alpine Fault material
from this next phase of drilling to see if it is
Her fellow Alpine drilling project leaders are Rupert
Sutherland, of GNS Science, and Dr John Townend, of Victoria
University of Wellington.
And the project is backed by about $1 million from the New
Zealand Marsden Fund, and significant offshore funding.
Otago geology staff, guided by Dr Toy, will be responsible
for rock samples recovered from the borehole.
They will analyse the rock, including by feeding it through a
CT scanner at Dunedin Hospital's oncology department.
''These images will reveal the internal structure of the
core, which results from fracturing associated with the
passage of seismic waves,'' she says.
Detailed analysis of the microstructure of such rock core
material can reveal big insights about how massive movements
can occur in an earthquake.
Born on Auckland's North Shore, Dr Toy mostly aspired to be
''a scientist, and engineer, or an architect'', when growing
''I have a physics and maths background, but have been
interested in geology since accompanying my stonemason father
to look for building stones in Auckland quarries as a child.
''I also love the outdoors. Geology allows me to combine
research into complex physical processes with time out in the
And how does she relax?
''I love sailing, sewing, reading, and getting out into New
Zealand's beautiful natural environment.
''I really love cycling, both for exercise but also for
Learning more about a predicted huge Alpine Fault earthquake
before it strikes
What is your research about?
''I investigate the mechanics of faults and shearzones in the
Earth's lithosphere, the crust and upper mantle, and in this
case the Alpine Fault.''
Why is it important?
''The Alpine Fault is late in its earthquake cycle. It has
the highest statistical probability of rupture in the near
future of any known fault in New Zealand.''
Most interesting aspect of your research?
''I'm really excited about recent developments in
understanding of the mechanics of fault zones that cause
large ground displacements, like the one that generated the
huge tsunami off Sendai, Japan, in 2011.''
In what way is it unique or distinctive?
''I focus on the microstructural record of earthquake
processes and look at things at really small scale - atomic
level, using extremely high resolution electron microscopy -
that have implications for really large-scale tectonics.''
Deep Fault Drilling Project - Alpine Fault
Researchers elsewhere in the world have previously drilled
into plate boundary faults after large earthquakes, but the
South Island project will be one of the first attempts to
probe a major fault before it ruptures.
Location and timing
The New Zealand-led international science team plans to drill
a single deep borehole into the Alpine Fault near Whataroa,
north of Franz Josef on the West Coast, starting in October.
What is the Alpine Fault?
It forms part of the boundary between the Australian and
Pacific tectonic plates in the South Island. It lies near the
base of the western range-front of the Southern Alps and runs
about 500km between Milford Sound and Marlborough.
Name: Virginia Toy (34)
Occupation: University of Otago senior lecturer in
Qualifications: PhD in geology.
Where did you train: Earlier qualifications from
Auckland University, Australian National University; PhD in
geology, Otago University (2008).
Work history: Engineering geologist at two Auckland
firms, postdoctoral researcher at two US universities, and
lecturing at Otago University.
Proudest: ''Being a principal investigator of this
extremely scientifically important project.''