US research ship kicks off summer of science

The US research ship Roger Revelle will be leaving CentrePort today for the first of three scientific voyages from December to February to study the Hikurangi subduction zone.

Scientists from the United States and New Zealand will be uncovering valuable insights into the physical conditions along the Hikurangi subduction zone, New Zealand’s largest fault, which extends along the length of the East Coast of the North Island.

Subduction zones develop a type of fault that are responsible for the largest earthquakes and tsunamis in the world, such as Sumatra 2004, Chile 2010, and Japan 2011.

The region has attracted international interest and funding for scientific projects to better understand subduction zones and the earthquake and tsunami risk they pose to coastal communities. It is important to remember that if you feel a long or strong earthquake then immediately get gone and evacuate to high ground.

Two of the voyages will involve deploying and later retrieving 42 seafloor instruments at 168 sites along the Hikurangi subduction zone.

The high-tech instruments will sit on the seafloor and record electromagnetic waves transmitted by an instrument that will travel along the seafloor controlled by scientists on board the research vessel.

Dr Samer Naif, Lamont-Doherty Earth Observatory, Columbia University who is leading two of the voyages, says they are interested in learning what fluid conditions generate earthquakes at the Hikurangi subduction zone, as fluid conditions affect the likelihood and type of earthquakes that occur at faults.

Scientists will use the information they collect to construct an image, like a medical MRI, of fluid conditions below the seafloor.

The other voyage, led by Dr Evan Solomon at the University of Washington, will use a remotely operated vehicle (ROV) to visually inspect the seafloor, deploy instruments capable of continuously monitoring the fluid conditions along the Hikurangi subduction zone, collect samples of sediment to depths of up to 10 metres, and make temperature measurements along the seafloor to better understand the role of fluids.

Dr Solomon says “results from these three voyages will fill in some of the missing pieces of the Hikurangi puzzle and also contribute to our global understanding of how subduction zones behave.”

The two projects are being funded by the U.S National Science Foundation and instruments are being provided by the Scripps Institution of Oceanography, University of California, University of Washington and Oregon State University.

The first and third voyage are being led by scientists Lamont-Doherty Earth Observatory (Columbia University) alongside New Zealand colleagues at GNS Science, while the second voyage is led by University of Washington and Oregon State University alongside GNS Science, NIWA, University of Otago, University of Auckland, and Macquarie University.

Back to Slow-Slip Earthquakes and Fluid Flow at the Hikurangi Subduction zone