Earthquake Report: Kaikōura, New Zealand Post # 02

Here is the first update on the 2016.11.13 (UTC) Mw 7.8 Kaikoura Earthquake and associated fault ruptures, ground shaking, and other geologic effects. I will be preparing several more posts on this subject.

I was invited to participate on a research cruise offshore of new Zealand. Our goal was to collect sediment cores in the deep sea so that we might test the hypothesis that strong ground shaking from earthquakes along the Hikurangi subduction zone generate submarine landslides that can be used to establish an earthquake chronology. This is a new method being used globally. I have applied this method in the northeastern Indian Ocean (offshore of Sumatra: the Andaman-Sumatra subduction zone), the northeastern Pacific (offshore of the Pacific northwest coasts of Washington, Oregon, and California: the Cascadia subduction zone and northern San Andreas fault), and in the western equatorial Atlantic Ocean (offshore of Guadeloupe: the subduction zone along the Lesser Antilles).

The chief scientists for this southwestern Pacific turbidite paleoseismology investigation are Drs. Philip Barnes (NIWA) and Jamie Howarth (GNS).

While we were at sea aboard the R/V Tangaroa, this M 7.8 and associated complicated earthquakes occurred. We initiated planning to modify our goals to include data collection in response to this earthquake series. This included (1) additional sediment coring and (2) seismic reflection and multibeam bathymetric mapping. The coring is important because this earthquake is a small earthquake for turbidite paleoseismology, so the results will be an important contribution to the global studies of trigger magnitude-distance relations. The seismic reflection data are important to determine the extent of surface rupture of the faults offshore. The multibeam mapping also helps extend our observations of surface rupture offshore. These observations will help constrain fault slip models. Some of the results from our cruise are presented below. We prepared this presentation for a press conference immediately following our cruise.

We are currently preparing samples to submit to a lab in New Zealand to test for the presence of short lived radionuclides (7Be and 234Th). We are also conducting biostratigraphic tests on the most recent sedimentary deposit. These tests are an important tool to justify our interpretations that we cored the M 7.8 turbidite using lithostratigraphic constraints.

Related Posts

  • My initial Earthquake Report is posted here. I discuss and present observations made following the earthquake.
  • My report for prior to the cruise here. I present some background information about New Zealand tectonics. I have learned much more and will post more about this in future reports.
  • I presented some updates on our cruise via my blog here. I list some of these posts below (dates are local time).

Information Sources

Press Conference

    Here are the slides that we put together for our press conference.

  • We arrived at port about 8 AM and the press conference was at 2 PM. No rest for the wicked. The fearless leaders of our R/V Tangaroa research cruise were Drs. Philip Barnes from NIWA and Jamie Howarth from GNS Science.
  • Here is the digital press release as displayed blow: (pdf)

Some Cruise Videos

  • Here is the link to the embedded video below. This was taken by Dr. Howarth and shows a core from recovery to discovery. (102 MB mp4)
  • Observations Made Prior to Earthquake

    In 2000, several Humboldt State University, Department of Geology students joined a faculty member (Dr. Raymond “Bud” Burke, a soils geomorphologist) in a trip to New Zealand. They traveled to work with Russ Van Dissen from GNS, an HSU graduate (he also went to Oregon State University and worked with Dr. Bob Yeats). Their efforts were to investigate faulting along the Kekerungu fault. They established that the Kekrungu fault is the main plate boundary fault in this region. Here is the accepted abstract currently being presented at a geological conference in New Zealand. These scientists had established that this fault system was capable of doing what it just did. I remember helping to prepare some field maps for this trip, but the GIS data available at the time was scarce and my maps were of little utility to the team.

      The students included

    • Steve N. Bacon
    • Ronna Bowers
    • Harland L. Goldstein
    • Joanna R. Redwine
    • Diane G. Sutherland
    • Stephen F. Tilinghast

    Here is the abstract:

    Leave a Reply

    Your email address will not be published. Required fields are marked *