TEPHRA SEISMITES

Evaluating earthquake hazards using liquefied volcanic-ash layers in lakes

Lake Ngaroto (photo by F van Schie)

Latest Updates

Tephra seismites group and supporters at lunch

August update

In recognition of having submitted the first of our papers from the project, and a lot of hard work thus far, our group and supporters met for a special lunch last Friday (13 Aug). Triaxial tests in the lab, led by Danche, got underway earlier this week – though these are now on hold with … Continue reading August update

First newsletter and team meeting

Our first newsletter update on research progress went out to colleagues and stakeholders this month. A copy can be found below. Last week we also had a visit from Auckland-based team member Professor Rolando Orense for our first in-person meeting, before he gave a New Zealand Geotechnical Society presentation.

Tephra sampling fieldwork

Late last month, the Tephra Seismites team went to visit one of our field sites and collect tephra samples for lab testing, to better understand how and why they might liquefy in an earthquake. We found Tuhua (Mayor Island) tephra (7.6 cal ka) and Mamaku tephra from the Okataina caldera (8.0 cal ka), which are … Continue reading Tephra sampling fieldwork

Project Summary

Liquefied volcanic-ash layers (‘tephra seismites’) preserved in lake sediments have never been reported. In northern New Zealand we have identified at least four such seismites in tephra-bearing lakes aged ~20,000 years in the Hamilton Basin. Our aim is to use this unique opportunity to develop a novel methodology to evaluate the frequency, possible magnitude, and likely locations of major earthquakes for the past 20,000 years in the basin. Click here to continue