Te Awa students experience science research

A group of Hawke's Bay students experienced unique earthquake research at their school last week.

Te Awa school was a site for specialised liquefaction research by QuakeCoRE and East Coast LAB on Wednesday.

A team of researchers is studying how liquefaction in the 1931 Hawke's Bay earthquake affected the region.

Historical New Zealand earthquake information is being combined with detailed soil investigations around the region to build a clearer picture of the liquefaction risk in the region.

Part of the research known as 'paleo liquefaction trenching' involved digging five trenches in the Napier and Hastings area to get detailed characteristics of the soil to help inform the research and look for evidence whether liquefaction occurred during the 1931 earthquake.

One of the sites was at Te Awa School, with a trench dug, 10 -15m long, 1-2m wide, and about 1.5m deep

Dr Sarah Bastin from the University of Canterbury and Professor Russell Green from Virginia Tech University undertook the investigations, spending time examining the soil before refilling the trench by the end of the day.

While the research was under way East Coast LAB Community Science co-ordinator Kate Boersen took the opportunity to take the Te Awa School students for an earthquake and liquefaction focused science lesson.

The students learnt about liquefaction and had the chance to undertake a liquefaction experiment.

The students also had the opportunity to look at the trench and have their questions answered by Dr Sara Bastin.

Te Awa School acting principal Stephanie Geddes said the students learnt a lot from the day.

"It was a great opportunity for our senior students to learn and experience first-hand what scientists do, what some of our local environmental hazards may be and how these science can affect us."

The research is hoped to eventually result in improved liquefaction hazard assessment in Hawke's Bay.

Research of recent New Zealand earthquakes has shown that the current liquefaction assessment methodologies used by engineers can in some areas overestimate the severity of liquefaction impacts in certain soil types and this additional work will add immense value to what is already known.

Liquefaction occurs during an earthquake in silty and sandy soil layers below the ground water table.

Fine sand, silt and water move up under pressure through cracks and other weak areas of the near surface soils to erupt on to the surface.

When this happens, the soil behaves like a liquid and can cause major damage to buried pipe networks, roads and buildings and other structures.

This research is part of the QuakeCoRE centre of research excellence in earthquake resilience, a project partner of East Coast LAB.

East Coast LAB (Life at the Boundary) is a collaborative project, which brings together scientists, emergency managers, experts and stakeholders across the East Coast to discover more about natural hazards and how they can affect us.