Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search


NZ scientists learn lessons from Samoa tsunami

NZ scientists learn lessons from Samoa tsunami

A team of NZ scientists say the results of their field work after the Samoa Tsunami are of interest internationally and here in New Zealand.

The team from the National Institute of Water & Atmospheric Research (NIWA) and GNS Science spent nearly two weeks in the field: six days in American Samoa and seven days in Samoa. In Samoa, the NIWA / GNS Science delegation was part of a UNESCO–IOC International Tsunami Survey Team.

This project was unique in that it involved a coordinated team of international scientists who sought to collect evidence across a wide spectrum of the tsunami’s impact on communities, individuals, infrastructure, and the environment.

“We broke new ground for the disaster loss assessment research community. Our results illustrate an effective use of cutting edge field methods,” says NIWA’s Dr Shona van Zijll de Jong.

The aim of the visit was to gather a wide range of information to help Samoa, and other Pacific Islands including New Zealand, become better prepared to cope with future disasters.

Samoa, like New Zealand, is vulnerable to a wide range of natural disasters such as earthquakes and tsunamis, cyclones and floods. Samoa’s recent experience with natural disasters, such as the two closely-spaced cyclones in 1990 and 1991, have assisted in better preparing many local communities to withstand the impact of such natural hazards and to plan for the future.

Preliminary results from their survey of the physical and human effects of the Samoa tsunami have direct relevance for New Zealand say the scientists involved.

Size of tsunami
The Samoa tsunami consisted of two to three significant waves; the second wave was said by witnesses to be larger. The delay between the earthquake and the arrival of the first wave was about 10 minutes in Samoa and 20 minutes in American Samoa.

The maximum height reached by the tsunami on the land was 14 metres above mean sea level in Samoa and 10 metres in American Samoa. The furthest inland the waves reached was over 700 metres from the shore.

“This size of tsunami is also possible for New Zealand, equivalent to about a one-in-500 year event for the most populated parts of New Zealand,” says GNS Science spokesman John Callan.

Building damage
Buildings sustained varying degrees of damage. The importance of reinforcement was very clear – traditional light timber buildings were typically completely destroyed at an inundation depth of 1.5m or higher, whereas adding minimal reinforced-concrete columns reduced the damage levels significantly.

Building damage was correlated with water depth, structural strength, shielding, condition of foundations, quality of building materials used, quality of workmanship, and adherence to the building code.

It was also very clear that plants, trees, and mangroves reduced flow speeds and depths over land – leading to greater chances of human survival and lower levels of building damage.

“The same thing will be true in New Zealand as in Samoa: solidly constructed buildings which are appropriately located will survive much better than flimsy buildings right on the beach,” says Dr Stefan Reese of NIWA.

“It’s also clear that practices such as flattening sand dunes or removing beach vegetation would increase the potential for tsunami damage.”

Community response
In Samoa, it was clear that community-based tsunami education activities had saved lives in some areas, while in others there was still some confusion about how to respond.

The impact of the tsunami may have permanently changed residential patterns in Samoa. “Many people are scared of the sea, and people are staying away from devastated villages” says Dr van Zijll de Jong.

“The sea has been a source of livelihood and identity for generations. The violence of the tsunami really shook them. Their sense of personal security and economic well-being is deeply shaken.”

The Government of Samoa is very supportive of communities that want to resettle further inland. However, the families that have moved inland are very aware of the challenges facing them in re establishing their communities, particularly with it now being cyclone season. There is a very strong social fabric in Samoa, through families, villages, religious organisations and right up into government at a local and national level. It is this strong social fabric that strengthens the local, cultural and economic features of the Samoan coastal communities and holds the basis for the resilience that allows people to more quickly recover from disasters says van Zijll de Jong.

The team also found that national and international response to the disaster had been extremely good. The interface between the Government of Samoa and in-coming international, regional and local humanitarian groups who had the capacity to respond to the disaster was impressive.

The team from NIWA and GNS Science was part of a UNESCO-IOC International Tsunami Survey team from New Zealand, Australia, Fiji, French-Polynesia, Italy, Japan, and the USA, in collaboration with teams from several ministries within the Government of Samoa.

The research report and methods are of interest to the local and international disaster loss assessment research community: New Zealand Ministry of Civil Defence and Emergency Management; the World Bank; United Nations Development Programme and Intergovernmental Oceanographic Commission (IOC) of UNESCO (United Nations Educational, Scientific and Cultural Organization)


© Scoop Media

Business Headlines | Sci-Tech Headlines


Westpac: Sets Out Plan To Go Cheque-Free

Westpac NZ has announced details of its plan to phase out cheques, after signalling in May that it would be supporting a move to other forms of payment. Cheques will cease to be available as a means of payment after 25 June 2021. Westpac NZ General ... More>>


NZTA: Major New Zealand Upgrade Programme Projects Go To Tender

Two major New Zealand Upgrade Programme projects are beginning tenders for construction. The New Zealand Upgrade Programme is a $6.8 billion investment to get our cities moving, to save lives and boost productivity in growth areas. The first Auckland ... More>>

Reserve Bank: RBNZ Seeks To Preserve Benefits Of Cash

The Reserve Bank – Te Pūtea Matua is taking on a new role of steward of the cash system “to preserve the benefits of cash for all who need them”, Assistant Governor Christian Hawkesby told the Royal Numismatics Society of New Zealand annual conference ... More>>


Economy: Double-Dip Recession Next Year, But Housing Rolls On

New Zealand's economy is expected to slip back into recession early next year as delayed job losses, falling consumer spending, and the absence of international tourists bites into growth. More>>


Microsoft New Zealand: Microsoft Expands “Highway To A Hundred Unicorns” Initiative To Support Startups In Asia Pacific

New Zealand, 14 October 2020 – Today Microsoft for Startups launches the Highway to a Hundred Unicorns initiative in Asia Pacific to strengthen the region’s startup ecosystem. This follows the initiative’s success in India, where 56 startups were ... More>>

Fonterra: Farmers Taking Another Step Towards New Zealand’s Low Emissions Food Production

They’re hot off the press and intended to help take the heat out of climate change. Fonterra farmers are already among the world’s most sustainable producers of milk and now have an additional tool in their sustainability toolbox. Over the last few ... More>>


Courts: Businessman Eric Watson Sentenced To A Four-Month Jail Term

New Zealand businessman Eric Watson has been sentenced to a four-month jail term in the UK for contempt of court, TVNZ reports. More>>

OECD: Area Employment Rate Falls By 4.0 Percentage Points, To 64.6% In Second Quarter Of 2020

The OECD area employment rate – the share of the working-age population with jobs – fell by 4.0 percentage points, to 64.6%, in the second quarter of 2020, its lowest level since the fourth quarter of 2010. Across the OECD area, 560 million persons ... More>>

Spark: Turns On 5G In Auckland And Offers A Glimpse Into The Future Of Smart Cities

Spark turned on 5G in downtown Auckland today and has partnered with Auckland Transport (AT) to showcase some of the latest in IoT (Internet of Things) technology and demonstrate what the future could look like for Auckland’s CBD with the power of 5G. 5G is ... More>>

Stats NZ: Monthly Migration Remains Low

Since the border closed in late-March 2020, net migration has averaged about 300 a month, Stats NZ said today. In the five months from April to August 2020, overall net migration was provisionally estimated at 1,700. This was made up of a net gain ... More>>

University of Canterbury: Proglacial Lakes Are Accelerating Glacier Ice Loss

Lake Tasman, New Zealand | 2016 | Photo: Dr Jenna Sutherland Meltwater lakes that form at glacier margins cause ice to recede much further and faster compared to glaciers that terminate on land, according to a new study. But the effects of these glacial ... More>>


Dairy: Fonterra Sells China Farms

Fonterra has agreed to sell its China farms for a total of $555 million (RMB 2.5 billion*1), after successfully developing the farms alongside local partners. Inner Mongolia Natural Dairy Co., Ltd, a subsidiary of China Youran Dairy Group Limited ... More>>