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


Scientist pieces together details of underwater landslides


New information about landslides that occur on the seafloor off New Zealand’s east coast will help scientists better understand why and where they happen, and the types of threats they pose.

NIWA marine geophysicist Dr Sally Watson has compiled a new database that brings together a vast array of information about offshore landslides that has been gathered from scientific voyages over many years.

“Our database maps where landslides have occurred, how big they are and where they are most common. We have pretty much got the entire east coast covered from Bluff to the East Cape but the ultimate goal is to expand it to make it New Zealand-wide.”

Dr Watson is presenting this information at this week’s annual Geosciences2019 conference in Hamilton and says one of the most interesting features of the database is the observation that landslides appear to be concentrated in particular regions.

“Landslides cluster in submarine canyons – that finding can either mean that canyons involve landslides as one of their formation processes, or that canyon processes are causing landslides. They are clearly linked in some way.”

Underwater landslides have the potential to cause tsunami but can also damage marine infrastructure and seafloor biological habitats.

“In the future I anticipate there may be a lot more offshore infrastructure, so the stability of underwater slopes is becoming increasingly important,” Dr Watson says.

“The good thing is that we have a lot of baseline maps for a lot of New Zealand so if we went back to a region and observed there was some change, we would be able to measure that as well.

“It is also important to understand what is shaping the seafloor – including the geological processes that are eroding it and delivering large amounts of sediment to the deep ocean.”

This may also lead to the ability to identify areas vulnerable to underwater landslides, which can be far bigger than those on land.

The second part of Dr Watson’s database project is to use the information to look back in time by examining the long-term record beneath the seabed of past landslides. This could enable scientists to determine whether there were times when landslides were particularly common.

“We use sound to image the subsurface and from that we can pick out deposits of landslides because they look very chaotic compared to everything else.

A perfect example of this occurred with the 2016 Kaikōura earthquake. Mapping of the seafloor was done before the earthquake and then repeated after it, showing huge changes to the seafloor.

“For a lot of these landslides, it’s not totally understood how or why they’ve occurred. At the moment we’re mostly observing trends and where they exist. From that we can try and understand why.”

Dr Watson has also recently had a paper published in the scientific journal Geology which dramatically increases our knowledge of how many methane seeps occur along the Hikurangi Margin, off the east coast of New Zealand.

The team measured hundreds of seep related features and believe they could be linked to deeper structural processes as well as potentially contributing to causing landslides. “That could help us to understand the faulting and sediment instability along the margin and how it’s changing.”


© Scoop Media

Business Headlines | Sci-Tech Headlines


Banking: Westpac NZ Lowers Merchant Fees For Small Businesses

Westpac NZ is rolling out a new merchant fee pricing structure that will lead to cost savings for more than 10,000 small and medium Kiwi businesses, and could make contactless transactions more widely available for customers. On 1 September, most ... More>>

REINZ: Million Dollar Plus Property Sales Increase 11.7% Nationally

The number of properties sold around the country for one million dollars or more during the first half (H1) of 2020 increased by 11.7% compared to H1 2019, with 5,426 million-dollar plus properties sold (up from 4,858 in H1 2019) according to the Real ... More>>

Waste: Government To Regulate Plastic Packaging, Tyres, E-Waste

The Government is stepping up action to deal with environmentally harmful products – including plastic packaging, tyres and e-waste – before they become waste. As part of the wider plan to reduce the amount of rubbish ending up in landfills, ... More>>


Bankers Association: Banking Becomes First Living Wage Accredited Industry

Banking has become New Zealand’s first fully living wage accredited industry, leading to nearly 1800 employees and contractors moving onto the living wage and gaining greater economic independence for them and their families. As of today, all ... More>>


Economy: Funding For 85% Of NZ Not-For-Profit Entities Impacted By COVID-19

Results of a recent Institute of Directors poll show that 85% of board members on not-for-profit organisations say COVID-19 has moderately or significantly affected their funding. The ‘pulse check’ conducted in the first two weeks of July looked ... More>>

Volcano Detection: Eruption Alert System Would Have Given 16 Hours’ Warning At Whakaari

An alert system that could have given 16 hours’ warning of last year’s eruption at Whakaari/White Island is ready for deployment, University of Auckland scientists say, with warning systems for Ruapehu and Tongariro the next priority. ... More>>

Property: Queenstown Rents Experience Biggest Drop In Seven Years

Rental prices in the Queenstown-Lakes district saw the biggest annual percentage drop in seven years after falling 28 per cent on June last year, according to the latest Trade Me Rental Price Index. Trade Me Property spokesperson Aaron Clancy said ... More>>

Seismology: The Quiet Earth

As many daily activities came to a halt during lockdown, the Earth itself became quiet, probably quieter than it has been since humans developed the technology to listen in. Seismologists have analysed datasets from more than 300 international ... More>>

RNZ: James Shaw Says Kiwibank, Not Ministers Should Decide On Investors

Climate Change Minister James Shaw says Kiwibank's decision to stop doing business with companies dealing in fossil fuels is the right one. More>>


FMA: Kiwis Confident Financial Markets Will Recover From COVID-19, Plan To Increase Investments

Despite the majority (60%) of investors experiencing losses as a result of COVID-19, the outlook on investing remains positive, according to a Financial Markets Authority (FMA) survey. Most Kiwis (71%) were optimistic that the pandemic will pass eventually ... More>>

FIRST Union: Warehouse Using Covid For Cover As Extensive Restructure Makes Everyone Worse Off

(FIRST Union comments on The Warehouse consultation and proposed restructure) 'Unfortunately the Warehouse have done the disappointing thing and used Covid-19 to justify a bunch of operational business decisions that will leave hundreds of workers without jobs ... More>>


Stats NZ: Mixed Performance By Regions Leaves National Emissions Picture Unchanged

Approximately two-thirds of New Zealand’s regions recorded decreases in their total greenhouse gas emissions, while one-third of regions saw increases between 2007 and 2018, Stats NZ said today. “While some regions reduced their emissions, ... More>>

RNZ: Economic Activity And Business Confidence Bouncing Back

Two surveys from ANZ show business confidence and economic activity have rebounded, but uncertainty about the future remains extreme. More>>