News Video | Policy | GPs | Hospitals | Medical | Mental Health | Welfare | Search

 

Deep Sediment Holds Clues To Past Climate Changes

Scientists are to drill two deep holes on the Wanganui coast to gain a better understanding of Southern Hemisphere climate and sea level changes over the past two and a half million years.

The sea level around New Zealand has risen and fallen 50 times in the past two and a half million years, due to expansion and contraction of ice sheets mainly in the Northern Hemisphere.

Sediment under the Wanganui coast contains one of the world’s best shallow marine records of these sea level changes.

Because of New Zealand’s unique geological setting the sediment profile under the Wanganui coast is detailed, highly accessible, and contains an uninterrupted record going back for millions of years. The only other sediment profiles in the world that come close are under several thousand meters of ocean.

The project is being led by the Institute of Geological & Nuclear Sciences Limited (GNS), with assistance from James Cook University in Queensland.

Project co-ordinator and GNS sedimentologist Tim Naish said sea level changes leave behind sedimentary deposits that can be analysed by geologists to gain a detailed understanding of the size and timing of past climatic changes.

“ Understanding past climate changes will help enormously in forecasting future climate trends,” Dr Naish said.

The information would also be valuable to petroleum exploration companies which would use the data to develop models to evaluate oil and gas potential in other parts of New Zealand.

Dr Naish said the sea level around New Zealand had been fairly static for 6000 years. Shorelines were 120m lower during the last ice age, 20,000 years ago. Each cycle, from low to high, lasted between 40,000 and 100,000 years.

“ Shorelines around New Zealand are currently at a high – the last time they were this high was 125,000 years ago.”

Until the mid-1970s it was thought there were only four main ice ages during the past two million years. The application of new investigative techniques had shown there had been 50 distinct glaciations during this period, Dr Naish said.

Sediment core from the drill holes will be brought to the surface for analysis in 3m lengths. One of the drill holes, near Castlecliff Beach, Wanganui, is to be 150m deep. The target depth at the other, 7km northwest of Castlecliff at Kai-iwi, is 250m.

This will be the first time that deep and continuous sediment cores from this area have been sampled for climate analysis. Petroleum exploration wells have been drilled near Wanganui in recent years, but were not studied for climate change.

Drilling is scheduled to start this week and will take about six weeks.

END

© Scoop Media

 
 
 
Culture Headlines | Health Headlines | Education Headlines

 
Legendary Bassist David Friesen Plays Wellington’s Newest Jazz Venue

Friesen is touring New Zealand to promote his latest album Another Time, Another Place, recorded live at Auckland's Creative Jazz Club in 2015. More>>

Howard Davis Review: The Father - Descending Into The Depths of Dementia

Florian Zeller's dazzling drama The Father explores the effects of a deeply unsettling illness that affects 62,000 Kiwis, a number expected to grow to 102,000 by 2030. More>>


Howard Davis Review: Blade Runner Redivivus

When Ridley Scott's innovative, neo-noir, sci-fi flick Blade Runner was originally released in 1982, at a cost of over $45 million, it was a commercial bomb. More>>

14-21 October: New Zealand Improv Festival In Wellington

Imagined curses, Shibuya’s traffic, the apocalypse, and motherhood have little in common, but all these and more serve as inspiration for the eclectic improvised offerings coming to BATS Theatre this October for the annual New Zealand Improv Festival. More>>

ALSO:

Bird Of The Year Off To A Flying Start

The competition asks New Zealanders to vote for their favourite bird in the hopes of raising awareness of the threats they face. More>>

Scoop Review Of Books:
Jenny Abrahamson's John & Charles Enys: Castle Hill Runholders, 1864-1891

This volume will be of interest to a range of readers interested in the South Island high country, New Zealand’s natural environment, and the history of science. More>>

 
 
 
 
 

LATEST HEADLINES

  • CULTURE
  • HEALTH
  • EDUCATION
 
 
  • Wellington
  • Christchurch
  • Auckland