New Zealand's glaciers are shrinking

May 9, 2018, Victoria University of Wellington

New Zealand's glaciers are some of our most prized landmarks, valued by residents and visitors alike. But according to scientific data, these glaciers are shrinking, melting into the ocean and causing the sea level to rise. Scientists at Victoria University of Wellington's Antarctic Research Centre, including Ph.D. student Lauren Vargo, are tracking those changes using the latest digital modelling techniques.

"We're looking at the using aerial photogrammetry, which is a type of aerial photography used to create models of the objects you're photographing," says Vargo.

"This means we can use the method we're developing to measure changes in the glaciers from the photographs we're taking."

Vargo's method has two parts. The first involves using the country's "great database of photos" taken over the past 40 years to measure how the glaciers have changed.

These photos come from the annual end of summer snowline survey supported by the NIWA project 'Climate Present and Past'.

As part of a collaboration between NIWA and Victoria University, Vargo took part in the snowline survey earlier this year along with Dr. Brian Anderson and Dr. Huw Horgan, also from the Antarctic Research Centre.

The Antarctic Research Centre team joined Dr. Andrew Lorrey, the NIWA project leader, and Dr. Trevor Chinn, founder of the snowline survey.

During the survey, scientists photograph the glaciers to see how much snow remains from the previous winter. The less snow that remains, the more the glacier will shrink.

Credit: Victoria University

The second part of Vargo's project is using the thousands of photos, both historic and new, to build complex digital models of the glaciers.

"I've taken all the photos from our recent trip to the Southern Alps and put them into software called Structure for Motion," says Vargo.

"This software gives us an orthophoto, which is a mosaic of all the photos we've taken of a glacier that gives us one comprehensive view of the current state of the glacier, as well as a digital elevation of the glacier showing whether the ice volume has increased or decreased."

This method will give scientists precise models of glaciers based only on photos. Current methods of glacier measurement involve physically hiking up glaciers, so this method will make glacier measurement easier. It will also make it possible to measure glaciers currently inaccessible by humans, giving accurate data on the changes in glaciers.

"If we can get these models precise and accurate enough, we'll be able to measure changes in ice volume across the entire Southern Alps using only these photographs," says Vargo.

It's still early days yet, but what are these models showing?

"Overall, we're seeing a retreat in almost all the glaciers we've studied," says Vargo.

"Globally, glaciers are one of the largest contributors to rise and in New Zealand they are tourism icons, and provide water to our major rivers. For these reasons, melting glaciers are a serious problem."

Explore further: Explaining New Zealand's unusual growing glaciers

Related Stories

Explaining New Zealand's unusual growing glaciers

February 15, 2017

Newly published research shows regional climate variability caused an "unusual" period in which some of New Zealand's glaciers grew bigger, while glaciers worldwide were shrinking.

NASA releases new, detailed Greenland glacier data

December 22, 2016

NASA's Oceans Melting Greenland (OMG) mission has released preliminary data on the heights of Greenland coastal glaciers from its first airborne campaign in March 2016. The new data show the dramatic increase in coverage ...

Southern Alps glaciers reducing rapidly

November 25, 2013

Historic records show Franz Josef Glacier retreated three kilometres in the last century and mathematical modeling indicates it is likely to retreat even more this century.

Recommended for you

A decade on, smartphone-like software finally heads to space

March 20, 2019

Once a traditional satellite is launched into space, its physical hardware and computer software stay mostly immutable for the rest of its existence as it orbits the Earth, even as the technology it serves on the ground continues ...

Tiny 'water bears' can teach us about survival

March 20, 2019

Earth's ultimate survivors can weather extreme heat, cold, radiation and even the vacuum of space. Now the U.S. military hopes these tiny critters called tardigrades can teach us about true toughness.

Researchers find hidden proteins in bacteria

March 20, 2019

Scientists at the University of Illinois at Chicago have developed a way to identify the beginning of every gene—known as a translation start site or a start codon—in bacterial cell DNA with a single experiment and, through ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Mark Thomas
not rated yet May 09, 2018
glaciers . . . in New Zealand they are tourism icons

The Fox and Franz Josef Glaciers on New Zealand's South Island have been photographed by millions of tourists over the last century or so. All those photographs provide an excellent record of the glacier's shocking retreat.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.