New Research Shows That Antarctica's Largest Floating Ice Shelf Is Highly Sensitive To Warming Of The Ocean

New Research Shows That Antarctica's Largest Floating Ice Shelf Is Highly Sensitive To Warming Of The Ocean Since the last ice age, the ice sheet retreated over a thousand kilometres in the Ross Sea region, more than any other region on the continent. Rich Jones, CC BY-ND

Scientists have long been concerned about the potential collapse of the West Antarctic Ice Sheet and its contribution to global sea level rise. Much of West Antarctica’s ice lies below sea level, and warming ocean temperatures may lead to runaway ice sheet retreat.

This process, called marine ice sheet instability, has already been observed along parts of the Amundsen Sea region, where warming of the ocean has led to melting underneath the floating ice shelves that fringe the continent. As these ice shelves thin, the ice grounded on land flows more rapidly into the ocean and raises the sea level.

Although the Amundsen Sea region has shown the most rapid changes to date, more ice actually drains from West Antarctica via the Ross Ice Shelf than any other area. How this ice sheet responds to climate change in the Ross Sea region is therefore a key factor in Antarctica’s contribution to global sea level rise in the future.

Periods of past ice sheet retreat can give us insights into how sensitive the Ross Sea region is to changes in ocean and air temperatures. Our research, published today, argues that ocean warming was a key driver of glacial retreat since the last ice age in the Ross Sea. This suggests that the Ross Ice Shelf is highly sensitive to changes in the ocean.

History of the Ross Sea

Since the last ice age, the ice sheet retreated more than 1,000km in the Ross Sea region – more than any other region on the continent. But there is little consensus among the scientific community about how much climate and the ocean have contributed to this retreat.

Much of what we know about the past ice sheet retreat in the Ross Sea comes from rock samples found in the Transantarctic Mountains. Dating techniques allow scientists to determine when these rocks were exposed to the surface as the ice around them retreated. These rock samples, which were collected far from where the initial ice retreat took place, have generally led to interpretations in which the ice sheet retreat happened much later than, and independently of, the rise in air and ocean temperatures following the last ice age.

But radiocarbon ages from sediments in the Ross Sea suggest an earlier retreat, more in line with when climate began to warm from the last ice age.

New Research Shows That Antarctica's Largest Floating Ice Shelf Is Highly Sensitive To Warming Of The Ocean An iceberg floating in the Ross Sea - an area that is sensitive to warming in the ocean. Rich Jones, CC BY-ND

Using models to understand the past

To investigate how sensitive this region was to past changes, we developed a regional model of the Antarctic ice sheet. The model works by simulating the physics of the ice sheet and its response to changes in ocean and air temperatures. The simulations are then compared to geological records to check accuracy.

Our main findings are that warming of the ocean and atmosphere were the main causes of the major glacial retreat that took place in the Ross Sea region since the last ice age. But the dominance of these two controls in influencing the ice sheet evolved through time. Although air temperatures influenced the timing of the initial ice sheet retreat, ocean warming became the main driver due to melting of the Ross Ice Shelf from below, similar to what is currently observed in the Amundsen Sea.

The model also identifies key areas of uncertainty of past ice sheet behaviour. Obtaining sediment and rock samples and oceanographic data would help to improve modelling capabilities. The Siple Coast region of the Ross Ice Shelf is especially sensitive to changes in melt rates at the base of the ice shelf, and is therefore a critical region to sample.

Implications for the future

Understanding processes that were important in the past allows us to improve and validate our model, which in turn gives us confidence in our future projections. Through its history, the ice sheet in the Ross Sea has been sensitive to changes in ocean and air temperatures. Currently, ocean warming underneath the Ross Ice Shelf is the main concern, given its potential to cause melting from below.

Challenges remain in determining exactly how ocean temperatures will change underneath the Ross Ice Shelf in the coming decades. This will depend on changes to patterns of ocean circulation, with complex interactions and feedback between sea ice, surface winds and melt water from the ice sheet.

Given the sensitivity of ice shelves to ocean warming, we need an integrated modelling approach that can accurately reproduce both the ocean circulation and dynamics of the ice sheet. But the computational cost is high.

Ultimately, these integrated projections of the Southern Ocean and Antarctic ice sheet will help policymakers and communities to develop meaningful adaptation strategies for cities and coastal infrastructure exposed to the risk of rising seas.The Conversation

About The Author

Dan Lowry, PhD candidate, Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Climate Change: What Everyone Needs to Know

by Joseph Romm
0190866101The essential primer on what will be the defining issue of our time, Climate Change: What Everyone Needs to Know® is a clear-eyed overview of the science, conflicts, and implications of our warming planet. From Joseph Romm, Chief Science Advisor for National Geographic's Years of Living Dangerously series and one of Rolling Stone's "100 people who are changing America," Climate Change offers user-friendly, scientifically rigorous answers to the most difficult (and commonly politicized) questions surrounding what climatologist Lonnie Thompson has deemed "a clear and present danger to civilization.". Available On Amazon

Climate Change: The Science of Global Warming and Our Energy Future second edition Edition

by Jason Smerdon
0231172834This second edition of Climate Change is an accessible and comprehensive guide to the science behind global warming. Exquisitely illustrated, the text is geared toward students at a variety of levels. Edmond A. Mathez and Jason E. Smerdon provide a broad, informative introduction to the science that underlies our understanding of the climate system and the effects of human activity on the warming of our planet.Mathez and Smerdon describe the roles that the atmosphere and ocean play in our climate, introduce the concept of radiation balance, and explain climate changes that occurred in the past. They also detail the human activities that influence the climate, such as greenhouse gas and aerosol emissions and deforestation, as well as the effects of natural phenomena.  Available On Amazon

The Science of Climate Change: A Hands-On Course

by Blair Lee, Alina Bachmann
194747300XThe Science of Climate Change: A Hands-On Course uses text and eighteen hands-on activities to explain and teach the science of global warming and climate change, how humans are responsible, and what can be done to slow or stop the rate of global warming and climate change. This book is a complete, comprehensive guide to an essential environmental topic. Subjects covered in this book include: how molecules transfer energy from the sun to warm the atmosphere, greenhouse gases, the greenhouse effect, global warming, the Industrial Revolution, the combustion reaction, feedback loops, the relationship between weather and climate, climate change, carbon sinks, extinction, carbon footprint, recycling, and alternative energy. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

EVIDENCE

PBS Nova's Polar Extremes
PBS Nova's Polar Extremes
by PBS
In this two-hour special, renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar…
Climate Research Struggles To Find Funding
Climate Research Struggles To Find Funding
by Kieran Cooke
Climate research is the poor relation of the academic world. Since 1990 it’s won less than 5% of the research funds…
Atlantic Current Could Falter Before 2100
Atlantic Current Could Falter Before 2100
by Tim Radford
v The Atlantic current won’t come to a full stop the day after tomorrow. But it could face a temporary halt later this…
Temperature in Antarctica Soars Past 69°F as NOAA Reports Last Month Was World's Hottest January on Record
Temperature in Antarctica Soars Past 69°F as NOAA Reports Last Month Was World's Hottest January on Record
by Jessica Corbett
While the reading in Antarctica still needs to be confirmed, the Brazilian scientists who logged it called the new…
CO₂ Levels And Climate Change: Is There Really A Controversy?
CO₂ Levels And Climate Change: Is There Really A Controversy?
by Guillaume Paris and Pierre-Henri Blard
The relationship between atmospheric CO2 levels and climate change is often perceived as a controversial subject.
Ancient Antarctic Ice Melt Caused Extreme Sea Level Rise 129,000 Years Ago – And It Could Happen Again
Ancient Antarctic Ice Melt Caused Extreme Sea Level Rise 129,000 Years Ago – And It Could Happen Again
by Chris Fogwill, et al
Our new research might be able to provide some insight into what effect a warmer world would have in Antarctica, by…
3 Things Historical Literature Can Teach Us About The Climate Crisis
3 Things Historical Literature Can Teach Us About The Climate Crisis
by David Higgins and Tess Somervell
New novels about climate change – climate fiction, or cli-fi – are being published all the time. The nature of the…
Antarctica Has Lost Nearly 3 Trillion Tonnes Of Ice Since 1992
Antarctica Has Lost Nearly 3 Trillion Tonnes Of Ice Since 1992
by Thomas Slater and Andrew Shepherd
It can be easy to overlook the monstrous scale of the Antarctic ice sheet. Ice, thick enough in many places to bury…

LATEST VIDEOS

How These Three Financial Firms Could Change The Direction Of The Climate Crisis
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
by Mangulina Jan Fichtner, et al
A silent revolution is happening in investing. It is a paradigm shift that will have a profound impact on corporations,…
PBS Nova's Polar Extremes
PBS Nova's Polar Extremes
by PBS
In this two-hour special, renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar…
A huge iceberg just broke off West Antarctica’s most endangered glacier
A Huge Iceberg Just Broke Off West Antarctica’s Most Endangered Glacier
by Madeleine Stone
Huge blocks of ice regularly shear away from Antarctica’s ice shelves, but the losses are speeding up.
The Rise Of Solar Power
by CNBC
Solar power is on the rise. You can see the evidence on rooftops and in the desert, where utility-scale solar plants…
World's Largest Batteries: Pumped Storage
by Practical Engineering
The vast majority of our grid-scale storage of electricity uses this clever method.
Hydrogen Fuels Rockets, But What About Power For Daily Life?
Hydrogen Fuels Rockets, But What About Power For Daily Life?
by Zhenguo Huang
Have you ever watched a space shuttle launch? The fuel used to thrust these enormous structures away from Earth’s…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
Big Rail Spends More on Denying Climate Change than Big Oil
by The Real News Network
A new study concludes that rail is the industry that's injected the most money into climate change denial propaganda…

LATEST ARTICLES

Why Australian Labor’s Climate Policy Is Too Little, Too Late
Why Australian Labor’s Climate Policy Is Too Little, Too Late
by Will Steffen
Opposition leader Anthony Albanese’s announcement on Friday that a Labor government would adopt a target of net-zero…
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
by Mangulina Jan Fichtner, et al
A silent revolution is happening in investing. It is a paradigm shift that will have a profound impact on corporations,…
Green Ammonia Could Slash Emissions From Farming And Power Ships Of The Future
Green Ammonia Could Slash Emissions From Farming And Power Ships Of The Future
by Bill David
For the past 100 years, a simple molecule has had an immensely positive impact on our world. Ammonia, which comprises…
Ideal US Cities To Survive Climate Change
Ideal US Cities To Survive Climate Change
by Johnna Crider
Climate scientists have shared where they think would be an ideal place to live in the United States in order to avoid…
Stories Of When Your Kids Make You Feel Old! | The Curls
Old Conservative White Men: Pass The Football To Someone Who Will Try To Score
by Robert Jennings, InnerSelf.com
We have had important US elections but this one in November 2020 is undoubtedly the most important. Why? America and…
How Tiny Microbes Are Revolutionizing Big Agriculture
How Tiny Microbes Are Revolutionizing Big Agriculture
by Mathew Wallenstein, Colorado State University
Walk into your typical U.S. or U.K. grocery store and feast your eyes on an amazing bounty of fresh and processed…
Uk’s Nuclear Future Hangs On Electricity Tax
Uk’s Nuclear Future Hangs On Electricity Tax
by Paul Brown
The new British prime minister, Boris Johnson, must soon decide whether to save the UK’s nuclear future with an…
Extreme Weather Could Push The U.S. Into Recession
Extreme Weather Could Push The U.S. Into Recession
by Karen Nikos
Physical climate risk from extreme weather events remains unaccounted for in financial markets, a new paper warns.