Victoria University of Wellington

Identifying how and why Antarctica's major ice sheets behaved the way they did in the early Miocene could help inform understanding of the sheets' behavior under a warming climate. Together, the ice sheets lock a volume of water equivalent to more than 50 meters of sea level rise and influence ocean currents that affect marine food webs and regional climates. Their fate has profound consequences for life nearly everywhere on Earth.   Nineteen million years ago, during a time known as the early Miocene, massive ice sheets in Antarctica rapidly and repeatedly grew and receded. The Miocene is widely considered a potential analog for Earth's climate in the coming century, should humanity remain on its current carbon emissions trajectory. Identifying how and why Antarctica's major ice sheets behaved the way they did in the early Miocene could help inform understanding of the sheets' behavior under a warming climate. Together, the ice sheets lock a volume of water equivalent to more than 50 meters of sea level rise and influence ocean currents that affect marine food webs and regional climates. Their fate has profound consequences for life nearly everywhere on Earth. While fluctuations in Antarctica's ice sheets have, over the span of millions of years, grown and diminished at regular intervals tied to natural oscillations in Earth's journey in orbit, researchers at the University of Wisconsin-Madison and their collaborators around the world have uncovered evidence that Antarctica's ice sheets grew and shrank more frequently during the Miocene epoch than was previously known. This new evidence, published recently in the Proceedings of the National Academy of Sciences, indicates that between about 19.2 and 18.8 million years ago, the ice sheets grew and receded multiple times over cycles of just a few thousand years. That is much more rapidly than can be explained by periodic shifts in the planet's orbit and rotational axis, known as Milankovitch cycles, which typically advance slowly, altering Earth's climate and ice sheets over tens or hundreds of thousands of years. "Our observation of this rapid volatility of the Antarctic ice sheets raises the interesting question of what's causing it," says Nick Sullivan, a 2022 UW-Madison PhD graduate who led the analysis for his dissertation research. The study offers an unprecedented window into the sheets' past behavior, and it relies on a well-preserved sediment record from the Antarctic Drilling Project, or ANDRILL. The project was an international scientific collaboration to gather evidence of past climatic conditions via sediment and rock drilled from hundreds of meters below the Antarctic seabed. In 2006 and 2007, drilling in McMurdo Sound off the coast of Antarctica in an area influenced by both of the continent's large ice sheets recovered detailed sediment records from the Miocene, close to the ice sheet. "We could clearly see the influence of long-term climate cycles on ice sheet extent in the rock and sediment cores we recovered in 2007, but our initial observations weren't detailed enough to detect shorter-term changes," says co-author Richard Levy, a professor at Victoria University of Wellington and principal scientist at GNS Science, a public research institute in New Zealand. The latest analysis led by Sullivan now allows scientists to "document past ice sheet change on timescales as short as five centuries or so," says Stephen Meyers, a UW-Madison geoscience professor who worked with Sullivan in his analysis. In fact, Meyers calls it a remarkable archive. That's because it contains small bits of gravel that fell to the seafloor as icebergs drifted away from the ice sheets after breaking away. The amount of gravel in ocean sediment records ice sheet changes, such as when the edge of an ice sheet gets closer to or further away from that particular part of the seafloor. While testing for evidence of Milankovitch cycles within the sediment, Sullivan found variations in the abundance of gravel, suggesting nearby ice sheets advanced and retreated in recurring intervals as brief as 1,200 years. It's unclear what triggered the ice sheets to advance and retreat at these geologically frequent intervals, but the team proposes several potential causes based on prior studies of ice sheets. One idea suggests that the ice sheets, building up over time, became steeper and top heavy, leading them to collapse. Another proposes that as thick ice sheets advanced over rough terrain, heat from friction helped to temporarily speed them up. "There are likely multiple mechanisms that were going on and interacting with each other," says Sullivan, including variations in the local climate and the ocean. Scientists around the world are working to better understand the many factors beyond Earth's orbit that control ice sheet behavior as the planet continues to warm. The early Miocene isn't perfectly analogous to today's world, but the new study suggests Antarctica's ice sheets could change rapidly and in unexpected ways in the coming centuries if carbon dioxide levels and temperatures continue to rise due to anthropogenic greenhouse gas emissions. "It was long thought that Antarctica's ice sheets remained large and stable over long periods of time. But the closer we look, the more we realize just how sensitive the ice sheets are to environmental change," says Levy. "This insight is key as we consider the pace at which we need to adapt to future sea level rise driven by melt and retreat of our planet's ice sheets."

Fathers and mothers who believe men should hold the power and authority in society and the family were less responsive to their children during family interactions, according to University of Auckland research. Fathers and mothers who believe men should hold the power and authority in society and the family were less responsive to their children during family interactions, according to University of Auckland research. The study was the first of its type. "For decades, sexism has been known to predict negative behaviours toward women, from discrimination to violence," says lead author Professor Nickola Overall, of Waipapa Taumata Rau, University of Auckland. "Our study suggests the effects flow through to poorer parenting." Video-recording family groups in the laboratory, researchers assessed parents' responsiveness, including warmth, involvement, engagement, and sensitivity toward their children. The less responsive parents -- both mothers and fathers -- had disclosed higher levels of "hostile sexism," an academic term for attitudes favouring male authority and antagonism toward women who challenge men's social power. The results for fathers were expected and highlight that the harmful effects of men's sexist attitudes may also involve poorer parenting, says Overall. The discovery that mothers who agree with hostile sexism were likely to be less responsive parents was unexpected. "It could be that these mothers follow the father's lead in family interactions, which leads to less engaged parenting," she says. "Another possibility is that mothers guard their traditional role as caregiver by restricting the father's parental involvement, which detracts from being responsive to the children." Responsive parenting is pivotal to healthy child development, and its absence can lead to behavioural issues, emotional difficulties, and lower academic achievement. There's no proof of causality in the University of Auckland research and alternative causes can't be ruled out. In addition, the laboratory setting will have altered participants behaviour, cutting for example the likelihood of displays of the most punitive parenting. "Despite these caveats, the current studies emphasize the importance of understanding how, why, and when sexist attitudes affect parenting -- a pivotal and overlooked domain that is intricately connected to the power-differentiated gender roles that reinforce gender inequality," Overall and her co-authors wrote in the journal Social Psychological and Personality Science. "The novel results offer new directions in understanding the broader impact of sexist attitudes on children across generations," says Overall. "There is also more to understand about why women continue to agree with sexist attitudes despite the harm they have for women and children." The link with less responsive parenting didn't exist for mothers and fathers classed as disclosing "benevolent sexism," a term for attitudes romanticizing traditional gender roles by emphasizing the virtues of men as providers and protectors and women as caregivers, Overall says. The first part of the research featured 95 mixed-gender couples with their five-year-old children. Observing families undertaking a collaborative task of building a cardboard tower, the researchers uncovered the statistical association between hostile sexism and less responsive parenting. A second study of 281 couples and their children observed in two different family tasks replicated the link. To establish levels of sexism, parents had answered questions such as: Both men and women can hold these beliefs and some women agree strongly with them Across 19 countries, nations such as Chile and South Africa were ranked high for "hostile sexism" while the likes Australia and the Netherlands were ranked lower, according to research published in 2000, which did not include New Zealand. "Improving child health and wellbeing is connected to improving the attitudes that confine women and men to specific roles, and vice versa," says Overall. The study co-authors were Dr Valerie Chang, Dr Annette Henderson and Dr Caitlin McRae, all from the University of Auckland, Dr Emily Cross of the University of Essex, and Dr Rachel Low of Victoria University of Wellington.

Scientists found weak, biologically-rich layers of sediments hundreds of meters beneath the seafloor which crumbled as oceans warmed and ice sheets declined. The landslides were discovered in the eastern Ross Sea in 2017, by an international team of scientists during the Italian ODYSSEA expedition, and scientists revisited the area in 2018 as part of the International Ocean Discovery Program (IODP) Expedition 374 where they collected sediment cores to understand what caused them. Scientists have discovered the cause of giant underwater landslides in Antarctica which they believe could have generated tsunami waves that stretched across the Southern Ocean. An international team of researchers has uncovered layers of weak, fossilised and biologically-rich sediments hundreds of metres beneath the seafloor. These formed beneath extensive areas of underwater landslides, many of which cut more than 100 metres into the seabed. Writing in Nature Communications, the scientists say these weak layers -- made up of historic biological material -- made the area susceptible to failure in the face of earthquakes and other seismic activity. They also highlight that the layers formed at a time when temperatures in Antarctica were up to 3°C warmer than they are today, when sea levels were higher and ice sheets much smaller than at present. With the planet currently going through a period of extensive climate change -- once again including warmer waters, rising sea levels and shrinking ice sheets -- researchers believe there is the potential for such incidents to be replicated. Through analysing the effects of past underwater landslides, they say future seismic events off the coast of Antarctica might again pose a risk of tsunami waves reaching the shores of South America, New Zealand and South East Asia. The landslides were discovered in the eastern Ross Sea in 2017 by an international team of scientists during the Italian ODYSSEA expedition. Scientists revisited the area in 2018 as part of the International Ocean Discovery Program (IODP) Expedition 374 where they collected sediment cores extending hundreds of meters beneath the seafloor. By analysing those samples, they found microscopic fossils which painted a picture of what the climate would have been like in the region millions of years ago and how it created the weak layers deep under the Ross Sea. The new study was led by Dr Jenny Gales, Lecturer in Hydrography and Ocean Exploration at the University of Plymouth, and part of IODP Expedition 374. She said: "Submarine landslides are a major geohazard with the potential to trigger tsunamis that can lead to huge loss of life. The landslides can also destroy infrastructure including subsea cables, meaning future such events would create a wide range of economic and social impacts. Thanks toexceptional preservation of the sediments beneath the seafloor, we have for the first time been able to show what caused these historical landslides in this region of Antarctica and also indicate the impact of such events in the future. Our findings highlight how we urgently need to enhance our understanding of how global climate change might influence the stability of these regions and potential for future tsunamis." Professor Rob McKay, Director of the Antarctic Research Centre at Victoria University of Wellington and co-chief scientist of IODP Expedition 374, added: "The main aim of our IODP drilling project in 2018 was to understand the influence that warming climate and oceans have had on melting Antarctica's ice sheets in the past in order to understand its future response. However, when Dr Gales and her colleagues on board the OGS Explora mapped these huge scarps and landslides the year before, it was quite a revelation to us to see how the past changes in climates we were studying from drilling were directly linked to submarine landslide events of this magnitude. We did not expect to see this, and it is a potential hazard that certainly warrants further investigation." Laura De Santis, a researcher at the National Institute of Oceanography and Applied Geophysics in Italy, and also co-chief scientist of IODP Expedition 374, said: "The sediment cores we analysed were obtained as part of IODP, the international seafloor scientific drilling project that has been active in the field of geoscience for over 50 years. The project aims to explore the history of planet Earth, including ocean currents, climate change, marine life and mineral deposits, by studying sediments and rocks beneath the seafloor." Jan Sverre Laberg, from The Arctic University of Norway, Tromsø, said: "Giant submarine landslides have occurred both on southern and northern high latitude continental margins, including the Antarctic and Norwegian continental margins. More knowledge on these events in Antarctica will also be relevant for submarine geohazard evaluation offshore Norway." Dr Amelia Shevenell, Associate Professor of Geological Oceanography at University of South Florida, College of Marine Science, said: "This study illustrates the importance of scientific ocean drilling and marine geology for understanding both past climate change and identifying regions susceptible to natural hazards to inform infrastructure decisions. Large landslides along the Antarctic margin have the potential to trigger tsunamis, which may result in substantial loss of life far from their origin. Further, national Antarctic programs are investigating the possibility of installing submarine cables to improve communications from Antarctic research bases. Our study, from the slope of the Ross Sea, is located seaward of major national and international research stations, indicating that marine geological and geophysical feasibility studies are essential to the success of these projects and should be completed early in the development process, before countries invest in and depend on this communication infrastructure."