The study suggests that Antarctica at that time was yet to develop extensive ice sheets. Back then, New Zealand was about 1100 km further south, at the same latitude as the southern tip of South America – so was closer to Antarctica – but the researchers found that the water temperature was 23-25°C at the sea surface and 11-13°C at the bottom.
“This is too warm to be the Antarctic water we know today,” said Dr Catherine (Cat) Burgess from Cardiff University and lead-author of the paper. “And the seawater chemistry shows there was little or no ice on the planet.”
These new insights come from the chemical analysis of exceptionally well preserved fossils of marine micro-organisms called foraminifers, discovered in marine rocks from New Zealand. The researchers tested the calcium carbonate shells from these fossils, which were found in 40 million-year-old sediments on a cliff face at Hampden Beach, South Island.
“Because the fossils are so well preserved, they provide more accurate temperature records.” added Dr Burgess. “Our findings demonstrate that the water temperature these creatures lived in was much warmer than previous records have shown.”
“Although we did not measure carbon dioxide, several studies suggest that greenhouse gases forty million years ago were similar to those levels that are forecast for the end of this century and beyond.
Our work provides another piece of evidence that, in a time period with relatively high carbon dioxide levels, temperatures were higher and ice sheets were much smaller and likely to have been completely absent.”
The rock sequence from the cliff face covers a time span of 70,000 years and shows cyclical temperature variations with a period of about 18,000 years. The temperature oscillation is likely to be related to the Earth’s orbital patterns.
The research was funded by the Natural Environment Research Council, the Netherlands Organisation for Scientific Research (NOW) and GNS Science, New Zealand.
Issued jointly by the Natural Environment Research Council and Cardiff University.
Marion O'Sullivan | alfa
PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target
22.05.2018 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Materials Sciences
23.05.2018 | Physics and Astronomy
23.05.2018 | Life Sciences