Nick Carne
An ancient graveyard containing hundreds of mummified Adélie penguins (Pygoscelis adeliae) in Antarctica tells a tale of past and likely future climatic calamities, Australian and Chinese scientists believe.
Radiocarbon dating of the carcasses and surrounding sediments revealed that most of the deaths were linked to two specific weather events about 200 and 750 years ago, each lasting several decades. That surprised the researchers, who had expected a larger range of dates given the high number of carcasses.{%recommended 6335%}
“We found that relatively short periods of climate anomaly in the past have caused terrible consequences to the penguin population,” says co-author Yuesong Gao, from the University of Science and Technology of China in Hefei, who worked with colleagues from the university and from the Australian Antarctic Division.
The worry for the future is that the climate pattern that best explains the collapse of these colonies – a model called zonal wavenumber 3 or ZW3 – has become more commonplace as the Earth’s climate has changed in response to anthropogenic greenhouse gas emissions.
As a result, some places in Antarctica saw more snow accumulation between 1970 and 2009 than in the previous 1000 years, the researchers say in a paper published in the Journal of Geophysical Research – Biogeosciences.
The graveyard was found on Long Peninsula in East Antarctica, and the researchers were struck by the unusually thick layers of sediments in which the mummies were buried.
These were evidence of a lot of water flowing over the surface over a short period of time which, they say, would require anomalously wet weather in the hyper-arid region. This is particularly deadly to penguin chicks which, unlike their parents, have not yet developed waterproof feathers.
