Why Finding Amber In Antarctica Is So Important

Except for scientists rotating in and out of Antarctica at its 70-plus seasonal and year-round research stations, this home to the South Pole doesn't have permanent residents, and for good reason: The icy continent has the coldest climate on Earth. However, the discovery of amber in the Pine Island Bay of West Antarctica's Amundsen Sea Embayment fills a gap in research that shows the continent's climate and landscape were actually once very different.

During a 2017 seafloor-drilling expedition, amber fragments were found in a sediment core discovered 946 meters below water, and their analysis was co-led by Alfred Wegener Institute sedimentologist Dr. Johann Philipp Klages and Saxon State Office for the Environment, Agriculture and Geology consultant Dr. Henny Gerschel. In findings published in Antarctic Science in November 2024, the authors explain finding microscopic animal and plant structures — including potential tree bark remains — in the fossilized resin (named Pine Island amber) that indicate there was a "swampy temperate rainforest" near the South Pole during the mid-Cretaceous age. The scientists also saw evidence of resin flow, which is a protective response trees have against bark damage.

Gerschel explained in a joint press release from Alfred Wegener Institute and TU Bergakademie Freiberg, "Considering its solid, transparent and translucent particles, the amber is of high quality, indicating its burial near the surface, as amber would dissipate under increasing thermal stress and burial depth." Klages added, "The analysed amber fragments allow direct insights into environmental conditions that prevailed in West Antarctica 90 million years ago. It was very exciting to realise that, at some point in their history, all seven continents had climatic conditions allowing resin-producing trees to survive."

The theory that Antarctica hasn't always been an ice-covered landscape isn't new. Throughout history, fossilized discoveries of pollen and roots have indicated that trees once grew on the continent. During the same 2017 expedition, scientists found a sediment core that preserved Cretaceous-period forest soil in practically its original state. The findings published in Nature in April 2020 described the specimen as containing a lot of plant spores and pollen, but most importantly, "an intact 3-metre-long network of in situ fossil roots."

With all of this evidence pointing to Antarctica having the characteristics of a rainforest so long ago, researchers believe that the west side of the continent likely had a mean annual temperature of about 53 degrees Fahrenheit. That's much warmer than the modern average annual temperature of about 14 degrees. However, this was only possible because the atmosphere had significantly more carbon dioxide than previously believed and there was no Antarctic ice sheet. Until that research was published, there weren't any meaningful details known about the area's climate.

The most recent discovery and analysis of the Pine Island amber makes these findings more concrete. Klages says, "Our goal now is to learn more about the forest ecosystem – if it burned down, if we can find traces of life included in the amber. This discovery allows a journey to the past in yet another more direct way."