Over the past few years, an international network of Earth scientists, known as the SvalCLIME team, has systematically reviewed Svalbard’s rock record.
By Kim Senger, Lead of the UArctic Thematic Network on Arctic Geology, Professor, University Centre in Svalbard
In collaboration with Grace Shephard, Morgan Jones, Sten-Andreas Grundvåg, William J Foster, Valentin Zuchuat, Denise Kulhanek, Aleksandra Smyrak-Sikora, and Sverre Planke
In part thanks to a UArctic cooperation grant funded by the Norwegian Ministry of Education and Research, the team proposed a large-scale international scientific drilling campaign to characterize the last 250 million years of climate change using Svalbard’s rock record.
Svalbard’s rock record is exceptional, because it records most of the last 400 million years, giving geoscientists insights on how the global climate and life have co-evolved. By understanding how the Earth System functioned in the past, geoscientists can contribute to predictions of how the Earth System may function in the future. This is important at a time when climate change is affecting large parts of the planet.
The Arctic is one of the most sensitive regions to climate change, with warming rates several times higher than the global averages. This is called the polar amplification effect and is caused by, among other things, the ice-albedo effect. As sea ice diminishes in extent, less of the incoming solar radiation is reflected, and the oceans warm. This in turn causes less sea ice over time, creating a positive feedback loop. Even today we struggle to understand the geosphere-hydrosphere-cryosphere-atmosphere interactions that, together with the biosphere, make up the Earth System. We also do not know whether this polar amplification effect was always there, or if it is only something that occurs when the Earth’s polar regions are glaciated.
As a land mass, Svalbard has drifted northwards through much of its history. This journey is reflected in its rocks, from continental sandstones deposited in equatorial, desert-like environments, through large carbonate platforms formed in progressively cooler waters, to siliciclastic deposition at mid-to-high latitudes. Coal, the foundation of all permanent settlements in Svalbard, was deposited at similar latitudes as Svalbard is today (including a very long polar night), clearly reflecting intervals when Earth’s climate state was much warmer in the past than today.
In parallel to Svalbard’s northwards tectonic drift, the global climate was oscillating between warmer and colder periods. Today’s period, the Quaternary, is actually one of the cooler intervals. In the past, numerous factors including large-scale volcanism, meteorite impacts, gas hydrate dissociation, and continent reorganizations contributed to a changing climate. Superimposed on the long-term evolution of Svalbard are also catastrophic events, such as the end-Permian mass extinction 252 million years ago which occurred due to extensive magmatism in present-day Siberia and resulted in ca. 90% of the species going extinct, known as the Great Dying. Scientists have conducted numerous studies using both outcrops and drill cores in Svalbard to decipher the causes of the extinction and characterize how quickly fauna and flora recovered from the extreme event.
Similarly, Svalbard records the Paleocene-Eocene Thermal Maximum, 56 million years ago, where global temperatures were much higher likely due to major volcanism in the North Atlantic. These events are considered by many scientists as good analogues for a world with very high atmospheric CO2 concentrations and high temperatures. What is unknown, however, is whether the polar amplification effect we see today was as important in the geological past.
In conclusion, the SvalCLIME team considers Svalbard a world-class archive of Earth’s history and looks forward to materializing the scientific drilling in the future.
Photo. Kim Senger
Thanks to financial support from Arctic governments, UArctic is able to provide funding towards collaborative projects of its members. The funding from the Norwegian Ministry of Education and Research supports collaboration between Norwegian UArctic member institutions and the wider network, and it targets new projects focused on Arctic research and education across all fields of science.
