Fossil diatom (IMAGE)

Princeton University

Fossil diatom

Caption

This diatom species, Fragilariopsis kerguelensis, is a floating algae that is abundant in the Antarctic Ocean and was the major species in the samples collected for the study by Princeton University and the Max Planck Institute for Chemistry. These microscopic organisms live near the sea surface, then die and sink to the sea floor. The nitrogen isotopes in their shells vary with the amount of unused nitrogen in the surface water. The researchers used that to trace nitrogen concentrations in Antarctic surface waters over the past 150,000 years, covering two ice ages and two warm interglacial periods.

Credit

(c) Michael Kloster, Alfred-Wegener-Institute

Usage Restrictions

Editorial use only

License

Licensed content

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.