Project rationale

 

PROJECT RATIONALE

Map of Antarctica showing active, quiescent and dormant volcanoesAntarctica is the place of intense volcanic activity; in particular Victoria Land comprises several volcanoes that are still active or have been active in recent times. The volcanic products (named tephra) emitted by these volcanoes during the past explosive eruptions have been deposited on very wide areas of the Antarctica region as large as thousands of square kilometers. 

Marine sediment sequences of the Ross Sea, Antarctica, can capture the volcanic particles produced during these explosive eruptions. If fingerprinted in detail (texture, mineral content, major and trace elements composition) and dated, tephra layers in sediment cores can provide important time-parallel markers useful for the synchronization of any geological and climatic event and provides an accuracy that is hardly achieved with other methods.

In Antarctica, tephrochronology, i.e. the study of tephra and their use as isochronous marker beds, was previously focused mainly toward the ice cores, the blue ice and the terrestrial records.

However, recent studies, carried out within the PNRA (project 2010/A2.12), have demonstrated that also marine sediments sampled on the continental shelf of the Ross Sea, along the North Victoria Land, have an extremely high potential for tephrochronological reconstructions. In fact, the area it is located downwind several active volcanoes, which have been active since 500 ka.

Especially in Antarctica, where classic methods for the dating of sediment sequence have great limitations (es. for the scarcity of carbonate sequences due to the low temperature) the use of tephra as potential stratigraphic markers of significant value would strongly contribute to the chronological framework of the area.