Hjem

Geofysisk institutt

Mandagskollokvium - GFI/BCCR seminar

Gina Moseley - Greenland Caves Project: The Potential for Constructing Speleothem Palaeoclimate Records for the Arctic

Abstract

Multiple lines of evidence currently exist that demonstrate the climate is changing across our planet and that the Arctic in particular is highly sensitive to these changes, warming up twice as fast as the global average. Understanding how the climate in the Arctic will develop in the future and its subsequent effects is thus a major concern. In order to improve understanding of the climate system within the Arctic, we have collected a suite of speleothem flowstone samples from solutional caves in the Ordovician-Silurian Centrum limestone of Kronprins Christian Land, Northeast Greenland. Under contemporary conditions, the region is arid, barren, and permanently frozen, however, the presence of these caves and thick flowstone deposits indicates a previous milder climate.

During the summer of 2015, the remnants of 26 caves were documented at 80.4°N in Northeast Greenland in a 1 kmlong valley. Calcite flowstone speleothems were found to be abundant within the caves, however, due to logistical constraints only small pilot samples were collected for analysis. Here we report the preliminary findings of the project.

We find that a number of samples are too old for U-Th dating, whilst others display open-system dynamics. Some samples were, however, deposited within the last 650,000 years and show consistent stable isotopic signatures, thus demonstrating promise for palaeoclimate reconstructions from speleothems in Greenland.