Abstract

Volcanism is known to act as a driver of change to the Earth system on a range of scales. Degassing of greenhouse gases may act to drive global warming, whilst the weathering of fresh volcanic material may enhance the silicate weathering feedback and aid cooling of Earth’s climate. At the same time, the intensity of volcanism responds to other aspects of the Earth system. For example, low sea levels and low ice volumes may both act to increase levels of volcanic activity through the release of pressure on magma chambers. These interactions in turn may control the level of impact volcanism has as a driver of change. To fully understand the interaction between volcanic activity and climate, however, reliable records of changing volcanic intensity through time are required. Such records have been, to date, either regional or of low resolution. Here, I will discuss two approaches to this problem, firstly through the compilation of volcanic material occurrence in deep sea sediment cores. Secondly, I will present the application of inversion of atmospheric carbon dioxide records as an approach to reconstructing periods of imbalance and likely volcanic activity in the carbon cycle. Both approaches highlight a shift in the late Pleistocene at around 400 ka, whereby more volcanic activity is reconstructed, and the activity becomes cyclical in nature. This may be linked to Mid Brunhes Transition, a period of strengthening in amplitude of glacial-interglacial cycles, and indicates how Earth system changes may impact volcanic intensity.