A glacial control on the eruption rate of Mt Erebus, Antarctica

Mt Erebus is the most active Antarctic volcano, on the flanks of the world’s largest ice sheet. Despite this, the interactions between its eruptions and the ice cover have not been studied in detail. Focusing on the most recent deglaciation, we build a glacial retreat model and compare this to recent lava geochemistry measurements to investigate the processes involved. This analysis exposes a previously unknown link between Antarctic glaciation and eruptions, of vital importance to the understanding of volcanism in this context. We find that deglaciation led to rapid emptying of the shallow magma plumbing system and a resulting peak in eruption rates synchronous with ice retreat. We also find that the present day lavas do not represent steady state conditions, but originate from a source with up to 30% more partial melting than older >4 ka eruptions. This finding that deglaciation affects volcanism both on short and longer timescales may prompt a re-evaluation of eruptions in glaciated and previously glaciated terrains both in Antarctica and beyond