Chasing earthquake and volcanism signals in a deep marine channel: the Hikurangi Channel New Zealand

Dr Lorna Strachan – University of Auckland

The deep marine Hikurangi Channel, located off the east coast of New Zealand, is a colossus. More than four times longer than any other located at an active continental margin, this trench-axis conduit can be traced for ~2000 km. Rapid continental uplift and frequent earthquakes associated with Hikurangi Subduction Margin and volcanic eruptions in the Taupō Volcanic Zone, together with active temperate weather systems mean that vast amounts of terrestrial, volcanic and shelfal sediment, nutrients, and (today) pollutants, are focussed through several canyons that feed the Hikurangi Channel. Recurrent powerful, sediment-laden underwater flows, known as turbidity currents, over the last 40,000 years, have left a remarkable and highly expanded greater than 100 m thick turbidite record that is allowing us to unravel the earthquake and volcanic signal of this margin over Quaternary timescales. Here I will discuss results from a large group of researchers working on understanding the Quaternary sedimentary systems of the Hikurangi Subduction margin. This will include preliminary results from IODP site 1520, together with multiple Holocene aged short cores (< 10 m thick).