The Sea Versus the Land - Will There Be a Winner?

The Geoscience Society of New Zealand Otago Branch presents the 2024 Hochstetter Lecture by David Barrell (GNS). David's lecture will explore forthcoming changes to Aotearoa’s coast, and underscore scientific questions, the pathway of discovery and enquiry, and what it means in wider contexts of Zealandia’s geological, tectonic, and landscape evolution. The presentation will be framed as a case example of how years of robust observations address important scientific questions and yield thought-provoking results.

Aotearoa New Zealand is the largest emergent part of the mainly submerged Zealandia continent. Plate-boundary tectonic deformation is responsible for Aotearoa’s ongoing emergence, and its margins are constantly under attack by waves in the vast surrounding ocean. Aotearoa’s landscape reflects an interplay between the rock foundations, the climate which gives precipitation to drive erosion and the river transport of sediment, and wave energy in the coastal zone which distributes the sediment once it reaches the sea.

Perspectives of ‘whole system’ processes and mass/energy budgets, coupled with eustatic ebb and flow of the sea across the continental shelf through glacial/interglacial climate cycles, provide an integrated approach for explaining the form of Aotearoa’s landscape and behaviour of its river systems.

This talk will explore the battle between sea and land, from the deep geological past through to modern times, and interpret the richly varied form of our coastline, from the long sweeping cliffs of some places, and indented bays and estuaries of others. Whole-system perspectives will be used to discuss likely coastal changes in coming decades to centuries under changing climate.

The Hochstetter Lecture is a public talk, and all are welcome to attend.