Lake Ohau Climate History

LOCH was an international collaboration between three research institutes and five universities: GNS Science, Victoria University of Wellington, the University of Otago, Northern Arizona University, the Istituto Nazionale di Geofisica e Vulcanologia, the University of New South Wales, Indiana State University and NIWA.

LOCH presented drilling challenges unlike any other in New Zealand. The drilling system had to operate in at least 100 m of water and recover near-continuous, high-quality core through an 80 m-thick sequence of soft sediment, including sand and mud.

Then there were Ōhau’s famous wind and wave conditions, which can be extreme. The team had to design a drilling system that could be mobilised quickly, moved to shelter during high winds and rough water, and then relocated above the borehole once conditions improved.

In 2015, marine surveyors Mtech Ltd, Webster Drilling & Exploration Ltd and engineers at Victoria University of Wellington designed the initial barge concept. In addition to the state-of-the-art barge, the pontoon and drill could be disassembled and transported in a standard shipping container.

Drilling began at two sites on the lake in February 2016. At 6 am on 3 March, the drilling crew literally hit rock bottom, recovering Ice Age gravels from 80 m below the lake floor. They had recovered a full geological record spanning from the Ice Age to 2016.

Webster Drilling’s contribution to the LOCH project demonstrated our ability to adapt and innovate to meet the specific needs of scientific research initiatives. By collaborating with Victoria University to design and implement a specialised drilling barge, we played a significant role in advancing the global understanding of climate history.