Scientists to investigate Alpine faultline

New Zealand scientists, will drill a single deep borehole into the Alpine Fault, at a point near Whataroa, north of Franz Josef on the West CoastFault. Photo / GNS

Scientists from New Zealand and around the world are ready to descend on the West Coast in a $3 million project to investigate the Alpine Fault with a deep drilling probe.

GNS science project leader Dr Rupert Sutherland said the plan was to drill a single borehole 1.3km into the South Island plate boundary to glean information about the inner workings of the faultline.

It will be the first borehole on the Alpine Fault to exceed 100m and penetrate bedrock.

The investigation exceeds the scope of all past investigations in terms of depth of penetration, and expenditure.

Work is already under way just south of Whataroa.

Dr Sutherland said about 80 scientists would analyse crucial information from the borehole.

He has an ambitious task ahead of him as project co-leader of the investigation, which is expected to hit bedrock at a depth of 100m.

Dr Sutherland expects the climax will be reached in late October to early November.

Currently, there are drillers but few scientists on site. They are drilling through surface layers and sediments. However, scientists will come in large numbers when the drill hits solid rock.

Experts are unsure what to expect as no one has ever drilled that far down before, Dr Sutherland says.

The team includes engineering geologists, environmental geophysicists, geochemists, fluid engineers, and structural geologists.

They expect to drill 20m a day, or about 1m an hour. Drillers work 24 hours a day on shifts.

It is expected to cost $3m excluding scientists and drillers' salaries.

The investigation is different to previous studies, where normally work occurs after an earthquake, not before. Sensors will be left after the scientists leave, producing more data.

- Greymouth Star