Scientists will leave for Antarctica post Christmas to take measurements of the Earth's magnetic field. And the same were first taken 100 years ago during Scott's Terra Nova Expedition.
There was a long gap between the Scott expedition's first measurements to the start of regular five-yearly measurements when Scott Base was established in 1957.
Tony Hurst and Stewart Bennie of GNS Science will spend two weeks on the ice collecting measurements at two locations to provide an update of the exact location of the South Magnetic Pole. This is where the geomagnetic field lines go vertically into the earth.
The pair will need to travel some distance from Scott Base as it is built on volcanic material ejected from Mount Erebus. The volcanic rocks are high in the iron-rich mineral magnetite, which gives anomalous magnetic readings.
They will travel by helicopter to Lake Vanda, 125km west of Scott Base, where they will spend four days camping in a small hut while taking their measurements. At Vanda, which is in one of the dry valleys, they will take the measurements on a conspicuous rock marked with an aluminium pin over which they will place their tripod.
On their return flight, they will stop off at Cape Evans, 30km from Scott Base, where they will take measurements at a small shelter near Scott's hut. The measurements are taken at an exact mark inside the shelter.
They use two instruments to measure the magnetic field.
The first is a magnetic theodolite that measures both the horizontal angle and the inclination of the magnetic field.
Their other - an Overhouser effect magnetometer - is a suitcase-sized instrument that gives a digital readout of the strength of the magnetic field in units called nanoTeslas or gammas. Both instruments are extremely sensitive and require careful handling.
The data they collect will be provided to an international database, which is used to calculate a world magnetic model. The model is updated every five years and has many civilian and military end uses, particularly in navigation.
Dr Hurst said for the past 100 years the South Magnetic Pole had been moving northwest by about 10km to 15km a year.
"The last field measurements in 2007 put the magnetic pole at 64.5 degrees south and 137.7 degrees east, about 50 kilometres off the Antarctic coast and due south of Australia," Dr Hurst said.
"In all likelihood our measurements will show this trend has continued and the magnetic south pole has moved further north and further out to sea."
With the gradual northward movement of the magnetic pole, the strength of the field at Scott Base had decreased by as much as 10 percent over the past century.
The worldwide coverage of magnetic measurements was patchy, with fewer measurements taken in the Pacific and Antarctica than in the populous continents.
"We see it as important that New Zealand plays its part in a global sense by providing accurate measurements in a region of the world where measurements are sparse."
The pair fly to Antarctica on 28 December and are due to return on 11 January. GNS Science pays for the project with funding received from the Ministry of Science and Innovation. In addition, Antarctica New Zealand provides logistics support. Source: http://www.voxy.co.nz/lifestyle/century-antarctic-magnetic-measurements/5/110441
There was a long gap between the Scott expedition's first measurements to the start of regular five-yearly measurements when Scott Base was established in 1957.
Tony Hurst and Stewart Bennie of GNS Science will spend two weeks on the ice collecting measurements at two locations to provide an update of the exact location of the South Magnetic Pole. This is where the geomagnetic field lines go vertically into the earth.
The pair will need to travel some distance from Scott Base as it is built on volcanic material ejected from Mount Erebus. The volcanic rocks are high in the iron-rich mineral magnetite, which gives anomalous magnetic readings.
They will travel by helicopter to Lake Vanda, 125km west of Scott Base, where they will spend four days camping in a small hut while taking their measurements. At Vanda, which is in one of the dry valleys, they will take the measurements on a conspicuous rock marked with an aluminium pin over which they will place their tripod.
On their return flight, they will stop off at Cape Evans, 30km from Scott Base, where they will take measurements at a small shelter near Scott's hut. The measurements are taken at an exact mark inside the shelter.
They use two instruments to measure the magnetic field.
The first is a magnetic theodolite that measures both the horizontal angle and the inclination of the magnetic field.
Their other - an Overhouser effect magnetometer - is a suitcase-sized instrument that gives a digital readout of the strength of the magnetic field in units called nanoTeslas or gammas. Both instruments are extremely sensitive and require careful handling.
The data they collect will be provided to an international database, which is used to calculate a world magnetic model. The model is updated every five years and has many civilian and military end uses, particularly in navigation.
Dr Hurst said for the past 100 years the South Magnetic Pole had been moving northwest by about 10km to 15km a year.
"The last field measurements in 2007 put the magnetic pole at 64.5 degrees south and 137.7 degrees east, about 50 kilometres off the Antarctic coast and due south of Australia," Dr Hurst said.
"In all likelihood our measurements will show this trend has continued and the magnetic south pole has moved further north and further out to sea."
With the gradual northward movement of the magnetic pole, the strength of the field at Scott Base had decreased by as much as 10 percent over the past century.
The worldwide coverage of magnetic measurements was patchy, with fewer measurements taken in the Pacific and Antarctica than in the populous continents.
"We see it as important that New Zealand plays its part in a global sense by providing accurate measurements in a region of the world where measurements are sparse."
The pair fly to Antarctica on 28 December and are due to return on 11 January. GNS Science pays for the project with funding received from the Ministry of Science and Innovation. In addition, Antarctica New Zealand provides logistics support. Source: http://www.voxy.co.nz/lifestyle/century-antarctic-magnetic-measurements/5/110441
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