A mag survey is done to measure the magnetics of the bedrock.  The instrument is worn with the display resting on your stomach.  Readings are taken in the field and downloaded to the computer.  At the end, you can generate a map showing the magnetics of the ground you covered.

The earth's magnetic field is continually changing slightly for unknown reasons.  To compensate for these minor variations, a base station is set up in a fixed location to record the daily variations and adjust the final data to reflect these.

Zdenek came to train us for a few days and then we were on our own.

Zdenek and Bjorn setting up the base station

It was cold every morning and finally, as suggested by those in charge, we didn't go out until around 10:00a.m. when the temperature was up to -25 Celsius.

The thing behind my head is the sensor.  The sensor is temporarily charged and discharged.  This is the reading that indicates how magnetic the rock below is.

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