Details of Award
NERC Reference : NER/A/S/2003/00330
Investigation of the global geomagnetic field during the last field reversal.
Grant Award
- Principal Investigator:
- Professor J Shaw, University of Liverpool, Earth Surface Dynamics
- Co-Investigator:
- Professor R Holme, University of Liverpool, Earth, Ocean and Ecological Sciences
- Grant held at:
- University of Liverpool, Earth Surface Dynamics
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- Global Change
- Environmental Risks and Hazards
- Science Topics:
- Planetary science
- Science-Based Archaeology
- Mantle & Core Processes
- Palaeoenvironments
- Abstract:
- The Earth's magnetic field is generated in the hot liquid core of the Earth. At the earth's surface it appears as a dipole field (the same shape as the field due to a bar magnet) with the north magnetic pole close to geographic North. From studies of ancient magnetic minerals contained in rocks, we find that the Earth's magnetic field has reversed its polarity many times in the past (North magnetic pole moves to South geographic pole). The last time this happened was just over 3/4 million years ago and many scientists believe that another reversal is imminent. Although the field has reversed many times we know very little about the strength and direction of the field during a reversal mainly because there are few reversals that are recorded globally and by the right rock type. The most recent field reversal, the Matuyama-Bruhnes Transition, has been studied the most and there are many sedimentary cores that show the detailed directional behaviour during the reversal. There are also seven well defined and globally distributed lava sequences that have recorded the field during this reversal. Because of the way the lavas record the field (thermal processes as the lava cools), it is possible to obtain absolute values of the geomagnetic field strength during the reversal. Traditional techniques have not been very successful in obtaining field strength values (only four determinations from a possible 19). Two recent developments have encouraged us to try to improve on this. More transitional flows (ones that record the field during the reversal) have recently been identified, there are now 68. A new technique had been developed that uses microwaves instead of heat to determine the field strength from lavas. This new microwave technique has recently been applied to lavas from Hawaii with 95% success rate. When applied to the 68 transitional lavas it should improve the number of absolute palaeointensities during the reversal by a factor of ten. Combining this new data with existing records will allow the field to be modelled during the reversal.
- NERC Reference:
- NER/A/S/2003/00330
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £168,078
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Equipment | Total - Indirect Costs |
|---|---|---|---|---|
| £74,799 | £12,874 | £10,749 | £18,689 | £50,968 |
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