Details of Award
NERC Reference : NE/C51982X/1
Are dynamo stability and field strength coupled? The geomagnetic field during the Cretaceous Normal Superchron.
Grant Award
- Principal Investigator:
- Professor J Shaw, University of Liverpool, Earth Surface Dynamics
- Co-Investigator:
- Dr M Hill, 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
- Mantle & Core Processes
- Abstract:
- The Earth's magnetic field is generated in the hot liquid outer core by a dynamo process. At the Earth's surface it appears as a dipole field (the same shape as the field due to a bar magnet). From studies of ancient magnetic minerals contained in rocks we find that the Earth's magnetic field has reversed it's 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. However, in Cretaceous times the dynamo remained unusually stable and the field remained in the same polarity (normal, the same as it is today) for approximately 37 million years. This is more than 100 times longer than the average length of polarity intervals for the past 40Ma. It is crucial for understanding deep Earth processes that this so called superchron behaviour is understood. One aspect that has been predicted but is at yet not known (due to lack of data) is whether the dynamo stability is related to the strength of the generated dipole field. Traditional techniques have not been very successful in obtaining field strength values. A new microwave technique, developed in Liverpool with NERC funding, has a much higher success rate. For instance this novel technique has recently been applied to lavas from Hawaii with 95% success rate, compared to 54% using conventional heating techniques, allowing us to extract much more information from geological samples. Using the microwave field intensity technique on selected samples will produce a large high quality data set for this particularly interesting time in the history of the Earth's magnetic field and will enable geoscientists to know whether a long term stable dynamo generates stronger or weaker fields than a dynamo that reverses frequently.
- NERC Reference:
- NE/C51982X/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £219,835
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £11,538 | £109,453 | £31,937 | £66,909 |
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