Distinguished Professor Emeritus
Contact Information: Website
Office: 241 Williamson Hall
Education: Ph.D. Geophysics, University of Newcastle-upon-Tyne, 1976
Areas of Interest / Research:
- Paleomagnetism
- Geomagnetism
- Environmental Magnetism
Dr. James E.T. Channell's research field is paleomagnetism, geomagnetism and environmental magnetism. Research activity in recent years can be subdivided into four categories:
1. The application of magnetic polarity stratigraphy to the generation of geologic time scales. Magnetic polarity stratigraphy (the record of geomagnetic polarity reversals in sediments and sedimentary rocks) is a preferred means of global stratigraphic correlation. The method can be used to correlate biostratigraphies, cyclostratigraphies, isotope stratigraphies and radiometric age determinations.
2. Environmental magnetism and geomagnetic paleointensity: the use of rock magnetic characteristics as sedimentological tools in recent sediments (e.g. magnetic granulometry) and the use of secular variation and paleointensities for high-resolution correlation of recent (last few Myr) sediments. Modern studies of past climate require millennial-scale correlation of climate-proxy records which usually cannot be provided by the stable isotopes, biostratigraphy or radiometric ages. Variations in the intensity of the geomagnetic dipole field, when recorded by sediments, appear to provide the desired means of global correlation.
3. Geomagnetism: high-resolution records of geomagnetic field behavior from deep-sea sediment drifts have revolutionized our knowledge of the geomagnetic field during the last ~2 million years. The records are now being used to constrain computer-generated models of the geodynamo. As a result, we have a clearer picture of the spatial and temporal characteristics of geomagnetic (secular) variation, and the morphology of polarity transition fields and magnetic excursions. Excursions occur at paleointensity minima, constitute pairs of polarity reversals when optimally recorded, and have durations of a few kyr or less. About seven excursions are well documented and age-calibrated in the Brunhes Chron, and about 10 have been recorded in the Matuyama Chron.
4. The application of paleomagnetism to paleogeographies in mountain belts, notably in the Alpine-Mediterranean area. The objective has been to reconstruct the pre-deformational relative position of rock bodies (on scales from individual thrust sheets to continents). Field-work has been carried out in Italy, Austria, Switzerland, Spain, Slovakia and Turkey in the last 15 years.