Mr Mark Bourne

Postgraduate Student

Email:	mark.bourne@earth.ox.ac.uk
TEL:	+44 (1865) 272001
FAX:	+44 (1865) 272072
Homepage:	http://www.earth.ox.ac.uk/~markb

Research Profile

My current research attempts to develop accurate observational records of geomagnetic excursions in order to gain some insight into how the Earth's magnetic field is generated and what controls its behaviour.

Geomagnetic excursions mark periods when the variation in the direction and intensity of the Earth's magnetic field greatly exceeds that of normal secular variation, and at times the field approaches a 'reversed state' before returning to a 'normal state'. Approximately 12 excursions of the Earth's magnetic field have been claimed to have occurred since the last full geomagnetic reversal at 780 ka, though the absolute chronology of these is uncertain.

I am currently developing a high resolution record of the Blake geomagnetic excursion from Ocean Drilling Program (ODP) Site 1062, Leg 172 on the Blake-Bahama Outer Ridge. I am particularly interested in obtaining an accurate duration of the directional excursion using ²³⁰Th_xs as a sedimentation rate proxy.

Beyond this preliminary study I hope to investigate the possibility of using magnetic excursions as a correlatory tool for climatic records from terrestrial, marine and ice cores.

Teaching Profile

Demonstrating

Atmosphere & Hydrosphere - 3rd years

Tutoring

Geomagnetism & Palaeomagnetism

Electricity & Magnetism - 1st years

Selected Publications

In Press: Bourne, M, Mac Niocaill, CM, Thomas, AL, Knudsen, MF, Henderson GM, (2012) Rapid directional changes associated with a 6.5 kyr-long Blake geomagnetic excursion at the Blake-Bahama Outer Ridge, Earth and Planetary Science Letters, DOI:10.1016/j.epsl.2012.04.017

Other Information

Member of the Oxford Palaeomagnetism & Rock Magnetism and Climotope Research Groups