Full Vector Studies of the Last 60 Thousand Years Derived From the East Maui Volcano, Hawaii

University Of Hawaii, Honolulu

Investigators

Abstract

The main purpose of the investigation is to study the variation of the ancient magnetic field of the Earth generated at the core of the planet and recorded by lavas erupted from the East Maui Volcano, Hawaii. We are studying variations of the paleofield by sampling ~93 lava flows that span the time rage of 200 to 60,000 years before present with the ultimate goal of understanding how the magnetic field of the Earth has been generated within the interior of the planet. The project involves directional analyses and paleointensity studies in order to achieve determinations of the total field vector for the last 60,000 years. The paleointensity experiments that are being used include the new Multispecimen Parallel Differential method, as well as those using the conventional Thellier-Coe method. The advantage of the new technique is that it represents a reliable way of determine absolute paleointensities that is independent of the domain state of the magnetic minerals. The results of this study will be compared with the paleosecular variation values obtained from coeval lavas elsewhere in the Hawaiian Islands. An important outcome of this study will be further refinement of our knowledge of global geomagnetic intensity variations, which are currently over represented from data from European sites. Improved paleointensity curves are essential for global magnetic field models and for the development of more realistic geodynamo models. They are also important as fundamental constraints for dating methods that use cosmogenic isotopes as 14C, beryllium etc. Detailed and reliable paleointensity curves are also useful as correlation and dating tools in archeology and upper Quaternary geology. The project involves international collaboration with researchers from the Netherlands, and is supporting undergraduate research projects of students at the School of Ocean and Earth Science and Technology of the University of Hawaii at Manoa. The project is contributing to the broadening of participation of underrepresented groups and in supporting research infrastructure.