AUTHOR=Kodama Kenneth P. TITLE=Grand challenges in geomagnetism and paleomagnetism JOURNAL=Frontiers in Earth Science VOLUME=1 YEAR=2013 URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2013.00003 DOI=10.3389/feart.2013.00003 ISSN=2296-6463