Micromagnetic Tomography for Paleomagnetism and Rock-Magnetism.
Jansen, Chloë ML
J Geophys Res Solid Earth
American Geophysical Union (AGU)
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de Groot, L. V., Fabian, K., Béguin, A., Kosters, M. E., Cortés-Ortuño, D., Fu, R. R., Jansen, C. M., et al. (2021). Micromagnetic Tomography for Paleomagnetism and Rock-Magnetism.. J Geophys Res Solid Earth, 126 (10) https://doi.org/10.1029/2021JB022364
Our understanding of the past behavior of the geomagnetic field arises from magnetic signals stored in geological materials, e.g., (volcanic) rocks. Bulk rock samples, however, often contain magnetic grains that differ in chemistry, size, and shape; some of them record the Earth's magnetic field well, others are unreliable. The presence of a small amount of adverse behaved magnetic grains in a sample may already obscure important information on the past state of the geomagnetic field. Recently it was shown that it is possible to determine magnetizations of individual grains in a sample by combining X-ray computed tomography and magnetic surface scanning measurements. Here we establish this new Micromagnetic Tomography (MMT) technique and make it suitable for use with different magnetic scanning techniques, and for both synthetic and natural samples. We acquired reliable magnetic directions by selecting subsets of grains in a synthetic sample, and we obtained rock-magnetic information of individual grains in a volcanic sample. This illustrates that MMT opens up entirely new venues of paleomagnetic and rock-magnetic research. MMT's unique ability to determine the magnetization of individual grains in a nondestructive way allows for a systematic analysis of how geological materials record and retain information on the past state of the Earth's magnetic field. Moreover, by interpreting only the contributions of known magnetically well-behaved grains in a sample, MMT has the potential to unlock paleomagnetic information from even the most complex, crucial, or valuable recorders that current methods are unable to recover.
Geomagnetism and Paleomagnetism/Marine Geology and Geophysics, ATMOSPHERIC COMPOSITION AND STRUCTURE, Air/sea constituent fluxes, Volcanic effects, BIOGEOSCIENCES, Climate dynamics, Modeling, COMPUTATIONAL GEOPHYSICS, Data analysis: algorithms and implementation, Numerical solutions, CRYOSPHERE, Avalanches, Mass balance, GEODESY AND GRAVITY, Ocean monitoring with geodetic techniques, Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions, Global change from geodesy, GEOMAGNETISM AND PALEOMAGNETISM, Rock and mineral magnetism, Instruments and techniques, GLOBAL CHANGE, Abrupt/rapid climate change, Climate variability, Earth system modeling, Impacts of global change, Land/atmosphere interactions, Oceans, Regional climate change, Sea level change, Solid Earth, Water cycles, HYDROLOGY, Climate impacts, Hydrological cycles and budgets, INFORMATICS, MARINE GEOLOGY AND GEOPHYSICS, Gravity and isostasy, ATMOSPHERIC PROCESSES, Climate change and variability, Climatology, General circulation, Ocean/atmosphere interactions, Regional modeling, Theoretical modeling, OCEANOGRAPHY: GENERAL, Climate and interannual variability, Numerical modeling, NATURAL HAZARDS, Atmospheric, Geological, Oceanic, Physical modeling, Climate impact, Risk, Disaster risk analysis and assessment, OCEANOGRAPHY: PHYSICAL, Air/sea interactions, Decadal ocean variability, Ocean influence of Earth rotation, Sea level: variations and mean, Surface waves and tides, Tsunamis and storm surges, PALEOCEANOGRAPHY, POLICY SCIENCES, Benefit‐cost analysis, RADIO SCIENCE, Radio oceanography, SEISMOLOGY, Earthquake ground motions and engineering seismology, Volcano seismology, VOLCANOLOGY, Volcano/climate interactions, Atmospheric effects, Volcano monitoring, Effusive volcanism, Mud volcanism, Explosive volcanism, Volcanic hazards and risks, Research Article, micromagnetic tomography, rock‐magnetism, scanning magnetometry, microCT
European Research Council (851460)
Dutch Science Foundation (ALWOP.641)
External DOI: https://doi.org/10.1029/2021JB022364
This record's URL: https://www.repository.cam.ac.uk/handle/1810/329338