Science & Data

Overview

I am an Earth scientist with more than 15 years of experience in experimental geophysics, rock magnetism, paleomagnetism, quantitative data analysis, and scientific instrumentation. My work focuses on a central problem in the Earth sciences: determining how reliably rocks and sediments record information about ancient magnetic fields, geological processes, and environmental conditions.

Throughout my scientific career, I have combined laboratory experiments, field observations, numerical and statistical analysis, and the development of new measurement techniques. Much of my research examines how physical processes, mineralogy, magnetic anisotropy, and experimental procedures can bias scientific observations—and how those effects can be identified, quantified, and corrected.

I have contributed to approximately 40 peer-reviewed publications and collaborated with researchers across geology, geophysics, materials science, volcanology, environmental science, and planetary science. I also develop Python tools for analyzing and visualizing magnetic data and publish independent technical work through Rock Paleo Magnetism.

Although I now work as a financial advisor, I remain actively engaged in scientific research, writing, and open-source development. Across these fields, my approach is consistent: examine the evidence carefully, identify hidden assumptions, quantify uncertainty, and communicate conclusions clearly.

Research Areas

My research spans rock magnetism and paleomagnetism, with a particular emphasis on data fidelity and the development of methods that improve the reliability of magnetic interpretations.

Magnetic anisotropy and data fidelity

I investigate how the directional dependence of magnetic properties affects paleomagnetic measurements and their interpretation. This work includes developing anisotropy measurement techniques, isolating different magnetic-fabric components, correcting biased paleomagnetic directions and intensities, and evaluating the uncertainties associated with those corrections.

Remanence acquisition and sedimentary bias

I use experimental deposition, numerical modeling, and statistical analysis to examine how sediments acquire and preserve magnetic remanence. A major focus is inclination shallowing, the systematic recording of magnetic directions that are too shallow, and its consequences for paleogeographic reconstructions and relative paleointensity estimates.

Remagnetization and paleogeographic reconstructions

I study how rocks can acquire secondary magnetizations long after their formation and how these overprints can be distinguished from primary magnetic records. This work improves the identification of regional remagnetization events and helps assess the reliability of apparent polar wander paths and reconstructions of Pangea.

Environmental magnetism

I apply magnetic measurements to questions involving climate, soil formation, sediment transport, depositional environments, mineral alteration, and redox conditions. This research includes developing magnetic proxies and methods for separating the contributions of different iron-bearing minerals.

Volcanology and magnetic materials

I investigate the magnetic properties of volcanic materials, including low-temperature magnetic properties to characterize volcanic products and iron-oxide nanoparticles.

Selected Research Contributions

My research has introduced and advanced techniques for measuring magnetic anisotropy, correcting biased paleomagnetic records, evaluating uncertainty, identifying remagnetization, and separating mineral contributions to magnetic measurements.

Hematite Anisotropy measurement and component isolation

Hematite-bearing sedimentary rocks contain important records of ancient magnetic fields, but conventional low-field anisotropy techniques may not adequately characterize the grains carrying their remanence. I developed the first successful high-field isothermal remanence anisotropy technique for measuring the magnetic anisotropy of hematite-bearing rocks. This made it possible to characterize the fabric of the remanence-carrying hematite population more directly and to use that information when evaluating depositional bias and paleomagnetic directions (Bilardello & Kodama, 2009). I subsequently developed a multispecimen approach for isolating different hematite anisotropy contributions, including the fabric associated with grains carrying the characteristic remanent magnetization (Bilardello, 2015).

Inclination Shallowing Corrections and paleogeographic implications

Sedimentary particles can rotate, roll, or realign during deposition and compaction, causing rocks to record magnetic inclinations that are systematically shallower than the ambient field. If unrecognized, this bias can distort paleolatitude estimates and continental reconstructions. My work was the first to compile and use distributions of experimentally determined shallowing factors to correct inclination shallowing in sedimentary rocks. This work helped move inclination correction away from reliance on a single assumed correction factor and toward an approach that better represented the variability observed in depositional systems (Bilardello & Kodama, 2008; Bilardello & Kodama, 2009).

I then evaluated how uncertainty in magnetic anisotropy and the correction process propagates into the resulting paleomagnetic directions, including the development and interpretation of elliptical confidence regions around corrected directions (Bilardello et al., 2011).

I also examined the consequences of inclination corrections for North American apparent polar wander paths and reconstructions of Pangea, demonstrating that measurement and depositional biases can influence interpretations at the scale of continents and supercontinents (Bilardello & Kodama, 2010b; Bilardello & Kodama, 2010c).

Relative Paleointensity and anisotropy-related bias

Relative paleointensity methods use the magnetization of sediments to estimate changes in the strength of Earth’s magnetic field. These estimates commonly assume that the normalizing parameter and the remanence are affected similarly by sedimentary processes. I investigated how inclination shallowing and magnetic anisotropy influence relative paleointensity estimates and evaluated an anisotropy-based correction for experimentally deposited sediments. This work demonstrated that depositional fabric can affect not only magnetic directions but also estimates of past field intensity (Molinek & Bilardello, 2018).

Remagnetization and great-circle analysis

Paleomagnetic datasets often contain overlapping primary and secondary magnetizations that cannot be completely separated using conventional demagnetization methods. I proposed an intersection-of-great-circles approach for identifying magnetic components shared among multiple samples. Applied to South American rocks, the method provided evidence for regionally extensive remagnetization and offered a way to identify common overprints even when individual samples did not yield fully isolated magnetic directions (Bilardello et al., 2018).

Environmental magnetic proxies and the goethite test

Bulk magnetic measurements frequently combine signals from several iron-bearing minerals, making it difficult to identify the contribution of a particular phase. I introduced an efficient MPMS HIRM-based Goethite Test that uses field and temperature-dependent remanence behavior to distinguish goethite from other magnetic mineral contributions. The approach provides a practical means of identifying and estimating mineral-specific contributions to bulk magnetization (Bilardello, 2019).

Technical and Field Expertise

Scientific computing and data analysis

I use Python to clean, analyze, model, and visualize scientific data. My work includes:

• Data processing with Pandas and NumPy

• Statistical and numerical analysis with SciPy and Scikit-learn

• Data visualization and the communication of multidimensional results

• Development of custom analytical and visualization workflows

• Coercivity-distribution analysis and unmixing

• Magnetic-anisotropy calculations and directional data analysis

• Nanoparticle grain-size estimation

• Reproducible research and open-source scientific code

My code and related resources are available through the Rock Paleo Magnetism repository and my GitHub profile.

Experimental methods and instrumentation

My laboratory experience includes:

• SQUID and vibrating sample magnetometers

• Magnetic susceptometers

• Variable- and low-temperature magnetic measurements

• Magnetic imaging and characterization tools

• Cryogenic systems and the safe handling of cryogens

• Experimental design, method validation, and instrument troubleshooting

• Development of measurement techniques and magnetic proxies

Geological fieldwork

I am an experienced geological mapper and paleomagnetic field researcher. My field experience includes:

• Geological and structural mapping

• Measurement of bedding, S–C fabrics, lineations, and slickenside orientations

• Paleomagnetic oriented-core drilling

• Sample-orientation and coordinate-system transformations

• Stratigraphic measurement using Jacob’s staff

• Surveying and spatial measurement using a total station

• Field planning, sampling design, documentation, and data quality control

Communication, Leadership, and Service

Scientific writing and public communication

I have extensive experience translating complex scientific questions into accessible, technically accurate writing. My work includes peer-reviewed articles, technical reports, educational publications, newsletters, websites, presentations, and open-source documentation.

I am the creator, editor, and author of Rock Paleo Magnetism, an independent publication examining magnetic methods, data interpretation, analytical bias, and reproducible research.

Previously, as an editor and author for the IRM Quarterly, I wrote more than 30 educational and technical articles on magnetic measurements, interpretation, instrumentation, laboratory activities, and developments in the rock-magnetic community. These articles have reached an international readership and have been cited in peer-reviewed scientific literature.

Open science and digital communication

Through the Rock Paleo Magnetism code repository, I provide open and reproducible Python resources for analyzing and visualizing rock-magnetic and paleomagnetic data.

I also led the complete redesign of the Institute for Rock Magnetism website, migrating it from an outdated Dreamweaver-based system to a modern Drupal platform. The project improved the organization, accessibility, usability, and public presentation of the institute’s scientific resources.

Mentoring and community leadership

My leadership and service experience includes:

• Mentoring students and early-career scientists

• Organizing international workshops, conferences, and educational programs

• Supporting collaboration among researchers from different disciplines and institutions

• Communicating technical information to specialist and nonspecialist audiences

• Developing educational resources for the scientific community

Diversity, equity, and inclusivity

I have supported diversity, equity, and inclusivity through institutional service, mentoring, professional development, and external advisory work.

My previous roles include membership on the University of Minnesota Department of Earth and Environmental Sciences equity and diversity committees and the College of Science and Engineering DEI Alliance Lead Team.

I have also served as an external advisory board member for the New Mexico Highlands University Partnership for Research and Education in Materials program and earned an Equity and Diversity Certificate through the University of Minnesota Office for Equity and Diversity.