My Research

The transfer of heat within Earth drives many processes operating the interior including mantle convection and plate tectonics. But the chemistry of Earth materials is an integral to how and where rocks deform, metamorphose and melt.

One of the key aspects of my research is developing large datasets to do continental to global scale analyses that yield insight into the thermal and chemical evolution of Earth. Much of my research is computer-based, involving computer modeling and data analytics and also includes laboratory investigations of the physical properties of rocks. The laboratory investigations are generally in support of the larger scale modeling efforts by developing methods to predict physical properties from their chemistry and/or mineralogy.

Software & Datasets

I have written codes for processing, analyzing, and modeling thermal data, geochemistry and heat flow. The codes are available in several repositories: https://github.com/dhasterok.

Global heat flow database: http://heatflow.org

Global whole-rock geochemical database compilation: https://doi.org/10.5281/zenodo.3359791

Geochemical data for protolith classification testing: https://doi.org/10.5281/zenodo.2586461

GIS data for tectonic plates and geological provinces: https://doi.org/10.5281/zenodo.6586972

Contribute

You can help by contributing geochemical data to the global geochemical database. To do so, complete the following template (example) and email me the files along with the article doi. Instructions for filling out the template are given in this PDF. Contribute your own data or a compilation that you have made for your own purposes. Contributors will receive an acknowledgement and significant contributors will be offered co-authorship on a future release. We have put together a video that discusses some tricks for filling out the template quickly. Thanks for your help!

If you contribute to our database, we will also work to ensure that your data are also added to GEOROC and searchable by the EarthChem library. We are in discussions right now how to do this effectively. Note that these libraries contain additional data (e.g., mineral data), but do not necessarily contain all the same metadata associated with samples.

Research Projects

I've included several snippets below that detail my past and current research. References are provided to published works, but you are always welcome to inquire for further information.

Plate and Province Models

Digital models and data standards

This project started because I was frustrated that I could not find a global digital model of geologic provinces and needed one. As with many things I do, the scale of the project grew as I thought about the potential uses of such a model. The global plate and province models include seamless polygons for crustal thickness, tectonic plates and deformation zones, geological provinces, and last orogen. It also includes lines for plate boundary types and the ocean-continent boundary. All the files are in a shapefile format and available on GitHub for the community to improve and as a static version on Zenodo with a QGIS file containing several additional global datasets that is useful for teaching and research.

Hasterok, D., Halpin, J., Hand, M., Collins, A., Kreemer, C., Gard, M., Glorie, S., (2022) New model of global geologic provinces tectonic plates. Earth-Science Reviews,

https://doi.org/10.1016/j.earscirev.2022.104069.

Hasterok, D., Halpin, J., Hand, M., Collins, A., Kreemer, C., Gard, M., Glorie, S., (2022) New model of global geologic provinces tectonic plates. Earth-Science Reviews, preprint,

https://doi.org/10.31223/X5TD1C.

Crustal Heat Production

The fire within

The radioactive decay of U, Th, and K generates heat. This additional heat locally raises temperatures and prolongs the time of cooling. However, heat production is poorly constrained within the crust because it has large natural variability and cannot be sensed in situ by geophysical methods. My work focuses on understanding the sources of variability in an attempt to develop predictors that can be used to improve our models of crustal heat generation.

Hasterok, D., Gard, M., Hand, M., (in prep.) Controls on trace element concentrations and the radiogenic heat production of volcanic arcs.

Hasterok, D., Gard, M., Cox, G., Hand, M., (2019) A 4 Ga record of granitic heat production: Implications for geodynamic evolution and crustal composition of the early Earth. Precambrian Research, 331, 105375. https://doi.org/10.1016/j.precamres.2019.105375

Hasterok, D., Gard, M., Webb, J., (2018) On the radiogenic heat production of metamorphic, igneous, and sedimentary rocks. Geoscience Frontiers, 9, 1777–1794. https://doi.org/10.1016/j.gsf.2017.10.012

Hasterok, D., Webb, J., (2017) On the radiogenic heat production of igneous rocks. Geoscience Frontiers, 8, 919–940. https://doi.org/10.1016/j.gsf.2017.03.006

Thermal Isostasy

Hot and high

Surface elevation is the result of several factors including compositional and thermal buoyancy. Thermal buoyancy is easily apparent in the subsidence pattern of ocean lithosphere, but variations in composition and thickness obscure the thermal contributions to continental lithosphere. My work involves developing methods to separate the chemical and thermal effects to gain insights into the relative contributions of the mantle and crust to the lithospheric temperatures.

Hasterok, D., Gard, M., (2016) Utilizing thermal isostasy to estimate sub-lithospheric heat flow and anomalous crustal radioactivity. Earth and Planetary Science Letters, 450, 197–207. https://doi.org/10.1016/j.epsl.2016.06.037

Hasterok, D., Chapman, D. S., (2011) Heat production and geotherms for the continental lithosphere. Earth Planet. Sci. Lett., 307, 59–70. https://doi.org/10.1016/j.epsl.2011.04.034

Hasterok, D., Chapman, D. S., (2007) Continental Thermal Isostasy I: Methods and Sensitivity. J. Geophys. Res., 112, B06414. https://doi.org/10.1029/2006JB004663

Hasterok, D., Chapman, D. S., (2007) Continental Thermal Isostasy II: Applications to North America. J. Geophys. Res., 112, B06415. https://doi.org/10.1029/2006JB004664

Global Geochemistry

Composition of the solid Earth

This database originally started when I had a summer student revisit an old idea—whether heat production and seismic velocity are correlated. To answer this question, I needed a global geochemical database and a way to predict physical properties from chemistry (see below). Our database is unique from others in that it includes predicted geophysical properties, incorporates machine learning to fill gaps in metadata (metamorphic protolith), and includes spatial metadata using the new plate and province models to speed filtering and aid interpretation.

Gard, M., Hasterok, D., Halpin, J., (2019) Global whole-rock geochemical database compilation. Earth System Science Data, 11, 1553–1566. https://doi.org/10.5194/essd-11-1553-2019

Hasterok, D., Gard, M., Bishop, C. M. B., Kelsey, D., (2019) Chemical identification of metamorphic protoliths using machine learning methods. Computers & Geosciences, 132, 56–68. https://doi.org/10.1016/j.cageo.2019.07.004

Cox, G. M., Lyons, T. W., Mitchell, R. N., Hasterok, D., Gard, M., (2018) Linking the rise of atmospheric oxygen to growth in the continental phosphorus inventory. Earth and Planetary Science Letters, 489, 28–36. https://doi.org/10.1016/j.epsl.2018.02.016

Tamblyn, R., Hasterok, D., Hand, M., Gard, M., 2021. Mantle heating at ca. 2 Ga by continental insulation: Evidence from granites and eclogites, Geology, https://doi.org/10.1130/g49288.1.

Global Heat Flow

Cooling of the Earth

This is where it all started. Heat flow is a rate of heat lost through the lithosphere and can be used for a proxy of temperatures within the interior. However, there are many spatial gaps in the observational record. My work in global heat loss has examined the cooling of the oceanic lithosphere, thermal isostasy and crustal radioactivity on continents, and exploration of conjugate margins as proxies for heat flow. Someday I may even get around to developing my own estimate for global heat loss. Our database can be found at heatflow.org.

Gard, M., Hasterok, D., (2021) A global Curie depth model utilising the equivalent source magnetic dipole method. Physics of the Earth and Planetary Interiors, 313, 106672. https://doi.org/10.1016/j.pepi.2021.106672

Goes, S., Hasterok, D., Schutt, D. L., Klöcking, M., (2020) Continental lithospheric temperatures: A review. Physics of the Earth and Planetary Interiors, 306, 106509. https://doi.org/10.1016/j.pepi.2020.106509

Pollett, A., Hasterok, D., Raimondo, T., Halpin, J. A., Hand, M., Bendall, B., McLaren, S., (2019) Heat Flow in Southern Australia and Connections With East Antarctica. Geochemistry, Geophysics, Geosystems, 20, 5352–5370. https://doi.org/10.1029/2019gc008418

Hasterok, D., Chapman, D. S., Davis, E. E., (2011) Oceanic heat flow: Implications for global heat loss. Earth Planet. Sci. Lett., 311, 386–395. https://doi.org/10.1016/j.epsl.2011.09.044

Hasterok, D., (2013) Global patterns and vigor of ventilated hydrothermal circulation through young seafloor. Earth Planet. Sci. Lett., 380, 12–20. https://doi.org/10.1016/j.epsl.2013.08.016

Physical Properties

From the laboratory to the crustal scale

If you want to compute geophysical properties of a rock from its chemistry, then you need a calibrated relationship derived from physical measurements. There are quite a number of calibrations for seismic velocity and density, most use modal mineralogy whereas very few use major oxide concentrations. While modal mineralogy is likely to be more accurate, especially if the proportion of end member can be accounted for, modal mineralogy is infrequently reported and, when it is, often rough estimates rather than precise measurements. Bulk chemistry, however, is commonly reported for a wide range of rocks giving the potential for statistical predictions of physical properties, but only once a calibration exists.

Sanso, C., Hasterok, D., (in prep.) Variability of thermal conductivity in metasedimentary rocks.

Willcocks, S., Hasterok, D., Halpin, J.A., Walsh, J., (in prep.) Thermal conductivity of Antarctica from measurements and models. Earth and Planetary Science Letters.

Willcocks, S., Hasterok, D., Jennings, S., (2021) Thermal refraction: implications for subglacial heat flux. Journal of Glaciology, 67 (265), 1–10. https://10.1017/jog.2021.38.

Jennings, S., Hasterok, D., Payne, J., (2019) A new compositionally-based thermal conductivity model for plutonic rocks. Geophysical Journal International, 219, 1377–1394. https://doi.org/10.1093/gji/ggz376