Selected publications

• ExoCcycle: A Generalized Framework for Spherical Community Detection and its Application to Defining Global Ocean Basins from Multi-Field Data - Model and Results

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-20

  otherOpen access

  This repository contains ExoCcycle, a python based library for creating exoplanetary-like bathymetry models and conducting carbon cycle analyses with bathymetry models. Currently, a primarily component of this library are its classes/methods/functions for objectively finding communities on the sphere of an input spherical shell. These methods are useful for define current, paleo-, and exo- ocean basins for use in and constructing intermediate C cycle models. However, there are additional domains of study that can readily make use of community detection of single or multiple fields on spherical shells. There is a jupyter notebook within the JN folder. After dowloading/cloning this library, open the GMD_Manuscript_Figures.ipynb to see examples of how this library can be used.

  PublisherDOI

• The Role of the Overriding Plate and Mantle Viscosity Structure on Deep Slab Morphology

  Geochemistry Geophysics Geosystems · 2025-09-30

  articleOpen access

  Abstract Using 2D numerical subduction models, we compare the morphology of deep slabs in the presence of an oceanic or continental overriding plate and viscosity jumps at either 660 km or 1,000 km depth as suggested by the latest geoid inversions. We demonstrate that a continental plate, combined with a 1,000 km depth viscosity increase, promotes slab penetration into the lower mantle. The same slab will deflect at 660 km depth if it subducts under an oceanic plate into a mantle where the viscosity increases at 660 km depth. To quantify these dynamics, we introduce a slab‐bending ratio, dividing the angle of the deepest tip of the slab (slab tip angle) by its dip angle below the plate interface (shallow slab angle), reflecting the overall steepness, and sinking history of the slab. Ocean‐ocean convergence models with a viscosity increase coincident with the phase transition at 660 km depth have low ratios and flattened slabs comparable to ocean‐ocean cases in nature (e.g., Izu‐Bonin). Coupling a continental overriding plate with a 1,000 km depth viscosity increase separate from the endothermic phase change results in slabs with high ratio values, and stepped morphologies similar to those observed for the Nazca plate beneath Southern Peru. Our results highlight that slab morphologies ultimately express the interaction between the type of overriding plate, slab‐induced flow, and phase transitions, modulated by the viscosity structure of the top of the lower mantle and transition zone, complementing studies of slab folding, buckling, and other deformation in the upper mantle.

  PublisherDOI

• Unraveling the Connection Between Subsurface Stress and Geomorphic Features

  Geophysical Research Letters · 2025-10-07 · 1 citations

  articleOpen accessSenior author

  Abstract The tectonic stress field induces surface deformation. At long wavelengths, both lithospheric heterogeneity (changes in the thickness and density of crust and lithospheric mantle) and basal tractions from mantle convection contribute to the stress field. Here, we analyze the global alignment of principal horizontal tectonic stresses, fault traces, and river flow directions to infer whether and how deep subsurface stresses control geomorphic features. We find that fault trace orientations are consistent with predictions from Anderson's fault theory. River directions largely align with fault traces and partly with stresses. The degree of alignment depends on fault regime, the source of stress, and river order. Extensional faulting is best predicted by stresses from lithospheric structure variations, while compressive faulting is best predicted by stresses from mantle flow. We propose a metric to quantify the relative influence of mantle flow or lithospheric heterogeneity on surface features, which provides a proxy for lithospheric strength.

  PublisherDOI

• How Phase Transitions Impact Changes in Mantle Convection Style Throughout Earth's History: From Stalled Plumes to Surface Dynamics

  Geochemistry Geophysics Geosystems · 2025-02-01 · 9 citations

  articleOpen access

  Abstract Mineral phase transitions can either hinder or accelerate mantle flow. In the present day, the formation of the bridgmanite + ferropericlase assemblage from ringwoodite at 660 km depth has been found to cause weak and intermittent layering of mantle convection. However, for the higher temperatures in Earth's past, different phase transitions could have controlled mantle dynamics. We investigate the potential changes in convection style during Earth's secular cooling using a new numerical technique that reformulates the energy conservation equation in terms of specific entropy instead of temperature. This approach enables us to accurately include the latent heat effect of phase transitions for mantle temperatures different from the average geotherm, and therefore fully incorporate the thermodynamic effects of realistic phase transitions in global‐scale mantle convection modeling. We set up 2‐D models with the geodynamics software Aspect , using thermodynamic properties computed by HeFESTo, while applying a viscosity profile constrained by the geoid and mineral physics data and a visco‐plastic rheology to reproduce plate‐like behavior and Earth‐like subduction morphologies. Our model results reveal the layering of plumes induced by the wadsleyite to garnet (majorite) + ferropericlase endothermic transition (between 450 and 590 km depth and over the 2000–2500 K temperature range). They show that this phase transition causes a large‐scale and long‐lasting temperature elevation in a depth range of 500–650 km depth if the potential temperature of the mantle is higher than 1800 K, indicating that mantle convection may have been partially layered in Earth's early history.

  PublisherDOI

• How Phase Transitions Impact Changes in Mantle Convection Style Throughout Earth’s History: From Stalled Plumes to Surface Dynamics

  2025-03-14

  preprintOpen access

  Mineral phase transitions can either hinder or accelerate mantle flow. In the present day Earth, the formation of the bridgmanite + ferropericlase assemblage from ringwoodite at 660 km depth has been found to cause weak and intermittent layering of mantle convection. However, for the higher temperatures in Earth’s past or on other planets, different phase transitions might have governed mantle dynamics and shaped mantle structure. Here, we apply a recently developed entropy formulation in mantle convection models with plate-like behavior to investigate the effect of phase transitions on changes in convection style throughout Earth's history. We have extended this method to include chemical heterogeneity, and we have implemented and tested the approach in the geodynamics software ASPECT. Our benchmark results show that this multicomponent entropy averaging method effectively captures the system's thermodynamic effects. Furthermore, we apply the entropy formulation in 2-D and 3-D geodynamic models, incorporating thermodynamic properties computed by HeFESTo. Our models reveal the impact of the endothermic transition from wadsleyite to garnet (majorite) and ferropericlase (occurring between 420–600 km depth and over the 2000–2500 K temperature range) in a mantle with potential temperatures hotter than 1700 K, which impedes rising mantle plumes. When encountering this phase transition, the plume conduits tilt significantly, and the plume heads spread out laterally. This change in plume morphology accumulates hot material in the transition zone, spawning secondary plumes.  Partial melt generated within these hot, stalling plumes may lead to chemical differentiation as plume material spreads laterally. On a larger scale, the phase transition can reduce the mass flux of plumes by ~90%. The stalling of plumes creates a long-lasting global hot layer and impedes mass exchange between lower and upper mantle, resulting in global thermal and chemical heterogeneity.Our models reveal a systematic change in convection style during planetary secular cooling. The wadsleyite to garnet (majorite) + ferropericlase phase transformation only occurs at high temperatures and therefore layering of plumes becomes less frequent and eventually stops as the mantle cools down. This indicates that mantle convection may have been partially layered early in Earth's history, or may be layered today in terrestrial planets with a hotter mantle. As the mantle potential temperature decreases and layering ceases, we observe an increase of surface mobility, suggesting that such a change in convection patterns also affects plate tectonics.

  PublisherDOI

• Retroarc foreland basins document past oceanic subduction history

  Earth and Planetary Science Letters · 2025-05-15

  articleSenior author
  PublisherDOI

• Determining mid-ocean ridge geography from upper mantle temperature

  Earth and Planetary Science Letters · 2024-06-13 · 2 citations

  articleOpen accessSenior author

  In this study, we examine the influence of the mantle and large-scale tectonics on the global mid-ocean ridge (MOR) system. Using solely seismically-inferred upper mantle temperatures below the melting zone (260-600 km) and an interpretable machine learning model (Random Forest and Principal Component Analysis), we can predict a priori the location (ocean basin and ridge system) of global MOR with up to 90% accuracy. Two features provide > 50% of the discriminative power: the temperature difference between the mid-layer (340-500 km) and other depths, and the depth-averaged temperature of the upper mantle. We suggest long-term (100s Myr) tectonic and large-scale convective processes primarily driven by deep subduction left ample, distinct but hidden fingerprints in the mantle that allow us to separate regions at ∼1000 km scale. Our result implies that the large-scale geophysical and geochemical differences observed along the MOR system are reflective, not primarily of shallow processes associated with melting, but of the integrated long-term tectonic, subduction, and convective flow history that determines the present-day upper mantle temperature structure.

  PublisherDOI

• The Role of the Overriding Plate and Mantle Viscosity Structure on Deep Slab Morphology

  2024-03-05

  preprintOpen access

  Using 2D numerical subduction models, we compare deep slab behaviour with oceanic and continental overriding plates and a mantle viscosity structure where the lower mantle viscosity jump occurs either at 660 km or at 1000 km depth as suggested by the latest geoid inversions. We demonstrate that a strong, thick, and buoyant continental plate, combined with a 1000 km depth viscosity increase, promotes slab penetration into the lower mantle. Conversely, the same slab will deflect at 660 km depth if this subducts under an oceanic plate into a mantle where the viscosity increases at the canonical 660 km depth. To quantify these dynamics, we introduce a slab bending ratio, by dividing the deep slab tip angle by the shallow slab angle, reflecting the steepness, and sinking history of the slab. Ocean-ocean convergence models with a viscosity increase coincident with the phase transition at 660 km depth have low ratios and flattened slabs comparable to ocean-ocean cases in nature (e.g., Izu-Bonin). Coupling a continental overriding plate with a 1000 km depth viscosity increase separate from the endothermic phase change results in slabs with high ratio values, and stepped morphologies similar to that observed for the Nazca plate beneath the Southern Peruvian arc. Our results highlight that slab morphologies ultimately express the interaction between the type of overriding plate, slab-induced flow, and phase transitions, modulated by the viscosity structure of the top of the lower mantle and transition zone.

  PublisherOA PDFDOI

• UNRAVELING THE CONNECTION BETWEEN SUBSURFACE STRESS AND GEOMORPHIC FEATURES

  Abstracts with programs - Geological Society of America · 2024-01-01

  articleOpen accessSenior author

  The tectonic stress field induces surface deformation. At long wavelengths, both lithospheric heterogeneity (changes in the thickness and density of crust and lithospheric mantle) and basal tractions from mantle convection contribute to the stress field. Here, we analyze the global alignment of principal horizontal tectonic stresses, fault traces, and river flow directions to infer whether and how deep subsurface stresses control geomorphic features. We find that fault trace orientations are consistent with predictions from Anderson's fault theory. River directions largely align with fault traces and partly with stresses. The degree of alignment depends on fault regime, the source of stress, and river order. Extensional faulting is best predicted by stresses from lithospheric structure variations, while compressive faulting is best predicted by stresses from mantle flow. We propose a metric to quantify the relative influence of mantle flow or lithospheric heterogeneity on surface features, which provides a proxy for lithospheric strength.

  PublisherOA PDFDOI

• ENCELADUS’S TECTONIC STRESS FIELD

  Abstracts with programs - Geological Society of America · 2024-01-01

  article1st authorCorresponding
  PublisherDOI