Earth’s Mid-mantle via Probabilistic Array Imaging
Description:
The Earth’s mid-mantle (800–1200 km depth) hosts enigmatic seismic discontinuities whose physical origins remain debated. Competing hypotheses attribute these features to either thermal anomalies, such as partial melting due to volatile transport, or compositional heterogeneities associated with ancient subducted crust. However, distinguishing between these scenarios remains a challenge; standard imaging techniques often fail to robustly resolve the polarity of weak seismic reflections amidst noise and reverberations that contaminate mid-mantle reflections. Consequently, previous global surveys relying on linear time-domain stacking have yielded only a fragmented perspective, where the global connectivity, topography, and distinct physical origin of mid-mantle discontinuities remain debated. To address these limitations, we present a new global imaging framework that integrates curvelet-based wavefield separation and deconvolution, with probabilistic array processing. Rather than relying on traditional linear stacking, we develop "probabilistic vespagrams" that rigorously account for uncertainties in signal coherence and wavelet estimation. This approach allows us to distinguish robust structural features from processing artifacts. We apply this workflow to a global dataset of SS and PP precursors to construct a probability map of mid-mantle discontinuities. By systematically quantifying the likelihood of positive (eclogitic/compositional) versus negative (thermal/melt) impedance contrasts globally, we aim to resolve the global distribution of mid-mantle heterogeneities and determine the relative dominance of compositional stratification versus partial melting by water transport in controlling deep-Earth dynamics
Session: New Frontiers in Seismic Observations and Modeling with Innovative Methods and Emerging Data on Earth and Other Planets [Poster]
Type: Poster
Date: 4/17/2026
Presentation Time: 08:00 AM (local time)
Presenting Author: Steve A. B. Carr
Student Presenter: Yes
Invited Presentation:
Poster Number: 109
Authors
Steve Carr Presenting Author Corresponding Author scarr13@ur.rochester.edu University of Rochester |
Tolulope Olugboji tolugboj@ur.rochester.edu University of Rochester |
Ziqi Zhang zzq@umd.edu University of Maryland |
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Earth’s Mid-mantle via Probabilistic Array Imaging
Category
New Frontiers in Seismic Observations and Modeling with Innovative Methods and Emerging Data on Earth and Other Planets