| 1. Domain | 1.1 Scope of the Domain | Boundaries | The range of phenomena the science includes and excludes. | Studies the physical properties, structure, and dynamic processes of the Earth (and other planetary bodies) using physics-based observations and models; includes seismology, gravity, magnetism, heat flow, electrical properties, geodynamics, and imaging of the subsurface. Excludes purely chemical, biological, or surface-only processes unless linked to physical fields. |
| | Scale | The spatial, temporal, or organizational level at which the science operates (e.g., quantum, cellular, social, cosmic). | Operates from atomic-scale lattice properties → rock-scale elastic behavior → crustal/plate-scale structure → mantle convection → whole-planet dynamics; temporal scales from milliseconds (seismic waves) to billions of years (thermal evolution). |
| 1.2 Ontological Commitments | Entities | The kinds of things assumed to exist within the domain (particles, organisms, agents, fields, etc.). | Seismic waves, stress/strain fields, gravity fields, magnetic fields, electrical conductivity, heat flow, lithosphere/asthenosphere, mantle plumes, faults, discontinuities, density anomalies, geophysical sensors, subsurface layers. |
| | Properties | The fundamental attributes these entities possess (mass, charge, genotype, preference, etc.). | Seismic velocity, density, magnetization, electrical resistivity, thermal conductivity, heat production, attenuation (Q), anisotropy, viscosity, strain rate, wave amplitude, acceleration, gravity anomalies. |
| | Categories | The basic ontological types used to classify domain elements (substances, processes, relations, structures). | Geophysical domains (seismology, gravity, magnetics, electromagnetics, heat flow, geodesy, geodynamics); subsurface structures (crust, mantle, core); material types (elastic, viscoelastic, viscous, conductive); wave types (P, S, surface waves). |
| 1.3 State-Variables | Variables | The measurable or definable properties that describe system conditions. | Stress, strain, seismic velocity, density, resistivity, temperature, pressure, magnetic field strength, gravity anomaly, displacement, velocity, acceleration, heat-flow rate, viscosity. |
| | Parameterization | How variables encode and represent the system’s state. | States encoded via seismic velocity profiles, density models, temperature gradients, magnetization vectors, resistivity curves, gravity anomalies, strain tensors, pressure gradients, geoid height anomalies. |
| 1.4 Admissible Idealizations | Simplifications | Conceptual reductions used to make the domain tractable (point masses, rational agents, perfect gases). | Elastic/viscoelastic approximations, isotropy, homogeneous layers, simple geometries, 1-D or 2-D Earth models, neglecting fluids or anisotropy, assuming steady-state heat flow, ignoring non-linear deformation at high strain. |
| | Validity Conditions | The limits and contexts in which idealizations hold or break down. | Valid for large-scale averages, first-order interpretations, small-strain elastic responses; breaks down near faults, melts, fluids, highly anisotropic rocks, strongly heterogeneous crust, or dynamic nonlinear deformation. |
| 1.5 Domain Assumptions | Structural Assumptions | Background ontological stances such as determinism, continuity, randomness, discreteness. | Earth processes obey physical laws (mechanics, thermodynamics, electromagnetism); material properties control wave propagation, deformation, and fields; Earth’s structure is inferable by remote sensing of fields and waves. |
| | Implicit Commitments | Unstated but necessary assumptions that shape the field’s conceptual structure. | Assumes stable physical constants, interpretable signals from depth, mappable field relationships, reliable inversion of physical observations, and meaningful scaling between lab measurements and Earth-scale behavior. |
| 1.6 Internal Coherence Requirements | Consistency | The demand that domain concepts do not contradict one another. | Requires agreement among seismic, gravity, magnetic, thermal, geodetic, rheological, and geodynamic interpretations; models must reconcile Earth structure, material properties, and observed fields. |
| | Compatibility | The requirement that entities, variables, and assumptions fit together into a unified descriptive framework. | Aligns with geology, geochemistry, tectonics, mineral physics, planetary science, and physics of materials within a unified physical model of Earth systems. |
| 2. Evidence Layer | 2.1 Observable Phenomena | Observables | The aspects of the domain that can produce detectable signals accessible to measurement. | Seismic wave travel times, waveforms, amplitudes, ground motion; gravity anomalies; magnetic anomalies; electrical resistivity/EM responses; heat-flow values; GNSS displacement; InSAR deformation fields; seismicity patterns; geoid variations; microseismic noise; planetary magnetic-field variations. |
| | Detection Limits | The boundaries of what can be resolved or sensed by current instruments or methods. | Limited by sensor noise floors, station spacing, signal attenuation, frequency bandwidth, survey depth penetration, atmospheric/ionospheric interference (InSAR/GNSS), magnetic noise, heat-flow probe accuracy, and resolution limits of seismic imaging. |
| 2.2 Measurement Systems | Units | Standardized quantifications (meters, seconds, volts, decibels, dollars, etc.) necessary for consistent comparison. | Time (s), velocity (km/s), acceleration (m/s²), gravity (mGal), magnetic field (nT), resistivity (Ω·m), heat flow (mW/m²), displacement (mm–cm), temperature (°C), pressure (GPa), geoid height (m). |
| | Instruments | Devices and tools (microscopes, spectrometers, sensors, surveys, detectors) used to produce measurements. | Seismometers, accelerometers, GNSS/GPS receivers, InSAR satellites, gravimeters (absolute/relative), magnetometers, EM induction systems, MT (magnetotelluric) arrays, heat-flow probes, borehole tools, ocean-bottom seismometers, superconducting gravimeters. |
| 2.3 Operational Definitions | Definitions | Terms defined by specific measurement procedures, ensuring empirical clarity. | Earthquake location defined by origin time + hypocenter; gravity anomaly defined by deviation from reference models; resistivity defined by potential/current response; seismic velocity defined by measured travel times; deformation defined by displacement field; magnetic anomaly defined by deviation from regional field. |
| | Procedures | The explicit steps required to perform a measurement in a reproducible way. | Seismic picking, waveform processing, gravity correction routines, magnetic filtering, EM impedance calculation, GNSS time-series processing, InSAR interferogram generation, heat-flow measurement protocols, instrument deployment and calibration workflows. |
| 2.4 Data Acquisition | Protocols | Formal processes for gathering data under controlled or standardized conditions. | Seismic arrays, continuous GNSS monitoring, InSAR repeat-pass acquisitions, gravity and magnetic traverses, MT soundings, controlled-source seismic surveys, heat-flow drilling, borehole logging, global geophysical network integration. |
| | Sampling | Rules determining which subset of the domain is measured and how representative it is. | Dense vs sparse seismic station arrays, multi-frequency EM sampling, repeated GNSS epochs, grid-based gravity/magnetic sampling, depth-profile sampling (boreholes), temporal sampling (sec-to-year scales), spatial sampling across fault zones or lithologic boundaries. |
| 2.5 Data Character & Format | Data Types | The form raw evidence takes (time series, spectra, images, counts, qualitative records). | Seismic traces, seismograms, gravity profiles, magnetic maps, resistivity curves, EM response spectra, GNSS time series, InSAR displacement maps, heat-flow logs, geoid models, waveform stacks, tomography volumes. |
| | Resolution | The granularity or precision with which data is captured. | Controlled by sensor spacing, signal frequency, noise level, inversion regularization, satellite revisit rates (InSAR), GNSS station density, seismic bandwidth, penetration depth (EM), and computational limits. |
| 2.6 Reliability & Calibration | Calibration | Adjustment procedures ensuring instruments produce accurate results. | Seismometer calibration pulses, GNSS clock corrections, InSAR atmospheric correction, gravimeter drift correction, magnetometer calibration, MT remote-reference processing, heat-flow probe calibration, global reference models (e.g., IGRF, WGS84). |
| | Error Characterization | Identification and quantification of noise, uncertainty, bias, and measurement error. | Picking errors, waveform noise, atmospheric delays (GNSS/InSAR), magnetotelluric noise, instrument drift, aliasing, inversion non-uniqueness, near-surface scattering, heat-flow disturbance, cycle slips, and baseline uncertainties. |
| 3. Structural Layer | 3.1 Patterns & Regularities | Laws / Relations | Stable, repeatable patterns governing how observables behave across conditions. | Seismic velocity increases with depth; gravity anomalies relate to density contrasts; magnetic anomalies reflect magnetization patterns; heat flow follows conductive and advective laws; stress accumulation and release govern seismic cycles; isostasy governs lithospheric balance; plate motions follow conservation of momentum. |
| | Invariants | Quantities or properties that remain constant under transformations (symmetries, conservation laws). | Wave types (P/S) obey invariant propagation rules; conservation of energy in wavefields; stable gravity and magnetic field harmonic structure; Earth’s layered structure (crust–mantle–core) follows consistent global patterns; invariant relationships between stress and strain under linear elasticity. |
| 3.2 Causal Architecture | Mechanisms | Underlying processes or structures that produce the observed regularities. | Seismic wave propagation, elastic deformation, brittle failure, viscous flow, magnetic induction, electrical conduction, heat conduction/advection, mantle convection, isostatic adjustment, core dynamo generation, attenuation via scattering and intrinsic losses. |
| | Pathways | Organized sequences of interactions forming a causal chain or network. | Stress accumulation → fault rupture → seismic wave release; mantle heating → convection → plate motion; magma rising → crustal deformation → volcanic activity; cooling → density increase → subsidence; electrical induction pathways via resistive and conductive layers. |
| 3.3 Theoretical Vocabulary | Concepts | Core terms that encode the domain’s structure (force, gene, equilibrium, field). | Stress, strain, anisotropy, attenuation (Q), density contrast, magnetic susceptibility, resistivity, conductivity, heat flux, geoid, isostasy, seismic tomography, elastic moduli, rheology, dispersion. |
| | Classifications | Taxonomies, categories, or typologies that organize entities and relations. | Seismic wave types (P, S, surface), crustal vs mantle structures, magnetic anomalies (induced/remanent), EM regimes (resistive/conductive), gravity anomalies (positive/negative), rheological regimes (elastic, viscous, viscoelastic, plastic). |
| 3.4 Formal Representations | Equations | Mathematical constructs expressing laws, relations, or mechanisms. | Wave equation, Navier–Stokes for mantle flow, Poisson’s equation for gravity, Maxwell’s equations for EM fields, Fourier’s law for heat conduction, plate-motion Euler pole equations, stress–strain tensor equations, energy attenuation relations. |
| | Models | Structured representations—mathematical, computational, or conceptual—used to predict and explain phenomena. | Seismic tomography models, gravity inversion models, magnetic forward/inverse models, MT/EM conductivity models, geodynamic convection models, heat-flow models, viscoelastic Earth models, earthquake cycle models, structural Earth models (1-D, 2-D, 3-D). |
| 3.5 Idealized Structures | Simplified Models | Purposeful abstractions that capture essential dynamics while omitting irrelevant detail. | 1-D layered Earth, homogeneous isotropic media, purely elastic or viscous behavior, steady-state heat flow, uniform magnetic field, spherical-shell Earth, linear rheology, no fluids or melts. |
| | Limit Conditions | Regimes where specific models or approximations hold (classical vs. quantum, linear vs. nonlinear). | Fail in highly heterogeneous crust, presence of fluids/melts, anisotropic rocks, brittle–ductile transitions, strongly non-linear rheology, rapid transients (earthquakes), near-surface scattering, three-phase systems, or magnetized crustal blocks. |
| 3.6 Integrative Frameworks | Unifying Theories | Higher-order structures that connect disparate laws or mechanisms under a coherent whole. | Integration of mechanics, electromagnetism, thermodynamics, and fluid dynamics to interpret Earth structure and dynamics; unification of seismic, gravity, magnetic, EM, heat-flow, and geodetic data into combined models of lithosphere, mantle, and core. |
| | Interdisciplinary Links | Points where the theory connects to adjacent sciences or larger explanatory systems. | Intersects with tectonics, petrology, thermodynamics, mineral physics, geomorphology, seismology, geodesy, planetary science, volcanology, and hazard assessment. |
| 4. Method Layer | 4.1 Inquiry Design | Experimental Design | Structured plans for manipulating variables to test causal claims. | Controlling seismic source type, frequency content, sensor spacing, EM source current, magnetic-field variation, thermal input, pressure/temperature in lab rock-physics setups, and survey geometry to test causal geophysical hypotheses. |
| | Observational Design | Systematic approaches for gathering non-manipulated data (surveys, field studies, natural experiments). | Monitoring natural seismicity, magnetic storms, gravity fluctuations, heat-flow variations, surface deformation, and time-varying EM fields without imposing artificial forcing. |
| 4.2 Testing & Validation | Hypothesis Testing | Procedures for evaluating whether evidence supports or contradicts specific claims. | Comparing predicted wave speeds, gravity/magnetic anomalies, EM responses, heat-flow patterns, and deformation signals with observations from seismic networks, gravimeters, MT arrays, GNSS, InSAR, and controlled-source surveys. |
| | Replication | The requirement that results be independently reproducible under similar conditions. | Repeating seismic picks, GNSS epochs, InSAR interferograms, gravity profiles, magnetic traverses, EM soundings, heat-flow logs, and laboratory rock-physics measurements across multiple instruments, times, or locations. |
| 4.3 Inference & Evaluation | Statistical Inference | Rules for drawing conclusions from noisy or incomplete data. | Calculating uncertainties in seismic travel times, gravity/magnetic anomalies, resistivity inversions, heat-flow gradients, GNSS displacement vectors, attenuation parameters, and stress/strain tensor estimates. |
| | Model Comparison | Criteria (fit, simplicity, predictive accuracy, robustness) used to evaluate competing models. | Evaluating competing Earth-structure models, inversion schemes, seismic-velocity models, gravity/magnetic forward models, MT/EM conductivity models, and geodynamic simulations based on fit, predictive accuracy, robustness, and parsimony. |
| 4.4 Error Management | Error Analysis | Identification and quantification of random and systematic errors. | Identifying sensor drift, picking errors, atmospheric noise (InSAR/GNSS), cultural noise (seismic/magnetic), inversion non-uniqueness, aliasing, scattering, depth-of-investigation limits, and temperature drift in heat-flow probes. |
| | Bias Control | Methods for minimizing subjective, instrumental, or procedural biases. | Standardizing instrument calibration, randomizing station placement when possible, removing cultural noise, blind-picking seismic arrivals, cross-validating sensors, ensuring uniform processing workflows, and performing sensitivity tests. |
| 4.5 Adjudication & Revision | Peer Scrutiny | Collective evaluation of claims through critique, review, and debate. | Independent review of seismic interpretations, gravity/magnetic inversions, MT/EM resistivity models, geodetic deformation patterns, thermal models, and geodynamic simulations by separate teams or labs. |
| | Theory Revision | Procedures for modifying, replacing, or discarding models based on new evidence. | Updating wave-propagation models, revising Earth-structure interpretations, correcting gravity/magnetic models, adjusting inversion constraints, modifying rheological assumptions, and incorporating contradictory field or lab results. |
| 4.6 Integrity Conditions | Transparency | Requirements to disclose methods, data, assumptions, and limitations. | Full disclosure of survey geometry, processing steps, inversion assumptions, filtering parameters, calibration routines, noise treatment, data exclusions, and uncertainty quantification. |
| | Ethical Standards | Norms ensuring responsible conduct in experimentation, data handling, and publication. | Honest reporting of limitations, failed data acquisition, ambiguous interpretations, uncertain inversions, respecting land-access rules, ensuring safe field operations, and maintaining integrity of geophysical datasets. |