Static spectra establish that Schumann Ignition Events (SIEs) exist — a reproducible theta–alpha-boundary coordination episode of the resting EEG, centroid 7.687 Hz near the Schumann cavity fundamental — but collapse the within-event trajectory onto a single frequency-domain summary, leaving open whether the event is a symmetric oscillation or an asymmetric build-and-release, a cascade or synchronous engagement, a periodic clock or a renewal process. We characterize SIEs at second-scale resolution (1-s sampling grid, ∼3.6-s effective) on a per-channel Morlet-wavelet φ-lattice substrate, across 18 cohort × condition combinations comprising 5,476 subject-recordings (∼3,800–4,200 unique subjects) and 19,097 events spanning ages 5–88 (five public datasets — HBN, LEMON, the Dortmund Vital Study, CHBMP, and TDBRAIN; the eleven Healthy Brain Network releases share one pediatric population, giving ∼5 effective independent datasets), reading the event through neural population dynamics, in which activity is a trajectory through a low-dimensional state space whose load-bearing observables are flow-field properties. The paper makes two contributions, and develops the developmental dissociation as an integrative reading rather than a third contribution. 1. The lattice kinematics of the event. At second-scale resolution the SIE is one phenomenon: a universal, amplitude-only, asymmetric SR1-region surge — a slow multi-second build and a fast (sub-second) release. It is cluster-significant in 18/18 cohorts (p = 0.002 permutation floor), narrow-band (a sharp 7.30–8.40 Hz core), purely amplitude-coded with no phase organisation (inter-trial coherence ≤ 0.11, far below evoked-response phase-reset levels), and posterior-alpha in topography (pairwise alpha cosine ≥ 0.91 in 17/18). The slow-build/fast-release asymmetry (rebound 2.0–5.3× the lead-down slope, 18/18) rules out symmetric-oscillator accounts, and direct tests rule out phase reset and traveling-wave propagation (cohort-mean phase slopes ≈ 0). "Lattice kinematics" names the event's within-event trajectory and flow-field properties — timescales, autonomous-versus-driven character, spatial extent, and coordination rank — read on the φ-lattice measurement grid; the kinematics are the event's, not the lattice's, which is a static coordinate system. 2. Localization in mechanism-class space. Two distinct, analysis-window-free timescales — a multi-second discharge build and a ∼60 s refractory-renewal recovery (per-subject log-normal inter-event intervals with a soft refractory floor; no periodic infraslow clock) — place the dynamics in the depletion-recovery process class. Within that class, three direct falsifications converge on threshold-crossing network adaptation (M1): events do not scale with recovered resource (IEI–amplitude null) and per-event dynamics are autonomous (panel-LDS input coefficient indistinguishable from zero in 14/18), jointly disfavouring T-channel and vesicle-pool depletion; and the per-event spatial-extent distribution is universally non-power-law (0/18; truncated Weibull preferred in 17/18), ruling out canonical-critical avalanche dynamics. A leakage-robust, rank-0 source-level coordination signal corroborates M1 over avalanche cascades. The reading is stated with an explicit partial collapse: sub-critical and finite-size-cutoff avalanche variants survive precisely because they look dynamically like M1 at scalp resolution, and the rank-0 architecture is corroborative rather than a second clean falsification. A substrate-invariant object on a variable host. The kinematic event and its mechanism class are age-invariant (0/129 FDR-significant per-channel age regressions within HBN at ages 5–22, with coarser cross-cohort nulls across 5–88), while the cortical substrate hosting the event restructures continuously through adolescence (within-HBN per-subject LDS manifold elaboration, Spearman ρ = −0.175). A within-subject montage de-confound — down-sampling HBN from 129 to 26 channels before source localization — shows the developmental source shift is not an electrode-density artifact: the deep midline (posterior cingulate) pediatric localization survives at sparse montage. Held as a synthesis rather than a full demonstration, since the corpus contains no dense-montage adult cohort, the integrative reading is a single dynamical object riding a developmentally variable cortical host. Together these results give the Schumann ignition event a single dynamical-systems description — a soft-refractory, threshold-crossing depletion-recovery discharge with cross-territory amplitude co-modulation and no phase-coordinated cascade — that is age-invariant across the lifespan even as the cortical territory hosting it restructures through adolescence. The companion papers establish the event's existence and static-spectral identity (Lacy, 2026a) and the φ-lattice log-frequency coordinate system used here purely as a measurement grid (Lacy, 2026b). Keywords: EEG; Schumann ignition events; event kinematics; depletion-recovery dynamics; threshold-crossing network adaptation; neural population dynamics; cortical-network development; φ-lattice Companion papers Lacy, M. (2026a). Schumann ignition events in spontaneous EEG: A conserved theta–alpha-boundary signature and a developmental coupling gradient. https://doi.org/10.5281/zenodo.19829181 Lacy, M. (2026b). Spectral differentiation: A log-frequency coordinate system for human EEG bands reveals a within-band developmental axis. https://doi.org/10.5281/zenodo.19632893 Lacy, M. (2026). Schumann-anchored golden ratio organization of human neural oscillations. Frontiers in Computational Neuroscience. https://doi.org/10.3389/fncom.2026.1786996 License: code MIT; text CC BY 4.0