. . . . "2026-10-09"^^ . . "Basal pressure vs acceleration onsets at Langhovde Glacier, January 2022: inconclusive (one event)" . "This record cannot tell whether basal water pressure rises before grounded-ice acceleration. The claim is therefore neither supported nor contradicted.\nWhat is clear:\n- In the one instrumented event (2–6 January 2022), rain and melt came first: rain began at 01:50 UTC on 2 January, and the basal pressure rise followed about 19 h later in every processing.\nWhat is not clear:\n- The order of pressure and acceleration depends on the processing.\n - Centred smoothing of the published 15 min GNSS puts the speed rise about 8 h before the pressure rise.\n - The same smoothing of the reprocessed 1 s GNSS puts pressure about 6 h before speed.\n - Every past-only (causal) estimate is indeterminate, with spreads of more than ±10 h.\nWhy sharper data did not resolve it:\n- The grounded and floating trunk stations share a ~12 h variability in speed that is larger than the event's speed-up. It is mostly not GNSS multipath and not a simple tidal response.\n- The borehole tilt sensor was still settling.\nThe proposed held-out comparison of three nested models needs several events. In a single-event hold-out, adding basal pressure and uplift did not improve on weather and speed history." . . "Basal pressure and forcing:\n- BH2201 basal water level peaked at 51.0 m a.s.l. (97% of flotation) at 23:07 UTC on 3 January 2022; 50.95 m after the measured air-pressure correction.\n- Rain led the pressure rise by a median of 18.6–18.9 h (causal) and 20.8–23.4 h (centred), in 30–32 of 32 rule × bandwidth × reference combinations.\nPressure to GNSS1 (grounded) speed, onset leads (positive = pressure first):\n- 15 min deposit:\n - centred median −8.0 h (\"level lags\", 20 of 30 combinations);\n - robust causal median +0.6 h, 13 earlier and 13 later (\"indeterminate\").\n- 1 s kinematic GNSS (100% fixed; 5.7 mm and 3.7 mm horizontal SD against the published 15 min positions):\n - centred median +5.75 h (\"level leads\", 16 of 32 combinations defined);\n - robust causal, corrected for detection delay, median +3.6 h, range −7.6 to +36.1 h, 13 of 32 defined (\"indeterminate\");\n - after sidereal filtering and tidal correction, still \"indeterminate\" (median +4.9 to +6.8 h).\n- Detection delay of the causal speed estimators on synthetic onsets: 3.0–8.9 h (15 min data); 3.4 h (1 s data, h = 3 h).\nSub-daily variability at GNSS1:\n- 12–13 h period, SD 0.047 m/d at h = 1 h, against an event speed-up of about 0.03 m/d (12.5%).\n- Sidereal filtering removed 14% (GNSS1) and 32% (GNSS2) of the 10–15 h variance.\n- A tidal model fitted before the event explained R² = 0.001 and 0.07 afterwards.\n- GNSS1 and GNSS2 band-passed (6–18 h) residuals correlate at r = 0.97 (east), 0.72 (north) and 0.84 (up). GNSS1 and receiver LG1 correlate at 0.17, 0.23 and 0.00.\nBed tilt and nested models:\n- Bed tilt in BH2201 drifted about 0.9 mrad/h, with 13 steps above 5 mrad (largest 77 mrad).\n- Nested models, one-event hold-out at GNSS1 (h = 3 h): skill of the pressure-and-uplift model relative to weather-and-speed was −0.24, −0.05 and −0.01 at 1, 3 and 6 h horizons.\n- Rolling-origin forecasts began only after the event onset." . "- One event, at one site, in one season. No conclusion about lead time in general, or at other glaciers, can be drawn.\n- The proposed predictive test was not run. The lead labels describe this event only.\n- Basal pressure comes from one borehole, about 190 m from the grounded GNSS station.\n- Onset times depend on the smoothing and the onset rule. All combinations are reported, not a chosen one.\n- The origin of the ~12 h speed variability is not established: real trunk motion is likely, but differential troposphere cannot be excluded. What the two extra GNSS receivers stand on is not documented in the archive.\n- The bed-tilt sensor was settling (drift and steps), so its onsets were withdrawn. The tilt-rate change during the pressure rise and the stick-slip-like steps after the peak are post hoc observations, not tested.\n- Several steps were amended after results were seen (dated in ANALYSIS_PLAN.md)." . . . . . "Anne Fouilloux" . "2026-10-09T19:16:05.382Z"^^ . . . . . "Basal pressure vs acceleration onsets at Langhovde Glacier, January 2022: inconclusive (one event)" . . "RSA" . "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" . "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" . . .