Under revision (phase_cycle_jump): Automated time-series QC flagged this headline series for independent review — step 2 (2026-07-03→2026-07-15) = -10.26 cm ≈ one phase cycle (12.1 cm).
Peak Cumulative (LOS)
-34.6 cm
Vertical Est. (34.2°)
-41.8 cm
3-Ref Sensitivity
[-34.6, -13.8] cm LOS
Rate (cm / 100 days)
-28.8 cm/100d
Annualized est.: -105.2 cm/yr
Latest Pair & Cumulative Summary
- Latest Consecutive Pair Step: -2.23 cm LOS (2026-10-07 to 2026-10-19 at p01: 36.593N 54.395E; cumulative at point: -34.65 cm)
- Affected Population (GHSL GHS-POP E2025, 108d eq., ≥ 0.72 cm 2σ): 97,823 residents (< -2 cm), 87,983 residents across 354.64 km² (< -5 cm).
Top 3 Most-Subsiding Areas
| Rank | 1 km Block Center (Lat, Lon) | Cumulative LOS | Rate |
|---|---|---|---|
| #1 | 36.6025, 54.4183 | -32.90 cm | -27.41 cm/100d |
| #2 | 36.6407, 54.4519 | -28.90 cm | -24.08 cm/100d |
| #3 | 36.9892, 54.5338 | -25.48 cm | -21.23 cm/100d |
Top 5 At-Risk Infrastructure Segments
Infrastructure corridor ranking (OSM canal/road overlay) has not been computed for this regional subset yet.
GNSS Comparison & Calibration Status
Continuous GNSS time-series validation was not bundled for this regional subset.
Cumulative Displacement Map
What This Means
- Peak measured ground motion in Gorgan reached -34.6 cm LOS (-28.8 cm/100d) from 2026-06-21 to 2026-10-19, but low coverage or wide reference spread makes this an indicative estimate.
- About 97,823 residents live on ground sinking faster than 2 cm per 108 days (and 87,983 residents across 354.64 km2 faster than 5 cm per 108 days, above the 0.72 cm 2-sigma noise floor).
- No local GNSS or canal-tilt overlay is bundled for this subset; field inspection and local piezometer records are needed to confirm infrastructure impacts.
Calibration & Quality Notice (PROVISIONAL): NISAR data are provisional. Calibration and validation are carried out by the NISAR project (NASA-JPL and ISRO), not by our team.
Sources: NASA-ISRO NISAR L2 GUNW (CRID P05023 via ASF DAAC); GHSL GHS-POP E2025 R2023A (JRC, CC BY 4.0); Nevada Geodetic Laboratory GNSS; OpenStreetMap (ODbL).
Sources: NASA-ISRO NISAR L2 GUNW (CRID P05023 via ASF DAAC); GHSL GHS-POP E2025 R2023A (JRC, CC BY 4.0); Nevada Geodetic Laboratory GNSS; OpenStreetMap (ODbL).