Data and code for: Dual-snowline satellite detection of tephra paroxysms on ice-clad volcanoes — a 40-year record and its physical detectability limits (Chilean Southern Volcanic Zone)

Companion data and code archive for the manuscript "Dual-snowline satellite detection of tephra paroxysms on ice-clad volcanoes: a 40-year record and its physical detectability limits (Chilean Southern Volcanic Zone)" (Kim & Jung, submitted to Remote Sensing of Environment). Contains: (1) per-scene dual-snowline indicator tables — 19,185 Landsat Collection-2 Level-2 scenes (1984–2026, 9 mountains), daily MOD10A1/MYD10A1 (2000–2026), and Sentinel-2 MSI L2A (2016–2026); (2) ERA5-Land monthly covariates and mechanism-channel tables (MCD43A3 albedo, MOD11A2 day/night LST, NCEP-R1 winds, sector snow loss); (3) all Google Earth Engine extraction scripts and analysis code (event study, sensitivity suite, blind changepoint scan, MODIS self-anomaly, SLC-off tests); (4) canonical statistical results and the source-verified eruption timeline. All stochastic steps use a fixed seed (42); the headline statistics reproduce from the archived CSVs without an Earth Engine account. See README.md for structure, reproduction commands, and source-data attribution (USGS, NASA, Copernicus, Smithsonian GVP).