Counting the Solomon Islands: How Many Islands Does the Archipelago Actually Contain?

Eivind Andaas 

Solomon Islands is widely reported to comprise approximately 900--1,000 islands, a figure repeated across government, tourism, and encyclopedic sources without a traceable methodology. We re-examine this figure using two independent, reproducible geospatial datasets: the USGS/Esri/UNEP-WCMC Global Islands database (30 m Landsat-derived classification) and OpenStreetMap (OSM) land polygon data (human-verified coastline digitization), both clipped to the Solomon Islands Exclusive Economic Zone (EEZ) and analyzed without an arbitrary minimum size threshold. The USGS dataset yields 1,738--1,771 islands; the OSM dataset yields 3,540, with the smallest verified feature at 34.89 m². Both figures substantially exceed the commonly cited number and should be read as reproducible estimates rather than a definitive count. Large-island counts (\textgreater1 km²) agree closely between sources (174 vs.~176); divergence grows steadily as the size threshold shrinks, from 4.9\% higher in OSM above 0.1 km² to 26.1\% higher above 0.0036 km², USGS's Landsat detection floor, indicating the gap is concentrated among small islets historically excluded from navigational and administrative counts. We identify tidal-state imagery capture, mangrove canopy misclassification, and the absence of an agreed, tide-referenced operational definition of ``island'' as open sources of uncertainty, and recommend a tide-referenced field survey as the necessary next step toward a definitive count.