Kīlauea hazard assessments include analyses of salts on volcanic ash

This close-up image (5000x magnification) of a Kīlauea volcanic ash sample collected on May 23, 2018, was captured by a scanning electron microscope. Visible on the ash surface are tiny salt crystals that can be leached from the ash. Most of the salts in this image are aluminum sodium sulfate and calcium sulfate. This image is about 50 microns across, which is half of the width of a human hair. USGS photo by D. Damby.