Volcanic Eruption of Anak Krakatau

In early September 2026, a small volcano located between Java and Sumatra in Indonesia experienced an explosive eruption. The image above shows white volcanic gas and steam and a brown ash cloud emanating from Anak Krakatau, as observed on September 5 by the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the NOAA-20 platform.

This data layer shows the aerosol index (pyrocumulonimbus) at 380nm. Index values ranged from 10 to 20 or greater (shades of dark yellow to orange to red), indicating the presence of the ash in the volcanic emissions. The aerosol index (AI) is a measurement—related to aerosol optical depth—that indicates an increased concentration of tiny particles called aerosols suspended in the atmosphere. In general, a lower AI value indicates clearer skies due to a lower concentration of aerosols. 

The eruption at Anak Krakatau caused some regional airline flights to be grounded. It also led to very poor air quality in surrounding regions, including the capital, Jakarta. The Indonesian meteorological agency indicated that the volcanic ash reached up to 20,000 feet in altitude to the east, and 50,000 feet in altitude to the west. 
 

This map layer shows the column density of sulfur dioxide (SO2) in the upper troposphere and stratosphere (corresponding to 17 km center of mass altitude). This data layer highlights how the explosive volcanic eruption ejected sulfur dioxide high into the atmosphere, ranging from shades of blue to white to indicate higher concentrations.

Read NASA Earth Observatory's article, Anak Krakatau Rumbles Again, for a closeup of the eruption from Landsat.

Visit Worldview to visualize near real-time imagery and historical imagery from NASA's Earth Science Data and Information System (ESDIS); find more imagery in the Worldview weekly image archive.