Eruption of Mount Sinabung volcano

By Scott Bachmeier • 19 February 2018

Himawari-8 RGB images [click to play animation]

An explosive eruption of Mount Sinabung began at 0153 UTC on 19 February 2018. Himawari-8 False-color Red-Green-Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed the primary plume of high-altitude ash moving northwestward, with ash at lower altitudes spreading out to the south and southeast of the volcano.

Mutli-spectral retrievals of Ash Cloud Height (below) indicated that the explosive eruption injected volcanic ash to altitudes generally within the 12-18 km range, possibly reaching heights of 18-20 km. Advisories issued by the Darwin VAAC listed the ash height at 45,000 feet (13.7 km).

Himawari-8 Ash Height product [click to play animation]

Ash Loading values (below) were also very high within the high-altitude portion of the plume.

Himawari-8 Ash Loading product [click to play animation]

The Ash Effective Radius product (below) indicated that very large particles were present in the portion of the plume immediately downwind of the eruption site.

Himawari-8 Ash Effective Radius product [click to play animation]

In a comparison of Himawari-8 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (below), note the very pronounced warm thermal anomaly or “hot spot” (large cluster of red pixels) on the 0150 UTC image — Himawari-8 was actually scanning that location at 01:54:31 UTC, just after the 0153 UTC eruption. Prior to the main eruption (beginning at 0120 UTC), a very narrow volcanic cloud — likely composed primarily of condensed steam — was seen streaming rapidly southward from the volcano summit.

Himawari-8 “Red” Visible (0.64 µm, left), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.4 µm, right) images [click to play Animated GIF | MP4 also available]

The coldest Himawari-8 cloud-top infrared brightness temperature was -73 ºC at 0300 UTC, which roughly corresponded to an altitude of 15 km on nearby WIMM (Medan) rawinsonde data at 00 UTC (below).