Semeru volcano (112.92 ° E and 8.108 ° s) , which is an active volcano in East Java Island o Indonesia, occurred thermal anomaly and intensified volcanic activity from December 2, 2012. Thesatellite monitoring showed that the area of thermal anomaly is about 7.35 km², and the maximum bright temperature reaches 305K, which is 15K higher than the background temperature. And, the thermal anomaly continued and maintained its intensity on December 2, 2021 (Fig. 1).

An explosive eruption began atSemeru volcano in East Java Island Indonesia, which is observed by satellite images at 8:00 (UTC) on December 4, 2021 (Fig. 2). The volcanic ash is gray white, mainly composed of water vapor and light mineral particles. It is estimated that the highest altitude of volcanic ash cloud is 7~10 km, which gradually spread southward at speed of about 80kilometers per hour (Fig. 3). As of December 7, a few eruptions can still be observed in the crater by the  satellite, and the height and influence range of volcanic ash cloud were significantly weaker than that on December 4 (Fig. 4). (Source: NSMC)

Fig. 1. Thermal anomaly monitoring by satellite of Semeru volcano in East Java Island of Indonesia (December 2, 2021)

Fig. 2. Explosive eruption of Semeru volcano monitoring by FY-4A  (0.65μm visible channel, 250m, December 4, 2021)

Fig. 3. Inversion of volcanic ash cloud height superimposed over satellite true color image ofSemeru volcano in East Java Island of Indonesia (2km resolution, December 4, 2021 Left 08:00 UTC, Right 08:30 UTC)

Fig. 4. Inversion of volcanic ash cloud height superimposed over satellite true color image ofSemeru volcano in East Java Island of Indonesia (2km resolution, December 7, 2021 04:20 UTC)