Hot spots at the summit have become larger and more frequently observed on recent MODIS satellite data. This indicates that activity has become more intense at the volcano with its active lava dome.
In addition, VSI scientists have detected an increase of seismicity and degassing since early May. This includes volcanic tremor from growing lava dome and deeper earthquakes, possibly related to new magma rising, and the occurrence of notable sulfur smell.
The alert level of the volcano was raised to 3 ("Siaga", "alarm") on a scale of 1-4 by the Indonesian Volcanological Survey.