29-30 April, 2001, GMS-5 visible

Comments: The 'visible' loop above shows a number of distinguishing features, such as the 'gravity' waves, appearing as ripples spreading outwards from the centre of the eruption, a relatively fast dissipation of the plume as the major eruption ceases, and the shadow of the eruption cloud on neighbouring clouds.

The TOMS (Total Ozone Mapping Spectrometer) products below seem to suggest that, although the cloud was high in sulphur dioxide, little additional aerosol content could be found in the region to the west of the volcano. The actual eruption started on the 26th; the SO2 image of 28-29 April may suggest a slight increase of SO2 to the west of the volcano (note that there is a strong underlying data gradient from east to west in each pass). The SO2 image from April 29 - 30 gives a strong SO2 signal west of the volcano, with no corresponding aerosol maximum.

Image source: collage from TOMS Aerosol & SO2 products, courtesy of NOAA/NASA

(Related page: Ulawun, September 2000)