The August 7-8 eruption of Kasatochi volcano (Aleutian Islands) produced a very large stratospheric SO2 cloud – possibly the largest since the August 1991 eruption of Hudson (Chile). Preliminary SO2 mass calculations using Ozone Monitoring Instrument (OMI) data suggest a total SO2 burden of ~1.5 Tg. This figure will be revised in the coming weeks but is more likely to go up than down. The SO2 cloud has drifted over a large area of North America and is now (August 14) reaching Europe.
The location of the SO2 can be tracked using these near-real time SO2 websites:
(Report from the ASU Volcano Listserv)