The eruption in August to October 1991 was a large plinian eruption with a VEI of 5, that ejected 4.3 km³ bulk volume (2.7 cubic km of dense rock equivalent material).
Parts of the glacier melted and ran down the mountain as mud flows (see glacier run).
 Due to the remoteness of the area, no-one was killed but hundreds of people were evacuated from the vicinity.
 Ash fell on Chile and Argentina as well as in the South Atlantic Ocean and on the Falkland Islands.
 In 1992, John Locke Blake, then resident on Estancia Condor, south of Rio Gallegos, in Argentina describes the effects of the eruption vividly.
 He describes an ash fall up to 15 cm in depth, covering some 150,000 to 180,000 square kilometres in a triangle from Los Antiguos to Deseado to San Julian to a depth of between 5 and 10 cm.
 He reports that the hygroscopicity of the silica caused the formation of morasses around drinking places causing sheep to be trapped and die in huge numbers.
 He records that 'ten years later, most of the farms in the affected area are empty, of sheep and of people'.

In addition to the ash, a large amount of sulfur dioxide gas and aerosols were ejected in the eruption.
 These contributed to those already in the atmosphere from the even larger 1991 eruption of Mount Pinatubo earlier in the year and helped cause a worldwide cooling effect over the following years.
 Ozone was also depleted, with the Antarctic ozone hole growing to its largest levels ever recorded in 1992 and 1993.

As a result of the Mount Pinatubo eruption, the Hudson eruption received little attention at the time.
The eruption in August to October 1991 was a large plinian eruption with a VEI of 5, that ejected 4.3 km³ bulk volume (2.7 cubic km of dense rock equivalent material). Parts of the glacier melted and ran down the mountain as mud flows (see glacier run).  Due to the remoteness of the area, no-one was killed but hundreds of people were evacuated from the vicinity.  Ash fell on Chile and Argentina as well as in the South Atlantic Ocean and on the Falkland Islands.  In 1992, John Locke Blake, then resident on Estancia Condor, south of Rio Gallegos, in Argentina describes the effects of the eruption vividly.  He describes an ash fall up to 15 cm in depth, covering some 150,000 to 180,000 square kilometres in a triangle from Los Antiguos to Deseado to San Julian to a depth of between 5 and 10 cm.  He reports that the hygroscopicity of the silica caused the formation of morasses around drinking places causing sheep to be trapped and die in huge numbers.  He records that 'ten years later, most of the farms in the affected area are empty, of sheep and of people'.
In addition to the ash, a large amount of sulfur dioxide gas and aerosols were ejected in the eruption.  These contributed to those already in the atmosphere from the even larger 1991 eruption of Mount Pinatubo earlier in the year and helped cause a worldwide cooling effect over the following years.  Ozone was also depleted, with the Antarctic ozone hole growing to its largest levels ever recorded in 1992 and 1993.
As a result of the Mount Pinatubo eruption, the Hudson eruption received little attention at the time.
Mount Hudson