This view from the southern end of the lake shows its immense size.  lts really too big to imagine an explosion blasting away the size of the lake (and at the centre 500ft deep) into the air.  Not surprisingly the effects of this were seen in China and Rome 1800 years ago.

This volcano is not predictable, whereas others are.  This means it could decide to do the same again.  Erk.

The two cones, one in the centre and one off to the left, are cinder cones from smaller volcanic vents.  The island right of centre is what is left of the epicentre of the explosion.