you came to the right place /z\ it seems to me

I did some more research on other possible volcanic events of note around 3500 years ago. The number of occurrences is a bit eerie. I am sure there are more, this was what I could find in under 10 minutes. Judge for yourself:

The Eruption of Thera site of one of the largest volcanic eruptions in recorded history 3500 years ago.

Rincón de la Vieja Volcano is an active andesitic complex volcano in north-western Costa Rica, about 25 km from Liberia, in the province of Guanacaste. Little is known about Rincón de la Vieja's early eruptive history. It lies within a larger caldera, which indicates that a very large eruption probably occurred thousands of years ago. Analysis of nearby pyroclastic flow deposits shows that they were erupted in a moderately large eruption about 3500 years ago

Mt.St.Helens happened 3500 years ago which produced 13 times more material than in 1980.

Hayes Volcano Southcentral Alaska
1500 BC Hayes Volcano was largely destroyed in its last eruption about 3500 years ago and is difficult to detect, even from the air.

It is believed Chato first erupted 38,000 years ago during the Pleistocene period and last erupted about 3,500 years ago. Costa rica

Aniakchak (Alaska) erupted catastrophically about 3500 years ago and has exhibited much post-caldera activity. It is considered active, and consists of a 10 km-wide by 0.5 to 1.0 km deep caldera that was formed during this major eruptive event.



I am sure there are more but you get the idea. thoughts?