Hmm, it doesn't have a separate spell id for the triggering, but you can use an expression like "spellid = 156673 and damageTaken > 100000" to see only the big hits taken by players standing in it.
Example in table form: http://worldoflogs.com/reports/efviwdwu ... %3E+100000
Example on analyze page, damage taken by target: http://worldoflogs.com/reports/efviwdwu ... boss=77428
Arrows: paste expression in there, and set filtering/smoothing to none to see sharp spikes instead of average rates. (It's still damage/second, so with a 2s time tick, it shows 60000 damage per 2 seconds = 120k hit; maybe it's time for a bar chart for just plot the actual value.)