Question: why are sunquakes only occasionally observed and can they influence the lower degree global modes?

Connor Macrae answered on 15 Jun 2015:

They are only occasionally observed as sometimes the flare that generates the quake does not produce enough of a momentum transfer that would otherwise generate the quake. Also, the flare can sometimes be too high in the solar atmosphere. Theoretically, they do influence the global modes, but the change in that modes amplitude is so small it can’t be seen above noise levels. That is why scientists like me are looking at much more energetic super-flares on other stars in the hope that a much greater seismic impact occurs and is visible using the forms of data analysis available to us.