Mauna Loa erupting

[MyManao]

I thought that each had its own magma source.  No?

One source, the 'hot spot,' which is assumed to be the upwelling of material created by convection currents in the Earth's mantle. 

Two separate volcanoes, in that each has a different petrological signature; the rock's composition is unique to each. That by most accounts is enough to make it hard to image a direct hydraulic connect. Some studies speak in terms of a sympathy that has months of lag between the two. I've heard others that suggest the point of divergence shallow enough to have a hydraulic connect, but the petrology..

Ever noticed there are two island chains running from here north? Where Mauna Loa and Hualalai are the beginnings of one, and Kilauea and Mauna Kea another? Single deep source, all sorts of funny business between here and there..
 
I kind of wonder if it's not the hydraulic system but the relationship between the land forms themselves. Mauna Loa was budging, and then deflated. Maybe the stresses exerted on Kilauea relaxing allowed Kilauea's summit to relax, which in turn allowed the magma column to fall. And even if it fell just a bit, that eruption in Halemaumau was barely there at all, so even the minimal drop in stress could lower it enough to hide the eruption from view. Maybe?