The phrase "massive outpouring" refers to a large or substantial release or expression of something, often involving strong emotions, opinions, or actions from a group of people. Full definition
I would attend staff meetings where there would be massive outpourings of prayer, where lunch breaks would be accompanied by discussions of the nature of the Trinity, and where, at any given moment, I could walk into a coworker's office to see them bowed over an open Bible, meditating on the Bread of Life. (relevantmagazine.com)
The plume below pulsed through the slab, leading to massive outpourings of magma, the pattern and timing of which appear consistent with the Steens — Columbia River flood basalts, which spewed out one million times more molten rock than the 1980 Mount Saint Helens eruption. (scientificamerican.com)
A massive outpouring of charity had made this reconstruction possible. (firstthings.com)