John Vidale is also director of the Pacific Northwest Seismic Network.
He says it's hard to compare the fans' half minute of stomping, jumping and shouting during a first quarter fumble return for a touchdown to the quick "pop" of a small earthquake.
Still he says, "the energy is very roughly the same."
The UW seismometer in question is located near CenturyLink Field.
Vidale says it also recorded "three or four more good bursts," always coinciding with Seahawks' touchdowns.
The same seismometer recorded fans' noisy reaction to Marshawn Lynch's "Beast Quake" back on Jan. 8, 2011, when Lynch ran 67 yards for a touchdown that clinched a playoff victory over the Saints.
Vidale says his lab didn't quantify that one with a magnitude.