Seattle has been bracing for a major earthquake for as far back as anyone can remember. More recently, it has been gearing up for Saturday night’s playoff between the Seahawks and the Carolina Panthers, a game that could put this sports-crazed city in contention for a second consecutive N.F.L. Super Bowl championship. Already, Seattle is awash in a blue-and-green tide of face paint, bumper stickers, pennants and earmuffs.

Now, geophysicists are connecting the dots. This week, they installed three earthquake monitors inside the Seahawks’ stadium, in what scientists say will be the first attempt to capture, almost in real time, the seismic effects of a rowdy, stomping, screaming, jumping, dancing crowd of 67,000-odd people.

The monitors are connected to the Pacific Northwest Seismic Network, which went live on Thursday with a website called QuickShake that will provide a different kind of color commentary to Saturday’s game as the sensors feed back the ground-shaking physical evidence of every big play, and big crowd emotion.

The primary goal is to push the boundary of how the earth’s motions — small and harmless at a football game, potentially catastrophic in a big earthquake — can be tracked, described and instantly viewed by the public in ways that might one day save lives.

“It’s wiggly,” said John Vidale, a professor of earth and space sciences at the University of Washington and director of the seismic network, describing the ground beneath CenturyLink Field. The land, just south of downtown, is composed of loose glacial till, and even the tiniest of earthquakes there — whether produced by mother earth or the hyped-up crowd in a sold-out playoff game — can ripple out and be measured.

Seahawks fans are famously raucous, and they have caused at least one temblor before: In 2011, in a game against the New Orleans Saints, when a seismic monitor a block from the stadium — positioned to listen for genuine tectonic trouble — fluttered without explanation. Puzzled researchers eventually linked the tiny but measurable upheaval to the 67-yard touchdown run by Seahawks running back Marshawn Lynch, which made the crowd go wild.

Serious science lies behind the stadium-monitoring effort. The Cascadia Subduction Zone, which snakes up the Pacific Coast from Northern California to Canada, is running out a clock of its own, with a megaquake of the sort that has ripped through this region in centuries past — most recently in 1700 — now overdue.

Every year, Dr. Vidale said, the Pacific Northwest has about a 1-in-300 chance of experiencing a magnitude 9 quake from the Cascadia if the two plates, one sliding under the other, give way with a big movement. Smaller faults lie directly under Seattle itself.

So the seismic network is focused on creating a real-time web-based monitoring and alert system that could give governments, businesses and residents a heads-up — perhaps a few minutes, perhaps less, depending on the epicenter — when the regional array of monitoring devices senses trouble. An initial version of that system will be tested starting next month.Connecting earth science to Seahawks mania also has the secondary goal of getting people familiar with, and connected to, the technology of a seismic warning system, which Dr. Vidale and other scientists hope will one day be incorporated into schools, homes and on smartphones and other mobile devices.

But on Saturday, at least, football will be the focus, with a kind of technological race as well, since feedback from the stadium monitors — running about two or three seconds off real time — will be faster than the televised game, which will be broadcast with roughly a 10-second delay.

What that means is that seismically inclined fans who have QuickShake and the game on at the same time could get a kind of early warning of their own: the squiggle lines visible on the website will be tracking events in the stadium that have, in TV time anyway, yet to be shown.

“They’ll be able to see fans get really excited before the play actually happens,” said Bill Steele, the communications manager at the seismic network.

After the 2011 fanquake, University of Washington scientists set up monitors inside the stadium to record and collect more data, but Saturday’s game will be the first attempt to share it with the public, using the additional monitors, in near-real-time transmission.

For scientists, the rush was on: since the team and its fans secured a home-field advantage for Saturday’s game in late December, at the end of the regular season, the seismologists required a crash course in writing and testing the software, which went live at 1 a.m. Thursday.

“We really had to blitz it out,” said Doug Gibbons, a research science assistant who was installing the monitors on Thursday. The devices, however high-tech, are lodged in humble settings: two in utility rooms on the stadium’s upper levels, and one on the ground level in a manager’s office.

As Mr. Gibbons worked, grounds crews were preparing the field for the game. Giant screens flashed images of the green-eyed Seahawk logo itself and of the famous tag line of the Seahawk fans, “We are 12.” (This signifies the force of the home-field crowd that adds up — beyond seismicity, so fans say — to the equivalent of an additional 12th player on the field.)

Dr. Vidale said the earthquake system he and his team were putting together was not about prediction, exactly, but rather warning. But he went out on a limb about the game: The Hawks will win, he said.