Richardson's spot on the defensive line could be filled by Kony Ealy, whom the Jets claimed off waivers this week and who played well in the preseason finale against the Eagles on Thursday night.
"We obviously think very highly of Sheldon", Jets general manager Mike Maccagnan said in a conference call with reporters.
Kearse, 27, has been one of Russell Wilson's secondary receivers for the last five seasons, catching 41 passes on a career-high 90 targets last season.
Richardson has tallied 18 sacks in his four seasons in the National Football League but had just one sack for NY in 2016.
United Kingdom said to ask European Union for more Brexit negotiating rounds
It will be decided in October if enough progress has been made from the current negotiations to press on towards the next stage. British public are overwhelmingly opposed to the government agreeing a large Brexit divorce bill with the EU .
In return, they got defensive lineman Sheldon Richardson and a 2018 seventh-round pick.
"If Richardson has a big year in Seattle and has no off field issues or run-ins with teammates he should command $18 million a year, " wrote Jason Fitzgerald of OvertheCap.com.
Update (3:19 p.m. ET): Albert Breer of Monday Morning Quarterback and Sports Illustrated is reporting that the Seahawks will also be sending a conditional second or third-round pick in the 2018 NFL Draft along with Kearse in exchange for Richardson. Now that they have acquired Richardson, they will attempt to find a new home for defensive lineman Ahtyuba Runin, according to Ian Rapoport. If Richardson leaves and gets a large contract, the Seahawks would likely get a 3rd round compensatory pick for Richardson. They got that extra fifth-round pick from Dallas during this year's draft. Seeming nearly forgotten is a catch that was no less important - a 35-yard touchdown on fourth-and-seven that put Seattle ahead for good against the 49ers in the 2014 NFC title game. The wideout agreed to a three-year, $13.5 million deal prior to the 2016 season. The move cleared over 5-million dollars in cap space.
"The Seahawks defense just became even scarier, " Tweeted Pro Football Focus. But Richardson has also spent time at outside linebacker, possibly giving the Seahawks the option of using him on the edge at times.