The Chesapeake Bay demonstrates some of the difficulties with sea level rise measurement.
Sea level rise in the Chesapeake Bay has been measured at about 3.9 mm/year. The USGS says that sea level rise is 1.8 mm/year. The rest is from subsidence caused by a meteor impact 35 million years ago and maybe some groundwater withdrawal. The meteor impact wasn’t discovered until about 20 years ago. Sea level rise isn’tjust the simple ocean warming/glaciers melting we keep hearing about.