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Comment by WalterBright | Hacker News Reader

The Seattle Times has, twice now, hilariously reported that the sea level at Seattle has risen 8 inches in the last century, caused by climate change.

It didn't question why this hasn't happened elsewhere in the world.

Further investigation showed that the land Seattle sits on has sunk 6 inches. (This may be due to the weight of the city buildings, or plate tectonics.)

There clearly is considerable difficulty in finding a reliable "zero reference point" from which to measure from.

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That is also happening in Manhattan/greater new York. The land is still rebounding from the ice age and the coasts happen to be at the point where they will slowly sink. Ocean level rise is also an issue but the base geology accelerates the issue in those locations

Yep. It's all along both coasts, but more to the north. https://en.wikipedia.org/wiki/Post-glacial_rebound

https://earthobservatory.nasa.gov/images/150192/tracking-30-...

I don't see what's funny about 4 inches just in the last three decades. 8 inches over the last hundred plus years at seattle

https://tidesandcurrents.noaa.gov/sltrends/sltrends_station....

seems very much in line then (given the lower rates before 1992). "Further investigation" was perhaps motivated by the search for something besides truth?

What's funny was the assumption that the ocean was rising rather than the land sinking.

Both are happening simultaneously

The limestone in the Florida Keys is not sinking, afaik. There, around a foot (.3m) rise in the last 100 years is indicated by the sea level data.

https://tidesandcurrents.noaa.gov/sltrends/sltrends_station....

It has happened elsewhere in the world. Global sea levels have risen about 8 inches over the past century or so, and are currently rising about an quarter inch a year.

There are also regional variations caused by the change in gravity causes by the mass redistribution and ocean currents, so it’s not the same everywhere.

The canonical “zero reference point” should be the geoid, but that also changes with time (https://en.wikipedia.org/wiki/Geoid#Temporal_change), so yes, it’s not trivial.

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