Bishop Hill has picked up a fascinating horsie tail from The Washington Times written by Soon and Morner mentioning how crowds peering dead horse style drove a pier into the silt. The rising snag for the sea-level paternalists came when the horses didn’t sink into the waves, no event, no pier sink. Reckon 150 tons did it.
Foundations count for a lot, either hydaulic/mass counterbalancing or the more obvious based directly on crustal rock but even that is floating.
Sea level gauging is deceptively difficult, what with marine creepy crawlies, waves wind weather, the moon looping, channels scouring, dredging, shipping movements. Technical troubles with variety of schemes used to make a gauge and read it often enough come snow, storm, illness and pay.
Sea level is easy to measure?
An infamous area for strange tides is the Solent.
Fishing people want to know, page for Cowes, Isle of Wight. http://www.tides4fishing.com/uk/england/cowes
The harbour “Tidal flows around the harbour can be exceptionally strong. If the opportunity arises, take a look at one of the Red Funnel car ferries as it approaches Cowes during a strong ebb, you will see the ship crabbing sideways with up to 45 degrees of set, to counter the cross current.” http://www.cowes.co.uk/tidal_flows_in_cowes.aspx
How about Lee-on-Solent where the weather station was featured on the Talkshop. Plot on this page here showing the four tides a day http://www.tidetimes.org.uk/lee-on-the-solent-tide-times
Tide comes up the English Channel and from there the two channels around the Isle of Wight to Southampton Water.
There will be other places like this in the world.
Another fun item are bores (apart from me) where we have the Severn Bore where I hope environmental vandalism will be resisted, no barrage.
There is the second greatest tidal range in the world,15 metres. The tide is funnelled, with the floor of the Severn estuary rising on rock, this trips a wave which is the Severn bore.
Nearby a couple of photos here give an idea on what was the deepest sea lock in the world when it opened. I’ve been there, a gulp, a tide range?
http://www.gloucesterdocks.me.uk/sharpness/olddock.htm
Now here is a reference tour de force for any able to take in whole books, covers an astounding range
From
Tides, Surges and Mean Sea-Level (Southampton University site)
David T. Pugh, Natural Environment Research Council, Swindon, UK, 1987 John Wiley. PDF (14M), 486 pages.
http://eprints.soton.ac.uk/19157/01/sea-level.pdf
Volcano folks, Zeke has pointed at a chiefio post http://tallbloke.wordpress.com/2012/10/08/some-volcanoes-are-triggered-by-cosmic-rays/#comment-38527
Then there’s post-glacial rebound.
http://upload.wikimedia.org/wikipedia/en/b/b3/Post-glacial_rebound_in_British_Isles.PNG
Post-glacial rebound “corrections” in fact manufacture about half of the +/- 180mm global sea level rise reported for the 20th century.
The detailed scientific back ground can be found at http://scienceandpublicpolicy.org/images/stories/papers/reprint/sea_level_not_rising.pdf
with a foreword by viscount Moncton
Not forgetting the TRF errors…
http://wattsupwiththat.com/2012/10/30/finally-jpl-intends-to-get-a-grasp-on-accurate-sea-level-and-ice-measurements/
NASA/JPL admits ‘TRF errors readily manifest as spurious sea level rise accelerations’. They want a new satellite to fix the problems.
Pier review, horsing around…
We were told the climate was stable.. (stealing from a Bishop Hill commenter)
Another sea level rise howler.
‘Apparently parts of Perth are subsiding by as much as 6mm year thanks to groundwater extraction, and one of those parts doing-the-subsiding happens to be around a tide gauge. More than half the scary rise is due to the gauge sinking.’
http://joannenova.com.au/2012/12/cherry-picking-sea-level-rises-in-perth-a-city-which-happens-to-be-sinking/
Perth (actually Fremantle) is an also-ran in the sea level rise competition, showing only about 200mm of SLR since 1900:
http://www.psmsl.org/data/obtaining/rlr.annual.plots/111_high.png
The world champion is Bangkok, which shows 900mm of SLR since groundwater pumping began there in the 1960s. If nothing is done to stop the subsidence the city will in fact be mostly inundated by 2050.
http://www.psmsl.org/data/obtaining/rlr.annual.plots/444_high.png
Sea level moves around rather little
http://www2.rgzm.de/Navis2/Harbours/Guernsey/SPP-home.htm
(from http://www2.rgzm.de/Navis2/Home/Frames.htm)
But the land moves up and down rather a lot. Here’s Skagway, Alaska, world champion of falling sea levels, down 1.2m since 1950.