Well Pete, neither of these solutions answers the question satisfactorily, but see what you think.

1. The Gulf of Thailand is not far from the equator. As the world spins, the sea bulges outwards near the equator. As the sea level rises (inexorably, irreversibly) the rise is exaggerated here because of the way Borneo, Sumatra and the Philippines funnel water into the Gulf. The problem with this theory is that it might explain tides, but hardly explains a long-term effect.

2. Thailand is sinking in the same way that England's south-east is sinking. That might well be, but it doesn't fit with what the report said in NS. And why mention Thailand when London is thought to be sinking by 2mm?

I'm sorry. Can't think of anything else. I hope somebody clever comes and answers the question for you.

The Gulf of Thailand has several characteristics that affect its temperature markedly.

(1) It is an almost uniform shallow depth.

(2) It has no through currents and is spectacularly landlocked.

(3) It is almost entirely surrounded by volcano-shaped or conical mountains.

(4) It is only 13 deg North of the equator.

(5) The water is clear because there are no large rivers draining into it.

In consequence, the mean sea temperature is around 29 deg C.

The density is slightly lower because of the temperature of a comparatively deep layer, and in consequence the water column is supported higher by the lateral pressure of the surrounding seas.

Whenever I go to the seaside, it keeps going up and down and up and down and up .. you get the idea.

I have to wonder what the statistical error is on a measurement that I can barely see on my Thomas the Tank Engine ruler, and which "they" presumably claim is accurately measurable through storms and tides from 200 miles up.

Personally, I think they got it 2mm too low last year.

I would love someone (Georg ?) to chip in with a description of how you measure the equivalent static level of 360 million square kilometres of ocean that slops around twice a month, twice a day, twice a minute and twice a second (as spring tides, daily tides, swells, and ripples). You quote 1.8mm, which I assume means they claim an accuracy of at least 0.2mm. I can't figure how I could do that in a bucket - it's less than eight thousands of an inch.

I am reminded that, when I was a lad, Everest had been measured by Andrew Waugh to be 29,002 feet high. Wikipedia says:

"Peak XV was calculated to be exactly 29,000 ft (8,839.2 m) high, but was publicly declared to be 29,002 ft (8,839.8 m). The arbitrary addition of 2 ft (61 cm) was to avoid the impression that an exact height of 29,000 feet (8,839.2 m) was nothing more than a rounded estimate."

There are always statistical measurement errors. Presumably if these guys are singling out the (fairly insignificant) Gulf of Thailand, then they have several thousand measurement points worldwide. One of them must be the least accurate, no? Especially year-on-year, any differences due to error can be in opposite directions.

I've often wondered how accurate these sea level measures are (or can be). I've always lived near the sea and it's certainly not changed visibly, but then low-lying islands do seem to have noticed a change. I dunno.