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Baldrick Still Does Not Get It!

November 25, 2012

By Paul Homewood

 

 

As Brits will know, TV presenter Tony Robinson is famous for three things :-

  • Playing Baldrick in Blackadder
  • Presenting Channel 4’s excellent archaeological TV series, Timewatch
  • As an uber warmist, who usually manages to slip those two little words “climate change” into just about every topic he covers.

Last night, Timewatch were on Looe Island (otherwise known as St George’s Island), just off the Cornish coastline, excavating a medieval chapel, St Michael’s.

They also investigated a similar chapel across on the mainland. BBC Cornwall report that

The chapel was transferred to the mainland in the 12th century after some pilgrims were drowned on St Michaels Day when trying to make the crossing in heavy seas.

This is also borne out in the formal archaeological evaluation prepared for the show by Wessex Archaeology, that stated

The construction of the chapel on the mainland by at least 1289 is believed to have taken place as a result of the number of pilgrims attempting to reach the island chapel on St Michael’s Day (29th September) in hazardous conditions. Access in the past, however, may have been much easier. The autumn equinox on the 23rd of September is marked by a large spring tide with the low neap tide following approximately seven days after . This would coincide with Michaelmas and it may well be that the pilgrims then walked across a natural causeway to the island chapel.

So, pilgrims had originally been able to walk across at high tide, but rising sea levels around the 12th or 13thC precluded this. The evaluation even put a figure on all of this

Recent investigation into sea-level changes in West Cornwall, the Isles of Scilly and South Devon have shown that there has been a rise in sea level over the past 2000 years of around 1-1.5m

So far, so good. We also know that the land is sinking in this part of Cornwall. Current estimates from DEFRA suggest about 1.1mm pa.

 

image

Rates of Isostatic Rebound in Great Britain (in mm/yr)

 

 

Wessex Archaeology refer to a paper by Massey et al 2008, which gives about half of this amount.

 

i1052-5173-19-9-52-f01

 

Current rate of relative land- and sea-level change in the British Isles in mm pa, showing relative land uplift as positive and relative subsidence as negative.

 

So, if the figure of 1 to 1.5m is correct, this would be largely due to the land sinking.

Now let’s fast forward to today. According to the Looe website,

Unlikely though it seems, on just a few occasions each year when there are exceptionally low tides, it is possible to walk from the mainland at Hannafore all the way to Looe Island (St. George’s Island). Of course weather conditions are not always suitable on these days but in late summer 2011, the low tide day was 29 September and it was a perfect balmy day for the crossing and more than 100 people, local residents and visitors, did the walk including the three ladies shown in the photo, all long time Looe residents who had never attempted the crossing before.

islandwalk1small

 

So, despite the fact that the land has probably sunk by up to a meter since the 12thC, intrepid wanderers today are able to walk across to the island at exactly the same time of the year as their ancestors did 800 years ago or more. Around that time though, rising sea levels made this impossible and necessitated the building of another chapel on the mainland.

The conclusion is inescapable. If sea levels were higher in the Middle Ages than now, so too were temperatures.

I think even Lord Percy would have got that one, Baldrick.

 

FOOTNOTE

Tide Gauge data from PSMSL shows that the sea level just along the coast at Newlyn has risen by 128mm since 1916. a rate of 1.35mm pa. More recently, the annual increase in the last ten years has been 0.9mm, and over the last thirty years, 1.26mm.

 

Plot of annual mean sea level data at NEWLYN.

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One Comment leave one →
  1. November 25, 2012 3:36 pm

    Not meaning to be ungallant, but one picture does suggest another explanation for any land tipping.

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