Saturday 13 May 2023

Mapping Mountains – Significant Height Revisions – The Fours – The 400m Hills of England


Jenny Binks Moss (SE 105 836) 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Jenny Binks Moss (SE 105 836)

The criteria for the list this height revision affects are:

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Jenny Binks Moss, and it is adjoined to the Whernside group of hills, which are situated in the central Pennines, and it is positioned with the A6108 road to its north-east, and a minor road to its north-west, and has the town of Middleham towards the north-east.

When the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 422m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Jenny Binks Moss (SE 105 836)

LIDAR analysis gives the highest ground on this hill as 419.7m positioned at SE 10504 83614, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 419.7m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, although it is relatively close to where the 422m spot height appears, and is 2.3m lower than the previously listed 422m summit height, which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  Whernside

Name:  Jenny Binks Moss

OS 1:50,000 map:  99

Summit Height (New Height):  419.7m (LIDAR)

Summit Grid Reference:  SE 10504 83614 (LIDAR)

Col Height:  390.6m (LIDAR)

Col Grid Reference:  SE 10032 83010 (LIDAR)

Drop:  29.1m (LIDAR)

 

Myrddyn Phillips and Aled Williams (May 2023)

 

 

 

  

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