Green Side (NT 906 076) – 390m Sub-Four addition
There has been an addition to the listing of the The Fours – The 400m Hills of England, with
the summit height, col height and their locations, the drop and status of the
hill confirmed by LIDAR analysis.
This was initiated by Joe Nuttall who produced a
summit analysis programme that used LIDAR with an alternative height map (DEM)
allowing identification of summits and cols and thereby drops. The resulting spreadsheet that Joe produced
contains over 29600 hills.
This spreadsheet is being evaluated by DoBIH
Editors and others, and for this particular hill it was Jim Bloomer who
initially assessed its height and that of its adjacent peak via LIDAR analysis.
Myrddyn Phillips then evaluated this hill’s
details via LIDAR analysis and confirmed its height and hence its addition as a
390m Sub-Four.
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| LIDAR image of Green Side (NT 906 076) |
The criteria for the list that this addition applies
to are:
The Fours – The 400m Hills of England.
English hills at or above 400m and below 500m in height that have 30m
minimum drop, accompanying the main listing of The Fours are three categories
of sub hills, with this hill being added to the 390m Sub-Four category, the
criteria for which are all English hills at or above 390m and below 400m in
height that have 30m minimum 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 Green Side, and it is adjoined to The Cheviot group
of hills, which are situated in the
north-eastern part of England (Region 33 Scottish Border to the River Tyne),
and it is positioned with a minor road to its south-east and farther afield has
the A68 road to its south-west, the B6341 road to its south-east and the A697
road to its east, and has the town of Rothbury towards the east south-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 not
classified but was listed with an estimated c 17m of drop, based on the 389m summit
height adjoined to a triangulation pillar that appears on the Ordnance Survey
1:50,000 Landranger and 1:25,000 Explorer map, and an estimated c 372 col
height based on interpolation of 5m contouring between 370m – 375m that appear
on the OS Maps website.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
Approximately 1km to the north-east of the triangulation
pillar atop Green Side is the hill named Lord’s Seat. The flush bracket adjoined to this trig
pillar is given as 389.534m and positioned at NT 90299 07313 in the OS Trig
Database, with its map height given as 389m.
As the map height of Lord’s Seat is 392m it was this hill that was
classified as the 390m Sub-Four with c 53m of drop.
However, it was not until LIDAR became available
that the details for these two hills 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 results for each summit:
Lord’s Seat:
392.2m at NT 91281 07968 and NT 91282 07966
Green Side:
395.5m at NT 90695 07602
As Green Side is higher than Lord’s Seat the respective cols
are swapped and Green Side becomes the 390m Sub-Four. However, the subsequent drop for Lord’s Seat
is sufficient for it to be classified as a 390m Double Sub-Four.
 |
| LIDAR image of Green Side and Lord's Seat |
Therefore, the addition of Green Side to 390m
Sub-Four status is due to LIDAR analysis, resulting in a 395.5m summit height
and a 339.5m col height, with these values giving this hill 56.0m of drop,
which is sufficient for 390m Sub-Four status.
The full details for the hill are:
Group: The Cheviot
Name: Green Side
OS 1:50,000 map: 80
Summit Height: 395.5m
(LIDAR)
Summit Grid Reference:
NT 90695 07602 (LIDAR)
Col Height: 339.5m
(LIDAR)
Col Grid Reference: NT
90531 07919 (LIDAR)
Drop: 56.0m (LIDAR)
For the additions, deletions and reclassifications to The Fours reported on Mapping Mountains
since the December 2013 publication of the list by Europeaklist please consult
the following Change Registers:
Our thanks to Joe Nuttall and Jim Bloomer for bringing the
details of this hill to our attention
Myrddyn Phillips and Aled Williams (August 2020)
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