Silver How (NY 324 066) – 390m Sub-Four reclassified to 390m
Double Sub-Four
There has been a reclassification 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 prompted by Joe Nuttall who produced a summit analysis
programme using LIDAR, and confirmed by LIDAR analysis conducted by Myrddyn
Phillips.
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LIDAR image of Silver How (NY 324 066) |
The criteria for the list that this
reclassification 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 reclassified from a 390m Sub-Four to a 390m
Double Sub-Four, the criteria for the former are all English hills at or above
390m and below 400m in height that have 30m minimum drop and the criteria for
the latter are all English hills at or above 390m and below 400m 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 Silver How, and it is adjoined to the Scafell Pike
group of hills, which are
situated in The Lake District (Region 34, Section 34B: The Central and Western
Fells), and it is positioned with the B5343 road to its south-west and a minor
road to its east, and has the village of Grasmere 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
included as a 390m Sub-Four and listed with an estimated c 31m of drop, based
on the 395m summit spot height that appears on the Ordnance Survey 1:25,000
Explorer map, and an estimated c 364m col height based on interpolation of 5m
contouring between 360m – 365m that appeared on the OS Maps website.
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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.
Therefore, the reclassification of this hill from
390m Sub-Four status to 390m Double Sub-Four status is due to LIDAR analysis,
resulting in a 393.8m summit height and a 364.1m col height, with these values
giving this hill 29.7m of drop, which is insufficient for it to be classified
as a 390m Sub-Four.
The full details for the hill are:
Group: Scafell Pike
Name: Silver How
OS 1:50,000 map: 90
Summit Height: 393.8m
(LIDAR)
Summit Grid Reference:
NY 32477 06643 (LIDAR)
Col Height: 364.1m
(LIDAR)
Col Grid Reference: NY
32135 96621 (LIDAR)
Drop: 29.7m (LIDAR)
Our thanks to Ronnie Bowron for bringing the details of this
hill to our attention.
For the additions, deletions and reclassifications to The Fours – The 400m Hills of England
reported on Mapping Mountains since the December 2013 publication of the 1st
edition of this list by Europeaklist please consult the following Change
Registers:
The Fours
The Fours – 400m Sub-Four
The Fours – 390m Sub-Four
The Fours – 390m Double Sub-Four
Myrddyn Phillips and Aled Williams (November 2022)
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