Tuesday 29 May 2018

Mapping Mountains – Hill Reclassifications – The Fours


High Nook (NY 120 189) – 400m Sub-Four deletion

There has been a deletion from the listing of The Fours due to LIDAR analysis conducted by Aled Williams.  The Fours is the title for the list of 400m hills of England and takes in all English hills at and above 400m and below 500m in height that have a minimum 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.

Accompanying the main list of The Fours are three categories of sub hills, with this hill being deleted from the 400m Sub-Fours.  The criteria for 400m Sub-Four status are all English hills at and above 400m and below 500m in height that have 20m and more and below 30m of drop. 
 
Prior to LIDAR analysis this hill was listed with 21m of drop based on the 488m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 467m col spot height that appears on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

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

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The name of the hill is High Nook and it is situated in the Central and Western Fells of the Lake District and is placed in Region 34, Section 34B, with its Cardinal Hill being Great Gable (NY 211 103).  The hill is positioned on the north-easterly ridge that descends from Gravel Fell and has the Highnook Beck to its north-west and the Whiteoak Beck to its east.

As the summit of the hill is a part of designated open access land it can be approached from a number of directions, with a public footpath leading toward the hill from the north, however this hill can easily be combined with adjacent hills to make an extended walk.

The deletion of High Nook from 400m Sub-Four status is due to LIDAR analysis conducted by Aled Williams.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.


Aled’s LIDAR analysis gives the hill the following details:

High Nook

Summit Height:  486.0m

Summit Grid Reference:  NY 12033 18915

Col Height:  466.1m

Col Grid Reference:  NY 11922 18855

Drop:  19.9m


LIDAR image of High Nook

Therefore, the 486.0m LIDAR analysis for the summit position at NY 12033 18915 and the 466.1m LIDAR analysis for the col position at NY 11922 18855 gives this hill 19.9m of drop, which is insufficient for it to retain its 400m Sub-Four status.


The full details for the hill are:

Cardinal Hill:  Great Gable

Summit Height:  486.0m (LIDAR)

Name:  High Nook

OS 1:50,000 map:  89

Summit Grid Reference:  NY 12033 18915 (LIDAR)

Drop:  19.9m (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:










Myrddyn Phillips and Aled Williams (May 2018)

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