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

Eastgate Quarry (NY 941 369) 

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 Eastgate Quarry (NY 941 369)

The criteria for the list this height revision affects 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 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 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

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

The name the hill is listed by is Eastgate Quarry and it is adjoined to the Burnhope Seat group of hills (Region 35, Section 35A: The Northern Pennines), and it is positioned with the A689 road to its north, and has the town of Stanhope towards the east north-east.

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

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was not included in the accompanying sub list, as it was considered not to meet the criteria used for this sub category, based on the hill being a part of a quarry and therefore contemporary Ordnance Survey maps do not show any meaningful contours, with a 387m spot height appearing on the Ordnance Survey 1:50,000 Landranger map for the uppermost height leading in to this quarry. 

Extract from the Ordnance Survey 1:50,000 Landranger map

Since the original publication of this list there have been a number of maps made available online.  Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website.  Whilst others were digitally updated such as the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the WalkLakes and DataMapWales websites.

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available maps and although no spot heights are given for this hill, its contours show the hill exists. 

Extract from the interactive mapping on the WalkLakes website

Another resource now available online is the interactive mapping hosted on the Welsh Government website and entitled the DataMapWales.  This mapping has 5m contours and its detail matches that produced from the OS Terrain 5 product, which compliments much of that produced from LIDAR.  It is this mapping that has a 413m summit height for this hill and col contouring between 385m – 390m. 

Extract from the interactive DataMapWales

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 Eastgate Quarry (NY 941 369)

LIDAR analysis gives this hill a summit height of 413.0m positioned at NY 94100 36976 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 413.0m and this was derived from LIDAR analysis, this is 26.0m higher than the 387m spot height that appears on the Ordnance Survey 1:50,000 Landranger map for the uppermost height leading in to this quarry, however the LIDAR height matches the rounded up height given on the interactive mapping entitled DataMapWales. 

 

The full details for the hill are:

Group:  Burnhope Seat

Name:  Eastgate Quarry

OS 1:50,000 map:  91, 92

Summit Height (New Height):  413.0m (LIDAR)

Summit Grid Reference:  NY 94100 36976 (LIDAR)

Col Height:  388.0m (LIDAR)

Col Grid Reference:  NY 93740 36402 (LIDAR)

Drop:  24.95m (LIDAR)

 

Myrddyn Phillips and Aled Williams (March 2023)