Cefn Cyfronydd (SJ 144 082) – 200m Twmpau reclassified to 100m Twmpau
There has been a reclassification to the list of 200m Twmpau and 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.
Cefn Cyfronydd (SJ 144 082) on the left |
200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.
The 200m Twmpau by Myrddyn Phillips |
The 100m Twmpau by Myrddyn Phillips |
When the original 200m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list and listed with an estimated c 200m summit height, based on interpolation of its uppermost 200m ring contour that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.
Extract from the Ordnance Survey 1:25,000 Explorer map |
LIDAR image of Cefn Cyfronydd (SJ 144 082) |
The Trimble GeoXH 6000 gathering data at the summit of Cefn Cyfronydd |
The full details for the hill are:
Group: Carnedd Wen
Name: Cefn Cyfronydd
OS 1:50,000 map: 125
Summit Height: 199.1m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SJ 14459 08297 (Trimble GeoXH 6000)
Bwlch Height: 150.6m (LIDAR)
Bwlch Grid Reference: SJ 14997 08587 (LIDAR)
Drop: 48.5m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Myrddyn Phillips (July
2021)
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