1989 "Juracao " Expedition Final Report
Picos de Europa, Spain
After the Instituto Geografico Nacional in Madrid had kindly supplied us with coordinates and itineraries of some of the official third order triangulation network vertices in the western Picos de Europa (Pena Santa, Pico Bricial, Cabezo de Llorosos, Torre Cerredo; amongst others), we were able to set up a local "fourth order'' trig network with a 2-3km mesh width in~1988 (from Andi Kaab's fieldwork, cf. the final report of the OUCC Las Brujas 1988 Expedition). Several key points and major caves have been included in or linked up to the network, as well as a 1:1000 photogrammetric map  of the western part of area F (produced by Sigrid Koneberg from her 1988 fieldwork), and most of the small cave entrances in that area were tied in this summer. Locations can now be communicated as UTM grid references, accurate to (typically) 0.2m horizontally and 0.5m vertically for major features, or 2-4m for minor ones. If desired, the grid coordinates may be converted to longitudes and latitudes, but the former are much more convenient to work with, since they represent a rectangular coordinate system with one metre (well, almost exactly, in that part of the world) unit length. The UTM grid is also shown on the 1:50,000 topographic map published by the Servicio Geografico del Ejercito (series L, sheet `Bele' 15-5). The careful observer will note that some of the altitudes given below differ a little from the figures in the maps. We believe ours to be nearer to the truth. (Our observations confirmed that the given third order network even exceeds the claimed accuracy, but other spot heights in the maps were probably derived from air photographs, with an uncertainty of a few metres at worst.)
There is a slight mismatch between the computed coordinates and the contours and spot heights shown on the map. When reading an altitude off the map, subtract 2m, and add 2m before entering a point of known (computed) height. Magnetic North in 1989 was about 3° 25' west of grid north; this figure must be subtracted from compass bearings to convert them into grid directions. Below, coordinates are always given in the order Easting, Northing, Altitude (above the level of the Mediterranean at Alicante). Longitudes are west of Greenwich.
Ario Refugio (doorstep below chimney on N side of building):
GR: 43981.7E 89798.8N 1630.5A; Lat.: 43° 14' 38.62'' Long.: 4° 55' 17.95''
GR: 44275.58E 89970.96N 1721.75A; Lat.: 43° 14' 44.463'' Long.: 4° 55' 05.098''
Cabeza El Verde:
GR: 44650.58E 89451.70N 1720.24A Lat.: 43° 14' 27.918'' Long.: 4° 54' 47.952''
Jultayu (foot of cross):
GR: 44220.39E 88014.82N 1941.53A Lat.: 43° 13' 41.047'' Long.: 4° 55' 05.555'$
GR: 42333.32E 87815.33N 2130.97A Lat.: 43° 13' 33.173'' Long.: 4° 56' 28.955''
Pico de la Jorcada:
GR: 41413.53E 87571.64N 2137.66A Lat.: 43° 13' 24.585'' Long.: 4° 57' 09.452''
GR: 41047.30E 88509.14N 1926.06A Lat.: 43° 13' 54.680'' Long.: 4° 57' 26.648''
Top Camp reference point:
GR: 41742.57E 88012.16N 1913.72A Lat.: 43° 13' 39.105'' Long.: 4° 56' 55.330''
Pozu del Xitu (1/5) (inscription):
GR: 43565.2E 89433.1N 1637.0A
2/7, boulder on edge of doline ($=$ station 2 of cave survey):
GR: 43978.2E 88012.7N 1848.1A
Pozu Jorcada Blanca (F2) (shaft above doline):
GR: 41671.5E 87749.6N 1967.0A
Pozu les Perdices: F7A (inscription)
GR: 41552.3E 87977.3N 1876.3A
- -, F7B (inscription
GR: 41566.4E 87954.6N 1881.9A
- -, F7C (start of roof of crawl)
GR: 41558.5E 87931.5N 1893.7A
F20 (rock bridge in entrance rift):
GR: 41290.3E 87889.4N 1970.2A
F40 (rim of doline, 2m above first survey station):
GR: 41176.5E 88157.6N 1936.7A
Sistema Conjurtao: 1/6 (first survey station, start of roof)
GR: 41236.6E 88115.3N 1916.7A
- -, 2/6 (rim of shaft $=$ survey station 0)
GR: 41166.8E 88020.5N 1983.6A
Further area F data appear in the section on "Other caves explored in 1989''.