Grotte Casteret
{{Short description|Limestone ice cave in Aragon, Spain}}
{{Infobox cave
| name = Grotte Casteret
| other_name = Gruta Helada de Casteret
| photo = Cascada helada de la cueva de Casteret - WLE Spain 2015.jpg
| photo_width =
| photo_caption = The Grande Salle in the Grotte Casteret
| map = Spain
| map_width =
| map_caption =
| map_alt =
| location = Aragon, Spain
| coords = {{coord|42.68514|N|0.032455|W|format=dms|display=inline,title}}
| coords_ref =
| height_variation = {{convert|80|m}}St. Pierre (2007), pp. 5
| depth =
| elevation = {{convert|2640|m}}
| discovery = 1926
| geology = Cretaceous limestone
| difficulty =
| hazards = Ice
| access = Controlled
| survey = SWETCC, 1961St. Pierre (2007), pp. 24–25
| survey_format =
}}
The Grotte Casteret, also known by its Spanish names Gruta de Casteret or Gruta Helada de Casteret, is a limestone ice cave, located high in the Spanish Pyrenees, within the Ordesa y Monte Perdido National Park. Discovered in 1926 by Norbert Casteret, it is known for its Grande Salle (Great Hall) which has a frozen lake some {{convert|2000|m2}} in area, its ice formations, and a {{convert|20|m|ft}} ice wall into a second chamber.
Description
The Grotte Casteret is situated at the top of a scree / snow couloir {{convert|670|m|yd}} ESE of the Brèche de Roland, and has an impressive entrance porch some {{convert|50|m|ft}} wide, and {{convert|15|m|ft}} high. After {{convert|60|m|ft}} the passage opens out into the vast ice-floored Grande Salle, about {{convert|70|m|ft}} long, {{convert|60|m|ft}} wide, and {{convert|4|m|ft}} high. Its floor is a frozen lake of clear ice with a surface area of about {{convert|2000|m2}}. Large ice columns dominate the end of the chamber. To the left of the chamber an opening leads into the Salle Maude at the base of a {{convert|20|m|ft}} ice-wall called Niagara.St. Pierre (2007)
Beyond the Grande Salle, the ice floor gives way to a mainly boulder-floored passage which leads after {{convert|120|m|ft}} leads to a {{convert|3|m|ft}} climb which emerges in a lapiaz field on the surface. Casteret's original survey shows the passage extending for a further {{convert|100|m|ft}}, but this is no longer accessible.
A third entrance, the Puits Florence, lies on the plateau above the cave. It is {{convert|60|m|ft}} deep, with the final {{convert|50|m|ft}} being a vertical shaft entering the Grande Salle.St. Pierre (2007), pp. 16
History
The cave was first entered by the family Casteret (Norbert Casteret, his mother, his wife, and his brother) in July 1926 when they explored most of the main passage. He and his wife returned in September 1926 when they achieved the through trip.Casteret (2007) The Salle Maude was discovered and explored in August 1950 by Casteret and his daughters Maude and Gilberte. The third entrance, the Puits Florence, was first descended in August 1975 by the Club Martel.St. Pierre (2007), pp. 10
Geology and formation
The Grotte Casteret is formed in Cretaceous limestone.{{cite web|title=A look at the geology in the Geopark|url=http://www.geoparquepirineos.com/contenidos.php?niv=1&cla=_2OA1CCRP9&cla2=_2OA1CGQUH&cla3=&tip=2&idi=3|publisher=Geoparque de Sobrarbe|accessdate=26 January 2014}} The ice in the Grande Salle is ponded and has formed as the result of cold air flowing through the system, with areas out of the draught being water.Casteret (1950), pp. 133 The deeper ice is considered to be very old, and possibly relict of a cold period of the Quaternary. The volume of ice in the Grande Salle has decreased since its discovery. In 1950 the entry into Salle Maude was a low crawl across the ice floor about {{convert|30|cm|in}} high. In 1988 it was reported that the gap was {{convert|150|cm|ft}} high as a result of the ice floor lowering.St. Pierre (2007), pp. 17–18
Access
Access is controlled by the Ordesa y Monte Perdido National Park authorities. A barrier has been erected within the entrance, and a sign prohibits access to the casual visitor. Two groups of up to 6 cavers, are allowed access for a maximum of four days per month.{{cite web|title=Gruta Helada de Casteret|url=http://www.ordesapirineos.com/guiaalpina/itinerarios/51.html|publisher=Parque Nacional de Ordesa y Monte Perdido|accessdate=24 January 2014}}{{cite web|title=Plan Rector de Uso y Gestion (PRUG) del Parque Nacional de Ordesa y Monte Perdido y Su Zona Perifeérica de Protección|url=http://www.aragon.es/estaticos/GobiernoAragon/Departamentos/AgriculturaGanaderiaMedioAmbiente/documentos_en_periodo_info_publica/ORDESA_PLAN_RECTOR_BORRADOR.pdf|publisher=Gobierno de Aragón|accessdate=24 January 2014|archive-url=https://web.archive.org/web/20140201205640/http://www.aragon.es/estaticos/GobiernoAragon/Departamentos/AgriculturaGanaderiaMedioAmbiente/documentos_en_periodo_info_publica/ORDESA_PLAN_RECTOR_BORRADOR.pdf|archive-date=1 February 2014|url-status=dead}}
References
=Notes=
{{reflist|2}}
=Sources=
- {{cite book|last=Casteret|first=Norbert|title=Ten Years Under the Earth|year=1950|publisher=Readers' Union|location=London|pages=122–133}}
- {{cite book|last=St. Pierre|first=David|title=Grotte Casteret|year=2007|publisher=British Cave Research Association|location=Great Hucklow, Buxton|isbn=978-0900265327}}