GRF STATION INFORMATION

STATION INFORMATION
						          Elevation of			 Start of
       Code	Latitude	      Longitude         Sensor (M)*    Components	Operation 
								  						*including
      GRA1 (GRF) 49.6919		11.2217	500		Z,N,E		Spring 1976	   depth
      GRA2	  49.6552		11.3594	505		Z		Spring 1976
      GRA3	  49.7622		11.3187	452		Z		Spring 1976
      GRA4	  49.5654		11.4359	502		Z		Spring 1979
      GRB1	  49.3913		11.6520	502		Z,N,E		Spring 1978
      GRB2	  49.2709		11.6700	543		Z		Spring 1978
      GRB3	  49.3435		11.8060	519		Z		Spring 1978
      GRB4	  49.4689		11.5608	510		Z		Spring 1979
      GRB5	  49.1121		11.6767	515		Z		Fall 1979
      GRC1	  48.9962		11.5214	513		Z,N,E		Spring 1979
      GRC2	  48.8676		11.3755	447		Z		Spring 1980
      GRC3	  48.8902		11.5858	445		Z		Spring 1979
      GRC4	  49.3867		11.5263	505		Z		Fall 1979
      
GEOLOGY:  Chalk and dolomite of Jurassic age (Malm) with a covering of a thin layer of sandy loam.

VAULT CONDITIONS:     Inner vault fixed with concrete on hard bedrock.  Inner vault is thermally isolated and contained in a 2-4 m deep outer vault witha diameter of 2 m.