Description of the Port Arthur data file
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This is the full (1184-day) data-set from the Port Arthur tide gauge.

Location: Port Arthur, Tasmania
          43 deg 08 min 50 secs South, 147 deg 51 min 10 sec East

Start time: 04:13:51 GMT on 24/6/1999

End time:   04:31:58 GMT on 20/9/2002

Instrument: Aquatrak 4100 with Vitel WLS2 logger

Temperature corrections were applied as per:

  Hunter, J.R., 2003. A note on the temperature correction of the 
    Aquatrak acoustic tide gauge, J. Atmos. Oceanic Technol., 
    Vol. 20, 1230-1235.

Format of data in file present_dat_gmt:

  First column: time in seconds after 00:00:00 GMT on 1/1/1999

  Second column: distance in mm measured DOWNWARDS from tide gauge 
    zero to water surface

  NOTE that nominal time interval is 6 minutes. However, this is 
  qualified by the following:

  1. A small correction has been applied to allow for clock drift.

  2. There is a small amount (around 0.03%) of missing data. Where
     data is missing, those records are also missing; i.e. there
     are no "missing data" flags.

Zero of tide gauge:

  The tide gauge zero is 3299.6 mm ABOVE AHD (Tasmania).

  For information on other local survey marks, see:

    Watson, C.S., 1999. A Contribution to Absolute Sea Level in 
      Tasmania, B. Surv. (Hons.) thesis, 200 pp., University of 
      Tasmania, Hobart, Tasmania, Australia.

Other useful information:

   Pugh, D., Hunter, J., Coleman, R. and Watson, C., 2002. A 
     comparison of historical and recent sea level measurements 
     at Port Arthur, Tasmania, International Hydrographic Review, 
     Vol. 3, No. 3 (New Series), 27-46.

   Hunter, J., Coleman, R. and Pugh, D., 2003. The sea level at 
     Port Arthur, Tasmania, from 1841 to the present, Geophysical 
     Research Letters, Vol. 30, No. 7, 54-1 to 54-4, 
     doi:10.1029/2002GL016813.

For further information, contact:

  John Hunter, 
  Antarctic Climate & Ecosystems Cooperative Research Centre,
  Private Bag 80, Hobart, Tasmania 7001, Australia.

  Ph: +61 3 6226 7849
  email: john.hunter@utas.edu.au

John Hunter, 8/3/2006