this survey ( in progress.. ) Pozu Jultayu

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NB Passage name details are displayed in the status bar when the cursor is moved over

How was this survey prepared?

The older data is taken from a dataset prepared originally for a BBC micro. 1998 data was provided as Survex file.

Data was not available for Tumbing Dice.

All the data was entered into Walls, together with dates and location so that appropriate magnetic corrections could be automatically applied. No instrument corrections were available for old surveys, but are provided for newer ones. Conversion of data from Survex or other formats to Walls is quite simple: for Survex the main difference is to change the comment marker from ....

A node list was created and parsed into a spreadsheet (Lotus 1-2-3, but most would be just as capable) which was then used to create the list of Stations, thus:.
Station { desc "ST" posn 0 0 0 }
Station { desc "B1" posn 1.54 -1.28 -0.02 }
Station { desc "B2" posn 2.7 -10.76 5.67 }
Station { desc "B3" posn 13.03 -23.8 2.99 }


A text editor (PFE) was then used to create the .wrl file. Each continuous section of passage to be shown with the same type of cross section was identified (easier said than done with old data: the symptom of not doing it is spurious connecting lines between unconnected surveys) and its stations included under a TubeSurvey node thus:

Tube_survey { desc "Jultayu Entrance"
xsect [ 10 10, -10 10, 0 0, 10 -10 ]
stations [
Station { desc "ST" posn 0 0 0 }
Station { desc "B1" posn 1.54 -1.28 -0.02 }
Station { desc "B2" posn 2.7 -10.76 5.67
scale 1 1 }
Station { desc "B3" posn 13.03 -23.8 2.99 }
Tube_survey { desc "Entrance shafts" stations [

< desc shows in status bar
< defining coordinates, anticlockwise

< scales subsequent xsect by width height

A header block was then added to specify predefined views, and the orientator

actually, it is also necessary to add a link station for every tube or else you end up with disconnected tubes

Pozu Jultayu.

The cave is 810m from lip of entrance to surface of sump pool. Total surveyed length is reported as* around 10km.

The exploration is described in Proc OUCC 9 (as 2/7),13 (as 2/7 - Pozu del Oju de la Bruja) and in Expedition Reports for 1989,1991,1992, 1998, 1999 and 2000 expeditions.

Still remaining to be discovered:

* I could digress into the fractal nature of cave length as opposed to the absolute value of depth, but will leave you to search out Earth Surface Processes and Landforms, Vol 12 No 5, pp475-480 (1987) if you are interested.