"Cartography (from Greek chartis = map and graphein = write) is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively." -Wikipedia
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Geological Maps
Geological maps are an invaluable tool for understanding the geology of an area. They can reveal entire geologic histories, identify potential resources and hazards, and explain the origin of a landscape. Geological maps use symbols, color and textures to denote the features (springs, outcrops, measurements), structure (faults, folds) and rock units in a given area. Special symbols are used to denote the orientations of planes (bedding, foliations) and lines (lineations, current direction) within the rocks. The surface distribution and structure of the rocks can be used to extrapolate the sub-surface geology in vertical slices called cross sections.
Excerpts from map of Swinburn, Central Otago, New Zealand by NCB 2011:
And the same area on Google Maps here
And the same area on Google Maps here
Excerpts from map of Pareora River, Hunter Hills, South Island by NCB 2006:
And the same area on Google Maps here
Map of an area of eastern California by NCB 2005:
And the same area on Google Maps here
Cave Maps
Cave maps have the added complexity of trying to represent complex three dimensional voids in space onto a flat sheet of paper! A cave map has to be uniquely adapted to the type of cave being mapped-- for mazy horizontal caves a plan view (top down view) will be the most useful, for vertical caves with lots of shafts and pits a profile view (side view) will be more revealing. Large and complex multi-leveled caves are sometimes mapped using a quad system with mosaics of upper level sheets and lower level sheets with connections between the two marked. A good cave map is a work of art and sometimes even a work of genius!
Making a cave map takes quite a bit of effort- to start with you are typically using very sensitive instruments in a very muddy, wet or humid environment. Surveying is inherently slow so there is the risk of the survey team getting cold or mutinying due to boredom. Keeping the survey paper clean and dry and not dropping your pencil down a near-bottomless pit can be near-impossible at times!
A typical survey team is usually comprised of 2-4 cavers. Stations are established at prominant locations. Distance is measured between stations with a tape measure or laser, azimuth (compass direction) is measured with a compass, and inclination (degrees up or down) is measured with an inclinometer. Together all three of these measurements give you a vector in space. By linking these vectors you can precisely map out the cave.
***Note: The maps below are not complete- some data has been removed to protect the locations of the caves.***
Survey record showing distance and directions between each station, as well as the distance to a wall left, right, up and down at each station. This data provides the backbone to map out the sketch of the cave to scale.
The sketch of the cave is built around the survey stations (small trangles) at a scale suitable for the size of the cave and amount of detail needed to be conveyed. Symbols are used to show the details on the floor, such as rocks and formations. Notes are made where necessary. Although this cave is relatively horizontal, plan, profile and cross sections have all been used to give a good three-dimensional understanding of the cave morphology.
The finished map after drafting with computer software:
The survey data can also be plotted in computer software to give statistics about the cave such as total length and depth. This can be very useful for visualizing large complex 3-D maze caves and understanding the speleogenesis (evolution) of the cave.
By georeferencing the data to the entrance(s), it is possible to see how the cave relates to the surface geology and predict where more cave or other entrances might be, or how close the cave is to connecting to another known cave!
Above: Plan view
Below: Profile view
Some other relatively short and uncomplicated cave maps:
Links to some major acheivements in cave mapping:
