Crack rose
A fissure rose is a circular graphic representation of the directional frequency of fissures , dividing surfaces , joints or cracks in the rock of a mountain, measured for example in a quarry, in a tunnel or another outcrop in which the rock of the subsoil is present (stream bed, road embankment, rocks , Cave). This is a geological term.
Fissure roses provide an overview of the predominant stroking directions and their frequency. These are first measured in a large number of individual measurements in a homogeneous range. The percentage of fracture directions per compass direction ( azimuth ) is applied radially outwards. The length of the rays corresponds to the percentage of the measurements allotted to the directions. The picture is vaguely reminiscent of a rose.
The measured values are always between 0 ° and 180 ° because the directions are defined in this way; the angles between 180 ° and 360 ° are mirrored at the center. Polar equal area projection is used for the display. The incidence or the angles of incidence are not shown with a fracture rose. Other representations are layered spheres , Schmidt's net , and Müller flags.