Curvature: What Is It?
 
Gaussian Curvature = 0
kG = 0; Ridge, Valley
(Isometric Folding
Gaussian Curvature
kG > 0: Dome, Bowl
kG < 0: Saddle
May form without
fractures from
horizontal sheet.
Must fracture
to form from
horizontal sheet.
Gaussian (k      * k       ) Curvature
min
max
Curvature - 3D
Computed for 2D tangent circles at each point on the surface

Generally computed in circle normal to the surface

Some curvatures:

  - Maximum (kmax): 
    Smallest radius circle

  - Minimum (kmin):
    Largest radius circle, will be
    perpendicular to Maximum

  - Most Positive: Tangent
    circle below surface    
    with smallest radius

  - Most Negative: Tangent circle
    above surface with smallest
    radius

  - Along Dip (kd)

  - Along Strike (ks)
Curvature - 2D
Curvature is
the inverse of
the radius of
the tangent circle at every point along the line.
Gaussian Curvature
G > 0 : Plane, ridge or valley
G = 0 : Dome, basin
G < 0 : Saddle