Terrestrial Lidar Imaging of active normal fault scarps Ioannis karamitros, athanassios ganas, alexandros chatzipetros

Physics Acronym of “Light Detection and Ranging” Remote sensing technology Ultraviolet, visible, or near infrared wavelength Distance between the laser and a surface is calculated by the time of flight of the emitted pulse and its reflected, returning counterpart Non intrusive visual recording system Terrestrial (TLS) and Airborne systems (taken from Mike Renslow, Spencer B. Gross, Inc.)

Specifications Can be mobile or stationary Maximum reliable survey range of about one kilometer Centimeter or even millimeter accuracy ILRIS (3D-HD) Optech Inc: Recording frequency of 2500 points per second High special accuracy 7mm at 100m distance

Product Quality Point Cloud: Resulting product of a scanning session Densely spaced network of elevation points Cartesian coordinates (x, y, z) The Data quality depends on: the spatial resolution of the scanner Inclination angle of the laser beam Distance between the scanner and the surface The surface material The surface color The condition of the surface

Intensity Intensity is the measure of the reflection strength of the laser pulse upon returning to the laser scanner Is dependent: on the reflectivity of the target material, range to the target (laser pulse becomes wider and less intense with distance) atmospheric conditions (presence of dust, rain, humidity levels, etc.). Example from Fowler et al. 2011

Normal Faults Fault: a fracture in the earth's crust Normal fault : the hanging wall moves downward relative to the footwall. A normal fault occurs when the crust is extended. Alternatively such a fault can be called an extensional fault. Ptolemais, Greece Fault Analysis Group

Arkitsa study Kokkalas et al (2007) Jones et al. (2009): TLS Arkitsa fault, northern Gulf of Evia, Greece Quantitative analysis and visualization of the nonplanar surfaces Measurements of the corrugation and fault geometry Relate the spatial variation in fault geometry to larger scale fault kinematics and dynamics.

Regional Setting of the Fault Scarp Messinian basin, Peloponnesus, Southern Greece. Eastern Messinia Fault Zone (EMFZ), western side of the Taygetus mountain range Normal fault (limestone bedrock) Survey of the fault plane on late May 2015 ILRIS (3D-HD) (Fountoulis et al., 2014)

Pidima Fault Scarp N-S Strike 10m perpendicular to the fault plane 1mm scan step Last return 9,436,368 initial cloud points

Point Cloud Creation Manual removal of remaining vegetation Semi-Automated removal of eroded points Computation of 3D site geometry parameters 5,713,381 cloud points 5mm pixel size Fault plane: maximum length 27.84m Maximum width 7.971m N S

Intensity values Intensity value on an 8- bit scale (0 - 255)

Geometry of scarp Dip Angle

Geometry of scarp Dip Direction

Geometry of scarp Mean Curvature of the Fault surface

Summary From the Pidima Fault Scarp: maximum length 27.84m Maximum width 7.971m 5mm pixel size Mean Dip angle: 70.56° Mean Dip Direction: N250.2°E Projection of intensity values and Mean Curvature

Thank you very much for your attention!