PHOTOGRAMMETRY (Airborne)
• A series of 24 photogrammetric targets were installed in 1981 and flown for four years, then discontinued
•The area was re-flown in September 2005
•Deformation rates ranging between < 1 mm/year and 3.5 mm/year were observed.
Another airborne technique utilized to map deformations is photogrammetry.  In 1981 a series of 24 targets were installed around South Peak but only flown (at 1:2,000 scale) until 1985.  We had the targets reflown in 2005 and analysis completed by Mike Chapman at Ryerson University.  These new results agreed very well with the trends observed on the modern instrumentation and visual observations with deformations with averaged rates of movement of up to 3.5 mm/year over the 24 year time frame.