NATO Workshop Veszprem 2004

Recent Monitoring of Crustal Movements in the

Eastern Mediterranean

The Usage of GPS Measurements

G. Stangl,

Federal Office of Metrology and Surveying, Austria

C. Bruyninx,

Royal Observatory of Belgium

NATO Workshop Veszprem 2004

Faults at Plate Boundaries

NATO Workshop Veszprem 2004

Detailed Model at Plate BoundariesModified from Barka (1992) and Rockwell and others

NATO Workshop Veszprem 2004

Usage of GPS Measurements

• Permanent Stations• Campaigns• Common Reference Frame, e.g. ITRF2000• Stacking Solutions• Removing unwanted Influences• Estimating Station Velocities from the refined Time

Series

NATO Workshop Veszprem 2004

Effects on Station Coordinates

• Different Reference Frames• Different Antenna Definitions• Modeling Errors• Seasonal Variations• Site Problems (Equipment,

Monumentation, Atmosphere)• Orbits and Clocks before 1992• Orbits and Clocks 1992-2004• Different Adjustments

• About 20 mm• About 10 mm• About 5 mm• Up to 10 mm• Up to 30 mm• Height 60 mm• About 50 mm• Up to 30 mm• Up to 20 mm

NATO Workshop Veszprem 2004

Reference System jumps

NATO Workshop Veszprem 2004

Jumps due to Equipment

NATO Workshop Veszprem 2004

Adjustment Problem (Reference Site GRAZ) Antenna Change Effect at RAMO

NATO Workshop Veszprem 2004

Stations

• Permanent (International Networks, public, well monitored), e.g. IGS, EPN ...

• Permanent (international Special Projects, public, monitoring

due to international guidelines?), e.g. UNAVCO• Permanent (National or Firms, private, incomplete information

about quality, no public information about availability, potential

access?)• Markers (No international Database for information, Stability

Problems, Protection?)

NATO Workshop Veszprem 2004

IGS and other Permanent Stations

NATO Workshop Veszprem 2004

Major Campaigns (Reilinger et al. 1997)

NATO Workshop Veszprem 2004

Major Campaigns and Results (McClusky et al. 2000)

NATO Workshop Veszprem 2004

Geophysical Signals (Postseismic)

NATO Workshop Veszprem 2004

Geophysical Signals (Change of Velocity?)

NATO Workshop Veszprem 2004

Velocities (Campaigns and Permanent Stations)

5

26

9

10

NATO Workshop Veszprem 2004

Conclusions

• GPS permanent stations and campaigns can deliver similar station velocities at the level of 1mm/year

• Time span should be at least 2 years (3 campaigns)• Major steps of improvement of accuracy 1993, 2000• General correlation to values from geology station

velocities can monitor crustal movements• Overall coverage poor – even at major faults• Permanent stations at each major tectonic unit

required (2-3)• Campaigns for filling gaps and discovering smaller

features