P1: Determination of contemporary uplift rates from geodetic observations

Supervisors

Prof. Urs Hugentobler, Prof. Xiaoxiang Zhu

Advisors (int.)

Dr.-Ing. Anja Schlicht (TUM), Dr.-Ing. Homa Ansari (TUM), Prof. Anke Friedrich (LMU)

Advisors (ext.)

Prof. Geoff Blewitt (Univ. Reno, Nevada)

Description

Geodetically measured geometrical uplift rates provide a boundary condition for modelling of uplift patterns. This project shall provide uplift rates measured with GNSS and SAR/InSAR in the selected test areas, associated with realistic estimates of uncertainties. This task includes the collection and quality control of GNSS tracking data in and around the test areas covering a multi-year time interval as well as SAR image sequences for selected sub-regions. The 1000 station GNSS network of the Plate Boundary Observatory (PBO) provide unique coverage across the target region relating to the Yellowstone-Columbia-River plume. In Europe e.g. data from the EUREF reference network is publicly available, for South Africa data from the TrigNet reference network can be accessed. Crucial is a proper modelling of loading effects, the proper alignment to a well-defined reference frame, and the estimation of a realistic uncertainty of the up-velocity.

Main objectives

• Selection, quality control and analysis of tracking data for large station networks covering multi-annual time periods to determine site velocities referenced to a global reference, with particular focus on the vertical components of deformation.
• Assessment of the available atmospheric, oceanic and hydrological loading models in order to separate local and regional effects. 
• Estimation of realistic velocity uncertainties based on the colored noise content of the position time series, using methods such as the Allan variance of the rate and assessment using collocated sites and data from other space geodetic techniques such as SLR and VLBI.
• Combination with deformation measurements obtained with SAR/InSAR.
• Comparison of the final vertical velocity field with the geologically derived velocity field (P3 and P4). The comparison will help to identify transients in the geodetic deformation fields on scales not covered by space geodetic techniques.

RTG coupling

Input:

• Static gravity field and geoid (P2).
• Geological expertise on the morphotectonic record of young active fault systems (North America and Europe) will help to identify short-term transients in the geodetic signals that may not otherwise be found (P3 and P4).

Output:

• Recent coordinate changes and uplift rates derived from geodetic measurements in the test areas associated with uncertainty estimates (P9).
• Joint interpretation of the results together with P1.
• Empirical uplift rates together with realistic uncertainty estimates serve as constraints for the geological model (P4) and the integrated process model (P7, P8).